WorldWideScience

Sample records for nitrogen fertilization alter

  1. Short-term fertilizer application alters phenotypic traits of symbiotic nitrogen fixing bacteria

    Directory of Open Access Journals (Sweden)

    Anna K. Simonsen

    2015-10-01

    Full Text Available Fertilizer application is a common anthropogenic alteration to terrestrial systems. Increased nutrient input can impact soil microbial diversity or function directly through altered soil environments, or indirectly through plant-microbe feedbacks, with potentially important effects on ecologically-important plant-associated mutualists. We investigated the impacts of plant fertilizer, containing all common macro and micronutrients on symbiotic nitrogen-fixing bacteria (rhizobia, a group of bacteria that are important for plant productivity and ecosystem function. We collected rhizobia nodule isolates from natural field soil that was treated with slow-release plant fertilizer over a single growing season and compared phenotypic traits related to free-living growth and host partner quality in these isolates to those of rhizobia from unfertilized soils. Through a series of single inoculation assays in controlled glasshouse conditions, we found that isolates from fertilized field soil provided legume hosts with higher mutualistic benefits. Through growth assays on media containing variable plant fertilizer concentrations, we found that plant fertilizer was generally beneficial for rhizobia growth. Rhizobia isolated from fertilized field soil had higher growth rates in the presence of plant fertilizer compared to isolates from unfertilized field soil, indicating that plant fertilizer application favoured rhizobia isolates with higher abilities to utilize fertilizer for free-living growth. We found a positive correlation between growth responses to fertilizer and mutualism benefits among isolates from fertilized field soil, demonstrating that variable plant fertilizer induces context-dependent genetic correlations, potentially changing the evolutionary trajectory of either trait through increased trait dependencies. Our study shows that short-term application is sufficient to alter the composition of rhizobia isolates in the population or community

  2. Short-term fertilizer application alters phenotypic traits of symbiotic nitrogen fixing bacteria.

    Science.gov (United States)

    Simonsen, Anna K; Han, Shery; Rekret, Phil; Rentschler, Christine S; Heath, Katy D; Stinchcombe, John R

    2015-01-01

    Fertilizer application is a common anthropogenic alteration to terrestrial systems. Increased nutrient input can impact soil microbial diversity or function directly through altered soil environments, or indirectly through plant-microbe feedbacks, with potentially important effects on ecologically-important plant-associated mutualists. We investigated the impacts of plant fertilizer, containing all common macro and micronutrients on symbiotic nitrogen-fixing bacteria (rhizobia), a group of bacteria that are important for plant productivity and ecosystem function. We collected rhizobia nodule isolates from natural field soil that was treated with slow-release plant fertilizer over a single growing season and compared phenotypic traits related to free-living growth and host partner quality in these isolates to those of rhizobia from unfertilized soils. Through a series of single inoculation assays in controlled glasshouse conditions, we found that isolates from fertilized field soil provided legume hosts with higher mutualistic benefits. Through growth assays on media containing variable plant fertilizer concentrations, we found that plant fertilizer was generally beneficial for rhizobia growth. Rhizobia isolated from fertilized field soil had higher growth rates in the presence of plant fertilizer compared to isolates from unfertilized field soil, indicating that plant fertilizer application favoured rhizobia isolates with higher abilities to utilize fertilizer for free-living growth. We found a positive correlation between growth responses to fertilizer and mutualism benefits among isolates from fertilized field soil, demonstrating that variable plant fertilizer induces context-dependent genetic correlations, potentially changing the evolutionary trajectory of either trait through increased trait dependencies. Our study shows that short-term application is sufficient to alter the composition of rhizobia isolates in the population or community, either directly

  3. [Effects of nitrogen fertilization on population dynamics and yield of high-yielding wheat and on alteration of soil nitrogen].

    Science.gov (United States)

    Ye, You-Liang; Wang, Gui-Liang; Zhu, Yun-Ji; Li, Huan-Huan; Huang, Yu-Fang

    2010-02-01

    Taking wheat varieties Yumai 49-198 (multi-spike phenotype) and Lankao Aizao 8 (large-spike phenotype) as test materials, field experiments were conducted at Wenxian and Lankao sites of Henan Province to study the effects of nitrogen fertilization on their population dynamics and yield and on the alteration of soil nitrogen. Five nitrogen application rates, i. e., 0, 90, 180, 270, and 360 N kg x hm(-2) were installed. The population amount of the two test varieties were all increased after emergence, reached the highest at jointing stage, and decreased afterwards. As for Yumai 49-198, its population amount had no significant differences at wintering and turning-green stages among the five nitrogen application rates and two experimental sites, but differed significantly after jointing stage with the nitrogen application rates. For Lankao Aizao 8, its population amount had no significant differences among the nitrogen application rates during whole growth period. The grain yield of the two varieties increased with the increase of nitrogen fertilization rate, but excessive nitrogen fertilization decreased the grain yield. Yumai 49-198 had the highest yield at 270 N kg x hm(-2), being 9523 and 9867 kg x hm(-2) at Wenxian and Lanako sites, respectively, while Lankao Aizao 8 had the highest yield at 180 N kg x hm(-2), being 9258 and 9832 kg x hm(-2) at Wenxian and Lanako sites, respectively. With the increase of nitrogen fertilization rate, soil nitrate N concentration and apparent nitrogen loss increased. At Wenxian and Lankao sites, the apparent soil nitrogen loss for Yumai 49-198 was 32.56% - 51.84% and - 16.7% - 42.6% of fertilized nitrogen, and that for Lankao Aizao 8 was 18.58% - 52.94% and - 11.5% - 45.8% of fertilized nitrogen, respectively. Considering the yield and environmental effect comprehensively, the nitrate N concentration in 0-90 cm soil layer in our case should not be exceeded 120 - 140 kg x hm(-2), and the maximal nitrogen application rate should not

  4. Efficiency of partner choice and sanctions in Lotus is not altered by nitrogen fertilization.

    Science.gov (United States)

    Regus, John U; Gano, Kelsey A; Hollowell, Amanda C; Sachs, Joel L

    2014-04-22

    Eukaryotic hosts must exhibit control mechanisms to select against ineffective bacterial symbionts. Hosts can minimize infection by less-effective symbionts (partner choice) and can divest of uncooperative bacteria after infection (sanctions). Yet, such host-control traits are predicted to be context dependent, especially if they are costly for hosts to express or maintain. Legumes form symbiosis with rhizobia that vary in symbiotic effectiveness (nitrogen fixation) and can enforce partner choice as well as sanctions. In nature, legumes acquire fixed nitrogen from both rhizobia and soils, and nitrogen deposition is rapidly enriching soils globally. If soil nitrogen is abundant, we predict host control to be downregulated, potentially allowing invasion of ineffective symbionts. We experimentally manipulated soil nitrogen to examine context dependence in host control. We co-inoculated Lotus strigosus from nitrogen depauperate soils with pairs of Bradyrhizobium strains that vary in symbiotic effectiveness and fertilized plants with either zero nitrogen or growth maximizing nitrogen. We found efficient partner choice and sanctions regardless of nitrogen fertilization, symbiotic partner combination or growth season. Strikingly, host control was efficient even when L. strigosus gained no significant benefit from rhizobial infection, suggesting that these traits are resilient to short-term changes in extrinsic nitrogen, whether natural or anthropogenic.

  5. Commercial Nitrogen Fertilizer Purchased

    Data.gov (United States)

    U.S. Environmental Protection Agency — Amounts of fertilizer nitrogen (N) purchased by states in individual years 2003, 2005, 2007, 2009 and 2011, and the % change in average amounts purchased per year...

  6. Environmental friendly nitrogen fertilization

    Institute of Scientific and Technical Information of China (English)

    Avi; Shaviv

    2005-01-01

    With the huge intensification of agriculture and the increasing awareness to human health and natural resources sustainability, there was a shift towards the development of environmental friendly N application approaches that support sustainable use of land and sustain food production.The effectiveness of such approaches depends on their ability to synchronize plant nitrogen demand with its supply and the ability to apply favored compositions and dosages of N-species.They are also influenced by farming scale and its sophistication, and include the following key concepts: (i) Improved application modes such as split or localized ("depot") application; (ii) use of bio-amendments like nitrification and urease inhibitors and combinations of (i) and (ii); (iii) use of controlled and slow release fertilizers; (iv) Fertigation-fertilization via irrigation systems including fully automated and controlled systems; and (v) precision fertilization in large scale farming systems. The paper describes the approaches and their action mechanisms and examines their agronomic and environmental significance. The relevance of the approaches for different farming scales, levels of agronomic intensification and agro-technical sophistication is examined as well.

  7. Efficiency of partner choice and sanctions in Lotus is not altered by nitrogen fertilization

    OpenAIRE

    2014-01-01

    Eukaryotic hosts must exhibit control mechanisms to select against ineffective bacterial symbionts. Hosts can minimize infection by less-effective symbionts (partner choice) and can divest of uncooperative bacteria after infection (sanctions). Yet, such host-control traits are predicted to be context dependent, especially if they are costly for hosts to express or maintain. Legumes form symbiosis with rhizobia that vary in symbiotic effectiveness (nitrogen fixation) and can enforce partner ch...

  8. Nitrogen fertility and irrigation effects on cottonseed composition

    Science.gov (United States)

    Cottonseed products have become a valuable secondary revenue source for cotton (Gossypium hirsutum L.) producers, but how production practices impact cottonseed composition is not clear. This research evaluated how cottonseed composition was altered by varying irrigation and nitrogen fertilization ...

  9. Warmer and drier conditions and nitrogen fertilizer application altered methanotroph abundance and methane emissions in a vegetable soil.

    Science.gov (United States)

    Ran, Yu; Xie, Jianli; Xu, Xiaoya; Li, Yong; Liu, Yapeng; Zhang, Qichun; Li, Zheng; Xu, Jianming; Di, Hongjie

    2016-11-12

    Methane (CH4) is a potent greenhouse gas, and soil can both be a source and sink for atmospheric CH4. It is not clear how future climate change may affect soil CH4 emissions and related microbial communities. The aim of this study was to determine the interactive effects of a simulated warmer and drier climate scenarios and the application of different nitrogen (N) sources (urea and manure) on CH4 emissions and related microbial community abundance in a vegetable soil. Greenhouses were used to control simulated climate conditions which gave 2.99 °C warmer and 6.2% lower water content conditions. The field experiment was divided into two phases. At the beginning of phase II, half of the greenhouses were removed to study possible legacy effects of the simulated warmer and drier conditions. The responses in methanogen and methanotroph abundance to a simulated climate change scenario were determined using real-time PCR. The results showed that the simulated warmer and drier conditions in the greenhouses significantly decreased CH4 emissions largely due to the lower soil moisture content. For the same reason, CH4 emissions of treatments in phase I were much lower than the same treatments in phase II. The abundance of methanotrophs showed a more significant response than methanogens to the simulated climate change scenario, increasing under simulated drier conditions. Methanogenic community abundance remained low, except where manure was applied which provided a source of organic C that stimulated methanogen growth. Soil moisture content was a major driver for methanotroph abundance and strongly affected CH4 emissions. The application of N source decreased CH4 emissions probably because of increased methanotrophic activity. CH4 emissions were positively correlated to methanogenic abundance and negatively correlated to methanotrophic abundance. These results demonstrate that projected future climate change conditions can have a feedback impact on CH4 emissions from the

  10. Global nitrogen fertilizer supply and demand outlook

    Institute of Scientific and Technical Information of China (English)

    Michel; Prud'homme

    2005-01-01

    This paper presents a brief overview of the world nitrogen fertilizer demand, high-lights trends in the global and regional developments of production capacity and provides a medium-term perspective of the global nitrogen supply/demand balance.

  11. Environmentally friendly slow-release nitrogen fertilizer.

    Science.gov (United States)

    Ni, Boli; Liu, Mingzhu; Lü, Shaoyu; Xie, Lihua; Wang, Yanfang

    2011-09-28

    To sustain the further world population, more fertilizers are required, which may become an environmental hazard, unless adequate technical and socioeconomic impacts are addressed. In the current study, slow-release formulations of nitrogen fertilizer were developed on the basis of natural attapulgite (APT) clay, ethylcellulose (EC) film, and sodium carboxymethylcellulose/hydroxyethylcellulose (CMC/HEC) hydrogel. The structural and chemical characteristics of the product were examined. The release profiles of urea, ammonium sulfate, and ammonium chloride as nitrogen fertilizer substrates were determined in soil. To further compare the release profiles of nitrogen from different fertilizer substrates, a mathematical model for nutrient release from the coated fertilizer was applied to calculate the diffusion coefficient D. The influence of the product on water-holding and water-retention capacities of soil was determined. The experimental data indicated that the product can effectively reduce nutrient loss, improve use efficiency of water, and prolong irrigation cycles in drought-prone environments.

  12. Calendula and camelina response to nitrogen fertility

    Science.gov (United States)

    The emerging oil-seed crops calendula (Calendula officinalis) and camelina (Camelina sativa L.) can provide a domestic, renewable, non-food alternative to imported oil sources for bioenergy and industrial purposes. However, very little information exists concerning nitrogen (N) fertilizer guidelines...

  13. Variation in foliar nitrogen and albedo in response to nitrogen fertilization and elevated CO2.

    Science.gov (United States)

    Wicklein, Haley F; Ollinger, Scott V; Martin, Mary E; Hollinger, David Y; Lepine, Lucie C; Day, Michelle C; Bartlett, Megan K; Richardson, Andrew D; Norby, Richard J

    2012-08-01

    Foliar nitrogen has been shown to be positively correlated with midsummer canopy albedo and canopy near infrared (NIR) reflectance over a broad range of plant functional types (e.g., forests, grasslands, and agricultural lands). To date, the mechanism(s) driving the nitrogen–albedo relationship have not been established, and it is unknown whether factors affecting nitrogen availability will also influence albedo. To address these questions, we examined variation in foliar nitrogen in relation to leaf spectral properties, leaf mass per unit area, and leaf water content for three deciduous species subjected to either nitrogen (Harvard Forest, MA, and Oak Ridge, TN) or CO(2) fertilization (Oak Ridge, TN). At Oak Ridge, we also obtained canopy reflectance data from the airborne visible/infrared imaging spectrometer (AVIRIS) to examine whether canopy-level spectral responses were consistent with leaf-level results. At the leaf level, results showed no differences in reflectance or transmittance between CO(2) or nitrogen treatments, despite significant changes in foliar nitrogen. Contrary to our expectations, there was a significant, but negative, relationship between foliar nitrogen and leaf albedo, a relationship that held for both full spectrum leaf albedo as well as leaf albedo in the NIR region alone. In contrast, remote sensing data indicated an increase in canopy NIR reflectance with nitrogen fertilization. Collectively, these results suggest that altered nitrogen availability can affect canopy albedo, albeit by mechanisms that involve canopy-level processes rather than changes in leaf-level reflectance.

  14. Estimation of Nitrogen Fertilizer Use Efficiency in Dryland Agroecosystem

    Institute of Scientific and Technical Information of China (English)

    LI Shi-qing; LI Sheng-xiu

    2001-01-01

    A field trial was carried out to study the nitrogen fertilizer recovery by four crops in succession in manurial loess soil in Yangling. The results showed that the nitrogen fertilizer not only had the significant effects on the first crop , but also had longer residual effects, even on the fourth crop. The average apparent nitrogen fertilizer recovery by the first crop was 31.7%, and the accumulative nitrogen recovery by the 4 crops was high as 62.3%, and the latter was double as the former. It is quite clear that the nitrogen fertilizer recovery by the first crop was not reliable for estimating the nitrogen fertilizer unless the residual effect of nitrogen fertilizer was included.

  15. Global assessment of nitrogen fertilizer: The SCOPE/IGBP Nitrogen Fertilizer Rapid Assessment Project

    Institute of Scientific and Technical Information of China (English)

    Arvin R. Mosier; J. Keith Syers; John R. Freney

    2005-01-01

    Nitrogen (N) availability is a key role in food and fiber production. Providing plant-available N through synthetic fertilizer in the 20th and early 21st century has been a major contributor to the increased production required to feed and clothe the growing human population.To continue to meet the global demands and to minimize environmental problems, significant improvements are needed in the efficiency with which fertilizer N is utilized within production systems. There are still major uncertainties regarding the fate of fertilizer N added to agricultural soils and the potential for reducing losses to the environment. Enhancing the technical and economic efficiency of fertilizer N is seen to promote a favorable situation for both agricultural production and the environment, and this has provided much of the impetus for a new N fertilizer project.To address this important issue, a rapid assessment project on N fertilizer (NFRAP) was conducted by SCOPE (the Scientific Committee on Problems of the Environment) during late 2003 and early 2004. This was the first formal project of the International Nitrogen Initiative (INI). As part of this assessment, a successful international workshop was held in Kampala, Uganda on 12 -16 January, 2004. This workshop brought together scientists from around the world to assess the fate of synthetic fertilizer N in the context of overall N inputs to agricultural systems, with a view to enhancing the efficiency of N use and reducing negative impacts on the environment.Regionalization of the assessment highlighted the problems of too little N for crop production to meet the nutrient requirements of sub-Saharan Africa and the oversupply of N in the major rice-growing areas of China. The results of the assessment are presented in a book (SCOPE 65)which is now available to provide a basis for further discussions on N fertilizer.

  16. Response of Nerica Rice to Nitrogen Fertilization

    Directory of Open Access Journals (Sweden)

    R Shultana

    2015-12-01

    Full Text Available An experiment was conducted during T. Aman season, 2014 at the Agronomy Research Field, Bangladesh Rice Research Institute, Gazipur to determine the optimum rate of nitrogen fertilizer for higher yield in nerica rice. The experiment comprised of three rice varieties viz. NERICA1, NERICA10 and BRRI dhan57; and five nitrogen levels viz. 0, 23, 46, 69 and 92 kg ha-1. The rice var. BRRI dhan57 with 69 and 92 kg N ha-1 produced significantly identical with higher panicles m-2. But NERICA1 and NERICA10 produced higher number of panicles with 46 and 69 kg N ha-1, respectively. However, BRRI dhan57 with 46 kg N ha-1 produced highest grains panicle-1 but NERICA1 and NERICA10 produced higher number of grains panicle-1 with 23 kg N ha-1. The highest percentage of sterility was recorded in NERICA10 with 69 kg N ha-1. The regression analysis gave the optimum dose of nitrogen for NERICA1, NERICA10 and BRRI dhan57 which were 69.25, 74.25 and 85.75 kg N ha-1, respectively.

  17. Alternate Nitrogen Amendments for Organic Fertilizers

    Directory of Open Access Journals (Sweden)

    M.K.C. Sridhar

    2001-01-01

    Full Text Available The use of compost or manure in agriculture as an organic source of nutrients is common in many tropical, developing countries like Nigeria. One of the drawbacks of such materials is their low nitrogen (N content (=1% N. Farmers commonly use chemical N fertilizers such as urea, calcium ammonium nitrate (CAN, and NPK formulations to obtain better crop growth and yield. These chemical supplements may have a negative impact on the environment through nitrate leaching into water, leading to eutrophication of surface waters that can affect public health. Gliricidia sepium, a fast-growing, tropical, perennial hedge plant was tested as a source of N in organo-mineral fertilizer formulations. Average nutrient content of Gliricidia is 3.8% N, 0.32% P, 1.8% K, 0.8% Ca, and 0.2% Mg. Using a sand culture and Amaranthus caudatus as a test crop, it was shown that amending commercial composts with 30% Gliricidia prunings would benefit many small-scale farmers and control environmental pollution.

  18. Effect of Nitrogen Phosphorus and Potassium Fertilization on Sago Growth

    OpenAIRE

    2014-01-01

    Fertilization is an important act of cultivation in an effort to provide plant nutrients to increase sago crop productivity. This research aimed to study the effect of nitrogen, phosphorus and potassium fertilizers towards the growth of sago palm. The study included three separate experiments i.e. experimental fertilization of nitrogen, phosphorus and potassium. The experiment was conducted by using a randomized block design (RBD) consisting of four levels of treatments and each treatment was...

  19. [Fate and balance of bulk blending controlled release fertilizer nitrogen under continuous cropping of mustard].

    Science.gov (United States)

    Zhang, Pan-Pan; Fan, Xiao-Lin

    2012-10-01

    Under the conditions of applying water soluble fertilizer and its bulk blending with controlled release fertilizer (BB-CRF), and by using micro-lysimeter, this paper quantitatively studied the nitrogen (N) uptake by mustard, the soil N losses from N2O emission, leaching and others, and the N residual in soil in three rotations of continuously cropped mustard. In the treatment of BB-CRF with 25% of controlled release nitrogen, the N uptake by mustard increased with rotations, and the yield by the end of the experiment was significantly higher than that in the treatment of water soluble fertilizer. The cumulated N2O emission loss and the N leaching loss were obviously higher in treatment water soluble fertilizer than in treatment BB-CRF. NO3(-)-N was the primary form of N in the leachate. In relative to water soluble fertilizer, BB-CRF altered the fates of fertilizer nitrogen, i.e., the N uptake by mustard and the N residual in soil increased by 75.4% and 76.0%, and the N leaching loss and other apparent N losses decreased by 27.1% and 66.3%, respectively. The application of BB-CRF could be an effective way to reduce the various losses of fertilizer N while increase the fertilizer N use efficiency, and the controlled release fertilizer is the environmentally friendly fertilizer with the property of high N use efficiency.

  20. Estimation of Symbiotically Fixed Nitrogen in Soybean Depending on Nitrogen Fertilization

    OpenAIRE

    1998-01-01

    Objectives of investigations were to determine optimal nitrogen rates for the highest soybean seed yield, compare reaction of nodulating and nonodulating soybean varieties to nitrogen fertilization and estimate the amounts of symbiotically fixed nitrogen depending on nitrogen rates. Estimation of the amounts of symbiotically fixed nitrogen was done using the nitrogen contents in soil before and after the vegetation and nitrogen contents in whole plants of nodulating and nonodulating varieties...

  1. Interactions of Water Management and Nitrogen Fertilizer on Nitrogen Absorption and Utilization in Rice

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-hua; CAO Wei-xing; DING Yan-feng; TIAN Yong-chao; JIANG Dong

    2003-01-01

    The interactions of water management and nitrogen fertilizer on nitrogen absorption and utili-zation were studied in rice with Wuxiangjing9 (japonica). The results showed that the nitrogen uptake and re-maining in straw increased and the percentage of nitrogen translocation (PNT) from vegetative organs, nitro-gen dry matter production efficiency (NDMPE) and nitrogen grain production efficiency (NGPE) decreasedwith nitrogen increasing. The nitrogen uptake and NGPE decreased when severe water stressed. However, ricenot only decreased the nitrogen uptake but also increased the PNT from vegetative organs, NDMPE and NGPEwhen mild water stressed. There were obvious interactions between nitrogen fertilizer and water management,such as with water stress increasing the effect of nitrogen on increasing nitrogen uptake was reduced and thaton decreasing NDMPE was intensified.

  2. Efficiency of nitrogen fertilizers for rice

    OpenAIRE

    Roger, Pierre-Armand; I. F. Grant; Reddy, P. M.; Watanabe, I.

    1987-01-01

    The photosynthetic biomass that develops in the floodwater of wetland rice fields affects nitrogen dynamics in the ecosystem. This review summarizes available data on the nature, productivity, and composition of the photosynthetic aquatic biomass, and its major activities regarding the nitrogen cycle, i.e., nitrogen fixation by free living blue-green algae and #Azolla$, nitrogen trapping, nitrogen accumulation at the soil surface, its effect on nitrogen losses by ammonia volatilization, nitro...

  3. effect of water harvesting methods, nitrogen-phosphorus fertilizer ...

    African Journals Online (AJOL)

    DR. AMINU

    recommended for better date palm production especially within the Sudan ecological zone of. Nigeria where ... Key words: Water harvesting method, Nitrogen-Phosphorus fertilizer, Date palm variety, Leaf. Tissue N ..... New Mexico University.

  4. Nitrogen fertilization affects silicon concentration, cell wall composition and biofuel potential of wheat straw

    DEFF Research Database (Denmark)

    Murozuka, Emiko; Laursen, Kristian Holst; Lindedam, Jane

    2014-01-01

    Nitrogen is an essential input factor required for plant growth and biomass production. However, very limited information is available on how nitrogen fertilization affects the quality of crop residues to be used as lignocellulosic feedstock. In the present study, straw of winter wheat plants grown...... linearly from 0.32% to 0.71% over the range of nitrogen treatments. Cellulose and hemicellulose were not affected by the nitrogen supply while lignin peaked at medium rates of nitrogen application. The nitrogen treatments had a distinct influence on the silicon concentration, which decreased from 2.5% to 1...... saccharification efficiency was negatively correlated with the rate of nitrogen supply. We conclude that the level of nitrogen supply to wheat plants alters the composition of cell wall components in the straw and that this may result in reduced saccharification efficiency....

  5. Effects of Nitrogen and Phosphorus Fertilizer on Agro ...

    African Journals Online (AJOL)

    SH

    Nitrogen fertilizer rate of 60 kg N ha-1 significantly produced higher values for plant ...... Journal of the American Society of ... citrus symposium 3, 1569-1578. 40. Fertilizer types on agro-morphological traits and yield of Thevetia peruviana. J ...

  6. [Effects of applying nitrogen fertilizer and fertilizer additive on rice yield and rice plant nitrogen uptake, translocation, and utilization].

    Science.gov (United States)

    Li, Wen-jun; Xia, Yong-qiu; Yang, Xiao-yun; Guo, Miao; Yan, Xiao-yuan

    2011-09-01

    A field experiment was conducted in the Taihu Lake region of southern Jiangsu to study the effects of applying nitrogen (N) fertilizer and fertilizer additive on the rice yield and the rice plant N uptake, translocation, and utilization. Applying N fertilizer had significant positive effects on the rice yield, accumulative absorbed N at all growth stages and at each growth stage, and N translocation rate after anthesis (P 0.05). The N translocation rate after anthesis and the N fertilizer use efficiency decreased with increasing N application rate. Applying fertilizer additive further improved the rice yield, accumulative absorbed N, N translocation rate after anthesis, and N fertilizer use efficiency, and this effect was more evident when the N application rate was equal to or greater than 200 kg x hm(-2). Relatively high rice yield and N use efficiency were achieved when applying 150 kg x hm(-2) of N fertilizer without the application of fertilizer additive.

  7. A Dynamic Knowledge Model for Nitrogen Fertilization in Wheat Management

    Institute of Scientific and Technical Information of China (English)

    ZHU Yan; CAO Wei-xing; DAI Ting-bo; SUN Chuan-fan

    2003-01-01

    By analyzing and extracting the research progress on nitrogen fertilization in wheat, a dynamic knowledge model for management decision-making on total nitrogen rate, ratios of organic to inorganic and of basal to dressing nitrogen under different environments and cultivars in wheat was developed with principle of nutrient balance and by integrating the quantitative effects of grain yield and quality targets, soil characters, variety traits and water management levels. Case studies on the nitrogen fertilization model with the data sets of different eco-sites, cultivars, soil fertility levels, grain yield and quality targets and water management levels indicate a good performance of the model system in decision-making and wide applicability.

  8. Discussing the Determination Standard of Recovery Efficiency of Nitrogen Fertilizer

    Directory of Open Access Journals (Sweden)

    TIAN Chang-yu

    2016-07-01

    Full Text Available Recovery efficiency of nitrogen fertilizer(REN is an important index for the increasing crop yield and reducing environmental benefits of nitrogen fertilizer. But the determination and calculation methods of REN have some problems to study. They are lower rate and higher variability of the rate than it should be. The long-term nitrogen fertilizer location test had been taken since 2007 to analyze the nitrogen uptake rate of wheat year after year and the REN rate was calculated annually. A reasonable measurement specification of REN determination method was put forward. The REN measurement specification was:(1The wheat nitrogen uptake of CK kept relatively stable after a few years; (2The wheat nitrogen uptake ratio of fetilized treatment retained stable; (3REN must be used the average of 3 years of steady period value. With this measurement specification of REN determination method, REN rate was in the range of 69.2%~76.2%(Wheat when applied nitrogen fertilizer in range of 120~180 kg N·hm-2. REN determination method should follow this specification. In this case the correct and reasonable REN parameter can be measured. The reasonable REN can be applied in scientific research and production.

  9. Electrochemical process for the preparation of nitrogen fertilizers

    Science.gov (United States)

    Aulich, Ted R.; Olson, Edwin S.; Jiang, Junhua

    2013-03-19

    The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be solid.

  10. Intercropping of wheat and pea as influenced by nitrogen fertilization

    DEFF Research Database (Denmark)

    Ghaley, B.B.; Hauggaard-Nielsen, Henrik; Jensen, Henning Høgh;

    2005-01-01

    The effect of sole and intercropping of field pea (Pisum sativum L.) and spring wheat (Triticum aestivum L.) on crop yield, fertilizer and soil nitrogen (N) use was tested on a sandy loam soil at three levels of urea fertilizer N (0, 4 and 8 g N m−2) applied at sowing. The 15N enrichment...... and natural abundance techniques were used to determine N accumulation in the crops from the soil, fertilizer and symbiotic N2 fixation. Intercrops of pea and wheat showed maximum productivity without the supply of N fertilizer. Intercropping increased total dry matter (DM) and N yield, grain DM and N yield......, grain N concentration, the proportion of N derived from symbiotic N2 fixation, and soil N accumulation. With increasing fertilizer N supply, intercropped and sole cropped wheat responded with increased yield, grain N yield and soil N accumulation, whereas the opposite was the case for pea. Fertilizer N...

  11. [Effects of water deficit and nitrogen fertilization on winter wheat growth and nitrogen uptake].

    Science.gov (United States)

    Qi, You-Ling; Zhang, Fu-Cang; Li, Kai-Feng

    2009-10-01

    Winter wheat plants were cultured in vitro tubes to study their growth and nitrogen uptake under effects of water deficit at different growth stages and nitrogen fertilization. Water deficit at any growth stages could obviously affect the plant height, leaf area, dry matter accumulation, and nitrogen uptake. Jointing stage was the most sensitive stage of winter wheat growth to water deficit, followed by flowering stage, grain-filling stage, and seedling stages. Rewatering after the water deficit at seedling stage had a significant compensation effect on winter wheat growth, and definite compensation effect was observed on the biomass accumulation and nitrogen absorption when rewatering was made after the water deficit at flowering stage. Under the same nitrogen fertilization levels, the nitrogen accumulation in root with water deficit at seedling, jointing, flowering, and grain-filling stages was reduced by 25.82%, 55.68%, 46.14%, and 16.34%, and the nitrogen accumulation in aboveground part was reduced by 33.37%, 51.71%, 27.01%, and 2.60%, respectively, compared with no water deficit. Under the same water deficit stages, the nitrogen content and accumulation of winter wheat decreased with decreasing nitrogen fertilization level, i. e., 0.3 g N x kg(-1) FM > 0.2 g N x kg(-1) FM > 0.1 g N x kg(-1) FM. Nitrogen fertilization had obvious regulation effect on winter wheat plant growth, dry matter accumulation, and nitrogen uptake under water stress.

  12. Carbon and nitrogen isotopic signatures and nitrogen profile to identify adulteration in organic fertilizers.

    Science.gov (United States)

    Verenitch, Sergei; Mazumder, Asit

    2012-08-29

    Recently it has been shown that stable isotopes of nitrogen can be used to discriminate between organic and synthetic fertilizers, but the robustness of the approach is questionable. This work developed a comprehensive method that is far more robust in identifying an adulteration of organic nitrogen fertilizers. Organic fertilizers of various types (manures, composts, blood meal, bone meal, fish meal, products of poultry and plant productions, molasses and seaweed based, and others) available on the North American market were analyzed to reveal the most sensitive criteria as well as their quantitative ranges, which can be used in their authentication. Organic nitrogen fertilizers of known origins with a wide δ(15)N range between -0.55 and 28.85‰ (n = 1258) were characterized for C and N content, δ(13)C, δ(15)N, viscosity, pH, and nitrogen profile (urea, ammonia, organic N, water insoluble N, and NO3). A statistically significant data set of characterized unique organic nitrogen fertilizers (n = 335) of various known origins has been assembled. Deliberately adulterated samples of different types of organic fertilizers mixed with synthetic fertilizers at a wide range of proportions have been used to develop the quantitative critical characteristics of organic fertilizers as the key indicators of their adulteration. Statistical analysis based on the discriminant functions of the quantitative critical characteristics of organic nitrogen fertilizers from 14 different source materials revealed a very high average rate of correct classification. The developed methodology has been successfully used as a source identification tool for numerous commercial nitrogen fertilizers available on the North American market.

  13. Evaluation of Groundwater Pollution Nitrogen Fertilizer Using Expert System

    OpenAIRE

    Ta-oun, Mongkon; Daud, Mohamed; Bardaie, Mohd Zohadie

    2017-01-01

    An expert system was used to correlate the availability of nitrogen fertilizer with the vulnerability of groundwater to pollution in Peninsula Malaysia to identify potential groundwater quality problems. The expert system could predict the groundwater pollution potential under several conditions of agricultural activities and exiting environments. Four categories of groundwater pollution potential were identified base on an N-fertilizer groundwater pollution potential index. A groundwater pol...

  14. Stabilized nitrogen fertilizers and application rate influence nitrogen losses under rainfed spring wheat

    Science.gov (United States)

    Nitrogen (N) losses associated with fertilizer application have negative economic and environmental consequences, but urease and nitrification inhibitors have potential to reduce N losses. The effectiveness of these inhibitors has been studied extensively in irrigated but not rainfed systems. Theref...

  15. The Position of Mineral Nitrogen Fertilizer in Efficient Use of Nitrogen and Land: A Review

    NARCIS (Netherlands)

    Schroder, J.J.

    2014-01-01

    Our attitude towards mineral nitrogen (N) fertilizers is ambivalent. N fertilizers have on one hand increased our supply of food, feed and other bio-based raw materials tremendously and also improved the use efficiency of land and labor, but have on the other hand a negative impact on the quality of

  16. JV Task-121 Electrochemical Synthesis of Nitrogen Fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Junhua Jiang; Ted Aulich

    2008-11-30

    An electrolytic renewable nitrogen fertilizer process that utilizes wind-generated electricity, N{sub 2} extracted from air, and syngas produced via the gasification of biomass to produce nitrogen fertilizer ammonia was developed at the University of North Dakota Energy & Environmental Research Center. This novel process provides an important way to directly utilize biosyngas generated mainly via the biomass gasification in place of the high-purity hydrogen which is required for Haber Bosch-based production of the fertilizer for the production of the widely used nitrogen fertilizers. Our preliminary economic projection shows that the economic competitiveness of the electrochemical nitrogen fertilizer process strongly depends upon the cost of hydrogen gas and the cost of electricity. It is therefore expected the cost of nitrogen fertilizer production could be considerably decreased owing to the direct use of cost-effective 'hydrogen-equivalent' biosyngas compared to the high-purity hydrogen. The technical feasibility of the electrolytic process has been proven via studying ammonia production using humidified carbon monoxide as the hydrogen-equivalent vs. the high-purity hydrogen. Process optimization efforts have been focused on the development of catalysts for ammonia formation, electrolytic membrane systems, and membrane-electrode assemblies. The status of the electrochemical ammonia process is characterized by a current efficiency of 43% using humidified carbon monoxide as a feedstock to the anode chamber and a current efficiency of 56% using high-purity hydrogen as the anode gas feedstock. Further optimization of the electrolytic process for higher current efficiency and decreased energy consumption is ongoing at the EERC.

  17. How much fertilizer nitrogen does sugarcane need?

    Science.gov (United States)

    Nitrogen rate recommendations for sugarcane in Louisiana take into account crop age (plant cane or stubble) and soil texture (light or heavy). Recommended rates in the 1950s ranged from 40 pounds N/A for plant cane on light-textured soil to 100 pounds of N/A for stubble cane on heavy-textured soil a...

  18. Nitrogen fertilization effects on sorghum forage yield and quality

    Science.gov (United States)

    The study objective was to determine the effect of nitrogen fertilization on yield and quality of photoperiod sensitive (PS) and non-PS forage sorghum, sorghum-sudangrass, and sudangrass compared to corn. This study was a randomized complete block design with treatments arranged in a 4 x 8 factorial...

  19. MANAGEMENT OF IRRIGATION AND NITROGEN FERTILIZERS TO REDUCE AMMONIA VOLATILIZATION

    Directory of Open Access Journals (Sweden)

    Fernando Viero

    2015-12-01

    Full Text Available ABSTRACT Nitrogen losses by ammonia (NH3 volatilization can be reduced by appropriate irrigation management or by alternative N sources, replacing urea. The objective of this study was to evaluate the efficiency of irrigation management and N source combinations in decreasing NH3 volatilization from an Argissolo Vermelho Distrófico típico cultivated for 28 years with black oat (Avena strigosa and maize (Zea mays, under no-tillage in the region of Depressão Central, Rio Grande do Sul, Brazil. The experiment was arranged in a randomized block design with split plots with three replications, where the main plots consisted of irrigation systems: no irrigation; irrigation immediately before and irrigation immediately after fertilization. The subplots were treated with different N sources: urea, urea with urease inhibitor and slow-release fertilizer, at an N rate of 180 kg ha-1, broadcast over maize, plus a control treatment without N fertilization. Ammonia volatilization was assessed using semi-open static collectors for 1, 2, 4, 6, and 10 days after N fertilization. In general, more than 90 % of total NH3-N losses occurred until three days after N fertilization, with peaks up to 15.4 kg ha-1 d-1. The irrigation was efficient to reduce NH3 losses only when applied after N fertilization. However, reductions varied according to the N fertilizer, and were higher for urea (67 % and slightly lower for urea with urease inhibitor (50 % and slow-release fertilizer (40 %, compared with the mean of the treatments without irrigation and irrigation before fertilization. The use of urea with urease inhibitor instead of urea was only promising under volatilization-favorable conditions (no irrigation or irrigation before N fertilization. Compared to urea, slow-release fertilizer did not reduce ammonia volatilization in any of the rainfed or irrigated treatments.

  20. Multispectral remote sensing for site-specific nitrogen fertilizer management

    Directory of Open Access Journals (Sweden)

    Nikrooz Bagheri

    2013-10-01

    Full Text Available The objective of this work was to evaluate the use of multispectral remote sensing for site-specific nitrogen fertilizer management. Satellite imagery from the advanced spaceborne thermal emission and reflection radiometer (Aster was acquired in a 23 ha corn-planted area in Iran. For the collection of field samples, a total of 53 pixels were selected by systematic randomized sampling. The total nitrogen content in corn leaf tissues in these pixels was evaluated. To predict corn canopy nitrogen content, different vegetation indices, such as normalized difference vegetation index (NDVI, soil-adjusted vegetation index (Savi, optimized soil-adjusted vegetation index (Osavi, modified chlorophyll absorption ratio index 2 (MCARI2, and modified triangle vegetation index 2 (MTVI2, were investigated. The supervised classification technique using the spectral angle mapper classifier (SAM was performed to generate a nitrogen fertilization map. The MTVI2 presented the highest correlation (R²=0.87 and is a good predictor of corn canopy nitrogen content in the V13 stage, at 60 days after cultivating. Aster imagery can be used to predict nitrogen status in corn canopy. Classification results indicate three levels of required nitrogen per pixel: low (0-2.5 kg, medium (2.5-3 kg, and high (3-3.3 kg.

  1. [Interactions of straw, nitrogen fertilizer and bacterivorous nematodes on soil labile carbon and nitrogen and greenhouse gas emissions].

    Science.gov (United States)

    Zhang, Teng-Hao; Wang, Nan; Liu, Man-Qiang; Li, Fang-Hui; Zhu, Kang-Li; Li, Hui-Xin; Hu, Feng

    2014-11-01

    A 3 x 2 factorial design of microcosm experiment was conducted to investigate the interactive effects of straw, nitrogen fertilizer and bacterivorous nematodes on soil microbial biomass carbon (C(mic)) and nitrogen (N(mic)), dissolved organic carbon (DOC) and nitrogen (DON), mineral nitrogen (NH(4+)-N and NO(3-)-N), and greenhouse gas (CO2, N2O and CH4) emissions. Results showed that straw amendment remarkably increased the numbers of bacterivorous nematodes and the contents of Cmic and Nmic, but Cmic and Nmic decreased with the increasing dose of nitrogen fertilization. The effects of bacterivorous nematodes strongly depended on either straw or nitrogen fertilization. The interactions of straw, nitrogen fertilization and bacterivorous nematodes on soil DOC, DON and mineral nitrogen were strong. Straw and nitrogen fertilization increased DOC and mineral nitrogen contents, but their influences on DON depended on the bacterivorous nematodes. The DOC and mineral nitrogen were negatively and positively influenced by the bacterivorous nematodes, re- spectively. Straw significantly promoted CO2 and N2O emissions but inhibited CH4 emission, while interactions between nematodes and nitrogen fertilization on emissions of greenhouse gases were obvious. In the presence of straw, nematodes increased cumulative CO2 emissions with low nitrogen fertilization, but decreased CO2 and N2O emissions with high nitrogen fertilization on the 56th day after incubation. In summary, mechanical understanding the soil ecological process would inevitably needs to consider the roles of soil microfauna.

  2. Effects of Nitrogenous Fertilizer on Pungency of Hot Pepper (Capsicum annuum L.) Fruits

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The response of pungency of hot pepper fruits nitrogenous fertilizer on was invesigated. The results indicated that nitrogenous fertilizer had a significant effect on the capsaicin content of hot pepper fruits at 35 and 42 days after flowering;capsaicin content gradually decreased, while peroxidase activity increased with nitrogenous fertilizer increasing.

  3. Nitrogen fertilization challenges the climate benefit of cellulosic biofuels

    Science.gov (United States)

    Ruan, Leilei; Bhardwaj, Ajay K.; Hamilton, Stephen K.; Robertson, G. Philip

    2016-06-01

    Cellulosic biofuels are intended to improve future energy and climate security. Nitrogen (N) fertilizer is commonly recommended to stimulate yields but can increase losses of the greenhouse gas nitrous oxide (N2O) and other forms of reactive N, including nitrate. We measured soil N2O emissions and nitrate leaching along a switchgrass (Panicum virgatum) high resolution N-fertilizer gradient for three years post-establishment. Results revealed an exponential increase in annual N2O emissions that each year became stronger (R 2 > 0.9, P fertilizer. Nitrate leaching (and calculated indirect N2O emissions) also increased exponentially in response to N inputs, but neither methane (CH4) uptake nor soil organic carbon changed detectably. Overall, N fertilizer inputs at rates greater than crop need curtailed the climate benefit of ethanol production almost two-fold, from a maximum mitigation capacity of -5.71 ± 0.22 Mg CO2e ha-1 yr-1 in switchgrass fertilized at 56 kg N ha-1 to only -2.97 ± 0.18 Mg CO2e ha-1 yr-1 in switchgrass fertilized at 196 kg N ha-1. Minimizing N fertilizer use will be an important strategy for fully realizing the climate benefits of cellulosic biofuel production.

  4. Aqueous and gaseous nitrogen losses induced by fertilizer application

    Energy Technology Data Exchange (ETDEWEB)

    Gu, C.; Maggi, F.; Riley, W.J.; Hornberger, G.M.; Xu, T.; Oldenburg, C.M.; Spycher, N.; Miller, N.L.; Venterea, R.T.; Steefel, C.

    2009-01-15

    In recent years concern has grown over the contribution of nitrogen (N) fertilizer use to nitrate (NO{sub 3}{sup -}) water pollution and nitrous oxide (N{sub 2}O), nitric oxide (NO), and ammonia (NH{sub 3}) atmospheric pollution. Characterizing soil N effluxes is essential in developing a strategy to mitigate N leaching and emissions to the atmosphere. In this paper, a previously described and tested mechanistic N cycle model (TOUGHREACT-N) was successfully tested against additional observations of soil pH and N{sub 2}O emissions after fertilization and irrigation, and before plant emergence. We used TOUGHREACT-N to explain the significantly different N gas emissions and nitrate leaching rates resulting from the different N fertilizer types, application methods, and soil properties. The N{sub 2}O emissions from NH{sub 4}{sup +}-N fertilizer were higher than from urea and NO{sub 3}{sup -}-N fertilizers in coarse-textured soils. This difference increased with decreases in fertilization application rate and increases in soil buffering capacity. In contrast to methods used to estimate global terrestrial gas emissions, we found strongly non-linear N{sub 2}O emissions as a function of fertilizer application rate and soil calcite content. Speciation of predicted gas N flux into N{sub 2}O and N{sub 2} depended on pH, fertilizer form, and soil properties. Our results highlighted the need to derive emission and leaching factors that account for fertilizer type, application method, and soil properties.

  5. Electrochemical process for the preparation of nitrogen fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Aulich, Ted R [Grand Forks, ND; Olson, Edwin S [Grand Forks, ND; Jiang, Junhua [Grand Forks, ND

    2012-04-10

    The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia, at low temperature and pressure, preferably at ambient temperature and pressure, utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen or hydrogen equivalent. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source or a hydrogen equivalent such as carbon monoxide or a mixture of carbon monoxide and hydrogen at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be aqueous, non-aqueous, or solid.

  6. Tropical legume crop rotation and nitrogen fertilizer effects on agronomic and nitrogen efficiency of rice.

    Science.gov (United States)

    Rahman, Motior M; Islam, Aminul M; Azirun, Sofian M; Boyce, Amru N

    2014-01-01

    Bush bean, long bean, mung bean, and winged bean plants were grown with N fertilizer at rates of 0, 2, 4, and 6 g N m(-2) preceding rice planting. Concurrently, rice was grown with N fertilizer at rates of 0, 4, 8, and 12 g N m(-2). No chemical fertilizer was used in the 2nd year of crop to estimate the nitrogen agronomic efficiency (NAE), nitrogen recovery efficiency (NRE), N uptake, and rice yield when legume crops were grown in rotation with rice. Rice after winged bean grown with N at the rate of 4 g N m(-2) achieved significantly higher NRE, NAE, and N uptake in both years. Rice after winged bean grown without N fertilizer produced 13-23% higher grain yield than rice after fallow rotation with 8 g N m(-2). The results revealed that rice after winged bean without fertilizer and rice after long bean with N fertilizer at the rate of 4 g N m(-2) can produce rice yield equivalent to that of rice after fallow with N fertilizer at rates of 8 g N m(-2). The NAE, NRE, and harvest index values for rice after winged bean or other legume crop rotation indicated a positive response for rice production without deteriorating soil fertility.

  7. Effects of nitrogen fertilizer on nitrogen use efficiency and yield of rice under different soil conditions

    Institute of Scientific and Technical Information of China (English)

    YE Quanbao; ZHANG Hongcheng; WEI Haiyan; ZHANG Ying; WANG Benfu; XIA Ke; HUO Zhongyang; DAI Qigen; XU Ke

    2007-01-01

    Four rice cultivars were used to study the effects of nitrogen fertilizer on nitrogen use efficiency,yield and characteristics of nitrogen uptake under two soil conditions (sandy and clay soil)in soil culture pool.The results were as follows.First,yield of rice in sandy and clay soil was increased by nitrogen application,and that in clay soil was higher than that in sandy soil,but the effect of nitrogen on yield increment was greater in sandy soil than in clay soil.Second,nitrogen utilization of rice was different under different soil conditions.Nitrogen harvest index(NHI)and physiological Nitrogen use efficiency(PNUE)were higher in sandy soil than in clay soil.Apparent Nitrogen recovery efficiency (ANRE),partial factor productivity for applied Nitrogen (PFP),and soil Nitrogen dependent rate(SNDR)were higher in clay soil than in sandy soil.Agronomic Nitrogen use efficiency(ANUE)was varied in different cultivars under different soil conditions.Third,N harvest index,agronomic N use efficiency,physiological N use efficiency,partial factor productivity for applied N,and soil N dependent rate were decreased significantly with the increment of the amount of nitrogen applied under two soil conditions.In sandy soil,ANRE was increased with the increasing nitrogen application and reached the highest value at high nitrogen level.However,in clay soil,ANRE was increased with the increasing of nitrogen application at first,and reached the highest value at medium nitrogen level,then decreased dramatically at high nitrogen level.Fourth,N uptake rate for rice straw and for rice grain and total N uptake rate for rice were higher in sandy clay soil than in sandy soil,but the difference between them was relatively small.Fifth,under different soil conditions,there were significant genotypic differences in the effects of applying nitrogen fertilizer on nitrogen use efficiency,yield,and characteristics of nitrogen uptake.

  8. Upscaling nitrogen-mycorrhizal effects to quantify CO2 fertilization.

    Science.gov (United States)

    Terrer, C.; Franklin, O.; Kaiser, C.; Vicca, S.; Stocker, B.; Prentice, I. C.; Soudzilovskaia, N.

    2016-12-01

    Terrestrial ecosystems sequester annually about a quarter of anthropogenic carbon dioxide (CO2) emissions. However, it has been proposed that nitrogen (N) availability will limit plants' capacity to absorb increasing quantities of CO2 in the atmosphere. Experiments in which plants are fumigated with elevated CO2 show contrasting results, leaving open the debate of whether the magnitude of the CO2 fertilization effect will be limited by N. By synthesizing data from CO2 experiments through meta-analysis, we found that the magnitude of the CO2 fertilization effect can be explained based on the interaction between N availability and type of mycorrhizal association. Indeed, N availability is the most important driver of the CO2 fertilization effect, however, plants that associate with ectomycorrhizal fungi can overcome N limitations and grow about 30% more under 650ppm than under 400ppm of atmospheric CO2. On the other hand, plants that associate with arbuscular mycorrhizal fungi show no CO2 fertilization effect under low N availability. Using this framework, we quantified biomass responses to CO2 as a function of the soil parameters that determine N availability for the two mycorrhizal types. Then, by overlaying the distribution of mycorrhizal plants with global projections of the soil parameters that determine N availability, we estimated the amount of extra CO2 that terrestrial plants can sequester in biomass for an increase in CO2, as well as the distribution of the CO2 fertilization effect. This synthesis reconciles contrasting views of the role of N in terrestrial carbon uptake and emphasizes the plant control on N availability through interaction with ectomycorrhizal fungi. Large-scale ecosystem models should account for the influence of nitrogen and mycorrhizae reported here, which will improve representation of the CO2 fertilization effect, critical for projecting ecosystem responses and feedbacks to climate change.

  9. Inoculation with Azospirillum, associated with nitrogen fertilization in maize

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Lana

    2012-06-01

    Full Text Available The biological nitrogen fixation is an alternative to supply the nitrogen needed for maize. The objective of this study was to evaluate the development and yield of maize in response to inoculation with Azospirillum associated with nitrogen fertilization. We conducted two field experiments in the summer harvest, the first in the 2000/2001 crop year in the region of Marechal Cândido Rondon, under conventional tillage, and second in the 2002/2003 agricultural year in the region of Cascavel, under no tillage. The experimental design in both experiments was a randomized complete block, with four replications, 2x2x2 factorial, with two levels of nitrogen at sowing (zero and 20 kg ha-1, two levels of inoculum (zero and 200 g ha-1 and two levels of nitrogen in topdressing (zero and 100 kg ha-1. There was evaluated the height of ear insertion, total plant height, leaf N content, shoot dry biomass and grain yield. The height of ear insertion and total plant height were not influenced by the factors under study. Nitrogen fertilization at sowing increased the leaf N content, causing the opposite effect when combined with inoculation. Inoculation with Azospirillum in the absence of nitrogen, provide productivity increases of 15.4% and 7.4% for 2000/2001 and 2002/2003 crops, respectively. The inoculation provided productivity similar to that obtained with 100 kg ha-1 in topdressing in crop 2000/2001, while in association with the topdressing, reduced productivity and shoot dry biomass in crop 2002/2003.

  10. Dynamics of the nitrogen content in aboveground phytomass on the turf after fertilization of different forms of fertilizers

    Directory of Open Access Journals (Sweden)

    Peter HRIC

    2017-06-01

    Full Text Available The aim of this experiment was to find out dynamics of the nitrogen (N content in aboveground phytomass on the turf after fertilization of different forms of fertilizers under non–irrigated conditions. The experiment was carried out in warm and dry conditions in the area of Nitra (Slovak Republic. There were included 7 treatments: 1. Without fertilization, 2. Saltpetre with dolomite, Superphosphate, Potassium salt, 3. Turf fertilizer 15–3–8 (+ 3MgO + 0.8Fe + 18S, 4. Slow release fertilizer SRF NPK 14–5–14 (+ 4CaO + 4MgO + 7S, 5. Controlled release fertilizer Duslocote NPK (S 13-9-18 (+ 6S, 6. Organic fertilizer Condit (5-1-1 and 7. Organic fertilizer Veget (3-2-1. In the begging of the seasons fertilizing by controlled release fertilizer Duslocote NPK (S 13-9-18 (+ 6S had a slow onset of action. The opposite trend had use of organic fertilizer Condit (5-1-1 on nitrogen content in aboveground turf phytomass. The nitrogen concentration was statistically higher in variants fertilized with inorganic fertilizer and organic fertilizer Condit (5-1-1 (33,727 mg*kg-1 – 36,737 mg*kg-1 as a non-fertilized turf (28,446 mg*kg-1. Higher nitrogen content in aboveground phytomass was after application of organic fertilizer Condit (5-1-1 into the turf in comparison with fertilization inorganic fertilizers.

  11. ORGANIC NITROGEN IN A TYPIC HAPLUDOX FERTILIZED WITH PIG SLURRY

    Directory of Open Access Journals (Sweden)

    Marco André Grohskopf

    2015-02-01

    Full Text Available The application of pig slurry may have a different effect on nitrogen dynamics in soil compared to mineral fertilization. Thus, the aim of this study was to determine the different forms of organic N in a Latossolo Vermelho distroférrico (Typic Hapludox and their relationship to N uptake by crops in response to 10 years of annual application of pig slurry and mineral fertilizer. The treatments were application rates of 0, 25, 50, 100, and 200 m3 ha-1 of pig slurry, in addition to mineral fertilizer, organized in a randomized block design with four replications. The N contents were determined in the plant tissue and in the forms of total N and acid hydrolyzed fractions: ammonium-N, hexosamine-N, α-amino-N, amide-N, and unidentified-N. Annual application of pig slurry or mineral fertilizer increased the total-N content in the 0-10 cm depth layer. The main fractions of organic N in the soil were α-amino-N when pig slurry was applied and unidentified-N in the case of mineral fertilizers. Pig slurry increased the N fractions considered as labile: α-amino-N, ammonium-N, and amide-N. The increase in these labile organic N fractions in the soil through pig slurry application allows greater N uptake by the maize and oat crops in a no-tillage system.

  12. Relative Efficacy of Liquid Nitrogen Fertilizers in Dryland Spring Wheat

    Directory of Open Access Journals (Sweden)

    Olga S. Walsh

    2016-01-01

    Full Text Available The study was conducted in 2012 and 2013 at three locations in North Central and Western Montana (total of 6 site-years to evaluate the relative efficacy of three liquid nitrogen (N fertilizer sources, urea ammonium nitrate (UAN, 32-0-0, liquid urea (LU, 21-0-0, and High NRGN (HNRGN, 27-0-0-1S, in spring wheat (Triticum aestivum L.. In addition to at-seeding urea application at 90 kg N ha−1 to all treatments (except for the unfertilized check plot, the liquid fertilizers were applied utilizing an all-terrain vehicle- (ATV- mounted stream-bar equipped sprayer at a rate of 45 kg N ha−1 at Feekes 5 growth stage (early tillering. Three dilution ratios of fertilizer to water were accessed: 100/0 (undiluted, 66/33, and 33/66. The effects of N source and the dilution ratio (fertilizer/water on N uptake (NUp, N use efficiency (NUE, spring wheat grain yield (GY, grain protein (GP content, and protein yield (PY were assessed. The dilution ratios had no effect on GY, GP, PY, NUp, and NUE at any of the site-years in this study. Taking into account agronomic and economic factors, LU can be recommended as the most suitable liquid N fertilizer source for spring wheat cropping systems of the Northern Great Plains.

  13. [Effects of soil fertility and nitrogen application rate on nitrogen absorption and translocation, grain yield, and grain protein content of wheat].

    Science.gov (United States)

    Wang, Yuefu; Yu, Zhenwen; Li, Xiangxia; Yu, Songlie

    2003-11-01

    The results of this study showed that nitrogen application improved the nitrogen uptake by wheat, especially during its late growth stage. Although a higher nitrogen application rate could increase the amount of absorbed nitrogen, an excess of nitrogen would remain in vegetative organs at the stage after flowering, owing to the low translocation rate of nitrogen from these organs to the grain, and hence, the nitrogen use efficiency and nitrogen harvest index were decreased. Compared with that on high fertility soil, the ratio of nitrogen absorbed from fertilizer to total absorbed nitrogen was higher when the wheat was grown on low fertility soil. On high fertility soil, wheat plant absorbed more nitrogen from top-dressed fertilizer than from basis fertilizer, and top-dressed fertilizer contributed more nitrogen to the grain. It was reversed on low fertility soil.

  14. Process and Equipment for Nitrogen Oxide Waste Conversion to Fertilizer

    Science.gov (United States)

    Lueck, Dale E. (Inventor); Parrish, Clyde F. (Inventor)

    2000-01-01

    The present invention describes a process for converting vapor streams from sources containing at least one nitrogen-containing oxidizing agent therein to a liquid fertilizer composition comprising the steps of: (1) directing a vapor stream containing at least nitrogen-containing oxidizing agent to a first contact zone; (2) contacting said vapor stream with water to form nitrogen oxide(s) from said at least one nitrogen- containing oxidizing agent; (3) directing said acid(s) as a second stream to a second contact zone; (4) exposing said second stream to hydrogen peroxide which is present within said second contact zone in a relative amount of at least 0.1% by weight of said second stream within said second contact zone to convert at least some of any nitrogen oxide species or ions other than in the nitrite form present within said second stream to nitrate ion; (5) sampling said stream within said second contact zone to determine the relative amount of hydrogen peroxide within said second contact zone; (6) adding hydrogen peroxide to said second contact zone when a level on hydrogen peroxide less than 0.1% by weight in said second stream is determined by said sampling; (7) adding a solution comprising potassium hydroxide to said second stream to maintain a pH between 6.0 and 11.0 within said second stream within said second contact zone to form a solution of potassium nitrate; and (8) removing sais solution of potassium nitrate from said second contact zone.

  15. Nitrogen fertilization of coffee: organic compost and Crotalaria juncea L.

    Directory of Open Access Journals (Sweden)

    João Batista Silva Araujo

    2013-12-01

    Full Text Available Information concerning the response of coffee to organic fertilizers is scarce. This study evaluates the effect of different doses of compost and Crotalaria juncea L. on growth, production and nitrogen nutrition of coffee trees. The treatments consisted of compost at rates of 25, 50, 75 and 100% of the recommended fertilization, with or without the aerial part of C. juncea. C. juncea was grown with NH4-N (2% 15N and applied to coffee. The use of C. juncea increased growth in height and diameter of the coffee canopy. In the first year, the percentage of N derived from C. juncea reached 8.5% at seven months and 4.1% at fifteen months after fertilization. In the second year, the percentage of N derived from C. juncea reached 17.9% N at the early harvest, five months after fertilization. Increased rates of compost increased pH , P , K , Ca , Mg , sum of bases , effective CEC, base saturation and organic matter and reduced potential acidity. 15N allowed the identification of the N contribution from C. juncea with percentage of leaf N derived from Crotalaria juncea from 9.2 to 17.9%.

  16. Nitrogen fertilizer improves boron phytoextraction by Brassica juncea grown in contaminated sediments and alleviates plant stress.

    Science.gov (United States)

    Giansoldati, Virginia; Tassi, Eliana; Morelli, Elisabetta; Gabellieri, Edi; Pedron, Francesca; Barbafieri, Meri

    2012-06-01

    In this study we evaluated the effect of different fertilizer treatments on Brassica plants grown on boron-contaminated sediments. Experiments were conducted in the laboratory and on the lysimeter scale. At laboratory scale (microcosm), five different fertilizers were tested for a 35-d period. On the lysimeter scale, nitrogen fertilization was tested at three different doses and plants were allowed to grow until the end of the vegetative phase (70 d). Results showed that nitrogen application had effectively increased plant biomass production, while B uptake was not affected. Total B phytoextracted increased three-fold when the highest nitrogen dose was applied. Phytotoxicity on Brassica was evaluated by biochemical parameters. In plants grown in unfertilized B-contaminated sediments, the activity of antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX) and pyrogallol peroxidase (PPX) increased, whereas catalase (CAT) decreased with respect to control plants. Addition of N progressively mitigated the alteration of enzymatic activity, thus suggesting that N can aid in alleviating B-induced oxidative stress. SOD activity was restored to control levels just at the lowest N treatment, whereas the CAT inhibition was partially restored only at the highest one. N application also lowered the B-induced increase in APX and PPX activities. Increased glutathione reductase activity indicated the need to restore the oxidative balance of glutathione. Data also suggest a role of glutathione and phytochelatins in B defense mechanisms. Results suggest that the nitrogen fertilizer was effective in improving B phytoextraction by increasing Brassica biomass and by alleviating B-induced oxidative stress. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Alterations to the Nitrogen Cycle in a Soil Exposed to Trace Veterinary Antibiotics

    Science.gov (United States)

    Devries, S. L.; Zhang, P.; Loving, M.; Pons, E.

    2013-12-01

    Agricultural soils are exposed to veterinary antibiotics when manure fertilizers containing residual active compounds are spread as fertilizers or fertilizer amendments. While there is evidence to suggest that trace antibiotics in soil may significantly alter the microbial community structure or function, a comprehensive assessment of nitrogen cycle dynamics in antibiotic amended soils is currently lacking. Because sustainable fertilizer practices are based on known parameters of soil nitrogen cycle variation, microbial inhibition or delayed activity caused by antibiotics may undermine the ability of modeling tools to make strong fertilizer management recommendations, leading to reduced fertilizer use efficiency and increased inputs of pollutant N species, including N2O and NO3-, to environmental reservoirs. The objective of this study is to assess the impact of six veterinary antibiotics on leachable nitrate concentrations in top soil and the saturated zone. Dose-response and time-series curves were constructed for column and incubation studies conducted on soils treated with sulfamethoxazole, sulfadiazine, sulfamethazine, narasin, gentamicin, and monensin. Dosages ranged from 1-500 ng/L in column studies and 1-500 ng/g in incubation tests and are consistent with concentrations that have been reported in environmental samples. The results to be presented indicate that exposure to veterinary antibiotics, even at concentrations that are well below previously established no-effect limit, may significantly alter the denitrification potential of affected soils.

  18. [Effects of watering and nitrogen fertilization on the growth, grain yield, and water- and nitrogen use efficiency of winter wheat].

    Science.gov (United States)

    Li, Li; Hong, Jian-Ping; Wang, Hong-Ting; Xiu, Ying-He; Zhang, Lu

    2013-05-01

    A field experiment with split-plot design was conducted to study the effects of watering, nitrogen fertilization, and their interactions on the growth, grain yield, and water- and nitrogen use efficiency of winter wheat. Four watering levels (0, 900, 1200, and 1500 m3 x hm(-2)) in main plots and five nitrogen fertilization levels (0, 90, 150, 210, and 270 kg N x hm(-2)) in sub-plots were designed. The results showed that the grain yield, nitrogen absorption, nitrogen use efficiency, and nitrogen productive efficiency of winter wheat increased with increasing level of watering, but the nitrogen use efficiency and nitrogen productive efficiency decreased with increasing nitrogen fertilization level. The grain yield, nitrogen absorption, and nitrogen harvest index were increased with increasing nitrogen fertilization level when the nitrogen application rate was 0-150 kg N x hm(-2), but not further increased significantly when the nitrogen application rate exceeded 150 kg x hm(-2). With the increasing level of watering, the water consumption amount (WCA) and the total water use efficiency increased, while the proportion of precipitation and soil water supply to WCA as well as the irrigation water use efficiency decreased. With the increasing level of nitrogen fertilization, the proportion of precipitation and watering amount to WCA increased, that of soil water supply to WCA decreased, and the total water use efficiency and irrigation water use efficiency decreased after an initial increase, with no significant differences among the treatments of 150, 210, and 270 kg N x hm(-2). It was considered that under our experimental condition, 1500 m3 x hm(-2) of watering amount plus 150 kg x hm(-2) of nitrogen fertilization could be the optimal combination for the high yielding and high efficiency.

  19. Long-term effect of tillage, nitrogen fertilization and cover crops on soil organic carbon and total nitrogen content

    OpenAIRE

    2011-01-01

    Metadata only record No-till practices, in conjunction with cover crops and nitrogen fertilization, have been shown to augment soil organic carbon content and total nitrogen content. However, interactions between these components in a no-till system are not well-known. This study offers a long-term (1993-2008) comparative analysis of conventional versus no-till practices as well as a some insight regarding the synergies between no-till, nitrogen fertilization, and cover crops. Maize, wheat...

  20. PENETRATION OF NITROGEN INTO WATER AS A RESULT OF FERTILIZATION OF LIGHT SOIL

    Directory of Open Access Journals (Sweden)

    Franciszek Czyżyk

    2014-10-01

    Full Text Available In this article there are present the results of six-year study of infiltration of nitrogen through the sand soil (loamy sand. Every year the soil was fertilized by compost (from sewage sludge and equivalent doses of nitrogen in mineral fertilizers. Two variants of compost fertilization (K1-10 and K2-15 g N·m-2 were used. Additionally two variants of NPK with equivalent doses of nitrogen as an ammonium nitrate supplemented with PK as a superphosphate and potassium salt were applied. Systematically there were investigated the volume of all leachates and their chemical composition. With increasing doses of fertilizers the concentrations of total nitrogen and nitrate nitrogen in the leachate were increased. The concentration of nitrogen in the leachate from the soil fertilized by nitrate was much greater than in compost with equivalent dose of nitrogen. Not only nitrates but also nitrogen from soluble organic compounds were rinsed from the soil. In the case of soil fertilized by compost the participation of nitrates in the total value of nitorgen in the leachate was 41-77%. However in the case of fertilization by ammonium sulphate this proportion was significantly higher and was in the range 60-95%. Over the years, a systematic soil fertilization by both ways increased the nitrogen concentrations in leachate. It shows that in the soil there is surplus of nitrogen, increasing during the time.

  1. Dynamics of the nitrogen content in aboveground phytomass on the turf after fertilization of different forms of fertilizers

    OpenAIRE

    HRIC, Peter; Ján JANČOVIČ; Peter KOVÁR; Ľuboš VOZÁR

    2017-01-01

    The aim of this experiment was to find out dynamics of the nitrogen (N) content in aboveground phytomass on the turf after fertilization of different forms of fertilizers under non–irrigated conditions. The experiment was carried out in warm and dry conditions in the area of Nitra (Slovak Republic). There were included 7 treatments: 1. Without fertilization, 2. Saltpetre with dolomite, Superphosphate, Potassium salt, 3. Turf fertilizer 15–3–8 (+ 3MgO + 0.8Fe + 18S), 4. Slow release fertilizer...

  2. Environmentally Friendly Nitrogen Fertilizers Appplication for Winter Cereals Considering the Mineral Nitrogen Content in Soil

    OpenAIRE

    Timbare, R.; Bušmanis, M.

    2006-01-01

    In order to improve nitrogen fertilizers application recommendations for cereals, the soil mineral nitrogen (Nmin) investigations (1995 – 2000) were carried out on sod – podzolic and brown – lesssive loamy sand and loamy soils in co-operation with other research institutions. The soil samples for determination of NO3 – N and NH4 – N were taken in depth 0 - 20, 21 – 40 and 41 – 60 cm in spring before the start of growth on winter cereals fields, but in 2001,2002- also in autumn before the sowi...

  3. Seasonal variation in soil nitrogen availability across a fertilization chronosequence in moist acidic tundra

    Science.gov (United States)

    McLaren, J. R.; Gough, L.; Weintraub, M. N.

    2012-12-01

    Changes in global climate may result in altered timing of seasonal events including the timing of the spring-thaw and fall freeze-up. In addition to this changing seasonality, arctic environments are experiencing overall increases in nutrient availability caused by climate warming resulting in alterations of plant species composition, such as the observed increases in the abundance of deciduous shrubs. Changing species composition may have large effects on nutrient dynamics in the surrounding ecosystem because of documented differences in how particular plant species influence soil nutrient availability. Although we have some idea of how plant identity influences soil nutrients, soil biogeochemical processes are strongly seasonal, and we have a poor understanding of how plant identity, or nutrient levels, may influence these seasonal patterns. We examined the responses of moist acidic tundra to experimentally increased soil nutrient availability and the accompanying increase in shrub abundance at the Arctic Long Term Ecological Research (LTER) site at Toolik Lake, Alaska. We examined a chrono-sequence of long-term fertilization experiments, composed of experiments fertilized for 5, 15 and 22 years, which has resulted in increasing shrub density with time since fertilization. The fertilized plots receive both nitrogen (N, 10 g/m2/yr) and phosphorus (5 g/m2/yr) annually following snowmelt. In the 2011 growing season we measured variation in soil available N weekly, including measures of ammonium (NH4), nitrate (NO3) and total free amino acids (TFAA). We found that differences between fertilized and control plots depended strongly on both the seasonal timing of measurements, as well as the duration of the fertilization treatment. Early in the growing season fertilization resulted in large increases in available soil N (both NH4 and NO3) across the entire chronosequence. As the season progressed, however, older fertilized plots show evidence of N saturation, where

  4. Effects of Nitrogen Fertilizers on the Growth and Nitrate Content of Lettuce (Lactuca sativa L.

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Liu

    2014-04-01

    Full Text Available Nitrogen is an essential element for plant growth and development; however, due to environmental pollution, high nitrate concentrations accumulate in the edible parts of these leafy vegetables, particularly if excessive nitrogen fertilizer has been applied. Consuming these crops can harm human health; thus, developing a suitable strategy for the agricultural application of nitrogen fertilizer is important. Organic, inorganic, and liquid fertilizers were utilized in this study to investigate their effect on nitrate concentrations and lettuce growth. The results of this pot experiment show that the total nitrogen concentration in soil and the nitrate concentration in lettuce increased as the amount of nitrogen fertilizer increased. If the recommended amount of inorganic fertilizer (200 kg·N·ha−1 is used as a standard of comparison, lettuce augmented with organic fertilizers (200 kg·N·ha−1 have significantly longer and wider leaves, higher shoot, and lower concentrations of nitrate.

  5. Effects of nitrogen fertilizers on the growth and nitrate content of lettuce (Lactuca sativa L.).

    Science.gov (United States)

    Liu, Cheng-Wei; Sung, Yu; Chen, Bo-Ching; Lai, Hung-Yu

    2014-04-22

    Nitrogen is an essential element for plant growth and development; however, due to environmental pollution, high nitrate concentrations accumulate in the edible parts of these leafy vegetables, particularly if excessive nitrogen fertilizer has been applied. Consuming these crops can harm human health; thus, developing a suitable strategy for the agricultural application of nitrogen fertilizer is important. Organic, inorganic, and liquid fertilizers were utilized in this study to investigate their effect on nitrate concentrations and lettuce growth. The results of this pot experiment show that the total nitrogen concentration in soil and the nitrate concentration in lettuce increased as the amount of nitrogen fertilizer increased. If the recommended amount of inorganic fertilizer (200 kg·N·ha⁻¹) is used as a standard of comparison, lettuce augmented with organic fertilizers (200 kg·N·ha⁻¹) have significantly longer and wider leaves, higher shoot, and lower concentrations of nitrate.

  6. Biological Nitrogen Fixation in Two Tropical Forests: Ecosystem-Level Patterns and Effects of Nitrogen Fertilization

    OpenAIRE

    Cusack, Daniela F.; Silver, Whendee; McDowell, William H.

    2009-01-01

    Humid tropical forests are often characterized by large nitrogen (N) pools, and are known to have large potential N losses. Although rarely measured, tropical forests likely maintain considerable biological N fixation (BNF) to balance N losses. We estimated inputs of N via BNF by free-living microbes for two tropical forests in Puerto Rico, and assessed the response to increased N availability using an on-going N fertilization experiment. Nitrogenase activity was measured across forest strata...

  7. Using soil enzymes to explain observed differences in the response of soil decomposition to nitrogen fertilization

    Science.gov (United States)

    Stone, M.; Weiss, M.; Goodale, C. L.

    2010-12-01

    Soil microbes produce extracellular enzymes that degrade a variety of carbon-rich polymers contained within soil organic matter (SOM). These enzymes are key regulators of the terrestrial carbon cycle. However, basic information about the kinetics of extracellular enzymes and key environmental variables that regulate their catalytic ability is lacking. This study aims to clarify the mechanisms by which microbial carbon-degrading enzymes drive different responses to nitrogen (N) fertilization in soil decomposition at two sites with long-term N fertilization experiments, the Bear Brook (BB) forest in Maine and Fernow Forest (FF) in West Virginia. We examined a suite of cellulolytic and lignolytic enzymes that break down common SOM constituents. We hypothesized that enzymes derived from the site with a higher mean annual temperature (FF) would be more heat-tolerant, and retain their catalytic efficiency (Km) as temperature rises, relative to enzymes from the colder environment (BB). We further hypothesized that cellulolytic enzyme activity would be unaffected by N, while oxidative enzyme activity would be suppressed in N-fertilized soils. To test these hypotheses and examine the interactive effects of temperature and N, we measured enzyme activity in unfertilized and N-fertilized soils under a range of laboratory temperature manipulations. Preliminary results show a significant decrease in cellulolytic enzyme efficiency with temperature at the colder site (BB), as well as a significant increase in efficiency due to N-fertilization for two cellulolytic enzymes. Oxidative enzyme activity shows a marginally significant reduction due to N-fertilization at BB. These results suggest that soil warming may produce a negative feedback on carbon turnover in certain climates, while N-fertilization may alter the relative decomposition rates of different soil organic matter constituents. FF activity will be analyzed in a similar manner and the two sites will be compared in order to

  8. Cumulative release characteristics of controlled-release nitrogen and potassium fertilizers and their effects on soil fertility, and cotton growth

    OpenAIRE

    Xiuyi Yang; Jibiao Geng; Chengliang Li; Min Zhang; Xiaofei Tian

    2016-01-01

    To investigate the interacting effects of polymer coated urea (PCU) and polymer coated potassium chloride (PCPC) on cotton growth, an experiment was conducted with containerized plants in 2014 and 2015. There were two kinds of nitrogen fertilizer, PCU and urea, which were combined with PCPC at three application rates (40, 80 and 120 kg ha−1). The kinds of nitrogen fertilizer formed the main plot, while individual rates of PCPC were the subplots. The results suggested N and K release patterns ...

  9. Cumulative release characteristics of controlled-release nitrogen and potassium fertilizers and their effects on soil fertility, and cotton growth

    OpenAIRE

    Xiuyi Yang; Jibiao Geng; Chengliang Li; Min Zhang; Xiaofei Tian

    2016-01-01

    To investigate the interacting effects of polymer coated urea (PCU) and polymer coated potassium chloride (PCPC) on cotton growth, an experiment was conducted with containerized plants in 2014 and 2015. There were two kinds of nitrogen fertilizer, PCU and urea, which were combined with PCPC at three application rates (40, 80 and 120 kg ha−1). The kinds of nitrogen fertilizer formed the main plot, while individual rates of PCPC were the subplots. The results suggested N and K release patterns ...

  10. Process for Nitrogen Oxide Waste Conversion to Fertilizer

    Science.gov (United States)

    Lueck, Dale E. (Inventor); Parrish, Clyde F. (Inventor)

    2003-01-01

    The present invention describes a process for converting vapor streams from sources containing at least one nitrogen-containing oxidizing agent therein to a liquid fertilizer composition comprising the steps of: a) directing a vapor stream containing at least one nitrogen-containing oxidizing agent to a first contact zone; b) contacting said vapor stream with water to form nitrogen oxide(s) from said at least one nitrogen-containing oxidizing agent; c) directing said acid(s) as a second stream to a second contact zone; d) exposing said second stream to hydrogen peroxide which is present within said second contact zone in a relative amount of at least 0.1% by weight of said second stream within said second contact zone to convert at least some of any nitrogen oxide species or ions other than in the nitrate form present within said second stream to nitrate ion; e) sampling said stream within said second contact zone to determine the relative amount of hydrogen peroxide within said second contact zone; f) adding hydrogen peroxide to said second contact zone when a level of hydrogen peroxide less than 0.1 % by weight in said second stream is determined by said sampling; g) adding a solution comprising potassium hydroxide to said second stream to maintain a pH between 6.0 and 11.0 within said second stream within said second contact zone to form a solution of potassium nitrate; and h) removing said solution of potassium nitrate from said second contact zone.

  11. Effect of Nitrogen Fertilizer on Photosynthetic Rate of Leymus chinensis in Grassland of Different Degrading Degrees

    Institute of Scientific and Technical Information of China (English)

    Mingming WANG; Yajing BAO; Zhenghai LI; Shaohuan YANG; Jingping JIAO; Yanyu GUO

    2012-01-01

    [Objective] This study aimed to investigate the effect of nitrogen fertilizer on photosynthetic rate of Leymus chinensis in the grasslands of different degrading degrees. [Method] With the L. chinensis in Inner Mongolia Baiyinxile Ranch as the research object, different rations of nitrogen fertilizer were applied to the grassland (0, 30, 50, 80 g/m^2). The effect of different gradients of nitrogen fertilizer on photo- synthetic rate of Leymus chinensis, and the effect on grasslands of different degrading degrees were analyzed. [Result] The photosynthetic rate of L. chinensis in- creased with the increase of nitrogen gradients; in the grassland communities with different degrading degrees, the responses of the photosynthetic rate of L. chinensis to nitrogen fertilizer were different, and the response in the grassland with severe degradation was the best. [Conclusion] Nitrogen fertilizer played an important role in enhancing the restoration degree of grassland.

  12. Effect of Nitrogen Fertilizer on Herbivores and Its Stimulation to Major Insect Pests in Rice

    Directory of Open Access Journals (Sweden)

    Zhong-xian LU

    2007-03-01

    Full Text Available Nitrogen is one of the most important factors in development of herbivore populations. The application of nitrogen fertilizer in plants can normally increase herbivore feeding preference, food consumption, survival, growth, reproduction, and population density, except few examples that nitrogen fertilizer reduces the herbivore performances. In most of the rice growing areas in Asia, the great increases in populations of major insect pests of rice, including planthoppers (Nilaparvata lugens and Sogatella furcifera, leaffolder (Cnaphalocrocis medinalis, and stem borers (Scirpophaga incertulas, Chilo suppressalis, S. innotata, C. polychrysus and Sesamia inferens were closely related to the long-term excessive application of nitrogen fertilizers. The optimal regime of nitrogen fertilizer in irrigated paddy fields is proposed to improve the fertilizer-nitrogen use efficiency and reduce the environmental pollution.

  13. Effect of Nitrogen Fertilizer on Herbivores and Its Stimulation to Major Insect Pests in Rice

    Institute of Scientific and Technical Information of China (English)

    LU Zhong-xian; YU Xiao-ping; Kong-luen HEONG; HU Cui

    2007-01-01

    Nitrogen is one of the most important factors in development of herbivore populations. The application of nitrogen fertilizer in plants can normally increase herbivore feeding preference, food consumption, survival, growth, reproduction, and population density, except few examples that nitrogen fertilizer reduces the herbivore performances. In most of the rice growing areas in Asia, the great increases in populations of major insect pests of rice, including planthoppers (Nilaparvata lugens and Sogatella furcifera), leaffolder (Cnaphalocrocis medinalis), and stem borers (Scirpophaga incertulas, Chilo suppressalis, S. innotata, C. polychrysus and Sesamia inferens) were closely related to the long-term excessive application of nitrogen fertilizers. The optimal regime of nitrogen fertilizer in irrigated paddy fields is proposed to improve the fertilizer-nitrogen use efficiency and reduce the environmental pollution.

  14. Operational nitrogen fertilizer management in dairy farming systems: identification of criteria and derivation of fertilizer application rates

    NARCIS (Netherlands)

    Vellinga, T.V.; Andre, G.; Schils, R.L.M.; Oenema, O.

    2004-01-01

    Fertilizer-nitrogen (N) management is a decisive factor in grass-based, intensive dairy farming, as it strongly influences economic and environmental performance but little attention has been paid to providing guidance on N-fertilizer management at an operational level to meet these criteria of perf

  15. Reducing fertilizer-nitrogen losses from rowcrop landscapes: Insights and implications from a spatially explicit watershed model

    Science.gov (United States)

    McLellan, Eileen; Schilling, Keith; Robertson, Dale

    2015-01-01

    We present conceptual and quantitative models that predict changes in fertilizer-derived nitrogen delivery from rowcrop landscapes caused by agricultural conservation efforts implemented to reduce nutrient inputs and transport and increase nutrient retention in the landscape. To evaluate the relative importance of changes in the sources, transport, and sinks of fertilizer-derived nitrogen across a region, we use the spatially explicit SPAtially Referenced Regression On Watershed attributes watershed model to map the distribution, at the small watershed scale within the Upper Mississippi-Ohio River Basin (UMORB), of: (1) fertilizer inputs; (2) nutrient attenuation during delivery of those inputs to the UMORB outlet; and (3) nitrogen export from the UMORB outlet. Comparing these spatial distributions suggests that the amount of fertilizer input and degree of nutrient attenuation are both important in determining the extent of nitrogen export. From a management perspective, this means that agricultural conservation efforts to reduce nitrogen export would benefit by: (1) expanding their focus to include activities that restore and enhance nutrient processing in these highly altered landscapes; and (2) targeting specific types of best management practices to watersheds where they will be most valuable. Doing so successfully may result in a shift in current approaches to conservation planning, outreach, and funding.

  16. [Effects of nitrogen regulators on fertilizer nitrogen transformation in meadow cinnamon soil and on pakchoi growth].

    Science.gov (United States)

    Sun, Zhi-Mei; Zhang, Kuo; Liu, Jian-Tao; Si, Huan-Sen; Wang, Yan-Qun

    2012-09-01

    Soil incubation test and pot experiment were conducted to investigate the effects of dicyandiamide (DCD) and its combination with nano-carbon on the transformation of fertilizers (urea and ammonium bicarbonate) nitrogen (N) in meadow cinnamon soil, a typical soil type in North China Plain, and on the growth of pakchoi (Brassica chinensis). In the first two weeks after applying urea and ammonium bicarbonate, the soil NH4+-N and NO3(-)-N contents varied greatly, but little variation was observed since then. The effects of the applied fertilizer N on the pakchoi growth and its N use efficiency differed significantly at early growth stages, but had little difference at harvesting stage. The DCD inhibited the transformation of the fertilizer N (especially ammonium bicarbonate N) into nitrate markedly, and this effect increased with increasing DCD dose. Under the conditions of our experiment, the optimal application rate of DCD was 1.0-1.5% of applied fertilize N, which could increase the pakchoi yield significantly, improve the leaf color, decrease the plant nitrate contents, and increase the fertilizer N use efficiency. The combination of DCD and nano-carbon exerted a synergistic effect on inhibiting soil ammonium oxidation, and also, promoted the pakchoi growth and N utilization at early growth stages significantly and decreased the plant nitrate level at harvesting stage.

  17. Influences of nitrogen fertilizer application rates on radish yield, nutrition quality, and nitrogen recovery efficiency

    Institute of Scientific and Technical Information of China (English)

    Yulin LIAO; Xiangmin RONG; Shengxian ZHENG; Qiang LIU; Meirong FAN; Jianwei PENG; Guixian XIE

    2009-01-01

    Radishes (Raphanus sativus L.) were grown in plastic pots in a screenhouse to investigate the influences of nitrogen fertilizer application rates (NFAR) on yield, nitrate content, nitrate reductase activity (NR), nutrition quality, and nitrogen recovery efficiency (NRE) at commercial mature stage. Five N-rate treatments, 0.644, 0.819, 0.995, 1.170, and 1.346 g·por-1, were set up in the screenhouse pot experiments, and nitrogen fertilizer (unlabeled N and l5N-labeled fertilizer) was applied as basal dressing and topdressing, respectively. The results indicated that the fresh and dry weight yields of radish increased with the increase of NFAR at the range of 0.099 to 0.180g N-kg-1 soil, decreased at 0.207 g N-kg-1 soil, and accordingly there was a significant quadratic relationship between the fresh and dry weight yields of radish and the NFAR. At the high addition of urea-N fertilizer, the nitrate content accumulated in the fleshy roots and leaves due to the decline in NR activity. From 0.644 to 0.819 g N-por1 NR increased most rapidly, the highest NR activity occurred at 0.819 g N-por-1, and the lowest NR activity happened at 1.346 g N-por-1. Soluble sugar and ascorbic acid initially increased to the highest value and then decreased, and, contrarily, crude fiber rapidly decreased with the increase of NFAR. Total N uptake (TNU), N derived from fertilizer (Ndff), and N derived from soil (Ndfs) in radish increased, except that Ndfs relatively and slightly decreased at the rate of 0.207 g N-kg'soil. The ratio of Ndff to TNU increased, but the ratio of Ndfs to TNU as well as NRE of N fertilizer decreased with the increase of NFAR. Therefore, the appropriate NFAR should be preferably recommended for improving the yields and nutrition qualities of radish and NRE of N fertilizer.

  18. Nitrogen phosphoric fertilizer production technology on the base of Central Kyzylkum phosphorites and ammonium nitrate melt

    Directory of Open Access Journals (Sweden)

    Shavkat Namazov

    2012-11-01

    Full Text Available The process of obtaining nitrogen phosphoric fertilizer by introduction Central Kyzylkum phosphates and ammonium nitrate melt is studied. On the base of these results production technology diagram for nitrogen phosphoric fertilizer is offered. The given technology was approved and developed at the functioning devices of OJSC “NAVOIAZOT” ammonium nitrate shop.

  19. Application technique affects the potential of mineral concentrates from livestock manure to replace inorganic nitrogen fertilizer

    NARCIS (Netherlands)

    Klop, G.; Velthof, G.L.; Groenigen, van J.W.

    2012-01-01

    It has been suggested that mineral concentrates (MCs) produced from livestock manure might partly replace inorganic N fertilizers, thereby further closing the nitrogen (N) cycle. Here, we quantified nitrogen use efficiency (NUE) and N loss pathways associated with MCs, compared with inorganic fertil

  20. Nitrogen budget in agroecosystems on gray forest soils under long-term fertilization

    Science.gov (United States)

    Nikitishen, V. I.; Lichko, V. I.

    2008-04-01

    Long-term stationary field experiments were performed to study the efficiency of increased rates of nitrogen fertilizer in crop rotations with cereal crops, perennial grasses, clover, and plow fallow on gray forest soils. It was found that an excess of mineral nitrogen (mainly of nitrates) accumulated in the soil in the case of unbalanced nitrogen fertilization and long-term fallowing creates conditions for the development of unfavorable processes in the nitrogen cycle. Significantly increasing nitrogen losses from the agroecosystem because of leaching and denitrification constitute a depletion hazard for the soil nitrogen pool.

  1. Nanocomposites for controlled release of nitrogen fertilizer;Nanocompositos para liberacao controlada de fertilizantes nitrogenados

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Viviane J.M. da; Visconte, Leila L.Y. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Profa. Eloisa Mano; Matos, Talita S.; Lima, Erica S.A.; Polidoro, Jose Carlos [EMBRAPA Solos, RJ (Brazil); Nascimento, Regina Sandra V. [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica

    2009-07-01

    The study aimed at the development of nano structured materials capable of reducing the rate of release of nitrogen in the soil from an agricultural nitrogen fertilizer. Four different systems of polymer composites were prepared: (1) montmorillonite clay/fertilizer, (2) montmorillonite clay/thermoplastic starch and fertilizer, (3) montmorillonite clay/fertilizer, thermoplastic starch and low-density polyethylene (LDPE) and also (4) montmorillonite clay/fertilizer, thermoplastic starch and polycaprolactone. It was confirmed the formation of nano structured materials by elemental analysis (CHN) and X-ray diffraction (XRD). The kinetics of nitrogen release was detected by enzymatic colorimetric analysis and spectroscopy in the ultraviolet/visible. The results showed that all materials evaluated were able to reduce the rate of release of nitrogen in the fertilizers. (author)

  2. Fertilizer nitrogen recovery of rice: /sup 15/N field studies (a short review)

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B.; Katyal, J.C. (Punjab Agricultural Univ., Ludhiana (India). Dept. of Soils)

    1980-12-01

    Reliable quantitative estimates of fertilizer nitrogen recovery by rice are obtained in field investigations with /sup 15/N-labelled materials. Values obtained by conventional 'difference method' of comparing fertilized and unfertilized plots are typically larger than the actual values. Estimating the recovery of fertilizer nitrogen is not a goal in itself. Although it has been an essential component of limited number of /sup 15/N-field experiments conducted with rice so far; these provide little or no information about crop growth stages when fertilizer N is most efficiently utilized by rice plant. Recently, the path coefficient analysis has been used to analyse the effect of N uptake on the development of yield components and their contribution to grain yield. Nitrogen-15 fertilizers along with path coefficient analysis can prove particularly useful in comparing the efficiency of different N fertilizers and in the development of new and more efficient nitrogen sources and management practices.

  3. Effects of nitrogen fertilization on the nutritive value of oat forages

    Science.gov (United States)

    Nitrogen fertilization is a routine part of forage management strategies for grasses, but the effects on forage nutritive value have been inconsistent. Our objectives were to evaluate the effects of N fertilization on the nutritive value of fall-grown oat fertilized at planting with 20, 40, 60, 80, ...

  4. Nitrogen fertilization effects on pasture photosynthesis, respiration, and ecosystem carbon content

    Science.gov (United States)

    Some studies have shown that increasing nitrogen (N) fertility can increase soil carbon (C) sequestration, whereas others suggest that N fertilization has no effect on sequestration. Increasing N fertilization typically increases annual photosynthetic C uptake (gross primary productivity or GPP) and...

  5. Developing a Fertilization Method Using Nitrogen Application Curve for Ornamental Crops

    OpenAIRE

    景山, 詳弘

    2005-01-01

    A serious ploblem has recently come to light, that excessive fertilization in horticultural production is often associated with salt accumulation in soil and pollution of the hydrosphere around the culture field. Optimum fertilization with value and timing should be a balance between crop nutient absorption values, and fertilization.In previous studies for cut flower production, I found that the rate of plant growth closely paralleled the amount of nitrogen absorption. When nitrogen supply wa...

  6. EFFECT OF NITROGEN FERTILIZATION ON GRAIN YIELD AND QUALITY OF HULLED AND HULLESS SPRING OATS

    OpenAIRE

    2015-01-01

    A field trial was set up in 2014 the growing season at the Bc Institute’s experimental field in Botinec aiming to investigate the effect of four levels of nitrogen fertilization on grain yield, test weight, thousand kernel weight and plant height of eight hulled and two hulless oat genotypes. Significant differences were found out among nitrogen fertilization levels as well as among the eight hulled genotypes for all traits. The interaction genotype × N fertilization was not significant. Sign...

  7. Nitrogen uptake dynamics, yield and quality as influenced by nitrogen fertilization in Piel de sapo melon

    Energy Technology Data Exchange (ETDEWEB)

    Castellanos, M. T.; Cabello, M. J.; Cartagena, M. C.; Tarquis, A. M.; Arce, A.; Ribas, F.

    2012-11-01

    The need to reduce nitrogen (N) fertilizer pollution strengthens the importance of improving the utilization efficiency of applied N to crops. This requires knowledge of crop N uptake characteristics and how fertilization management affects it. A three-year field experiment was conducted from May to September in central Spain to investigate the influence of different N rates, which ranged from 11 to 393 kg ha{sup -}1, applied through drip irrigation, on the dynamics of N uptake, nitrogen use efficiency (NUE), fruit yield and quality of a Piel de sapo melon crop (Cucumis melo L. cv. Sancho). Both N concentration and N content increased in different plant parts with the N rate. Leaves had the highest N concentration, which declined by 40-50% from 34-41 days after transplanting (DAT), while the highest N uptake rate was observed from 30-35 to 70-80 DAT, coinciding with fruit development. In each year, NUE declined with increasing N rate. With N fertilizer applications close to the optimum N rate of 90-100 kg ha -1, the fruits removed approximately 60 kg N ha -1, and the amount of N in the crop residue was about 80 kg N ha -1; this serves to replenish the organic nutrient pool in the soil and may be used by subsequent crops following mineralization. (Author) 36 refs.

  8. Reproductive response to nitrogen and phosphorus fertilization along the Hawaiian archipelago's natural soil fertility gradient.

    Science.gov (United States)

    DiManno, Nicole M; Ostertag, Rebecca

    2016-01-01

    Nitrogen (N) and phosphorus (P) are the most important nutrients involved in plant reproduction and typically the most limiting in terrestrial ecosystems. The natural soil fertility gradient of the Hawaiian archipelago, in which younger islands are N limited and older islands are P limited, provides a model system to examine questions regarding allocation of nutrients. Using fertilized plots (+N or +P) at the extreme sites of the Hawaiian archipelago, vegetative productivity (e.g., net primary productivity, growth, and litterfall) and foliar nutrient responses have previously been studied for the dominant canopy tree, Metrosideros polymorpha. Here, we investigated whether the reproductive response of M. polymorpha mirrors the previously found vegetative productivity and foliar nutrient responses, by quantifying: (1) inflorescence and seed productivity, and (2) nutrient concentration of reproductive structures. Fertilization with N and P did not significantly affect the productivity of inflorescences or seeds, or seed viability at either site. However, nutrient concentrations increased after fertilization; %P increased in inflorescences in the +P treatment at the P-limited site. Seeds and inflorescences generally contained higher nutrient concentrations than leaves at both sites. Unlike foliar data, reproductive strategies of M. polymorpha differed depending on soil nutrient limitation with emphasis on quality (higher seed viability/greater nutrient concentrations) at the P-limited site. We suggest that in response to P additions M. polymorpha employs a nutrient conservation strategy for its inflorescences and an investment strategy for its seeds. Examining N and P simultaneously challenges a basic assumption that reproductive allocation follows a similar pattern to the often measured aboveground productivity.

  9. Nitrogen loss by volatilization of nitrogen fertilizers applied to coffee orchard

    Directory of Open Access Journals (Sweden)

    Anderson William Dominghetti

    2016-04-01

    Full Text Available ABSTRACT Ammonia volatilization (N-NH3 is one of the main pathways of Nitrogen loss reducing nitrogen use efficiency in coffee orchard. This work aimed at quantifying ammonia volatilization (N-NH3 losses from N-sources to be used in coffee plantations fertilization in Brazil. The experiment was conducted in the field on a dystrophic red latosol (Ferralsol in FAO's classification at the Coffee Research Sector, University of Lavras, MG, Brazil. The experimental design was of complete randomized blocks with three repetitions of the following treatments: conventional urea, ammonium nitrate and urea + 0.15% Cu and 0.4% B, urea + anionic polymers, urea + elementary sulfur (S0 + polymers, and urea + plastic resin. These N sources were split into three doses of 150 kg ha-1 and band applied. The N-NH3 losses by volatilization and variations of pH (H2O were measured, before and after N application. The N-sources contributed to reduce the soil pH, measured after the third nitrogen fertilization. The N-NH3 losses by volatilization (average from three applications was as follows: urea + anionic polymers (35.8% > conventional urea (31.2% = urea + S0 + polymers (31.0% > urea + 0.15% Cu + 0.4 % B (25.6% > urea + plastic resin (8.6% = ammonium nitrate (1.0%.

  10. Long-term fertilization alters the relative importance of nitrate reduction pathways in salt marsh sediments

    Science.gov (United States)

    Peng, Xuefeng; Ji, Qixing; Angell, John H.; Kearns, Patrick J.; Yang, Hannah J.; Bowen, Jennifer L.; Ward, Bess B.

    2016-08-01

    Salt marshes provide numerous valuable ecological services. In particular, nitrogen (N) removal in salt marsh sediments alleviates N loading to the coastal ocean. N removal reduces the threat of eutrophication caused by increased N inputs from anthropogenic sources. It is unclear, however, whether chronic nutrient overenrichment alters the capacity of salt marshes to remove anthropogenic N. To assess the effect of nutrient enrichment on N cycling in salt marsh sediments, we examined important N cycle pathways in experimental fertilization plots in a New England salt marsh. We determined rates of nitrification, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) using sediment slurry incubations with 15N labeled ammonium or nitrate tracers under oxic headspace (20% oxygen/80% helium). Nitrification and denitrification rates were more than tenfold higher in fertilized plots compared to control plots. By contrast, DNRA, which retains N in the system, was high in control plots but not detected in fertilized plots. The relative contribution of DNRA to total nitrate reduction largely depends on the carbon/nitrate ratio in the sediment. These results suggest that long-term fertilization shifts N cycling in salt marsh sediments from predominantly retention to removal.

  11. Human papillomavirus infection and fertility alteration: a systematic review.

    Science.gov (United States)

    Souho, Tiatou; Benlemlih, Mohamed; Bennani, Bahia

    2015-01-01

    HPV is the most prevalent sexually transmitted infection and its effect in cancer induction is well documented. HPV infections are mostly asymptomatic, but it is unclear whether HPV infections can result in alterations of reproductive health. To determine the relationship between human papillomavirus infections and reproductive health in both men and women. A systematic literature review was performed in PubMed and ScienceDirect data bases from January 1994 through August 2014. HPV infections are shown to be significantly associated to many adverse effects in the reproductive function. These adverse effects were reported in different levels from cells production to pregnancy and may be related to the infecting genotype. It appears from this study that HPV detection and genotyping could be of great value in infertility diagnosis at least in idiopathic infertility cases. Like for the risk of carcinogenesis, another classification of HPV regarding the risk of fertility alteration may be considered after deep investigations.

  12. Efficient Management of Nitrogen Fertilizers for Flooded Rice in Relation to Nitrogen Transformations in Flooded Soils

    Institute of Scientific and Technical Information of China (English)

    ZHUZHAO-LIANG

    1992-01-01

    Recent progresses in efficient management of nitrogen fertilizers for flooded rice in relation to nitrogen transformations in flooded soil were reviewed.Considerable progress has been achieved in the investigation on the mechanism of ammonia loss and the factors affecting it .However,little progress has been obtained in the investigations on nitrification-denitrification loss owing to the lack of method for estimating the fluxes of gaseous N products.Thus,so far the management practices developed or under investigation primarily for reducing ammonia loss are feasible or promising,while those for reducing nitrification-denitrification loss seem obscure,except the point deep placement. In addition,it was emphasized that the prediction of soil N supply and the recommendation of the optimal rate of N application based on it are only semi-quantitative.The priorities in research for improving the prediction are indicated.

  13. Growth With of Alfalfa Mutant in Different Nitrogen Fertilizer and Defoliation Intensity

    Directory of Open Access Journals (Sweden)

    Widyati Slamet

    2012-10-01

    Full Text Available The research was conducted to evaluate growth  of alfalfa mutan (plant height increment, number of leaves and dry matter production in different  Nitrogen Fertilizer and defoliation intensity. The design used was randomized block design 4x2 factorial with 3 replications. The first was dosage of Nitrogen fertilizerNitrogen   (0, 30, 60 and 90 kg N / ha,  the second factor was defoliation intensity (5 and 10 cm. Variables observed alfalfa growth (plant height increment, number of leaves, the production of dry matter (DM forage. The results showed that different N fertilization did not affect the growth of alfalfa mutants. Defoliation intensity  affectedmnumber of leaves and   DM  production of alfalfa mutant. Fertilization to 90 kg N / ha has not affected the growth and   defoliation  intensity 10 cm gave better growth on alfalfa mutant.   [Keywords: alfalfa mutant; Nitrogen fertilizer; defoliation; growth

  14. [Assessment on the availability of nitrogen fertilization in improving carbon sequestration potential of China's cropland soil].

    Science.gov (United States)

    Lu, Fei; Wang, Xiao-Ke; Han, Bing; Ouyang, Zhi-Yun; Duan, Xiao-Nan; Zheng, Hua

    2008-10-01

    With reference to the situation of nitrogen fertilization in 2003 and the recommendations from agricultural experts on fertilization to different crops, two scenarios, namely, 'current situation' and 'fertilization as recommended', were set for estimating the current and potential carbon sequestration of China's cropland soil under nitrogen fertilization. After collecting and analyzing the typical data from the long-term agricultural experiment stations all over China, and based on the recent studies of soil organic matter and nutrient dynamics, we plotted China into four agricultural regions, and estimated the carbon sequestration rate and potential of cropland soil under the two scenarios in each province of China. Meanwhile, with the data concerning fossil fuel consumption for fertilizer production and nitrogen fertilization, the greenhouse gas leakage caused by nitrogen fertilizer production and application was estimated with the help of the parameters given by domestic studies and IPCC. We further proposed that the available carbon sequestration potential of cropland soil could be taken as the criterion of the validity and availability of carbon sequestration measures. The results showed that the application of synthetic nitrogen fertilizer could bring about a carbon sequestration potential of 21.9 Tg C x a(-1) in current situation, and 30.2 Tg C x a(-1) with fertilization as recommended. However, under the two scenarios, the greenhouse gas leakage caused by fertilizer production and application would reach 72.9 Tg C x a(-1) and 91.4 Tg C x a(-1), and thus, the actual available carbon sequestration potential would be -51.0 Tg C x a(-1) and -61.1 Tg C x a(-1), respectively. The situation was even worse under the 'fertilization as recommended' scenario, because the increase in the amount of nitrogen fertilization would lead to 10. 1 Tg C x a(-1) or more net greenhouse gas emission. All these results indicated that the application of synthetic nitrogen fertilizer

  15. Effect of Different Application Rate of Nitrogen Fertilizer Under Straw Return on Maize Yield and Inorganic Nitrogen Accumulation

    Directory of Open Access Journals (Sweden)

    ZHANG Xin

    2014-06-01

    Full Text Available We investigated the influences of different nitrogen fertilizer rate on maize production, nitrogen use efficiency and soil nitrate nitrogen at straw return farmland for two years. The results showed that maize production increased with the increment of nitrogen fertilizer. The maize production was the highest at 216 kg·hm -2(N216of nitrogen use and began to decrease when the amount of nitrogen use was beyond 216 kg· hm -2. There were significant interannual differences on maize production in the same treatment. The maize production in 2010 increased 0.69%~4.75% compared with that in 2009. Nitrogen use efficiency, nitrogen agronomic efficiency and nitrogen harvest index improved with the year of straw return. The highest nitrate nitrogen accumulation was found in the treatment of 240 kg· hm -2(N240in 0~100 cm soil layer. Soil nitrate content increased with the depth of soil. This may potentially increased the risk of nitrate pollution on shallow groundwater. Compared with N240, the nitrate nitrogen accumulation of N168(168 kg·hm -2 , N192(192 kg·hm -2 and N216(216 kg·hm -2 were equally reduced by respectively 39.87%, 35.84% and 29.38% in 0~100 cm soil layer. Considering the maize production, nitrogen use efficiency and ecological environmental benefits, the optimum amount of nitrogen use should be 200 kg·hm -2.

  16. Global nitrogen and phosphorus fertilizer use for agriculture production in the past half century: shifted hot spots and nutrient imbalance

    Science.gov (United States)

    Lu, Chaoqun; Tian, Hanqin

    2017-03-01

    In addition to enhancing agricultural productivity, synthetic nitrogen (N) and phosphorous (P) fertilizer application in croplands dramatically alters global nutrient budget, water quality, greenhouse gas balance, and their feedback to the climate system. However, due to the lack of geospatial fertilizer input data, current Earth system and land surface modeling studies have to ignore or use oversimplified data (e.g., static, spatially uniform fertilizer use) to characterize agricultural N and P input over decadal or century-long periods. In this study, we therefore develop global time series gridded data of annual synthetic N and P fertilizer use rate in agricultural lands, matched with HYDE 3.2 historical land use maps, at a resolution of 0.5° × 0.5° latitude-longitude during 1961-2013. Our data indicate N and P fertilizer use rates on per unit cropland area increased by approximately 8 times and 3 times, respectively, since the year 1961 when IFA (International Fertilizer Industry Association) and FAO (Food and Agricultural Organization) surveys of country-level fertilizer input became available. Considering cropland expansion, the increase in total fertilizer consumption is even larger. Hotspots of agricultural N fertilizer application shifted from the US and western Europe in the 1960s to eastern Asia in the early 21st century. P fertilizer input shows a similar pattern with an additional current hotspot in Brazil. We found a global increase in fertilizer N / P ratio by 0.8 g N g-1 P per decade (p doi:10.1594/PANGAEA.863323.

  17. [Mechanisms for the increased fertilizer nitrogen use efficiency of rice in wheat-rice rotation system under combined application of inorganic and organic fertilizers].

    Science.gov (United States)

    Liu, Yi-Ren; Li, Xiang; Yu, Jie; Shen, Qi-Rong; Xu, Yang-Chun

    2012-01-01

    A pot experiment was conducted to study the effects of combined application of organic and inorganic fertilizers on the nitrogen uptake by rice and the nitrogen supply by soil in a wheat-rice rotation system, and approach the mechanisms for the increased fertilizer nitrogen use efficiency of rice under the combined fertilization from the viewpoint of microbiology. Comparing with applying inorganic fertilizers, combined application of organic and inorganic fertilizers decreased the soil microbial biomass carbon and nitrogen and soil mineral nitrogen contents before tillering stage, but increased them significantly from heading to filling stage. Under the combined fertilization, the dynamics of soil nitrogen supply matched best the dynamics of rice nitrogen uptake and utilization, which promoted the nitrogen accumulation in rice plant and the increase of rice yield and biomass, and increased the fertilizer nitrogen use efficiency of rice significantly. Combined application of inorganic and organic fertilizers also promoted the propagation of soil microbes, and consequently, more mineral nitrogen in soil was immobilized by the microbes at rice early growth stage, and the immobilized nitrogen was gradually released at the mid and late growth stages of rice, being able to better satisfy the nitrogen demand of rice in its various growth and development stages.

  18. Nitrogen fertilization has a stronger effect on soil nitrogen-fixing bacterial communities than elevated atmospheric CO2.

    Science.gov (United States)

    Berthrong, Sean T; Yeager, Chris M; Gallegos-Graves, Laverne; Steven, Blaire; Eichorst, Stephanie A; Jackson, Robert B; Kuske, Cheryl R

    2014-05-01

    Biological nitrogen fixation is the primary supply of N to most ecosystems, yet there is considerable uncertainty about how N-fixing bacteria will respond to global change factors such as increasing atmospheric CO2 and N deposition. Using the nifH gene as a molecular marker, we studied how the community structure of N-fixing soil bacteria from temperate pine, aspen, and sweet gum stands and a brackish tidal marsh responded to multiyear elevated CO2 conditions. We also examined how N availability, specifically, N fertilization, interacted with elevated CO2 to affect these communities in the temperate pine forest. Based on data from Sanger sequencing and quantitative PCR, the soil nifH composition in the three forest systems was dominated by species in the Geobacteraceae and, to a lesser extent, Alphaproteobacteria. The N-fixing-bacterial-community structure was subtly altered after 10 or more years of elevated atmospheric CO2, and the observed shifts differed in each biome. In the pine forest, N fertilization had a stronger effect on nifH community structure than elevated CO2 and suppressed the diversity and abundance of N-fixing bacteria under elevated atmospheric CO2 conditions. These results indicate that N-fixing bacteria have complex, interacting responses that will be important for understanding ecosystem productivity in a changing climate.

  19. Cereal area and nitrogen use efficiency are drivers of future nitrogen fertilizer consumption

    Institute of Scientific and Technical Information of China (English)

    Achim Dobermann; Kenneth G. Cassman

    2005-01-01

    At a global scale, cereal yields and fertilizer N consumption have increased in a near-linear fashion during the past 40 years and are highly correlated with one another. However,large differences exist in historical trends of N fertilizer usage and nitrogen use efficiency (NUE)among regions, countries, and crops. The reasons for these differences must be understood to estimate future N fertilizer requirements. Global nitrogen needs will depend on: (i) changes in cropped cereal area and the associated yield increases required to meet increasing cereal demand from population and income growth, and (ii) changes in NUE at the farm level. Our analysis indicates that the anticipated 38% increase in global cereal demand by 2025 can be met by a 30% increase in N use on cereals, provided that the steady decline in cereal harvest area is halted and the yield response to applied N can be increased by 20%. If losses of cereal cropping area continue at the rate of the past 20 years (-0.33% per year) and NUE cannot be increased substantially, a 60% increase in global N use on cereals would be required to meet cereal demand. Interventions to increase NUE and reduce N losses to the environment must be accomplished at the farm- or field-scale through a combination of improved technologies and carefully crafted local policies that contribute to the adoption of improved N management; uniform regional or national directives are unlikey to be effective at both sustaining yield increases and improving NUE. Examples from several countries show that increases in NUE at rates of 1% per year or more can be achieved if adequate investments are made in research and extension. Failure to arrest the decrease in cereal crop area and to improve NUE in the world's most important agricultural systems will likely cause severe damage to environmental services at local, regional, and global scales due to a large increase in reactive N load in the environment.

  20. Cereal area and nitrogen use efficiency are drivers of future nitrogen fertilizer consumption.

    Science.gov (United States)

    Dobermann, Achim; Cassman, Kenneth G

    2005-12-01

    At a global scale, cereal yields and fertilizer N consumption have increased in a near-linear fashion during the past 40 years and are highly correlated with one another. However, large differences exist in historical trends of N fertilizer usage and nitrogen use efficiency (NUE) among regions, countries, and crops. The reasons for these differences must be understood to estimate future N fertilizer requirements. Global nitrogen needs will depend on: (i) changes in cropped cereal area and the associated yield increases required to meet increasing cereal demand from population and income growth, and (ii) changes in NUE at the farm level. Our analysis indicates that the anticipated 38% increase in global cereal demand by 2025 can be met by a 30% increase in N use on cereals, provided that the steady decline in cereal harvest area is halted and the yield response to applied N can be increased by 20%. If losses of cereal cropping area continue at the rate of the past 20 years (-0.33% per year) and NUE cannot be increased substantially, a 60% increase in global N use on cereals would be required to meet cereal demand. Interventions to increase NUE and reduce N losses to the environment must be accomplished at the farm- or field-scale through a combination of improved technologies and carefully crafted local policies that contribute to the adoption of improved N management; uniform regional or national directives are unlikey to be effective at both sustaining yield increases and improving NUE. Examples from several countries show that increases in NUE at rates of 1% per year or more can be achieved if adequate investments are made in research and extension. Failure to arrest the decrease in cereal crop area and to improve NUE in the world's most important agricultural systems will likely cause severe damage to environmental services at local, regional, and global scales due to a large increase in reactive N load in the environment.

  1. Criteria for Selecting Optimal Nitrogen Fertilizer Rates for Precision Agriculture

    Directory of Open Access Journals (Sweden)

    Bruno Basso

    Full Text Available Yield rates vary spatially and maps produced by the yield monitor systems are evidence of the degree of withinfield variability. The magnitude of this variability is a good indication of the suitability of implementing a spatially variable management plan. Crop simulation models have the potential to integrate the effects of temporal and multiple stress interaction on crop growth under different environmental and management conditions. The strength of these models is their ability to account for stress by simulating the temporal interaction of stress on plant growth each day during the season. The objective of paper is to present a procedure that allows for the selection of optimal nitrogen fertilizer rates to be applied spatially on previously identified management zones through crop simulation modelling. The integration of yield maps, remote sensing imagery, ground truth measurements, electrical resistivity imaging allowed for the identifications of three distinct management zones based on their ability to produce yield and their stability over time (Basso et al., 2009. After validating the model, we simulated 7 N rates from 0 to 180 kg N/ha with a 30 kg N/ha increment. The model results illustrate the different N responses for each of the zone. The analysis allowed us to identify the optimal N rate for each of the zone based on agronomic, economic and environmental sustainability of N management.

  2. Criteria for Selecting Optimal Nitrogen Fertilizer Rates for Precision Agriculture

    Directory of Open Access Journals (Sweden)

    Francesco Basso

    2011-02-01

    Full Text Available Yield rates vary spatially and maps produced by the yield monitor systems are evidence of the degree of withinfield variability. The magnitude of this variability is a good indication of the suitability of implementing a spatially variable management plan. Crop simulation models have the potential to integrate the effects of temporal and multiple stress interaction on crop growth under different environmental and management conditions. The strength of these models is their ability to account for stress by simulating the temporal interaction of stress on plant growth each day during the season. The objective of paper is to present a procedure that allows for the selection of optimal nitrogen fertilizer rates to be applied spatially on previously identified management zones through crop simulation modelling. The integration of yield maps, remote sensing imagery, ground truth measurements, electrical resistivity imaging allowed for the identifications of three distinct management zones based on their ability to produce yield and their stability over time (Basso et al., 2009. After validating the model, we simulated 7 N rates from 0 to 180 kg N/ha with a 30 kg N/ha increment. The model results illustrate the different N responses for each of the zone. The analysis allowed us to identify the optimal N rate for each of the zone based on agronomic, economic and environmental sustainability of N management.

  3. The effect of nitrogen fertilization on morphology traits of sweet sorghum cultivated on sandy soil

    Directory of Open Access Journals (Sweden)

    Ewelina Szydełko-Rabska

    2015-01-01

    Full Text Available The paper presents results of the experiment conducted in 2010-2012 on the influence of nitrogen fertilizer type (ammonium sulfate, calcium nitrate, ammonium nitrate and urea on sweet sorghum cultivated on sandy soil. Selected morphological traits and fresh and dry matter biomass were analyzed. Although fertilization significantly increased fresh and dry aboveground biomass, it did not affect sweet sorghum yield. Fresh aboveground biomass was highest under fertilization with ammonium nitrate (59.3 t ha-1. Fertilization influenced also yield growth rate, which ranged from 23.3 t ha-1 (under fertilization with urea to 26.5 t ha-1 (under fertilization with ammonium nitrate. The highest dry matter content (26.1% and dry matter yield (15.3 t ha-1 were obtained under ammonium sulfate. Nitrogen efficiency was affected by nitrogen fertilization and ranged from 40.4 (under fertilization with urea to 52.4 kg D.M. kg-1 N (under fertilization with ammonium sulfate. On the contrary, nitrogen physiological efficiency was not affected.

  4. [Effects of fertilization on cotton growth and nitrogen use efficiency under salinity stress].

    Science.gov (United States)

    Dai, Jian-Long; Lu, He-Quan; Li, Zhen-Huai; Duan, Liu-Sheng; Dong, He-Zhong

    2013-12-01

    Cotton (Gossypium hirsutum) was raised at different salinity levels (0, 0.15% and 0.30%) by irrigating with fresh- or sea-water. The effects of fertilization (N, NK, NP and NPK) on plant growth, nitrogen (N) uptake and N use efficiency were studied. The results showed that salinity and fertilization both affected the biomass, agronomic N use efficiency, N bioavailability and nitrogen accumulation of plants, and significant interaction was observed between the two factors. Fertilization could improve N use efficiency and nitrogen accumulation of plants under salinity stress, and significantly promoted the cotton yield. Among the fertilization treatments, N combined with P and K had the best effect. The benefit of fertilization was better under low salinity (0.15%) than under moderate salinity (0.3%).

  5. Estimates of nitrogen-fertilizer sales for the conterminous United States in 1987

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains estimates of nitrogen-fertilizer sales for the conterminous United States in 1987 as reported by the U.S. Environmental Protection Agency...

  6. Estimates of nitrogen-fertilizer sales for the conterminous United States in 1986

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains estimates of nitrogen-fertilizer sales for the conterminous United States in 1986 as reported by the U.S. Environmental Protection Agency...

  7. Estimates of nitrogen-fertilizer sales for the conterminous United States in 1989

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains estimates of nitrogen-fertilizer sales for the conterminous United States in 1989 as reported by the U.S. Environmental Protection Agency...

  8. Estimates of nitrogen-fertilizer sales for the conterminous United States in 1988

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains estimates of nitrogen-fertilizer sales for the conterminous United States in 1988 as reported by the U.S. Environmental Protection Agency...

  9. Estimates of nitrogen-fertilizer sales for the conterminous United States in 1985

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains estimates of nitrogen-fertilizer sales for the conterminous United States in 1985 as reported by the U.S. Environmental Protection Agency...

  10. Estimates of nitrogen-fertilizer sales for the conterminous United States in 1991

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains estimates of nitrogen-fertilizer sales for the conterminous United States in 1991 as reported by the U.S. Environmental Protection Agency...

  11. Estimates of nitrogen-fertilizer sales for the conterminous United States in 1990

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage contains estimates of nitrogen-fertilizer sales for the conterminous United States in 1990 as reported by the U.S. Environmental Protection Agency...

  12. Application of fertilizer nitrogen to farm land in the United States Pacific Northwest for 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the amount of fertilizer nitrogen that was applied to farm land in the Pacific...

  13. Application of fertilizer nitrogen to nonfarm land in the United States Pacific Northwest for 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial data set was created by the U.S. Geological Survey (USGS) to represent the amount of fertilizer nitrogen that was applied to nonfarm land in the Pacific...

  14. Disponibilidade de nitrogênio em diversos fertilizantes nitrogenados Nitrogen availability in several nitrogenous fertilizers

    Directory of Open Access Journals (Sweden)

    R. A. Catani

    1954-01-01

    Full Text Available Neste trabalho são apresentados os resultados preliminares obtidos com a aplicação de diferentes fertilizantes nitrogenados, a fim de se determinar a forma de nitrogênio preferida pelo arroz durante os dois primeiros meses do ciclo vegetativo. Para isso instalou-se uma experiência em vasos contendo terra-roxa misturada e empregando-se os seguintes materiais nitrogenados : salitre do Chile, sulfato de amónio, calciocianamida, uréia, torta de algodão, farinha de chifre e casco, e solução de amoníaco. Os resultados apontaram a uréia como o fertilizante que propiciou maior produção de matéria sêca. Seguiram-se-lhe o sulfato de amônio, solução de amoníaco, farinha de chifre e casco, calciocianamida, torta de algodão e, finalmente, o salitre.This paper presents the results from a study of the influence of several nitrogenous fertilizers on rice (Oryza sativa L.. The experiment was performed according to Mits-cherlich pot technique, and each treatment was replicated twice. The treatments tried and the total weight of the rice plants per pot, two monts after germination, are given below : Treatment Total weight (dry matter of rice plant per pot (grams 1. Check ---------------------------------------- 4.5 2. PK without N. -------------------------------- 27.0 3. PK + N (Sodium nitrate from Chile ------------ 21.5 4. PK + N (Amonium sulfate -------------------- 52.5 5. PK + N (Calcium cyanamide ------------------- 27.0 6. PK + N (Urea -------------------------------- 62.0 7. PK + N (Cotton seed meal -------------------- 23.5 8. PK + N (Hoof and horn meal ------------------ 28.0 9. PK + N (Amonia solution ---------------------- 37.5 Treatment N.° 1 did not receive any fertilizer. Treatment N.° 2 received 2.2 g of P2O5 in the form of CaH4 (PO42 and 3.0 g of K2O in the form of K2SO4, per pot, both in solution. Treatments Nos. 3, 4, 5, 6, 7, 8, and 9 received the same amount of phosphorus and potassium as N.° 2, and the amount of the

  15. Nitrogen fertilization enhances water-use efficiency in a saline environment.

    Science.gov (United States)

    Martin, Katherine C; Bruhn, Dan; Lovelock, Catherine E; Feller, Ilka C; Evans, John R; Ball, Marilyn C

    2010-03-01

    Effects of salinity and nutrients on carbon gain in relation to water use were studied in the grey mangrove, Avicennia marina, growing along a natural salinity gradient in south-eastern Australia. Tall trees characterized areas of seawater salinities (fringe zone) and stunted trees dominated landward hypersaline areas (scrub zone). Trees were fertilized with nitrogen (+N) or phosphorus (+P) or unfertilized. There was no significant effect of +P on shoot growth, whereas +N enhanced canopy development, particularly in scrub trees. Scrub trees maintained greater CO(2) assimilation per unit water transpired (water-use efficiency, WUE) and had lower nitrogen-use efficiency (NUE; CO(2) assimilation rate per unit leaf nitrogen) than fringe trees. The CO(2) assimilation rates of +N trees were similar to those in other treatments, but were achieved at lower transpiration rates, stomatal conductance and intercellular CO(2) concentrations. Maintaining comparable assimilation rates at lower stomatal conductance requires greater ribulose 1.5-bisphosphate carboxylase/oxygenase activity, consistent with greater N content per unit leaf area in +N trees. Hence, +N enhanced WUE at the expense of NUE. Instantaneous WUE estimates were supported by less negative foliar delta(13)C values for +N trees and scrub control trees. Thus, nutrient enrichment may alter the structure and function of mangrove forests along salinity gradients.

  16. Effects of Watering and Nitrogen Fertilization on Yield and Water and Nitrogen Use Efficiency of Cropping Oil Sunflower

    Directory of Open Access Journals (Sweden)

    TAN Jian-xin

    2015-10-01

    Full Text Available The field experiment with split-plot design was conducted to study the effects of the interaction of water and nitrogen fertilization on the growth and yield of oil sunflower, water and nitrogen use efficiency of cropping oil sunflower. This experiment set three irrigation rate treatments, including high irrigation treatment (5 250 m3·hm-2, middle irrigation treatment (3 750 m3·hm-2, low irrigation treatment (2 250 m3·hm-2, and four nitrogen application rate treatments, covering no nitrogen fertilization treatment (0 kg·hm-2, low nitrogen application treatment (120 kg·hm-2, middle nitrogen application treatment (240 kg·hm-2 and high nitrogen application treatment (360 kg·hm-2. The results showed that the nitrogen absorption and nitrogen use efficiency of cropping oil sunflower increased as the irrigation rate increased. With the nitrogen application rate increased, the yield of cropping oil sunflower was increased when the nitrogen application rate was 0~240 kg·hm-2, but beyond the 240 kg·hm-2, there was no significant increase. With the irrigation rate increased, the water consumption amount of cropping oil sunflower increased all the time, but the water use efficiency increased first, and hen decreased. Besides there was no significant difference between 240 kg·hm-2 and 360 kg·hm-2 treatment. Under our experiment condition, during the cropping oil sunflower growth period, when the irrigation rate was 5 250 m3·hm-2 (high irrigation rate and the nitrogen ertilization was 360 m3·hm-2 (high nitrogen application rate, the yield of cropping oil sunflower was 3 598 kg·hm-2. When the irrigation rate was 3 750 m3·hm-2 (middle irrigation rate and the nitrogen fertilization was 240 m3·hm-2 (middle nitrogen application rate, the yield was 3 518 kg·hm-2, with the yield components similar with the high irrigation rate and high nitrogen application rate treatment. Considering various factors, middle irrigation rate and middle nitrogen

  17. Nitrogen fertilization plans for the main crops of Turkey to mitigate nitrates pollution

    Directory of Open Access Journals (Sweden)

    Theodore Karyotis

    2014-01-01

    Full Text Available To create a rational nitrogen fertilization plan, a mass nitrogen (N balance was used for the main crops of Turkey. The following components are included in the suggested N fertilization plans: the quantity of N fertilizer which is required by the crop for a targeted and sustainable yield, nitrogen inputs available to the crop without fertilization, nitrogen losses mainly due to nitrates leaching and emissions to the atmosphere. This simple equation was transformed to a more detailed one and fertilization plans are based on the total N required to produce a crop of a targeted yield, N mineralized from Soil Organic Matter (SOM, the residual plant available inorganic N before sowing or planting, input of nitrogen from rainfall and losses through leaching and emissions. This work is based on available data and is an open sheet balance which can be easily used by local authorities. Decreased N fertilization can be applied without significant yield reduction and this can be explained by increased N use efficiency, as a result of proper time of application and splitting of N fertilizers in doses. This model can be appropriately adapted according to site-specific conditions, whilst new parameters can be added to improve precision of the performed calculations.

  18. Fertilization with phosphorus increases soil nitrogen absorption in young plants of Eucalyptus grandis.

    Science.gov (United States)

    Corina Graciano; Juan F. Goya; Jorge L. Frangi; Juan J. Guiamet

    2006-01-01

    Nitrogen (N) and phosphorus (P) are the nutrients that most commonly limit tree growth. Interactions between fertilization and soil type are well known, and in soils with moderate or low N availability, N-fertilization is frequently recommended to improve tree nutrition. The aim of this paper was to analyze how different doses of P and N applied in three different...

  19. Novel slow release nanocomposite nitrogen fertilizers: the impact of polymers on nanocomposite properties and function

    Science.gov (United States)

    Efficient use of fertilizers, especially nitrogen, is essential and strategic to agricultural production. Among the technologies that can contribute to efficient use of fertilizers are slow or controlled release products. This paper describes the impact on structure, urea release rate and function i...

  20. Differential effects of nitrogenous fertilizers on methane-consuming microbes in rice field and forest soil

    NARCIS (Netherlands)

    Mohanty, S.R.; Bodelier, P.L.E.; Floris, V.; Conrad, R.

    2006-01-01

    The impact of environmental perturbation (e.g., nitrogenous fertilizers) on the dynamics of methane fluxes from soils and wetland systems is poorly understood. Results of fertilizer studies are often contradictory, even within similar ecosystems. In the present study the hypothesis of whether these

  1. Fertilizer value of nitrogen captured using ammonia scrubbers attached to animal production facilities

    Science.gov (United States)

    Over half of the nitrogen (N) excreted from broiler chickens is lost to the atmosphere before the manure is removed from the barns, resulting in air and water pollution and the loss of a valuable fertilizer resource. The objective of this study was to determine the fertilizer efficiency of N, which...

  2. Spring nitrogen fertilization of ryegrass-bermudagrass for phytoremediation of phosphorus-enriched soils

    Science.gov (United States)

    Nitrogen fertilization of forage grasses is critical for optimizing biomass and utilization of manure soil nutrients. Field studies were conducted in 2007-09 to determine the effects of spring N fertilization on amelioration of high soil P when cool-season, annual ryegrass (Lolium multiflorum L.) is...

  3. Moss-specific changes in nitrogen fixation following two decades of warming, shading, and fertilizer addition

    DEFF Research Database (Denmark)

    Sørensen, Pernille Lærkedal; Lett, Signe; Michelsen, Anders

    2012-01-01

    is the main source of new nitrogen to arctic ecosystems. In order to gain information on future nitrogen fixation rates in a changing climate, we studied the effects of two decades of warming with passive greenhouses, shading with sackcloth, and fertilization with NPK fertilizer on nitrogen fixation rates....... To expand the knowledge on species-specific responses, we measured nitrogen fixation associated with two moss species: Hylocomium splendens and Aulacomnium turgidum. Our expectations of decreased nitrogen fixation rates in the fertilizer and shading treatments were met. However, contrary to our expectation...... temperature increase induced by the warming treatment was low and insignificant as vegetation height and total vascular plant cover of the warmed plots increased, and moss cover decreased. Hence, truly long-term studies lasting more than two decades provide insights on changes in key biogeochemical processes...

  4. Decade-long soil nitrogen constraint on the CO2 fertilization of plant biomass

    Science.gov (United States)

    Reich, Peter B.; Hobbie, Sarah E.

    2013-03-01

    The stimulation of plant growth by elevated CO2 concentration has been widely observed. Such fertilization, and associated carbon storage, could dampen future increases in atmospheric CO2 levels and associated climate warming. However, the CO2 fertilization of plant biomass may be sensitive to nitrogen supply. Herein we show that in the latest decade of a long-term perennial grassland experiment, low ambient soil nitrogen availability constrained the positive response of plant biomass to elevated CO2, a result not seen in the first years (1998-2000) of the study. From 2001 to 2010, elevated CO2 stimulated plant biomass half as much under ambient as under enriched nitrogen supply, an effect mirrored over this period by more positive effects of elevated CO2 on soil nitrogen supply (net nitrogen mineralization) and plant nitrogen status under enriched than ambient nitrogen supply. The results did not strongly support either the progressive nitrogen limitation hypothesis, or the alternative hypothesis of priming of soil nitrogen release by elevated CO2. As nitrogen limitation to productivity is widespread, persistent nitrogen constraints on terrestrial responses to rising CO2 are probably pervasive. Further incorporation of such interactions into Earth system models is recommended to better predict future CO2 fertilization effects and impacts on the global carbon cycle.

  5. GIS Modelling for Site-Specific Nitrogen Fertilization towards Soil Sustainability

    Directory of Open Access Journals (Sweden)

    Antonis Papadopoulos

    2015-05-01

    Full Text Available Farmers need to make decisions that in most cases incorporate the concept of prediction and can hardly be revoked. One such decision is the application of fertilizing inputs. During past crop management and decision-making on fertilizing practices, many significant errors have been recorded, which have led and continue to lead to reduced production and environmental burden. The methodology followed in this paper involves the use of GIS, fuzzy logic and expert knowledge, in order to model physical processes associated with nitrogen balance in cultivated ecosystems and to evaluate the capabilities of or limitations on the use of certain fertilizers, based on spatial criteria. An original spatial decision support system was designed, developed and applied in a given study area. The system is composed of two modules (“fertilizing rate” and “fertilizing type”, making use of soil, climate and cultivation practices’ data, as recorded in the area of interest in quantitative or categorical form. The results of the application spatially classify the involved area according to its demand for nitrogen on the basis of the characteristics of each sub-region. The “fertilizing rate” module suggests reduced fertilizing doses of nitrogenous fertilizers compared to those already applied in the area. The system further divides the area into zones where specific types of fertilizers should be applied, giving a certain prescription for the method and time of application.

  6. Key ecological responses to nitrogen are altered by climate change

    Science.gov (United States)

    Greaver, T.L.; Clark, C.M.; Compton, J.E.; Vallano, D.; Talhelm, A. F.; Weaver, C.P.; Band, L.E.; Baron, J. S.; Davidson, E.A.; Tague, C.L.; Felker-Quinn, E.; Lynch, J.A.; Herrick, J.D.; Liu, L.; Goodale, C.L.; Novak, K. J.; Haeuber, R. A.

    2016-01-01

    Climate change and anthropogenic nitrogen deposition are both important ecological threats. Evaluating their cumulative effects provides a more holistic view of ecosystem vulnerability to human activities, which would better inform policy decisions aimed to protect the sustainability of ecosystems. Our knowledge of the cumulative effects of these stressors is growing, but we lack an integrated understanding. In this Review, we describe how climate change alters key processes in terrestrial and freshwater ecosystems related to nitrogen cycling and availability, and the response of ecosystems to nitrogen addition in terms of carbon cycling, acidification and biodiversity.

  7. Key ecological responses to nitrogen are altered by climate change

    Science.gov (United States)

    Greaver, T. L.; Clark, C. M.; Compton, J. E.; Vallano, D.; Talhelm, A. F.; Weaver, C. P.; Band, L. E.; Baron, J. S.; Davidson, E. A.; Tague, C. L.; Felker-Quinn, E.; Lynch, J. A.; Herrick, J. D.; Liu, L.; Goodale, C. L.; Novak, K. J.; Haeuber, R. A.

    2016-09-01

    Climate change and anthropogenic nitrogen deposition are both important ecological threats. Evaluating their cumulative effects provides a more holistic view of ecosystem vulnerability to human activities, which would better inform policy decisions aimed to protect the sustainability of ecosystems. Our knowledge of the cumulative effects of these stressors is growing, but we lack an integrated understanding. In this Review, we describe how climate change alters key processes in terrestrial and freshwater ecosystems related to nitrogen cycling and availability, and the response of ecosystems to nitrogen addition in terms of carbon cycling, acidification and biodiversity.

  8. Effect of vermicompost and chemical nitrogen fertilizer application on the various functioning of maize seeds

    Directory of Open Access Journals (Sweden)

    Esmaeil Namazi

    2015-06-01

    Full Text Available Present study was conducted to analyze the effect of Vermicompost and chemical Nitrogen fertilizer on the function and component of maize seed traits. A factorial test with complete randomize block designs was conducted at the city of Behbahan in the year 2012 with 4 repetitions. Analyzed treatments contains three level of chemical Nitrogen fertilizer viz 50, 75 and 100 percent of soil test area and application of vermicompost is also conducted at 3 levels of check (0, 5 and 10 tons in hectare. Results of the study showed a significant correlation between the quantitative traits of maize seed and various levels of chemical Nitrogen fertilizer and vermicompost. Highest functioning of maize seed was obtained from the treatment containing 100 percent Nitrogen and 10 tons/hectare of vermicompost while the lowest amount was obtained from the treatment containing 50 percent Nitrogen without vermicompost application. Furthermore, application of vermicompost and chemical Nitrogen fertilizer affects the biological function and increase in the yield of seed in rows and weight of each 1000 seeds, also has positive and meaningful effect on the index of maize seed's harvesting. The results of the study revealed that the application of Nitrogen fertilizer at the levels of 50 and 75 percents of area soil test and vermicompost at the level of 5 tons in a hectare in this area are appropriate to obtain the maximum yield and proper functioning.

  9. Environmental analysis of sunflower production with different forms of mineral nitrogen fertilizers.

    Science.gov (United States)

    Spinelli, D; Bardi, L; Fierro, A; Jez, S; Basosi, R

    2013-11-15

    Environmental profiles of mineral nitrogen fertilizers were used to evaluate the environmental disturbances related to their use in cultivation systems in Europe. Since the production of mineral fertilizers requires a large amount of energy, the present study of bioenergy systems is relevant in order to achieve crop yields less dependent on fossil fuels and to reduce the environmental impact due to fertilization. In this study, the suitability of the LCA methodology to analyze the environmental impact of sunflower cultivation systems with different forms of mineral nitrogen fertilizers urea and ammonium nitrate was investigated. Effects on climate change were estimated by the use of Ecoinvent 2.2 database default value for soil N2O emission factor (1%) and local emission data (0.8%) of mineral nitrogen applied to soils. LCA analysis showed a higher impact on environmental categories (human health and ecosystem quality) for the system in which urea was used as a nitrogen source. Use of urea fertilizer showed a higher impact on resource consumption due to fossil fuel consumption. Use of mineral nitrogen fertilizers showed a higher environmental burden than other inputs required for sunflower cultivation systems under study. Urea and ammonium nitrate showed, respectively, a 7.8% and 4.9% reduced impact of N2O as greenhouse gas by using direct field data of soil N2O emission factor compared to the default soil emission factor of 2006 IPCC Guidelines. Use of ammonium nitrate as mineral nitrogen fertilizer in sunflower cultivation would have a lower impact on environmental categories considered. Further environmental analysis of available technologies for fertilizer production might be also evaluated in order to reduce the environmental impacts of each fertilizer.

  10. Decoupling of soil carbon and nitrogen turnover partly explains increased net ecosystem production in response to nitrogen fertilization

    Science.gov (United States)

    Ehtesham, Emad; Bengtson, Per

    2017-04-01

    During the last decade there has been an ongoing controversy regarding the extent to which nitrogen fertilization can increase carbon sequestration and net ecosystem production in forest ecosystems. The debate is complicated by the fact that increased nitrogen availability caused by nitrogen deposition has coincided with increasing atmospheric carbon dioxide concentrations. The latter could further stimulate primary production but also result in increased allocation of carbon to root exudates, which could potentially ‘prime’ the decomposition of soil organic matter. Here we show that increased input of labile carbon to forest soil caused a decoupling of soil carbon and nitrogen cycling, which was manifested as a reduction in respiration of soil organic matter that coincided with a substantial increase in gross nitrogen mineralization. An estimate of the magnitude of the effect demonstrates that the decoupling could potentially result in an increase in net ecosystem production by up to 51 kg C ha-1 day-1 in nitrogen fertilized stands during peak summer. Even if the effect is several times lower on an annual basis, the results still suggest that nitrogen fertilization can have a much stronger influence on net ecosystem production than can be expected from a direct stimulation of primary production alone.

  11. The Effects of Long Term Nitrogen Fertilization on Soil Respiration in Rocky Mountain National Park

    Science.gov (United States)

    Allen, J.; Denning, S.; Baron, J.

    2015-12-01

    Anthropogenic activities contribute to increased levels of nitrogen deposition and elevated CO2 concentrations in terrestrial ecosystems. The role that soils play in biogeochemical cycles is an important area of uncertainty in ecosystem ecology. One of the main reasons for this uncertainty is that we have limited understanding of belowground microbial activity and how this activity is linked to soil processes. In particular, elevated CO2 may influence soil nitrogen processes that regulate nitrogen availability to plants. Warming and nitrogen fertilization may both contribute to loss of stored carbon from mountain ecosystems, because they contribute to microbial decomposition of organic matter. To study the effects of long-term nitrogen fertilization on soil respiration, we analyzed results from a 25-year field experiment in Rocky Mountain National Park. Field treatments are in old growth Engelmann spruce forests. Soil respiration responses to the effects of nitrogen fertilization on soil carbon cycling, via respiration, were investigated during the 2013 growing season. Soil moisture, temperature, and respiration rates were measured in six 30 x 30 m plots, of the six plots three are fertilized with 25 kg N ha-1 yr-1 as ammonium nitrate (NH4NO3) pellets and three receives ambient atmospheric nitrogen deposition (1-6 kg N/ha/yr) in Rocky Mountain National Park. We found that respirations rates in the fertilized plots were not significantly higher than respiration rates in the unfertilized plots. We speculate that acclimation to long-term fertilization and relatively high levels of nitrogen deposition in the control plots both contribute to the insensitivity of soil respiration to fertilization at this site.

  12. Changes of weed infestation in winter wheat field under the influence of nitrogen fertilizing intensification

    Directory of Open Access Journals (Sweden)

    Jerzy Szymona

    2013-12-01

    Full Text Available In a strict field experiment we have studied the influence of various doses of nitrogen fertilization (0, 100, 175 kg N per ha on the species composition and the number on weeds occurring in a field of winter wheat, cultivated on humus fertile soil. The optimum nitrogen dose for wheat (100 kg N per ha did not cause vast differences in the weed community, in comparison with a control (without fertilization with N. However, its enlargement to 175 kg N per ha limited the number of species witch invested wheat with weeds, causing at the same time the compensation of nitrophilus species.

  13. Effects of types and application rates of nitrogen fertilizer on the development and nitrogen utilization of summer maize

    Institute of Scientific and Technical Information of China (English)

    Zhenxie YI; Pu WANG; Hongbin TAO; Hongfang ZHANG; Lixia SHEN

    2008-01-01

    To reduce nitrogen fertilizer (NF) loss and improve nitrogen use efficiency (NUE) in summer maize, the effects of the different application rates of three types of NF (urea, coated urea and compound fertilizer) on the growth and development and NUE of summer maize (cultivars: Zhengdan958 and Nongda108) were studied in 2004. The main findings of this study were: (1) The yields of the two cultivars increased significantly with each The increase in the yield of summer maize treated with compound fertilizer was greater than the yield of those treated with either of the other two fertilizers at the same application rate, while the differences among the three types of NF were not significant. (2) Grain number per ear of the two cultivars rose in relation to the increase in N application rate, while its relationship with the type of NF was very weak. The type of NF had a greater impact on 1000-grain weight, and a difference between cultivars was observed. (3) Leaf area index (LAI), dry matter weight and leaf chlorophyll content grew in relation to the increase in N application rate, and were improved more sharply by compound fertilizer or coated urea than by urea alone. (4) Compared to the results achieved with urea, the NUEs of summer maize treated with coated urea and compound fertilizer were higher but the nitrogen harvest index was not improved. In addition, the NUEs of three types of NF exhibited a genotype difference from summer maize.

  14. Plant maturity and nitrogen fertilization affected fructan metabolism in harvestable tissues of timothy (Phleum pratense L.).

    Science.gov (United States)

    Ould-Ahmed, Marouf; Decau, Marie-Laure; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; Lafrenière, Carole; Drouin, Pascal

    2014-10-15

    Timothy (Phleum pratense L.) is an important grass forage used for pasture, hay, and silage in regions with cool and humid growth seasons. One of the factors affecting the nutritive value of this grass is the concentration of non-structural carbohydrates (NSC), mainly represented by fructans. NSC concentration depends on multiple factors, making it hardly predictable. To provide a better understanding of NSC metabolism in timothy, the effects of maturity stage and nitrogen (N) fertilization level on biomass, NSC and N-compound concentrations were investigated in the tissues used for forage (leaf blades and stems surrounded by leaf sheaths) of hydroponically grown plants. Moreover, activities and relative expression level of enzymes involved in fructan metabolism were measured in the same tissues. Forage biomass was not altered by the fertilization level but was strongly modified by the stage of development. It increased from vegetative to heading stages while leaf-to-stem biomass ratio decreased. Total NSC concentration, which was not altered by N fertilization level, increased between heading and anthesis due to an accumulation of fructans in leaf blades. Fructan metabolizing enzyme activities (fructosyltransferase-FT and fructan exohydrolase-FEH) were not or only slightly altered by both maturity stage and N fertilization level. Conversely, the relative transcript levels of genes coding for enzymes involved in fructan metabolism were modified by N supply (PpFT1 and Pp6-FEH1) or maturity stage (PpFT2). The relative transcript level of PpFT1 was the highest in low N plants while that of Pp6-FEH1 was the highest in high N plants. Morevoer, transcript level of PpFT1 was negatively correlated with nitrate concentration while that of PpFT2 was positively correlated with sucrose concentration. This distinct regulation of the two genes coding for 6-sucrose:fructan fructosyltransferase (6-SFT) may allow a fine adequation of C allocation towards fructan synthesis in

  15. Derivation of a Variable Rate Nitrogen Application Model for In-Season Fertilization of Corn

    Science.gov (United States)

    Nitrogen fertilizers used in crop production contribute to pollution of groundwater by nitrate and occurrence of hypoxia in the Gulf of Mexico. Economic and environmental pressures are forcing producers to improve nitrogen use efficiency. The objective of this study was to develop a production-based...

  16. Nitrogen Fertilizer Dependency and Its Contradictions: A Theoretical Exploration of Social-Ecological Metabolism

    Science.gov (United States)

    Mancus, Philip

    2007-01-01

    The global agro-food system relies heavily on inorganic nitrogenous fertilizers. In addition to consuming enormous amounts of energy, this manufactured input contributes to the accumulation of reactive nitrogen in the biosphere and undermines the biological basis of agricultural production itself. While technological inefficiency and population…

  17. Interactions among irrigation and nitrogen fertility regimes on Mid-South cotton production

    Science.gov (United States)

    Increasing costs for irrigation and nitrogen fertilization has led to the desire from cotton (Gossypium hirsutum L.) producers to make the most efficient use of these inputs. Objectives for this research were to determine how cotton responded to varying levels of irrigation and nitrogen fertilizati...

  18. [Proteomics of rice leaf and grain at late growth stage under different nitrogen fertilization levels].

    Science.gov (United States)

    Ning, Shu-ju; Zhao, Min; Xiang, Xiao-liang; Wei, Dao-zhi

    2010-10-01

    Taking super-rice Liangyoupeijiu as test material, and by the method of two-dimensional gel electrophoresis (2-DE), this paper studied the changes in the leaf and grain proteomics of the variety at its late growth stage under different levels of nitrogen fertilization (1/2 times of normal nitrogen level, 20 mg x L(-1); normal nitrogen level, 40 mg x L(-1); 2 times of normal nitrogen level, 80 mg x L(-1)), with the biological functions of 16 leaf proteins, 9 inferior grain proteins, and 4 superior grain proteins identified and analyzed. Nitrogen fertilization could affect and regulate the plant photosynthesis via affecting the activation of photosynthesis-related enzymes and of CO2, the light system unit, and the constitution of electron transfer chain at the late growth stage of the variety. It could also promote the expression of the enzymes related to the energy synthesis and growth in inferior grains. High nitrogen fertilization level was not beneficial to the synthesis of starch in superior grain, but sufficient nitrogen supply was still important for the substance accumulation and metabolism. Therefore, rational nitrogen fertilization could increase the photosynthesis rate of flag leaves, enhance the source function, delay the functional early ageing, and promote the grain-filling at late growth stage.

  19. Effect of Phosphorus Fertilizer on Nitrogen Fixation by Some Grain ...

    African Journals Online (AJOL)

    acer

    ABSTRACT: Nitrogen fixation by grain legumes contributes N to tropical soils. But in Sudano –. Sahelian .... at 650C, weighed and analyzed for the N concentrations (Marr ... The increase of whole plant growth and plant nitrogen concentration ...

  20. Impact of cotton planting date and nitrogen fertilization on Bemisia argentifolii populations

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONGBI; DONG-MEILIN; KEH-SHENLII; NICKC.TOSCANO

    2005-01-01

    The silverleaf whitefly (Bemisia argentifolii Bellows and Perring) is a widely distributed pest of cotton (Gossypium hirsutum L.) and the population levels may be affected by rates of nitrogen fertilization and planting date. Field experiments were conducted to investigate the impact of cotton planting date and nitrogen fertilization on silverleaf whitefly population dynamics. Cotton was planted on 26 April and 8 June, for the early and late plantings, respectively. Nitrogen treatments consisted of soil applications of 0, 112, 168 and 224 kg of nitrogen per hectare. The population levels of adult whiteflies were much higher on early-planted cotton than on late planting. Also, increased numbers of adult whiteflies on both early and late plantings occurred with increasing amounts of applied nitrogen.Applied nitrogen increased seed cotton yields of early plantings but had no effect on the yields of late plantings.

  1. Management, regulation and environmental impacts of nitrogen fertilization in northwestern Europe under the Nitrates Directive

    DEFF Research Database (Denmark)

    van Grinsven, H.J.M.; ten Berge, H.F.M.; Dalgaard, Tommy;

    2012-01-01

    . Issues of concern and improvement of the implementation of the NiD are accounting for the fertilizer value of nitrogen in manure, and relating application limits for total nitrogen (N) to potential crop yield and N removal. The most significant environmental effect of the implementation of the NiD since....... This decrease is less prominent for groundwater in view of delayed response of nitrate in deep aquifers. In spite of improved fertilization practices, the southeast of the Netherlands, the Flemish Region and Brittany remain to be regions of major concern in view of a combination of a high nitrogen surplus, high...... reporting period for the NiD (2004–2007) and results of the MITERRA-EUROPE model. Implementation of the NiD in the considered member states is fairly comparable regarding restrictions for where and when to apply fertilizer and manure, but very different regarding application limits for N fertilization...

  2. Endophytic fungus Phomopsis liquidambari and different doses of N-fertilizer alter microbial community structure and function in rhizosphere of rice

    Science.gov (United States)

    Siddikee, Md. Ashaduzzaman; Zereen, Mst Israt; Li, Cai-Feng; Dai, Chuan-Chao

    2016-09-01

    Microbial community structure and functions of rhizosphere soil of rice were investigated after applying low and high doses of nitrogenous fertilizer and Phomopsis liquidambari. Average well color development, substrate richness, catabolic diversity and soil enzymes activities varied after applying N-fertilizer and P. liquidambari and were greater in P. liquidambari treated soil than only N-fertilization. Multivariate analysis distinctly separated the catabolic and enzymes activity profile which statistically proved alteration of microbial functional diversity. Nitrogen fertilizer altered microbial community structure revealed by the increased content of total PLFAs, specific subgroup marker PLFAs except fungal PLFAs and by the decreased ratio of G+/G‑, sat/monunsat, iso/anteiso, F/B except trans/cis while P. liquidambari inoculation enhanced N-fertilization effect except increased fungal PLFA and decreased trans/cis. PCA using identified marker PLFAs revealed definite discrimination among the treatments which further statistically confirmed structural changed of microbial community. Nitrogenase activity representative of N-fixing community decreased in N-fertilizer treatment while P. liquidambari inoculation increased. In short, application of P. liquidambari with low doses of N-fertilizer improved rice growth and reduced N-fertilizer requirement by increasing enzymes activities involved in C, N and P cycling, structural and functional diversity of microbes, nitrogenase activity involved in N2 fixation and accumulation of total-N.

  3. THE INFLUENCE OF NITROGEN FERTILIZATION APPLIED IN DIFFERENT DOSES ON FODDER QUALITY OF MEADOW SWARD

    Directory of Open Access Journals (Sweden)

    Kazimierz Jankowski

    2013-07-01

    Full Text Available The experiment was organized in four replicants in arrangement split-plot with plots having a surface equal 9 m2. The basic fertilization was applied under the first regrowth. It was a mixture of unary fertilizers (ammonium nitrate, superphosphate, potassic salt or polifoska. One form of supplementary fertilization was applied under the second and third regrowth. It was the stable form of fertilizer applied to soil. This form of supplemented nitrogen gave respectively: 50 kg N·ha-l; 80 kg N·ha-l; 110 kg N·ha-1 per each moving. During the vegetation season three movings were harvested. From each movings the sampIes of green matter were taken for chemical analyses, i.e. total protein content, soluble carbohydrates and net energy (NEL. The obtained results showed large differences in fodder quality of the meadow sward fertilized with three doses of nitrogen.

  4. Effects of nitrogen and phosphorus fertilization on soil carbon fractions in alpine meadows on the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Li, Jin Hua; Yang, Yu Jie; Li, Bo Wen; Li, Wen Jin; Wang, Gang; Knops, Johannes M H

    2014-01-01

    In grassland ecosystems, N and P fertilization often increase plant productivity, but there is no concensus if fertilization affects soil C fractions. We tested effects of N, P and N+P fertilization at 5, 10, 15 g m-2 yr-1 (N5, N10, N15, P5, P10, P15, N5P5, N10P10, and N15P15) compared to unfertilized control on soil C, soil microbial biomass and functional diversity at the 0-20 cm and 20-40 cm depth in an alpine meadow after 5 years of continuous fertilization. Fertilization increased total aboveground biomass of community and grass but decreased legume and forb biomass compared to no fertilization. All fertilization treatments decreased the C:N ratios of legumes and roots compared to control, however fertilization at rates of 5 and 15 g m-2 yr-1 decreased the C:N ratios of the grasses. Compared to the control, soil microbial biomass C increased in N5, N10, P5, and P10 in 0-20 cm, and increased in N10 and P5 while decreased in other treatments in 20-40 cm. Most of the fertilization treatments decreased the respiratory quotient (qCO2) in 0-20 cm but increased qCO2 in 20-40 cm. Fertilization increased soil microbial functional diversity (except N15) but decreased cumulative C mineralization (except in N15 in 0-20 cm and N5 in 20-40 cm). Soil organic C (SOC) decreased in P5 and P15 in 0-20 cm and for most of the fertilization treatments (except N15P15) in 20-40 cm. Overall, these results suggested that soils will not be a C sink (except N15P15). Nitrogen and phosphorus fertilization may lower the SOC pool by altering the plant biomass composition, especially the C:N ratios of different plant functional groups, and modifying C substrate utilization patterns of soil microbial communities. The N+P fertilization at 15 g m-2 yr-1 may be used in increasing plant aboveground biomass and soil C accumulation under these meadows.

  5. [Effects of nitrogen and phosphorus fertilization on litterfall production and nutrient dynamics in a Schima superba forest in Zhejiang Province of East China].

    Science.gov (United States)

    Lü, Yan; Zheng, Ze-Mei; Meiliban, Mamuti; Lu, Jiang; Wang, Xi-Hua

    2013-11-01

    In 2011, an investigation was made on the litterfall production and nutrient dynamics in a phosphorus-limited subtropical evergreen broadleaved forest dominated by Schima superba in Tiantong, Zhejiang Province of East China under different levels of nitrogen (N) and phosphorous (P) fertilization. After the N and P fertilization, the annual litterfall production ranged from 6.82 to 8.30 t x hm(-2) x a(-1), with three peaks in May or June, August, and October, respectively. Under fertilization, the annual average N and P concentrations of the litterfall (except the annual average N concentration under P fertilization) increased, and had a seasonal variation. There were no significant differences in the nitrogen return amount (60.05-71.47 kg x hm(-2) x a(-1)) and phosphorus return amount (2.94-3.93 kg x hm(-2) x a(-1)) of the litterfall among different treatments. As compared to the control, the N:P ratio of the litterfall under fertilization was higher at the beginning of the experiment (spring, 2011), but lower in the winter, 2011, indicating that nitrogen and phosphorus fertilization could alter the original nitrogen and phosphorus limited conditions of the studied forest ecosystem.

  6. Metabolite analysis of the effects of elevated CO2 and nitrogen fertilization on the association between tall fescue (Schedonorus arundinaceus) and its fungal symbiont Neotyphodium coenophialum.

    Science.gov (United States)

    Ryan, Geraldine D; Rasmussen, Susanne; Xue, Hong; Parsons, Anthony J; Newman, Jonathan A

    2014-01-01

    Atmospheric CO2 is expected to increase to between 550 ppm and 1000 ppm in the next century. CO2-induced changes in plant physiology can have ecosystem-wide implications and may alter plant-plant, plant-herbivore and plant-symbiont interactions. We examined the effects of three concentrations of CO2 (390, 800 and 1000 ppm) and two concentrations of nitrogen fertilizer (0.004 g N/week versus 0.2 g N/week) on the physiological response of Neotyphodium fungal endophyte-infected and uninfected tall fescue plants. We used quantitative PCR to estimate the concentration of endophyte under altered CO2 and N conditions. We found that elevated CO2 increased the concentration of water-soluble carbohydrates and decreased the concentration of plant total amino acids in plants. Fungal-derived alkaloids decreased in response to elevated CO2 and increased in response to nitrogen fertilization. Endophyte concentration (expressed as the number of copies of an endophyte-specific gene per total genomic DNA) increased under elevated CO2 and nitrogen fertilization. The correlation between endophyte concentration and alkaloid production observed at ambient conditions was not observed under elevated CO2. These results suggest that nutrient exchange dynamics important for maintaining the symbiotic relationship between fungal endophytes and their grass hosts may be altered by changes in environmental variables such as CO2 and nitrogen fertilization.

  7. Interactions of tissue and fertilizer nitrogen on decomposition dynamics of lignin-rich conifer litter

    Science.gov (United States)

    Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E.

    2012-01-01

    High tissue nitrogen (N) accelerates decomposition of high-quality leaf litter in the early phases of mass loss, but the influence of initial tissue N variation on the decomposition of lignin-rich litter is less resolved. Because environmental changes such as atmospheric N deposition and elevated CO2 can alter tissue N levels within species more rapidly than they alter the species composition of ecosystems, it is important to consider how within-species variation in tissue N may shape litter decomposition and associated N dynamics. Douglas-fir (Pseudotsuga menziesii ) is a widespread lignin-rich conifer that dominates forests of high carbon (C) storage across western North America, and displays wide variation in tissue and litter N that reflects landscape variation in soil N. We collected eight unique Douglas-fir litter sources that spanned a two-fold range in initial N concentrations (0.67–1.31%) with a narrow range of lignin (29–35%), and examined relationships between initial litter chemistry, decomposition, and N dynamics in both ambient and N fertilized plots at four sites over 3 yr. High initial litter N slowed decomposition rates in both early (0.67 yr) and late (3 yr) stages in unfertilized plots. Applications of N fertilizer to litters accelerated early-stage decomposition, but slowed late-stage decomposition, and most strongly affected low-N litters, which equalized decomposition rates across litters regardless of initial N concentrations. Decomposition of N-fertilized litters correlated positively with initial litter manganese (Mn) concentrations, with litter Mn variation reflecting faster turnover of canopy foliage in high N sites, producing younger litterfall with high N and low Mn. Although both internal and external N inhibited decomposition at 3 yr, most litters exhibited net N immobilization, with strongest immobilization in low-N litter and in N-fertilized plots. Our observation for lignin-rich litter that high initial N can slow decomposition

  8. Long Term Sugarcane Crop Residue Retention Offers Limited Potential to Reduce Nitrogen Fertilizer Rates in Australian Wet Tropical Environments.

    Science.gov (United States)

    Meier, Elizabeth A; Thorburn, Peter J

    2016-01-01

    The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG) emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1) reduce emissions [e.g., those that reduce nitrous oxide (N2O) emissions by avoiding excess nitrogen (N) fertilizer application], and (2) increase soil organic carbon (SOC) stocks (e.g., by retaining instead of burning crop residues). Sugarcane is a globally important crop that can have substantial inputs of N fertilizer and which produces large amounts of crop residues ('trash'). Management of N fertilizer and trash affects soil carbon and nitrogen cycling, and hence GHG emissions. Trash has historically been burned at harvest, but increasingly is being retained on the soil surface as a 'trash blanket' in many countries. The potential for trash retention to alter N fertilizer requirements and sequester SOC was investigated in this study. The APSIM model was calibrated with data from field and laboratory studies of trash decomposition in the wet tropics of northern Australia. APSIM was then validated against four independent data sets, before simulating location × soil × fertilizer × trash management scenarios. Soil carbon increased in trash blanketed soils relative to SOC in soils with burnt trash. However, further increases in SOC for the study region may be limited because the SOC in trash blanketed soils could be approaching equilibrium; future GHG mitigation efforts in this region should therefore focus on N fertilizer management. Simulated N fertilizer rates were able to be reduced from conventional rates regardless of trash management, because of low yield potential in the wet tropics. For crops subjected to continuous trash blanketing, there was substantial immobilization of N in decomposing trash so conventional N fertilizer rates were required for up to 24 years after trash blanketing commenced. After this period, there was potential to reduce N fertilizer

  9. [Coupling effects of partitioning alternative drip irrigation with plastic mulch and nitrogen fertilization on cotton dry matter accumulation and nitrogen use].

    Science.gov (United States)

    Li, Pei-Ling; Zhang, Fu-Cang

    2013-02-01

    A field experiment with complete combination design was conducted to study the effects of partitioning alternative drip irrigation with plastic mulch and nitrogen fertilization on the dry matter accumulation and nitrogen use efficiency of cotton plant. Three levels of irrigation (260, 200, and 140 mm) and of nitrogen fertilizer (270, 180, and 90 kg.hm-2) were installed. The cotton dry mass was the highest in treatments medium nitrogen/high water and high nitrogen/high water. As compared with that in high nitrogen/high water treatment, the nitrogen use efficiency for dry matter accumulation in medium nitrogen/high water treatment was increased by 34.0% -44.6%, with an average of 34.7% , while the water use efficiency was decreased by 6.4% -10.7%, averagely 10.2%. As for the nitrogen accumulation in cotton plant, the nitrogen use efficiency was the highest in medium nitrogen/high water treatment, and the water use efficiency was the highest in high nitrogen/medium water treatment. Compared with high nitrogen/high water treatment, medium nitrogen/high water treatment increased the nitrogen use efficiency for cotton nitrogen accumulation by 29.0% -41.7%, but decreased the water use efficiency for cotton nitrogen accumulation by 5.5%-14.0%. Among the treatments of coupling water and nitrogen of higher cotton yield, treatment medium nitrogen/high water had the higher cotton nitrogen recovery rate, nitrogen agronomic efficiency, and apparent use efficiency than the treatments high nitrogen/medium water and high nitrogen/high water, but no significant differences were observed in the nitrogen absorption ratio and nitrogen physiological efficiency. Treatment medium nitrogen/high water was most beneficial to the coupling effects of water and nitrogen under partitioning alternate drip irrigation with plastic mulch and nitrogen fertilization.

  10. Morphogenetic characteristics in Tanzania grass conhsorted with Stylosanthes Campo Grande or fertilized with nitrogen under grazing

    Directory of Open Access Journals (Sweden)

    Túlio Otávio Jardim D'Almeida Lins

    2015-08-01

    Full Text Available This study aimed to study morphogenic and structural characteristics of Tanzania grass (Panicum maximum cv. Tanzania intercropped with Estilosantes Campo Grande (Stylosanthes capitata and Stylosanthes macrocephala or fertilized with nitrogen. The pasture was managed under continuous stocking and variable stocking rate. Were used a randomized complete blocks with split plots and three replications. The treatments were: Tanzania grass + Stylosanthes; Tanzania grass + 75 Kg N.ha. year-1; Tanzania grass + 150Kg N.ha.year-1; Tanzania grass + 225 Kg N.ha.year-1. Were used urea and ammonium nitrate as nitrogen source. The morphogenetic evaluations were conducted in the spring and summer. Were evaluated 15 tillers per paddock, twice a week for four weeks per season in study. The morphogenic characteristics were not affected by nitrogen fertilization or consortium, except the leaf elongation rate (LER. The highest values for this variable were observed in the spring in the fertilized pastures. Therefore, it is concluded that nitrogen fertilization influences the leaf elongation rate (LER of Tanzania grass, and this one when is intercropped with Stylosanthes Campo Grande show morphogenic characteristics similar when fertilized with nitrogen, except for rate leaf elongation.

  11. [Effects of nitrogen fertilization rate and harvest time on summer maize grain yield and its quality].

    Science.gov (United States)

    Zhang, Xue-lin; Wang, Qun; Zhao, Ya-li; Yang, Qing-hua; Li, Chao-hai

    2010-10-01

    In order to approach the optimal nitrogen fertilization rate and suitable harvest time for the high grain yield and quality of summer maize in Huanghe-Haihe Area, a field experiment with five nitrogen fertilization rates (0, 113, 181, 249, and 375 kg N x hm(-2)) and two harvest time (S1: September 23, conventional harvest time for local farmers, and S2: September 29, 6 days delayed) was conducted. The results showed that the kernel number, grain yield, and 1000-grain mass increased with nitrogen fertilization rate, but the differences were not significant. With increasing nitrogen fertilization rate, the protein and lysine contents of the grains increased, while the starch content decreased. After 6 days delayed for harvest, the grain yield, 1000-grain mass, and the starch and lysine contents of the grains increased, but the protein and crude fat contents decreased. Based on the yield level, the optimal nitrogen fertilization rate for the summer maize in Huanghe-Haihe Area was 113-180 kg N x hm(-2), and the suitable harvest time was from September 29 to October 5.

  12. [Effects of irrigation amount and nitrogen fertilization rate on wheat yield and soil nitrate content].

    Science.gov (United States)

    Jiang, Dong-Yan; Yu, Zhen-Wen; Xu, Zhen-Zhu

    2011-02-01

    A field experiment was conducted to study the effects of irrigation amount and nitrogen fertilization rate on wheat yield and soil nitrate content. With the increase of irrigation amount, the soil nitrate content in 0-200 cm layer at the same nitrogen fertilization rates had a trend of decrease -increase-decrease. Under irrigation, the soil nitrate content was significantly lower in 0-80 cm layer while significantly higher in 80-200 cm layer, compared with the control. As the irrigation amount increased, the translocation of soil nitrate nitrogen to deeper layers accelerated dramatically, with the content decreased in 0-80 cm layer, increased in 120-200 cm layer, and peaked in 120-140 cm layer. When the nitrogen fertilization rate increased from 210 kg x hm(-2) to 300 kg x hm(-2) the soil nitrate content at the same irrigation amounts increased significantly through anthesis, filling, and maturity stages. With the increase of irrigation amount, the grain yield decreased after an initial increase, being the highest when the irrigation amount in whole growth period was 60 mm. The grain yield, grain protein content, and grain protein yield all increased significantly with increasing nitrogen fertilization rate. Under the conditions of the present experiment, the treatment with nitrogen fertilization rate 210 kg N x hm(-2) and irrigation amount 60 mm (split into two times) had the highest grain yield, grain protein content, grain protein yield, and harvest index but the least NO3(-)-N leaching, being the more available irrigation and nitrogen fertilization mode for wheat production in the study area.

  13. Balance sheet method assessment for nitrogen fertilization in bread wheat: I. yield and quality

    Directory of Open Access Journals (Sweden)

    Mario Monotti

    2011-02-01

    Full Text Available In the European Union the production of high quality wheat is mainly located in the Mediterranean regions where the climatic conditions positively affect protein concentration in the grain. High quality wheat calls for proper management of nitrogen fertilization, thus there is a need to verify whether the limitations imposed by local governments on maximum rate of nitrogen fertilization admitted may affect bread making quality. Trials were conducted in fourteen environments (E to study the effects of different nitrogen fertilizations on eight cultivars (C, belonging to four quality grades (Q. Nitrogen (N was applied to crops according to three rates/modalities: N1 corresponding to the maximum rate admitted calculated according to a balance sheet method and distributed at the stage of spike initiation; N2 with 50 kg ha-1 of nitrogen more than N1, also distributed at the stage of spike initiation; N3 with 50 kg ha-1 of nitrogen more than N1 but distributed at the stage of flag leaf appearance. The effects of environment, nitrogen and cultivar were significant for grain yield, test weight, 1000 kernel weight, heading time, plant height and for quality traits (protein content and alveograph indices. The existence of variability among cultivars and quality grades in the response to rate and timing of nitrogen fertilization was demonstrated by the significance of NxC and NxQ interactions. Dry matter and nitrogen contents of plant at anthesis and at harvest were significantly affected by the main sources of variation. High quality cultivars yielded more grain of better quality with higher N rates (N2 and N3 as compared to the maximum rate of nitrogen admitted by the local government (N1. These results demonstrated that the adopted balance sheet method for the calculation of N requirements of wheat crop adversely affects the full potential expression of the cultivars belonging to superior bread making quality grades.

  14. Soil Profile Nitrate Response to Nitrogen Fertilization of Winter Triticale

    Science.gov (United States)

    Growing triticale (XTriticosecale Wittmack) as a winter crop has the potential to utilize residual nitrate-nitrogen (NO3-N) from previous crops, thus reducing its availability for leaching. Our objectives were to quantify nitrogen (N) capture and changes in soil NO3-N levels in response to N fertili...

  15. [Effects of controlled-release fertilizers on summer maize grain yield, field ammonia volatilization, and fertilizer nitrogen use efficiency].

    Science.gov (United States)

    Zhao, Bin; Dong, Shu-Ting; Wang, Kong-Jun; Zhang, Ji-Wang; Liu, Peng

    2009-11-01

    A field experiment with colophony-coated fertilizer (CRF) and sulfur-coated fertilizer (SCF) showed that under the same application rates of N, P and K, applying CRF and SCF increased the summer maize grain yield by 13.15% and 14.15%, respectively, compared to the application of common compound fertilizer CCF. When the applied amount of CRF and SCF was decreased by 25%, the yield increment was 9.69% and 10.04%, respectively; and when the applied amount of CRF and SCF was decreased by 50%, the yield had less difference with that under CCF application. The field ammonia volatilization rate in treatments CRF and SCF increased slowly, with a peak appeared 7 days later than that in treatment CCF, and the total amount of ammonia volatilization in treatments CRF and SCF was ranged from 0.78 kg N x hm(-2) to 4.43 kg N x hm(-2), with a decrement of 51.34%-91.34% compared to that in treatment CCF. The fertilizer nitrogen use efficiency and agronomic nitrogen use efficiency of CRF and SCF were also significantly higher than those of CCF.

  16. [Effects of applying controlled-release fertilizer blended with conventional nitrogen fertilizer on Chinese cabbage yield and quality as well as nitrogen losses].

    Science.gov (United States)

    Yang, Jun-gang; Xu, Kai; Tong, Er-jian; Cao, Bing; Ni, Xiao-hui; Xu, Jun-xiang

    2010-12-01

    An open field experiment was conducted to study the effects of applying controlled-release fertilizer blended with rapidly available chemical N fertilizer on Chinese cabbage yield and quality as well as nitrogen losses, including ammonia volatilization and NO3- -N accumulation and leaching in Beijing suburb. The results showed that a combined application of 2:1 controlled-release fertilizer and urea fertilizer (total N rate 150 kg x hm(-2)) did not induce the reduction of Chinese cabbage yield, and decreased the leaf nitrate and organic acid contents significantly, compared with conventional urea N application (300 kg x hm(-2)), and had no significant difference in the cabbage yield and leaf nitrate content, compared with applying 150 kg x hm(-2) of urea N. The combined application of 2:1 controlled-release fertilizer and urea fertilizer improved the N use efficiency of Chinese cabbage, and reduced the ammonia volatilization and NO3- -N leaching. At harvest, the NO3- -N concentrations in 20-40, 60-80 and 80-100 cm soil layers were significantly lower in the combined application treatment than in urea N treatment.

  17. A Preliminary Study on Natural Matrix Materials for Controlled Release Nitrogen Fertilizers

    Institute of Scientific and Technical Information of China (English)

    DU Chang-Wen; ZHOU Jian-Min; WANG Huo-Yan; LI Shou-Tian

    2004-01-01

    A controlled release N fertilizer was developed by the carrier method using natural polysaccharides (PS)and urea. The results showed that mixing of PS and urea led to significant control of urea release. When a cross-linker (boric acid or glutaraldehyde) was added, a better control effect was observed. During a 30 min leaching time the nitrogen release rate from the controlled release fertilizer was nearly constant, which was significantly different from normal urea. One of the controlled release mechanisms was related to space resistance from a large molecular structure. Infrared (IR) analysis indicated that interaction of PS with urea was through a hydrogen bond or a covalent bond. These bonds created an α-helix or high molecular network fertilizer carrier system, which was another reason for a controlled nutrient release. Pot experiment showed that nitrogen use efficiency could increase significantly with a carrier fertilizer.

  18. Growth and Yield of Chili Pepper as Affected by Weed Based Organic Compost and Nitrogen Fertilizer

    Directory of Open Access Journals (Sweden)

    Nanik Setyowati

    2014-01-01

    Full Text Available Fertility improvement of Ultisol is inevitable to increase growth and yield of chili pepper since the nutrient availability and organic matter of this soil is relatively low. Application of organic fertilizer will enhance microorganism activity in soil, thereafter will improve the availability of nutrients as well as other chemical, physical, biological properties of the soil. Most of manure releases nutrient quite slowly; therefore, addition of nitrogen to soil is expected to speed up the availability of nutrient to plant. Weed based organic fertilizers from Wedelia (Wedelia trilobata and Siam weed (Chromolaena odorata biomass have potential to substitute inorganic fertilizer. The objective of the experiment was to compare the effects of weed based organic compost and dry leaves compost with or without addition of nitrogen fertilizer on growth and yield of chili pepper. The experiment was carried out using Completely Randomized Design (CRD with treatments of 200 kg urea ha-1; Wedelia compost (WDC 20 ton ha-1; WDC 15, 10, and 5 ton ha-1 with addition of 200 kg urea ha-1 respectively; Siam weed compost (SWC 20 ton ha-1, SWC 15, 10, and 5 ton ha-1 with addition of  200 kg urea ha-1 respectively; and dry leaves compost (DLC 20 ton ha-1, DLC 15, 10, and 5 ton ha-1 with addition of 200 kg urea ha-1 respectively. The result revealed that composts with or without addition of nitrogen fertilizer had similar responses on the growth of chili pepper. Wedelia and Siam weeds compost at 20 ton ha-1 tended to give better yield of chili pepper as compared to application of urea alone. This result indicated that weed based organic fertilizers could substitute nitrogen fertilizer.

  19. Influence of nitrogen fertilizers on the yield and composition of thyme (Thymus vulgaris).

    Science.gov (United States)

    Baranauskiene, Renata; Venskutonis, Petras Rimantas; Viskelis, Pranas; Dambrauskiene, Edita

    2003-12-17

    The influence of nitrogen fertilizers on the yield of crop, as well as on the production and composition of the essential oil and some other chemical characteristics of thyme, was investigated. Different levels of fertilizers (N = 0, 45, 90, and 135 kg x ha(-)(1)) were applied. It was found that fertilizers increase thyme crop, but differences in the yield of essential oil were not remarkable. However, the use of certain amounts of nitrogen fertilizers resulted in higher yields of essential oil obtainable from the cultivation area unit (dm(3) ha(-)(1)). Totally, 61 constituents were identified in thyme essential oil by capillary GC and GC-MS. Thymol was the dominating compound in the all analyzed oils (44.4-58.1%), followed by p-cymene (9.1-18.5%), gamma-terpinene (6.9-18.9%), and carvacrol (2.4-4.2%). Differences in the percentage of these and other compounds in thyme herb cultivated under different fertilization doses were not significant; very slight changes in the percentage composition were detected after drying. Some variations in the amount of individual constituents expressed in arbitrary units per kilogram of herb (which is almost equivalent to mg x kg(-)(1)) were observed. The highest amounts of sugars and sucrose, in particular, were determined in the second year of thyme cultivation. Differences in the content of dry soluble substances were not meaningful, and there was no effect of nitrogen fertilizers on this chemical characteristic. Some effect of fertilization on the content of vitamin C and carotenes was observed in the first year of thyme cultivation. It was determined that nitrogen fertilizers influence the amount of nitrates, which was highest in the second-year-first-harvest.

  20. [Further reduction of nitrogen fertilizer application in paddy field under green manuring of Taihu Area, China].

    Science.gov (United States)

    Zhao, Dong; Yan, Ting-mei; Qiao, Jun; Yang, Lin-zhang; Tang, Fang; Song, Yun-fei

    2015-06-01

    This study focused on the nitrogen loss via runoff, change of nitrogen in different forms in surface water in paddy field, and grain yield, through further reduction of nitrogen fertilizer application rate under green manuring without basal dressing. Results showed that with 150 kg · hm(-2) inorganic N fertilizer input after return of green manure to soil, no basal dressing could not only sharply reduce N concentration in surface water and decrease 17.2% of N loss, but also increase 2.8% of grain yield in comparison with basal dressing. It was a worthwhile farming method that inorganic nitrogen fertilizer was not used for basal dressing but for topdressing after return of green ma- nure to soil in Taihu Area. However, the grain yield would decrease if the rate of topdressing nitro- gen was excessively reduced or increased. After all, it was feasible to realize harmonization of grain yield and environmental benefits in Taihu Area, with 133 kg · hm(-2) inorganic N fertilizer input after return of green manure to soil as well as no application of basal dressing, which could greatly reduce N fertilizer input and N loss as well as ensure rice yield.

  1. Effects of Different Nitrogen Fertilizer Levels on Lodging and Yield of Rice

    Institute of Scientific and Technical Information of China (English)

    Hechuan YANG; Liquan WU; Xinfeng HAN; Hui SHAO; Jian KE; Rongfu WANG

    2012-01-01

    [Objective] This study aimed to investigate the effects of different fertilizer levels on lodging and yield of rice. [Method] A total of four treatments were de- signed and applied with 6, 9, 12 and 15 kg of nitrogen fertilizer, respectively. After seedling transplanting, the biological characteristics of rice at different growth stages in each treatment and the biological and economic characteristics of rice after lodg- ing were determined for statistical analysis. [Result] Application with 15 kg of nitro- gen fertilizer had significant promotion effect on the increase of rice yield; compared with the control (6 kg of nitrogen fertilizer), rice yield in three experimental treat- ments (9, 12 and 15 kg of nitrogen fertilizer, respectively) increased by 50.74%, 89.11% and 94.48%, respectively; lodging-resistance mechanical strengths of the three experimental treatments were 103.97%, 132.01% and 89.83% of the control, respectively; rice lodging resistance of treatment C (12 kg of nitrogen fertilizer) was the strongest, with the highest yield. [Conclusion] This study provides reference data and technical support for the rational fertilization of rice production.

  2. [Evaluation of nitrogen loss way in summer maize system under different fertilizer N managements].

    Science.gov (United States)

    Lin, Li; Hu, Ke-Lin; Li, Guang-De; Wang, Huan-Yuan

    2011-09-01

    The objective of this study was to investigate nitrogen (N) loss from soil-crop systems under different fertilizer N managements, and to provide some suggestions on optimizing fertilizer management practices. The experiment was carried in high yield production area of Huantai county in Shandong province in 2009. Four kinds of fertilizer N application practices were designed, including CK, farmer practice (FP), optimizing fertilizer application (OPT) and controlled release fertilizer (CRT) for studying the fate of N during the maize growth season in 2009. The water and nitrogen management model (WNMM) was used to simulate the dynamics of soil water and N fate. The results indicated that the ratio of nitrate leaching and NH3 volatilization accounting of fertilizer N ranged from 6% to 18% and 5% to 34%, and their means were 12.7% and 20.7%, respectively. The amount of N leaching under OPT was 14.5 kg x hm(-2), was the lowest in all treatments. The amount of NH3 volatilization under CRT was 7.6 kg x hm(-2), respectively, was the lowest in all treatments. The order of total N loss under four treatments followed as: FP > OPT > CRF approximately CK. Both OPT and CRT treatments are the best management practices considering their high grain yield, water and nitrogen use efficiencies, and environmental protection.

  3. [Effects of controlled release nitrogen fertilizer application on dry matter accumulation and nitrogen balance of summer maize].

    Science.gov (United States)

    Si, Dong-Xia; Cui, Zhen-Ling; Chen, Xin-Ping; Lü, Fu-Tang

    2014-06-01

    Effects of four controlled release nitrogen (N) fertilizers, including two kinds of polyester coated urea (Ncau, CRU) and phosphate (NhnP) and humic acid (NhnF) coated urea on assimilates accumulation and nitrogen balance of summer maize were investigated in a mode of one-time fertilization at the regional N recommended rate. The results showed that the N release curves of the two controlled release fertilizers CRU and Ncau matched well with the summer maize N uptake. Compared with the regional N recommendation rate, CRU could increase maize yield by 4.2% and Ncau could maintain the same yield level. CRU significantly increased the dry matter accumulation rate after anthesis of summer maize, but Ncau markedly increased the dry matter accumulated ratio before anthesis. Meanwhile, CRU could reduce the apparent N losses by 19 kg N x hm(-2) in the case of large precipitation. However, NhnF and NhnP caused the yield losses by 0.1%-8.9%, and enhanced the apparent N losses. Therefore, both CRU and Ncau with one-time fertilization could be a simplified alternative to the "total control, staging regulation" fertilization technique at the regional N recommended rate for summer maize production.

  4. Additional nitrogen fertilization at heading time of rice down-regulates cellulose synthesis in seed endosperm.

    Science.gov (United States)

    Midorikawa, Keiko; Kuroda, Masaharu; Terauchi, Kaede; Hoshi, Masako; Ikenaga, Sachiko; Ishimaru, Yoshiro; Abe, Keiko; Asakura, Tomiko

    2014-01-01

    The balance between carbon and nitrogen is a key determinant of seed storage components, and thus, is of great importance to rice and other seed-based food crops. To clarify the influence of the rhizosphere carbon/nitrogen balance during the maturation stage of several seed components, transcriptome analysis was performed on the seeds from rice plants that were provided additional nitrogen fertilization at heading time. As a result, it was assessed that genes associated with molecular processes such as photosynthesis, trehalose metabolism, carbon fixation, amino acid metabolism, and cell wall metabolism were differentially expressed. Moreover, cellulose and sucrose synthases, which are involved in cellulose synthesis, were down-regulated. Therefore, we compared cellulose content of mature seeds that were treated with additional nitrogen fertilization with those from control plants using calcofluor staining. In these experiments, cellulose content in endosperm from plants receiving additional nitrogen fertilization was less than that in control endosperm. Other starch synthesis-related genes such as starch synthase 1, starch phosphorylase 2, and branching enzyme 3 were also down-regulated, whereas some α-amylase and β-amylase genes were up-regulated. On the other hand, mRNA expression of amino acid biosynthesis-related molecules was up-regulated. Moreover, additional nitrogen fertilization caused accumulation of storage proteins and up-regulated Cys-poor prolamin mRNA expression. These data suggest that additional nitrogen fertilization at heading time changes the expression of some storage substance-related genes and reduces cellulose levels in endosperm.

  5. Optical crop sensor for variable-rate nitrogen fertilization in corn: II - indices of fertilizer efficiency and corn yield

    Directory of Open Access Journals (Sweden)

    Jardes Bragagnolo

    2013-10-01

    Full Text Available Generally, in tropical and subtropical agroecosystems, the efficiency of nitrogen (N fertilization is low, inducing a temporal variability of crop yield, economic losses, and environmental impacts. Variable-rate N fertilization (VRF, based on optical spectrometry crop sensors, could increase the N use efficiency (NUE. The objective of this study was to evaluate the corn grain yield and N fertilization efficiency under VRF determined by an optical sensor in comparison to the traditional single-application N fertilization (TSF. With this purpose, three experiments with no-tillage corn were carried out in the 2008/09 and 2010/11 growing seasons on a Hapludox in South Brazil, in a completely randomized design, at three different sites that were analyzed separately. The following crop properties were evaluated: aboveground dry matter production and quantity of N uptake at corn flowering, grain yield, and vegetation index determined by an N-Sensor® ALS optical sensor. Across the sites, the corn N fertilizer had a positive effect on corn N uptake, resulting in increased corn dry matter and grain yield. However, N fertilization induced lower increases of corn grain yield at site 2, where there was a severe drought during the growing period. The VRF defined by the optical crop sensor increased the apparent N recovery (NRE and agronomic efficiency of N (NAE compared to the traditional fertilizer strategy. In the average of sites 1 and 3, which were not affected by drought, VRF promoted an increase of 28.0 and 41.3 % in NAE and NRE, respectively. Despite these results, no increases in corn grain yield were observed by the use of VRF compared to TSF.

  6. Temperature sensitivity of soil respiration: Synthetic effects of nitrogen and phosphorus fertilization on Chinese Loess Plateau.

    Science.gov (United States)

    Wang, Rui; Sun, Qiqi; Wang, Ying; Liu, Qingfang; Du, Lanlan; Zhao, Man; Gao, Xin; Hu, Yaxian; Guo, Shengli

    2017-01-01

    Nitrogen (N) and phosphorus (P) fertilization has the potential to alter soil respiration temperature sensitivity (Q10) by changing soil biochemical and crop physiological process. A four-year field experiment was conducted to determine how Q10 responded to these biochemical and physiological changes in rain-fed agro-ecosystems on the semi-arid Loess Plateau. Soil respiration, as well as biotic and abiotic factors were measured in winter wheat (Triticum aestivum L.), with three fertilization treatments: (no fertilization (CK), 160kgNhm(-1) (N), and 160kgNha(-1) with 39kgPha(-1) (N+P). Mean annual soil respiration rate (calculated by averaging the four years) in the N treatment and N+P treatment was 18% and 48% higher than that in the CK treatment, respectively; and it was increased by 26% (14%-48%) in the N+P treatment as compared with that in the N treatment. The decrease of Q10 in the N and N+P treatments against the CK treatment was not stable for each year, ranging from 0.01 to 0.28. The maximum decrease of Q10 in the N and N+P treatments was 10% and 15% in 2014-2015, while in other years the decrease of Q10 was numerical but not significant. Soil microbial biomass carbon (SMBC) was increased by 10% and 50%, dissolved organic carbon (DOC) was increased by 6% and 21%, and photosynthesis rate was increased ranging from 6% to 33% with N and N+P fertilization. The relative abundance of Acidobacteria, Actinobacteria and Chloroflexi were significantly higher by 32.9%-54.1% in N addition soils (N and N+P) compared to CK treatment, whereas additional P application into soils increased the relative abundance of the family Micrococcaceae, Nocardioidaceae and Chitinophagaceae. Soil respiration was positively related to SMBC, DOC and photosynthesis rate (paffect soil respiration and temperature sensitivity differently. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Effects of a Control Release Nitrogen Fertilizer and Thinning on the Nitrogen Dynamics of a Mid-Rotation Loblolly Pine Stand in the Piedmont of Virginia

    OpenAIRE

    Elliot, James Robertson

    2006-01-01

    Nitrogen deficiency is characteristic of many mid-rotation loblolly pine (Pinus taeda L.) plantations in the Piedmont region of the southeastern USA. Fertilization with urea is the most common method used to correct this deficiency. Previous studies show that urea fertilization produces a rapid pulse of available nitrogen (N) with only a portion being utilized by plantation trees. Controlled release fertilizers release available N more slowly over a longer period of time and therefore may ...

  8. Effects of a Control Release Nitrogen Fertilizer and Thinning on the Nitrogen Dynamics of a Mid-Rotation Loblolly Pine Stand in the Piedmont of Virginia

    OpenAIRE

    Elliot, James Robertson

    2006-01-01

    Nitrogen deficiency is characteristic of many mid-rotation loblolly pine (Pinus taeda L.) plantations in the Piedmont region of the southeastern USA. Fertilization with urea is the most common method used to correct this deficiency. Previous studies show that urea fertilization produces a rapid pulse of available nitrogen (N) with only a portion being utilized by plantation trees. Controlled release fertilizers release available N more slowly over a longer period of time and therefore may ...

  9. Effect of Different Nitrogen Fertilizer Application Strategies on Rice Growth and Yield

    Institute of Scientific and Technical Information of China (English)

    Dong JIA; Jingjing LU; Yajun SUN; Shuang SONG; Han DU; Lei HAN

    2016-01-01

    Nitrogen fertilizer is an important factor for crop production. The N application strategies named as former nitrogen moved backward( FNMB) are tested in three ecological regions to optimize the N application in rice. The dry matter accumulation and distribution,yield and quality are studied to understand the formation of yield and quality of rice under different N application strategies. The result indicates that former nitrogen moved backward( FNMB) can increase tiller number and dry matter accumulation; effective ears and yield can be increased with the increase of fertilization; rational nitrogen application can help to establish scientific group structure,harmonize yield component,and then achieve high ratio of input to output and benefit.

  10. The effect of nitrogen fertilization on the COS and CS2 emissions from temperature forest soils

    Science.gov (United States)

    Melillo, Jerry M.; Steudler, Paul A.

    1989-11-01

    The net fluxes of carbonyl sulfide (COS) and CS2 to the atmosphere from nitrogen amended and unamended deciduous and coniferous forest soils were measured during the spring of 1986. It was found that emissions of these gases from acidic forest soils were substantially increased after nitrogen fertilization. The total (COS + CS2) emissions were increased by nearly a factor of three in the hardwood stand and were more than doubled in the pine stand. Furthermore, vegetation type appeared to have an influence on which was the dominant sulfur gas released from the forest soils. The added nitrogen caused a dramatic increase in COS emissions from the hardwood stand (a factor of 3 increase), while CS2 emissions from this site were not affected. The opposite response was observed in the pine stand; that is, the nitrogen fertilization had no effect on COS emissions, but did stimulate CS2 emissions (a factor of more than 9 increase).

  11. Biochemical suitability of crop residues for cellulosic ethanol: disincentives to nitrogen fertilization in corn agriculture.

    Science.gov (United States)

    Gallagher, Morgan E; Hockaday, William C; Masiello, Caroline A; Snapp, Sieglinde; McSwiney, Claire P; Baldock, Jeffrey A

    2011-03-01

    Concerns about energy security and climate change have increased biofuel demand, particularly ethanol produced from cellulosic feedstocks (e.g., food crop residues). A central challenge to cropping for cellulosic ethanol is the potential environmental damage from increased fertilizer use. Previous analyses have assumed that cropping for carbohydrate in residue will require the same amount of fertilizer as cropping for grain. Using (13)C nuclear magnetic resonance, we show that increases in biomass in response to fertilization are not uniform across biochemical classes (carbohydrate, protein, lipid, lignin) or tissues (leaf and stem, grain, reproductive support). Although corn grain responds vigorously and nonlinearly, corn residue shows only modest increases in carbohydrate yields in response to high levels of fertilization (25% increase with 202 kg N ha(-1)). Lignin yields in the residue increased almost twice as much as carbohydrate yields in response to nitrogen, implying that residue feedstock quality declines as more fertilizer is applied. Fertilization also increases the decomposability of corn residue, implying that soil carbon sequestration becomes less efficient with increased fertilizer. Our results suggest that even when corn is grown for grain, benefits of fertilization decline rapidly after the ecosystem's N demands are met. Heavy application of fertilizer yields minimal grain benefits and almost no benefits in residue carbohydrates, while degrading the cellulosic ethanol feedstock quality and soil carbon sequestration capacity.

  12. Effect of Nitrogen Fertilizers on Movement and Transformation of Phosphorus in an Acid Soil

    Institute of Scientific and Technical Information of China (English)

    DU Zhen-Yu; ZHOU Jian-Min; WANG Huo-Yan; DU Chang-Wen; CHEN Xiao-Qin

    2005-01-01

    The effects of two different nitrogen fertilizers (urea and NH4Cl) with monocalcium phosphate (MCP) on the movement and transformation of fertilizer P in soil microsites along with soil pH changes at different distances from the fertilizer application site were studied in an incubation experiment. A highly acidic red soil (Ultisol, pH 4.57) from south China with MCP fertilizer alone or in combination with NH4Cl or urea was added to the surface of soil cylinders and packed in wax blocks. After 7 and 28 days, the extraction and analysis of each 2 mm layer from the interface of the soil and fertilizer showed that added NH4Cl or urea did not change the movement distance of fertilizer P. However, P transformation was significantly affected (P < 0.05). After 7 days, at 0-8 mm distance from the fertilizer site the addition of urea significantly decreased the water-extractable P concentration; however, after 28 days the effect of N addition had disappeared. Also,at limited distances close to the fertilizer site NH4Cl application with MCP significantly increased acid-extractable P and available P, while with the addition of urea they significantly decreased. Compared with application of MCP alone,addition of urea significantly increased soil pH in fertilizer microsites, whereas the addition of NH4Cl significantly decreased soil pH.

  13. The dynamics of nitrogen derived from a chemical nitrogen fertilizer with treated swine slurry in paddy soil-plant systems.

    Science.gov (United States)

    Lee, Joonhee; Choi, Hong L

    2017-01-01

    A well-managed chemical nitrogen (N) fertilization practice combined with treated swine slurry (TSS) is necessary to improve sustainability and N use efficiency in rice farming. However, little is known about the fate of N derived from chemical N fertilizer with and without TSS in paddy soil-plant systems. The objectives of this study were (1) to estimate the contribution of applied N fertilizer to N turnover in rice paddy soil with different N fertilization practices that were manipulated by the quantity of treated swine slurry and chemical N fertilizer (i.e., HTSS+LAS, a high amount of TSS with a low amount of ammonium sulfate; LTSS+HAS, a low amount of TSS with a high amount of ammonium sulfate; AS, ammonium sulfate with phosphorus and potassium; C, the control) and (2) to compare the rice response to applied N derived from each N fertilization practice. Rice biomass yield, 15N recovery in both rice grain and stems, soil total N (TN), soil inorganic N, and soil 15N recovery were analyzed. Similar amounts of 15N uptake by rice in the TSS+AS plots were obtained, indicating that the effects of the different quantities of TSS on chemical fertilizer N recovery in rice during the experimental period were not significant. The soil 15N recoveries of HTSS+LAS, LTSS+HAS, and AS in each soil layer were not significantly different. For the HTSS+LAS, LTSS+HAS and AS applications, total 15N recoveries were 42%, 43% and 54%, respectively. Because the effects of reducing the use of chemical N fertilizer were attributed to enhancing soil quality and cost-effectiveness, HTSS+LAS could be an appropriate N fertilization practice for improving the long-term sustainability of paddy soil-plant systems. However, N losses, especially through the coupled nitrification-denitrification process, can diminish the benefits that HTSS+LAS offers.

  14. Can the anaerobic potentially mineralizable nitrogen test improve predictions of fertilizer nitrogen rates in the Cornbelt?

    Science.gov (United States)

    Correctly estimating the amount of mineralizable nitrogen (N) can enhance nitrogen use efficiency. The anaerobic potentially mineralizable nitrogen (PMNAn) test is a tool that may help improve predictions of N uptake, grain yield, and the economical optimum nitrogen rate (EONR) of corn (Zea mays L...

  15. Determination of kjeldahl nitrogen in fertilizers by AOAC official methods 978.02: effect of copper sulfate as a catalyst.

    Science.gov (United States)

    Abrams, Dean; Metcalf, David; Hojjatie, Michael

    2014-01-01

    In AOAC Official Method 955.04, Nitrogen (Total) in Fertilizers, Kjeldahl Method, fertilizer materials are analyzed using mercuric oxide or metallic mercury HgO or Hg) as a catalyst. AOAC Official Methods 970.02, Nitrogen (Total) in Fertilizers is a comprehensive total nitrogen (including nitrate nitrogen) method adding chromium metal. AOAC Official Method 978.02, Nitrogen (Total) in Fertilizers is a modified comprehensive nitrogen method used to measure total nitrogen in fertilizers with two types of catalysts. In this method, either copper sulfate or chromium metal is added to analyze for total Kjeldahl nitrogen. In this study, the part of AOAC Official Method 978.02 that is for nitrate-free fertilizer products was modified. The objective was to examine the necessity of copper sulfate as a catalyst for the nitrate-free fertilizer products. Copper salts are not environmentally friendly and are considered pollutants. Products such as ammonium sulfate, diammonium phosphate, monoammonium phosphate, urea-containing fertilizers such as isobutylene diurea (IBDU), and urea-triazone fertilizer solutions were examined. The first part of the study was to measure Kjeldahl nitrogen as recommended by AOAC Official Method 978.02. The second part of the study was to exclude the addition of copper sulfate from AOAC Official Method 978.02 to examine the necessity of copper sulfate as a catalyst in nitrate-free fertilizers, which was the primary objective. Our findings indicate that copper sulfate can be eliminated from the method with no significant difference in the results for the nitrogen content of the fertilizer products.

  16. [Effects of nitrogen and phosphorus fertilizer on atrazine degradation and detoxification by degrading strain HB-5].

    Science.gov (United States)

    Su, Jun; Zhu, Lu-Sheng; Li, Xu-Hua; Wang, Jun; Xie, Hui; Wang, Jin-Hua; Wang, Qi; Jia, Wen-Tao

    2010-10-01

    An atrazine-degrading strain HB-5 was used as a bacteria for biodegradation. Treatments of soil with nitrogen single, phosphate single and nitrogen phosphate together with HB-5 were carried out for degradation and eco-toxicity test; then, relationship between atrazine degradation rate and soil available nitrogen, available phosphorus were discussed. Atrazine residues were determined by HPLC; available nitrogen was determined with alkaline hydrolysis diffusion method; available phosphorus was determined with 0.5 mol/L-NaHCO3 extraction and molybdenum stibium anti-color method, and toxicity test was carried out with micronucleus test of Vicia faba root tip cells. The results showed that: After separately or together application, nitrogenous and phosphorous fertilizers could significantly accelerate atrazine degradation than soil with HB-5 only. On day 5, the order of atrazine degradation was ANP > AP > AN > A; 7 days later, no statistically significant differences were found between treatments. The available nitrogen and phosphorus level in soil reduced as the degradation rate increased in the soil. The soil of eco-toxicity test results indicated that the eco-toxicity significantly reduced with the degradation of atrazine by HB-5, and the eco-toxicity on treatments of soil with fertilizer were all below the treatments without fertilizer. On day 5, the order of eco-toxicity was ANP atrazine degradation in soil but also could reduce the soil eco-toxicity effects that atrazine caused. All these results could be keystone of atrazine pollution remediation in contaminated soil in the future.

  17. Nitrogen fertilization in irrigated common bean at different times, with and without dose division

    Directory of Open Access Journals (Sweden)

    Danilo Pereira Ramos

    2014-03-01

    Full Text Available This article aims to evaluate the effect of nitrogen fertilization at different times on the agronomic characteristics of common bean cultivars, within the intercrop period. An experiment was installed in the town of Gurupi, Tocantins, Brazil, with randomized blocks, under a 3 x 5 factorial scheme, consisting of 3 cultivars and 5 nitrogen application times, with 4 repetitions. We evaluated the cultivars IAC Alvorada, IPR Juriti, and BRS Requinte. Regarding nitrogen fertilization, we evaluated 5 times, the first corresponding to control (E1 = N zero and the others applying 100 kg.ha-1 of nitrogen, using urea as their source, as follows: E2 = 100% of N applied at sowing; E3 = 100% of N applied 25 days after emergence (DAE; E4 = 50% of N applied 20 DAE and 50% 30 DAE; E5 = 33% of N applied 15 DAE, 33% 25 DAE, and 33% 35 DAE. There was genetic variability among cultivars with regard to response, as well as differences between nitrogen fertilization times. The cultivars IAC Alvorada and IPR Juriti obtained higher grain yields. The nitrogen application time divided into 15, 25 and 35 DAE enabled a higher grain yield for the cultivars IAC Alvorada and IPR Juriti.

  18. Effects of hand weeding strip and nitrogen fertilizer on corn plants.

    Science.gov (United States)

    da Silva, João Renato Vaz; Martins, Dagoberto; Cardoso, Leonildo A; Carbonari, Caio Antonio

    2005-01-01

    The objective of the present research was to evaluate effects of different strip weed control associated with nitrogen fertilizer on corn applied after planting. The experiment was set and conducted in Botucatu, São Paulo State, Brazil, and the hybrid planted was Dekalb 333-B. A completely randomized block design with four replications was used. Experimental plots were disposed as a factorial scheme 2 x 2 x 4, constituted by two types of weeding on row (with or without manual hoeing), two types of weeding on inter-row (with or without manual hoeing), and four nitrogen levels applied after planting (00, 60, 90, and 120 kg ha(-1)). Plots were composed by six rows with 5 m length. Nitrogen fertilizer was applied at 35 days after emergence (d.a.e). For weed community it was evaluated: weed density, dominancy, frequency, and relative importance. The main weed species were: Brachiaria plantiginea, Amaranthus retroflexus, Bidens pilosa, Cyperus rotunds, Brachiaria decumbens, Euphorbia heterofila, Oxalis latifolia, Acanthospermum hispidum, Commelina benghalensis. It was evaluated corn height at 40 and 100 d.a.e., first ear insertion height at 100 d.a.e., and final grain yield at harvesting. Plants and first ear insertion height were affected when nitrogen fertilizer was not applied. Treatments without weed control showed that weed interfered negatively with plants height. There were no correlation between weeds and nitrogen fertilizer for all parameters evaluated. Parcels without weed showed the highest ear weights and final grain production. Treatments that received nitrogen fertilizer, independently of studied arrangement, provided higher yields.

  19. The influence of nitrogen fertilization on the magnitude of rhizosphere effects

    Science.gov (United States)

    Zhu, B.; Panke-Buisse, K.; Kao-Kniffin, J.

    2012-12-01

    The labile carbon released from roots to the rhizosphere enhances soil microbial activity and nutrient availability, but factors that regulate such "rhizosphere effects" are poorly understood. Nitrogen fertilization may suppress rhizosphere effects by reducing plant carbon allocation belowground. Here we investigated the impact of nitrogen fertilization (+100 mg NH4NO3-N kg soil-1) on the magnitude of rhizosphere effects of two grass species (Bermuda grass Cynodon dactylon and smooth crabgrass Digitaria ischaemum) grown in a nutrient-poor soil for 80-100 days inside a growth chamber. Rhizosphere effects were estimated by the percentage difference between the planted soil (rhizosphere soil) and the unplanted soil (bulk soil) for several assays. We found that the rhizosphere soil of both plants had higher pH (+ 0.5~0.7 units), similar microbial biomass carbon, but lower microbial biomass nitrogen (- 27~37%) compared to the bulk soil. The rate of net N mineralization and the activity of three soil enzymes that degrade chitin (NAG), protein (LAP) and lignin (peroxidase) and produce mineral nitrogen were generally enhanced by the rhizosphere effects (up to 80%). Although nitrogen fertilization significantly increased plant biomass, it generally affected microbial biomass, activity and net N mineralization rate to a similar extent between rhizosphere soil and bulk soil, and thus did not significantly impact the magnitude of rhizosphere effects. Moreover, the community structure of soil bacteria (indicated by T-RFLP) showed remarkable divergence between the planted and unplanted soils, but not between the control and fertilized soils. Collectively, these results suggest that grass roots affects soil microbial activity and community structure, but short-term nitrogen fertilization may not significantly influence these rhizosphere effects.

  20. Wheat and Rice Growth Stages and Fertilization Regimes Alter Soil Bacterial Community Structure, But Not Diversity.

    Science.gov (United States)

    Wang, Jichen; Xue, Chao; Song, Yang; Wang, Lei; Huang, Qiwei; Shen, Qirong

    2016-01-01

    Maintaining soil fertility and the microbial communities that determine fertility is critical to sustainable agricultural strategies, and the use of different organic fertilizer (OF) regimes represents an important practice in attempts to preserve soil quality. However, little is known about the dynamic response of bacterial communities to fertilization regimes across crop growth stages. In this study, we examined microbial community structure and diversity across eight representative growth stages of wheat-rice rotation under four different fertilization treatments: no nitrogen fertilizer (NNF), chemical fertilizer (CF), organic-inorganic mixed fertilizer (OIMF), and OF. Quantitative PCR (QPCR) and high-throughput sequencing of bacterial 16S rRNA gene fragments revealed that growth stage as the best predictor of bacterial community abundance and structure. Additionally, bacterial community compositions differed between wheat and rice rotations. Relative to soils under wheat rotation, soils under rice rotation contained higher relative abundances (RA) of anaerobic and mesophilic microbes and lower RA of aerophilic microbes. With respect to fertilization regime, NNF plots had a higher abundance of nitrogen-fixing Cyanobacteria. OIMF had a lower abundance of ammonia-oxidizing Thaumarchaeota compared with CF. Application of chemical fertilizers (CF and OIMF treatments) significantly increased the abundance of some generally oligotrophic bacteria such those belonging to the Acidobacteria, while more copiotrophic of the phylum Proteobacteria increased with OF application. A high correlation coefficient was found when comparing RA of Acidobacteria based upon QPCR vs. sequence analysis, yet poor correlations were found for the α- and β- Proteobacteria, highlighting the caution required when interpreting these molecular data. In total, crop, fertilization scheme and plant developmental stage all influenced soil microbial community structure, but not total levels of alpha

  1. Long-term manure incorporation with chemical fertilizers reduced environmental nitrogen loss in rain-fed cropping systems

    Science.gov (United States)

    Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization in intensive farming systems are essential for sustainable agriculture and food security around the world. The objective of this study was to determine the long-term effects of various fertilization...

  2. Wheat and Rice Growth Stages and Fertilization Regimes Alter Soil Bacterial Community Structure, but Not Diversity

    Directory of Open Access Journals (Sweden)

    Jichen Wang

    2016-08-01

    Full Text Available Maintaining soil fertility and the microbial communities that determine fertility is critical to sustainable agricultural strategies, and the use of different organic fertilizer regimes represents an important practice in attempts to preserve soil quality. However, little is known about the dynamic response of bacterial communities to fertilization regimes across crop growth stages. In this study, we examined microbial community structure and diversity across eight representative growth stages of wheat-rice rotation under four different fertilization treatments: no nitrogen fertilizer (NNF, chemical fertilizer (CF, organic-inorganic mixed fertilizer (OIMF and organic fertilizer (OF. Quantitative PCR (QPCR and high-throughput sequencing of bacterial 16S rRNA gene fragments revealed that growth stage as the best predictor of bacterial community abundance and structure. Additionally, bacterial community compositions differed between wheat and rice rotations. Relative to soils under wheat rotation, soils under rice rotation contained higher relative abundances (RA of anaerobic and mesophilic microbes and lower RA of aerophilic microbes. With respect to fertilization regime, NNF plots had a higher abundance of nitrogen–fixing Cyanobacteria. OIMF had a lower abundance of ammonia-oxidizing Thaumarchaeota compared with CF. Application of chemical fertilizers (CF and OIMF treatments significantly increased the abundance of some generally oligotrophic bacteria such those belonging to the Acidobacteria, while more copiotrophic of the phylum Proteobacteria increased with organic fertilizer application. A high correlation coefficient was found when comparing RA of Acidobacteria based upon QPCR versus sequence analysis, yet poor correlations were found for the Alpha- and Beta- Proteobacteria, highlighting the caution required when interpreting these molecular data. In total, crop, fertilization scheme and plant developmental stage all influenced soil

  3. Nitrogen

    Science.gov (United States)

    Apodaca, Lori E.

    2013-01-01

    The article presents an overview of the nitrogen chemical market as of July 2013, including the production of ammonia compounds. Industrial uses for ammonia include fertilizers, explosives, and plastics. Other topics include industrial capacity of U.S. ammonia producers CF Industries Holdings Inc., Koch Nitrogen Co., PCS Nitrogen, Inc., and Agrium Inc., the impact of natural gas prices on the nitrogen industry, and demand for corn crops for ethanol production.

  4. Growth of bermudagrass with white clover or nitrogen fertilizer

    Science.gov (United States)

    White clover (Trifolium repens) var ‘Durana’ was oversown into established bermudagrass (Cynodon dactylon) in 2009. Soil analysis indicated potassium (K) was low and potash at 112 and 336 kg/ha was added as main plots. Nitrogen as ammonium nitrate or an ammonium sulfate/urea blend was added as 0, 34...

  5. Corn nitrogen fertilization rate tools compared over eight Midwest states

    Science.gov (United States)

    Publicly-available nitrogen (N) rate recommendation tools are utilized to help maximize yield in corn production. These tools often fail when N is over-applied and results in excess N being lost to the environment, or when N is under-applied and results in decreased yield and economic returns. Perfo...

  6. Male fertility potential alteration in rheumatic diseases: a systematic review

    Directory of Open Access Journals (Sweden)

    Bruno Camargo Tiseo

    2016-02-01

    Full Text Available ABSTRACT Background Improved targeted therapies for rheumatic diseases were developed recently resulting in a better prognosis for affected patients. Nowadays, patients are living longer and with improved quality of life, including fertility potential. These patients are affected by impaired reproductive function and the causes are often multifactorial related to particularities of each disease. This review highlights how rheumatic diseases and their management affect testicular function and male fertility. Materials and Methods A systematic review of literature of all published data after 1970 was conducted. Data was collected about fertility abnormalities in male patients with systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, ankylosing spondylitis, Behçet disease and gout. Two independent researchers carried out the search in online databases. Results A total of 19 articles were included addressing the following diseases: 7 systemic lupus erythematosus, 6 Behçet disease, 4 ankylosing spondylitis, 2 rheumatoid arthritis, 2 dermatomyositis and one gout. Systemic lupus erythematosus clearly affects gonadal function impairing spermatogenesis mainly due to antisperm antibodies and cyclophosphamide therapy. Behçet disease, gout and ankylosing spondylitis patients, including those under anti-TNF therapy in the latter disease, do not seem to have reduced fertility whereas in dermatomyositis, the fertility potential is hampered by disease activity and by alkylating agents. Data regarding rheumatoid arthritis is scarce, gonadal dysfunction observed as consequence of disease activity and antisperm antibodies. Conclusions Reduced fertility potential is not uncommon. Its frequency and severity vary among the different rheumatic diseases. Permanent infertility is rare and often associated with alkylating agent therapy.

  7. Cholesterol depletion disorganizes oocyte membrane rafts altering mouse fertilization.

    Directory of Open Access Journals (Sweden)

    Jorgelina Buschiazzo

    Full Text Available Drastic membrane reorganization occurs when mammalian sperm binds to and fuses with the oocyte membrane. Two oocyte protein families are essential for fertilization, tetraspanins and glycosylphosphatidylinositol-anchored proteins. The firsts are associated to tetraspanin-enriched microdomains and the seconds to lipid rafts. Here we report membrane raft involvement in mouse fertilization assessed by cholesterol modulation using methyl-β-cyclodextrin. Cholesterol removal induced: (1 a decrease of the fertilization rate and index; and (2 a delay in the extrusion of the second polar body. Cholesterol repletion recovered the fertilization ability of cholesterol-depleted oocytes, indicating reversibility of these effects. In vivo time-lapse analyses using fluorescent cholesterol permitted to identify the time-point at which the probe is mainly located at the plasma membrane enabling the estimation of the extent of the cholesterol depletion. We confirmed that the mouse oocyte is rich in rafts according to the presence of the raft marker lipid, ganglioside GM1 on the membrane of living oocytes and we identified the coexistence of two types of microdomains, planar rafts and caveolae-like structures, by terms of two differential rafts markers, flotillin-2 and caveolin-1, respectively. Moreover, this is the first report that shows characteristic caveolae-like invaginations in the mouse oocyte identified by electron microscopy. Raft disruption by cholesterol depletion disturbed the subcellular localization of the signal molecule c-Src and the inhibition of Src kinase proteins prevented second polar body extrusion, consistent with a role of Src-related kinases in fertilization via signaling complexes. Our data highlight the functional importance of intact membrane rafts for mouse fertilization and its dependence on cholesterol.

  8. Male fertility potential alteration in rheumatic diseases: a systematic review

    Science.gov (United States)

    Tiseo, Bruno Camargo; Cocuzza, Marcello; Bonfá, Eloisa; Srougi, Miguel; Clovis, A

    2016-01-01

    ABSTRACT Background Improved targeted therapies for rheumatic diseases were developed recently resulting in a better prognosis for affected patients. Nowadays, patients are living longer and with improved quality of life, including fertility potential. These patients are affected by impaired reproductive function and the causes are often multifactorial related to particularities of each disease. This review highlights how rheumatic diseases and their management affect testicular function and male fertility. Materials and Methods A systematic review of literature of all published data after 1970 was conducted. Data was collected about fertility abnormalities in male patients with systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, ankylosing spondylitis, Behçet disease and gout. Two independent researchers carried out the search in online databases. Results A total of 19 articles were included addressing the following diseases: 7 systemic lupus erythematosus, 6 Behçet disease, 4 ankylosing spondylitis, 2 rheumatoid arthritis, 2 dermatomyositis and one gout. Systemic lupus erythematosus clearly affects gonadal function impairing spermatogenesis mainly due to antisperm antibodies and cyclophosphamide therapy. Behçet disease, gout and ankylosing spondylitis patients, including those under anti-TNF therapy in the latter disease, do not seem to have reduced fertility whereas in dermatomyositis, the fertility potential is hampered by disease activity and by alkylating agents. Data regarding rheumatoid arthritis is scarce, gonadal dysfunction observed as consequence of disease activity and antisperm antibodies. Conclusions Reduced fertility potential is not uncommon. Its frequency and severity vary among the different rheumatic diseases. Permanent infertility is rare and often associated with alkylating agent therapy. PMID:27120778

  9. [Effects of organic-inorganic mixed fertilizers on rice yield and nitrogen use efficiency].

    Science.gov (United States)

    Zhang, Xiao-li; Meng, Lin; Wang, Qiu-jun; Luo, Jia; Huang, Qi-wei; Xu, Yang-chun; Yang, Xing-ming; Shen, Qi-rong

    2009-03-01

    A field experiment was carried to study the effects of organic-inorganic mixed fertilizers on rice yield, nitrogen (N) use efficiency, soil N supply, and soil microbial diversity. Rapeseed cake compost (RCC), pig manure compost (PMC), and Chinese medicine residue compost (MRC) were mixed with chemical N, P and K fertilizers. All the treatments except CK received the same rate of N. The results showed that all N fertilizer application treatments had higher rice yield (7918.8-9449.2 kg x hm(-2)) than the control (6947.9 kg x hm(-2)). Compared with that of chemical fertilizers (CF) treatment (7918.8 kg x hm(-2)), the yield of the three organic-inorganic mixed fertilizers treatments ranged in 8532.0-9449.2 kg x hm(-2), and the increment was 7.7%-19.3%. Compared with treatment CF, the treatments of organic-inorganic mixed fertilizers were significantly higher in N accumulation, N transportation efficiency, N recovery rate, agronomic N use efficiency, and physiological N use efficiency. These mixed fertilizers treatments promoted rice N uptake and improved soil N supply, and thus, increased N use efficiency, compared with treatments CF and CK. Neighbor joining analysis indicated that soil bacterial communities in the five treatments could be classified into three categories, i.e., CF and CK, PMC and MRC, and RCC, implying that the application of exogenous organic materials could affect soil bacterial communities, while applying chemical fertilizers had little effect on them.

  10. Effect of Nitrogenous Fertilizer Treatment on Mineral Metabolism in Grazing Yaks

    Institute of Scientific and Technical Information of China (English)

    SHEN Xiao-yun

    2009-01-01

    To assess the impact of N fertilization on contents of mineral elements in herbage and the effect of increased forage S on the copper metabolism of grazing yaks, study was conducted during the summer grazing season (2005, 2006, and 2007). Pasture replicates (20 ha; n=3 per treatment) received the same fertilizer treatment in each growing season, consisting of i) 90 kg N ha-1 from quickly available nitrogen, ii) 90 kg N ha-! from ammonium nitrate, iii) 90 kg N ha-1 from ammonium sulfate, and iv) control (nofertilizer). Forage sampling was collected at 60 days intervals following fertilization (10 samples per pasture) for Cu, Mo, Mn,Se, Fe, Zn, Ca, and E To determine the effect of fertilizer treatment on mineral metabolism in grazing yaks, liver and blood samples were collected at the start and end of the study period in 2005, 2006, and 2007. Ammonium sulfate fertilization increased (P< 0.01) forage S concentration. Plant tissue N concentrations were increased by N fertilization, regardless of source in 2005, 2006, and 2007. Yaks grazing S fertilization pastures had lower (P<0.05) liver and blood Cu concentrations at the end of the study period in 2005, 2006, and 2007, compared with urea, ammonium nitrate, and control. Nominal increases in forage in vitro organic matter digestibility were realized by fertilization, regardless of N source in each year.

  11. The effects of nitrogen fertilization on N2O emissions from a rubber plantation

    Science.gov (United States)

    Zhou, Wen-Jun; Ji, Hong-Li; Zhu, Jing; Zhang, Yi-Ping; Sha, Li-Qing; Liu, Yun-Tong; Zhang, Xiang; Zhao, Wei; Dong, Yu-Xin; Bai, Xiao-Long; Lin, You-Xin; Zhang, Jun-Hui; Zheng, Xun-Hua

    2016-06-01

    To gain the effects of N fertilizer applications on N2O emissions and local climate change in fertilized rubber (Hevea brasiliensis) plantations in the tropics, we measured N2O fluxes from fertilized (75 kg N ha-1 yr-1) and unfertilized rubber plantations at Xishuangbanna in southwest China over a 2-year period. The N2O emissions from the fertilized and unfertilized plots were 4.0 and 2.5 kg N ha-1 yr-1, respectively, and the N2O emission factor was 1.96%. Soil moisture, soil temperature, and the area weighted mean ammoniacal nitrogen (NH4+-N) content controlled the variations in N2O flux from the fertilized and unfertilized rubber plantations. NH4+-N did not influence temporal changes in N2O emissions from the trench, slope, or terrace plots, but controlled spatial variations in N2O emissions among the treatments. On a unit area basis, the 100-year carbon dioxide equivalence of the fertilized rubber plantation N2O offsets 5.8% and 31.5% of carbon sink of the rubber plantation and local tropical rainforest, respectively. When entire land area in Xishuangbanna is considered, N2O emissions from fertilized rubber plantations offset 17.1% of the tropical rainforest’s carbon sink. The results show that if tropical rainforests are converted to fertilized rubber plantations, regional N2O emissions may enhance local climate warming.

  12. Foliar Spray of Nitrogen Fertilizer on Raised Bed Increases Yield of Transplanted Aman Rice over Conventional Method

    OpenAIRE

    M. H. M. Bhuyan; Mst. R. Ferdousi; Iqbal, M. T.

    2012-01-01

    Bed planting with foliar nitrogen fertilizer application of rice production systems is very new, and research on it is still at introductory phase. Influence of foliar application of nitrogen fertilizer on growth and yield of transplanted aman rice and evaluation of water and fertilizer application efficiency of rice-fallow-rice cropping system were investigated under raised bed cultivation method. Results showed that foliar spray in bed planting method increased grain yield of transplanted a...

  13. Winter triticale response to nitrogen fertilization when grown after corn or soybean

    Science.gov (United States)

    Winter triticale (XTriticosecale Wittmack) could be more widely grown as a forage, grain, or cover crop in the U.S. Corn and Soybean Belt, but research needed to establish best management practices is limited. This study was conducted to determine the amount of nitrogen (N) fertilizer needed to opti...

  14. Bud Necrosis of Green Ash Nursery Trees is Influenced by Nitrogen Availability and Fertilizer Type

    Science.gov (United States)

    A study was conducted to determine whether nitrogen (N) status of nursery-grown green ash (Fraxinus pennsylvanica ‘Summit’) trees in the autumn is related to tip die back during the following spring. In 2005, different rates of N from either urea formaldehyde (UF) or a controlled release fertilizer ...

  15. Growth of tropical legume cover crops as influenced by nitrogen fertilization and Rhizobia

    Science.gov (United States)

    Tropical legume cover crops are important components in cropping systems due to their role in improving soil quality. Information is limited on the influence of nitrogen (N) fertilization on growth of tropical legume cover crops grown on Oxisols. A greenhouse experiment was conducted to evaluate the...

  16. Accounting for residual effects of previously applied nitrogen fertilizer on intensively managed grasslands

    NARCIS (Netherlands)

    Vellinga, Th.V.; Andre, G.; Schils, R.L.M.; Kraak, T.; Oenema, O.

    2010-01-01

    Only 0·20–0·70 of the fertilizer-nitrogen (N) applied to grassland is taken up in herbage in the harvest directly following application. Residual effects at subsequent harvests can be large but are poorly quantified, and rarely taken into account in current management practices. An increased

  17. Performance of low-input turfgrass species as affected by mowing and nitrogen fertilization in Minnesota

    Science.gov (United States)

    In Minnesota, most lawns and higher cut turfgrass areas consist primarily of species such as Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.) that require significant management inputs such as frequent mowing and nitrogen fertility. Several studies have shown that oth...

  18. Maize stover and cob cell wall composition and ethanol potential as affected by nitrogen fertilization

    Science.gov (United States)

    Maize (Zea mays L.) stover and cobs are potential feedstock sources for cellulosic ethanol production. Nitrogen (N) fertilization is an important management decision that influences cellulosic biomass and grain production, but its effect on cell wall composition and subsequent cellulosic ethanol pro...

  19. Public-private partnering for improving performance of corn nitrogen fertilization tools

    Science.gov (United States)

    Nitrogen fertilization for corn production is complicated by soil and weather variability, yet such has far-reaching economic and environmental implications. To address this challenge, alternative N management strategies have been explored extensively in recent years for determining the most consist...

  20. [Response of black soil organic carbon, nitrogen and its availability to longterm fertilization].

    Science.gov (United States)

    Luo, Kun; Hu, Rong-Gui; Zhang, Wen-Ju; Zhou, Bao-Ku; Xu, Ming-Gang; Zhang, Jing-Ye; Xia, Ping-Ping

    2013-02-01

    Based on the long-term fertilization experiments, effects of various fertilization practices on the soil organic carbon (SOC) and total nitrogen (TN) in the surface (0-20 cm) and subsurface (20-40 cm) black soil in northeast China were studied. Results showed that, compared with the CK, long-term application of organic manure, especially the combination of mineral fertilizers and organic manure significantly increased the organic SOC and TN in the surface soil. Application of mineral fertilizers plus organic manure with conventional (NPM) and high application (N2P2M2) rate increased SOC significantly by 24. 6% and 25.1% , and TN by 29.5% and 32.8%, respectively. However, there was no significant difference among the treatments for SOC and TN at the subsurface. Compared with the CK (CKh), mineral fertilizer plus organic manure (NPM and N2P2M2) did not only increase the soil microbial biomass carbon (SMBC) and nitrogen (SMBN) , dissolved organic carbon (DOC) and nitrogen (DN), but also significantly increased the ratio of SMBC and DOC to SOC, SMBN and TN to TN. Application of the NPM and N2P2M2 increased the value of SMBC/SOC by 0.36 to 0.59 and SMBN/TN by 1.21 to 1.95 percentage points, respectively. The value of DOC/SOC and DN/TN ranged from 0.53% to 0.72% and 1.41% to 1.78%, respectively. This result indicated that SMBC, SMBN, DOC, DN and SMBC/ SOC, SMBN/TN, DOC/SOC, DN/TN were more sensitive than SOC and TN to long-term fertilization in the soil profile, and were better indicators for the impact of long-term fertilization soil fertility. The concluded that the application of manure especially manure plus mineral fertilizers can increase soil nutrients activity in the surface and subsurface black soil, acting as a helpful practice to improve soil fertility and the ability of nutrient supply, while it may cause potential environment pollution on carbon and nitrogen loss in the agroecosystem.

  1. [Effects of fertilization method and nitrogen application rate on soil nitrogen vertical migration in a Populus xeuramericana cv. 'Guariento' plantation].

    Science.gov (United States)

    Dai, Teng-fei; Xi, Ben-ye; Yan, Xiao-li; Jia, Li-ming

    2015-06-01

    A field experiment was conducted to investigate the effects of fertilization methods, i.e., drip (DF) and furrow fertilization (GF), and nitrogen (N) application rates (25, 50, 75 g N · plant(-1) · time(-1)) on the dynamics of soil N vertical migration in a Populus x euramericana cv. 'Guariento' plantation. The results showed that soil NH4(+)-N and NO3(-)-N contents decreased with the increasing soil depth under different fertilization methods and N application rates. In the DF treatment, soil NH4(+)-N and NO3(-)-N were mainly concentrated in the 0-40 cm soil layer, and their contents ascended firstly and then descended, reaching their maximum values at the 5th day (211.1 mg · kg(-1)) and 10th day (128.8 mg · kg(-1)) after fertilization, respectively. In the GF treatment, soil NH4(+)-N and NO3(-)-N were mainly concentrated in the 0-20 cm layer, and the content of soil NO3(-)-N rose gradually and reached its maximum at the 20th day (175.7 mg · kg(-1)) after fertilization, while the NH4(+)-N content did not change significantly after fertilization. Overall, N fertilizer had an effect within 20 days in the DF treatment, and more than 20 days in the GF treatment. In the DF treatment, the content and migration depth of soil NH4(+)-N and NO3(-)-N increased with the N application rate. In the GF treatment, the NO3(-)-N content increased with the N application rate, but the NH4(+)-N content was not influenced. Under the DF treatment, the hydrolysis rate, nitrification rate and migration depth of urea were higher or larger than that under the GF treatment, and more N accumulated in deep soil as the N application rate increased. Considering the distribution characteristics of fine roots and soil N, DF would be a better fertilization method in P. xeuramericana cv. 'Guariento' plantation, since it could supply N to larger distribution area of fine roots. When the N application rate was 50 g · tree(-1) each time, nitrogen mainly distributed in the zone of fine roots and

  2. Variations in the Use of Resources for Food: Land, Nitrogen Fertilizer and Food Nexus

    Directory of Open Access Journals (Sweden)

    María José Ibarrola-Rivas

    2016-12-01

    Full Text Available Future dietary changes will increase the global demand for agricultural resources per person. Food production requires several resources which are interrelated: land, water, nutrients and energy. Other studies have calculated the per capita requirements of only one resource (nitrogen or land. In this paper, we combine several parameters (diets, production systems and nitrogen-land trade-off in one analysis in order to provide a more integrated assessment of the impacts of the use of agricultural resources for food. We estimated the trade-off between the per capita use of synthetic nitrogen fertilizer and crop land. With our methodology, we are able to identify separately the impacts of the type of diet and of the type of production system. We use national level data of five countries as examples of global extremes: from extensive to highly intensive systems, and from very basic diets to very affluent diets. The present differences in diets and production systems result in large differences in the per capita use of resources which ranges from 3 to 30 kg of nitrogen fertilizer use per person, and from 1800 to 4500 m2 of arable land use per person. As the results show, in 2050, the average per capita availability of crop land will not be enough to produce food for affluent diets with present production systems. Our results are useful to assess future requirements of nitrogen fertilizer for the limited land available on the planet.

  3. Characteristics and Performance of Novel Water-Absorbent Slow Release Nitrogen Fertilizers

    Institute of Scientific and Technical Information of China (English)

    HE Xu-sheng; LIAO Zong-wen; HUANG Pei-zhao; DUAN Ji-xian; GE Ren-shan; LI Hong-bo; GENG Zeng-chao

    2007-01-01

    In this article, a research on the characteristics and performance of water-absorbent slow release nitrogen fertilizer (WASRNF)using infrared spectroscopy (IR), scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA), was present. The results indicate that the water absorbency and nitrogen analysis of WASRNF is 103 g g-1 and 30%, respectively, and WASRNF exhibits approximately neutral pH and very low salt index.WASRNF is a copolymer of nitrogen fertilizer and super absorbent polymer (SAP) monomers which is formed through hydrogen bond interaction, and the molecule contains hydrophilic groups, which is responsible for the absorption and water retention capacity of the molecule. WASRNF is a gel that exhibits the ability to swell, but does not dissolve in water.WASRNF shows non-homogenous nature as a whole, but in local zone it is homogenous, the copolymer molecule shows chain network that is the physical structure responsible for absorption and retention of water in WASRNF. The water retained in WASRNF exists as free and nonfreezing bound and freezing bound water states, with the free and the nonfreezing water accounting for more than 95% of water retained in WASRNF, and the nonfreezing bound water for less than 5%. WASRNF functions in delaying the release of nitrogen from it, thereby serving a novel slow release nitrogenous fertilizer.

  4. Effect Of Different Nitrogen Fertilization Levels On Yield Of Maize Zea Mays L. As Winter Forage

    Directory of Open Access Journals (Sweden)

    Rihab M. El Zubair

    2015-08-01

    Full Text Available Abstract The study was conducted for two consecutive seasons 20102011 and 20112012 at the Demonstration Farm of the college of Forestry and Range Sciences Sudan University of Science and Technology Soba Khartoum .the aims of this study was to evaluate the effect of nitrogen fertilization levels on forage maize as a potential winter crop in central Sudan in terms on biomass yield. Three nitrogen fertilization levels were examined. The treatments were arranged in a Randomized Complete Block Design RCBD with four replicates. Parameters studied were plant density plant fresh weight g plant dry weight g and forage yield tonsha. Results obtained reveal that application did not significant affect forage plant density. Application of nitrogen increase fresh and dry weight per plant in all counts .fresh forage yield in terms of fresh forage and dry matter production was significantly increased with application of nitrogen .It was concluded that application of nitrogen fertilizer increase yield of forage maze during the winter season in central Sudan.

  5. Effects of Fertilizer Nitrogen on Short-Term Nitrogen Loss in Bypass Flow in a Vertisol

    NARCIS (Netherlands)

    Sigunga, D.O.; Janssen, B.H.; Oenema, O.

    2008-01-01

    Bypass flow, the vertical flow of free water along the walls of macropores or preferential flow paths in the soil, can lead to movement of fertilizer nutrients beyond the reach of plants. Fertilizer type and the rate of application, as well as the amount, frequency, and intensity of rainfall, can in

  6. Tillage, cropping sequence, and nitrogen fertilization influence dryland soil nitrogen dynamics

    Science.gov (United States)

    Management practices are needed to reduce dryland N losses through N leaching and N2O emissions (a greenhouse gas) by increasing soil N storage and reducing N fertilization rate without influencing crop yields. The effects of tillage and cropping sequence combination and N fertilization rate were st...

  7. In Winter Wheat, No-Till Increases Mycorrhizal Colonization thus Reducing the Need for Nitrogen Fertilization

    Directory of Open Access Journals (Sweden)

    Julien Verzeaux

    2016-06-01

    Full Text Available Arbuscular mycorrhizal fungi (AMF play a major role in the uptake of nutrients by agricultural plants. Nevertheless, some agricultural practices can interrupt fungal-plant signaling and thus impede the establishment of the mycorrhizal symbiosis. A field experiment performed over a 5-year period demonstrated that both the absence of tillage and of nitrogen (N fertilization improved AMF colonization of wheat roots. Moreover, under no-till conditions, N uptake and aboveground biomass production did not vary significantly between N-fertilized and N-unfertilized plots. In contrast, both N uptake and above ground biomass were much lower when N fertilizer was not added during conventional tillage. This finding strongly suggests that for wheat, no-till farming is a sustainable agricultural system that allows a gradual reduction in N fertilizer use by promoting AMF functionality and at the same time increasing N uptake.

  8. Recovery of nitrogen fertilizer by traditional and improved rice cultivars in the Bhutan Highlands

    DEFF Research Database (Denmark)

    Ghaley, Bhim Bahadur; Høgh-Jensen, Henning; Christiansen, Jørgen Lindskrog

    2010-01-01

    The recovery of soil derived nitrogen (NDFS) and fertilizer N (NDFF) was investigated in highland rice (Oryza sativa L.) fields in Bhutan, characterized by high inputs of farmyard manure (FYM). The effect of 60 kg N ha-1 (60 N) applied in two splits to a traditional and an improved cultivar...... greater harvest index (HI). The mean percentage recovery of fertilizer N (REN) applied at 45 days after transplanting (DAT) was 34% compared to 22% at 7 DAT, resulting in 56% greater uptake of NDFF at 45 DAT. The overall REN for both the improved and the traditional cultivars were 25.7% and 30......% respectively, with no difference between cultivars, but REN decreased with increasing FYM inputs. Fertilizer N recommendations that allow for previous FYM inputs combined with applications timed to coincide with maximum crop demand (45 DAT), and the use of improved cultivars, could enhance N fertilizer...

  9. Effect of plant growth promoting rhizobacteria (PGPR application, nitrogen and zinc sulphate fertilizer on yield and nitrogen uptake in rapeseed (Brassica napus L.

    Directory of Open Access Journals (Sweden)

    N. Jafari

    2016-05-01

    Full Text Available In order to study the effects of simultaneous application of ZnSO4 and biological fertilizer, Azotobacter chroococcum and Azospirillum brasilense, on grain yield and nitrogen uptake efficiency in rapeseed (Brassica napus L., cv. Hyola308, a field experiment was conducted as split plot factorial based on randomized complete block design at research field of Faculty of Agricultural Sciences, University of Guilan, Iran, during growing season of 2007-2008. Results showed that urea fertilizer, ZnSO4 fertilizer and biological fertilizer had significant effects on nitrogen uptake and accumulation. Maximum grain yield (2568 kg.ha-1 were obtained in 150kgN + ZnSO4+ bio treatment. Maximum accumulation of nitrogen in rosette stage (4.9% and nitrogen content of grain (3.6% was obtained in 150 kg N.ha-1N + ZnSO4 + bio. Maximum Nitrogen uptake efficiency and nitrogen use efficiency (0.86 and 29.56 kg.kg-1, respectively were obtained in 50 kgN.ha-1N + ZnSO4 + bio. In regard to significant effects of ZnSO4 and biological fertilizer with lower N rate and high nitrogen uptake efficiency of rapeseed, it seems that the ability of uptake and use of nitrogen fertilizers was greater for seed formation in the presence of ZnSO4 and biological fertilizer in rapeseed, cv. Hyola308. The most important of mechanisms of PGPRs is increase the bioavailability of mineral nutrients with biological nitrogen fixation and soluble phosphorus and potassium that lead to economize nitrogen fertilizer in rapeseed production and minimizing environmental pollution risk.

  10. Nitrogen Fertilization Effects on Productivity and Nitrogen Loss in Three Grass-Based Perennial Bioenergy Cropping Systems.

    Science.gov (United States)

    Duran, Brianna E L; Duncan, David S; Oates, Lawrence G; Kucharik, Christopher J; Jackson, Randall D

    2016-01-01

    Nitrogen (N) fertilization can greatly improve plant productivity but needs to be carefully managed to avoid harmful environmental impacts. Nutrient management guidelines aimed at reducing harmful forms of N loss such as nitrous oxide (N2O) emissions and nitrate (NO3(-)) leaching have been tailored for many cropping systems. The developing bioenergy industry is likely to make use of novel cropping systems, such as polycultures of perennial species, for which we have limited nutrient management experience. We studied how a switchgrass (Panicum virgatum) monoculture, a 5-species native grass mixture and an 18-species restored prairie responded to annual fertilizer applications of 56 kg N ha(-1) in a field-scale agronomic trial in south-central Wisconsin over a 2-year period. We observed greater fertilizer-induced N2O emissions and sub-rooting zone NO3(-) concentrations in the switchgrass monoculture than in either polyculture. Fertilization increased aboveground net primary productivity in the polycultures, but not in the switchgrass monoculture. Switchgrass was generally more productive, while the two polycultures did not differ from each other in productivity or N loss. Our results highlight differences between polycultures and a switchgrass monoculture in responding to N fertilization.

  11. Effects of single basal application of coated compound fertilizer on yield and nitrogen use efficiency in double-cropped rice

    OpenAIRE

    Jiana Chen; Fangbo Cao; Hairong Xiong; Min Huang; Yingbin Zou; Yuanfu Xiong

    2017-01-01

    Fertilizer plays an important role in increasing rice yield. More than half of all fertilizer applied to the field is not taken up, resulting in environmental damage and substantial economic losses. To address these concerns, a low-cost, coated compound fertilizer named “Xiang Nong Da” (XND), requiring only a single basal application, was studied. A two-year field experiment was conducted to test the effects of XND application on rice yield and nitrogen fertilizer use efficiency. An ordinary ...

  12. Bedrock nitrogen inputs support litter nitrogen fixation and temperate forest ecosystem fertility

    Science.gov (United States)

    Dynarski, K. A.; Mitchell, S. A.; Morford, S.; Houlton, B. Z.

    2015-12-01

    Nitrogen (N) is one of the most frequently limiting nutrients to terrestrial ecosystem productivity worldwide. As atmospheric carbon dioxide concentrations continue to rise, progressive N limitation is expected to constrain the ability of terrestrial ecosystems to store additional C, making an understanding of N inputs to terrestrial ecosystems increasingly important. In temperate forests, rock reservoirs and biological N fixation (BNF) represent two significant, but poorly characterized, inputs of bioavailable N. Recent research has demonstrated that bedrock can provide a substantial amount of ecosystem-available N in moderate-to-high relief areas with N-rich sedimentary bedrock. In these same ecosystems, asymbiotic BNF performed by heterotrophic microbes in plant litter can provide an additional N input of up to ~2 kg N ha-1 yr-1. Here, we tested the hypothesis that rock N inputs support increased litter BNF via enhanced ecosystem N fertility. We measured rates of BNF along with rock, soil, foliage, and litter chemistry across sites varying substantially in rock N concentrations (from 32 to 800 ppm N). The sites are dominated by Douglas fir and share similar climates and landscape positions (eroding slopes), yet display marked increases in foliar and soil N content as a function of rock N concentrations (foliar: R2=0.18, p<0.001, soil: R2=0.50, p=0.001). We found a significant positive correlation between rock N content and litter BNF rates (R2=0.11, p=0.0035), with rates of BNF at sites with greater than 400 ppm N in bedrock more than double rates of BNF at sites with lower than 400 ppm N in bedrock (p<0.001). These patterns could not be explained by increases in other rock-derived nutrients such as phosphorus or molybdenum, as neither of these known BNF controls increased over the rock N gradient. We found declining foliar lignin:N ratios with increased rock N, suggesting that rock N inputs can increase litter quality, supporting greater microbial activity

  13. Nitrogen fertilization and root growth dynamics of durum wheat for a sustainable production

    Directory of Open Access Journals (Sweden)

    Donato De Giorgio

    2012-07-01

    Full Text Available In an area of the Apulian Tavoliere (southern Italy, the effects of three levels of nitrogen fertilization (0, 50 and 100 kg N ha–1 on root development, growth analysis and yield parameters of durum wheat were evaluated. The research was conducted over a four-year period (1994-97. The non-destructive mini-rhizotron method was used to study the root system at stem extension and at the beginning of heading and ripening stages. At the end of tillering and at boot and flowering stages, samples of wheat biomass were taken and subjected to growth analysis. Yield data and the main biometric parameters were collected at harvest time. The doses of nitrogen (N fertilizer 50 and 100 kg N ha–1 had a greater effect on root development in the 20-30 cm soil layer and on epigeal biomass than the control test (N0 without nitrogen fertilization. In the test (N0 the growth of root and epigeal biomass was slower during the first vegetative phases, however, afterwards both of them recovered and the root system was mainly developed in the 30-40 cm soil layer. A better development of root system in deeper soil layers, without nitrogen supply, has allowed the plant to overcome more easily the water-deficit and thermal stresses during the ripening stage. The results of this research have shown that the production of grain with 50 kg ha–1 of N is similar to those of 100 kg ha–1 of N doses and higher than the test without nitrogen fertilization. In this kind of environment can be recommended a nitrogen dose of 50 kg ha–1 for obtaining an increase in grain production with low costs and reduced agricultural sources of pollution.

  14. Efficiency of nitrogen fertilizer applied at corn sowing in contrasting growing seasons in Paraguay

    Directory of Open Access Journals (Sweden)

    Telmo Jorge Carneiro Amado

    2013-12-01

    Full Text Available In order to select soil management practices that increase the nitrogen-use efficiency (NUE in agro-ecosystems, the different indices of agronomic fertilizer efficiency must be evaluated under varied weather conditions. This study assessed the NUE indices in no-till corn in southern Paraguay. Nitrogen fertilizer rates from 0 to 180 kg ha-1 were applied in a single application at corn sowing and the crop response investigated in two growing seasons (2010 and 2011. The experimental design was a randomized block with three replications. Based on the data of grain yield, dry matter, and N uptake, the following fertilizer indices were assessed: agronomic N-use efficiency (ANE, apparent N recovery efficiency (NRE, N physiological efficiency (NPE, partial factor productivity (PFP, and partial nutrient balance (PNB. The weather conditions varied largely during the experimental period; the rainfall distribution was favorable for crop growth in the first season and unfavorable in the second. The PFP and ANE indices, as expected, decreased with increasing N fertilizer rates. A general analysis of the N fertilizer indices in the first season showed that the maximum rate (180 kg ha-1 obtained the highest corn yield and also optimized the efficiency of NPE, NRE and ANE. In the second season, under water stress, the most efficient N fertilizer rate (60 kg ha-1 was three times lower than in the first season, indicating a strong influence of weather conditions on NUE. Considering that weather instability is typical for southern Paraguay, anticipated full N fertilization at corn sowing is not recommended due the temporal variability of the optimum N fertilizer rate needed to achieve high ANE.

  15. Effects of combined application of organic and inorganic fertilizers plus nitrification inhibitor DMPP on nitrogen runoff loss in vegetable soils.

    Science.gov (United States)

    Yu, Qiaogang; Ma, Junwei; Zou, Ping; Lin, Hui; Sun, Wanchun; Yin, Jianzhen; Fu, Jianrong

    2015-01-01

    The application of nitrogen fertilizers leads to various ecological problems such as large amounts of nitrogen runoff loss causing water body eutrophication. The proposal that nitrification inhibitors could be used as nitrogen runoff loss retardants has been suggested in many countries. In this study, simulated artificial rainfall was used to illustrate the effect of the nitrification inhibitor DMPP (3,4-dimethyl pyrazole phosphate) on nitrogen loss from vegetable fields under combined organic and inorganic nitrogen fertilizer application. The results showed that during the three-time simulated artificial rainfall period, the ammonium nitrogen content in the surface runoff water collected from the DMPP application treatment increased by 1.05, 1.13, and 1.10 times compared to regular organic and inorganic combined fertilization treatment, respectively. In the organic and inorganic combined fertilization with DMPP addition treatment, the nitrate nitrogen content decreased by 38.8, 43.0, and 30.1% in the three simulated artificial rainfall runoff water, respectively. Besides, the nitrite nitrogen content decreased by 95.4, 96.7, and 94.1% in the three-time simulated artificial rainfall runoff water, respectively. A robust decline in the nitrate and nitrite nitrogen surface runoff loss could be observed in the treatments after the DMPP addition. The nitrite nitrogen in DMPP addition treatment exhibited a significant low level, which is near to the no fertilizer application treatment. Compared to only organic and inorganic combined fertilizer treatment, the total inorganic nitrogen runoff loss declined by 22.0 to 45.3% in the organic and inorganic combined fertilizers with DMPP addition treatment. Therefore, DMPP could be used as an effective nitrification inhibitor to control the soil ammonium oxidation in agriculture and decline the nitrogen runoff loss, minimizing the nitrogen transformation risk to the water body and being beneficial for the ecological environment.

  16. New technologies reduce greenhouse gas emissions from nitrogenous fertilizer in China.

    Science.gov (United States)

    Zhang, Wei-Feng; Dou, Zheng-Xia; He, Pan; Ju, Xiao-Tang; Powlson, David; Chadwick, Dave; Norse, David; Lu, Yue-Lai; Zhang, Ying; Wu, Liang; Chen, Xin-Ping; Cassman, Kenneth G; Zhang, Fu-Suo

    2013-05-21

    Synthetic nitrogen (N) fertilizer has played a key role in enhancing food production and keeping half of the world's population adequately fed. However, decades of N fertilizer overuse in many parts of the world have contributed to soil, water, and air pollution; reducing excessive N losses and emissions is a central environmental challenge in the 21st century. China's participation is essential to global efforts in reducing N-related greenhouse gas (GHG) emissions because China is the largest producer and consumer of fertilizer N. To evaluate the impact of China's use of N fertilizer, we quantify the carbon footprint of China's N fertilizer production and consumption chain using life cycle analysis. For every ton of N fertilizer manufactured and used, 13.5 tons of CO2-equivalent (eq) (t CO2-eq) is emitted, compared with 9.7 t CO2-eq in Europe. Emissions in China tripled from 1980 [131 terrogram (Tg) of CO2-eq (Tg CO2-eq)] to 2010 (452 Tg CO2-eq). N fertilizer-related emissions constitute about 7% of GHG emissions from the entire Chinese economy and exceed soil carbon gain resulting from N fertilizer use by several-fold. We identified potential emission reductions by comparing prevailing technologies and management practices in China with more advanced options worldwide. Mitigation opportunities include improving methane recovery during coal mining, enhancing energy efficiency in fertilizer manufacture, and minimizing N overuse in field-level crop production. We find that use of advanced technologies could cut N fertilizer-related emissions by 20-63%, amounting to 102-357 Tg CO2-eq annually. Such reduction would decrease China's total GHG emissions by 2-6%, which is significant on a global scale.

  17. [Effects of long-term fertilization on soil organic nitrogen components in paddy soil derived from red earth].

    Science.gov (United States)

    Zong, Hai-ying; Wang, Kai-rong; Xie, Xiao-li

    2008-08-01

    A 16-year long-term fertilization experiment was conducted on paddy soil derived from red earth to investigate the effects of different fertilization patterns on the concentrations of soil organic nitrogen (N) components. When chemical fertilizers were applied only, the soil nitrogen content was slightly influenced. Organic fertilization, especially its combination with chemical fertilization, could significantly increase the contents of soil mineralizable N and organic nitrogen by 55.2% and 38.8%, respectively. In addition, organic fertilization could significantly improve the components of acid hydrolysable N, and lead to the increase of ammonium N (AN) , amino sugar N (ASN), and hydrolysable unidentified N (HUN) by 36.5%, 68.4%, and 73.9%, respectively. When the organic fertilization was combined with chemical fertilization, soil amino acid N content was increased by 71.1%, while HUN content was decreased by 34.5%. In all fertilization treatments, the cumulative amount of soil mineralized N increased with increasing incubation time. The content of soil mineralized N under organic fertilization and its combination with chemical fertilization was higher than that under chemical fertilization.

  18. Assessing Nitrogen Fertilization Strategies in Winter Wheat and Cotton Crops in Northern Greece

    Institute of Scientific and Technical Information of China (English)

    E. POLYCHRONAKI; C. DOUMA; C. GIOURGA; A. LOUMOU

    2012-01-01

    The management of fertilizer application is crucial for agricultural production and environmental safety.The objective of this study was to assess the efficiency of different fertilizatior.strategies,applying fertilizers with and without nitrification inhibitors (NIs)in split application,in Greece.The assessment criteria used were based on crop yield,soil nitrogen (N) concentrations and economic efficiency.For this purpose two crops (winter wheat and cotton) were selected in order to explore the optimum fertilization strategy for each crop.Three treatments combining fertilizers with NIs were tested compared with conventional fertilization (CF).Slight differences in the quantity and the combination of fertilizers with NIs applied resulted in variable effects on crop yield,soil N and economic return.Split N application of 102 kg ha-1,with half of the total amount applied at seeding,resulted in higher grain yield of winter wheat,lower NO3-N in soil and higher economic return.This result reveals the importance of N application at seeding in wheat crop.Fertilization strategy with 109.5 kg N ha-1 and split P application resulted in higher cotton yield and higher economic profit.Split P application seemed to increase yield,even though it is not a common practise in the area.

  19. The 15N isotope to evaluate fertilizer nitrogen absorption efficiency by the coffee plant.

    Science.gov (United States)

    Fenilli, Tatiele A B; Reichart, Klaus; Bacchi, Osny O S; Trivelin, Paulo C O; Dourado-Neto, Durval

    2007-12-01

    The use of the 15N label for agronomic research involving nitrogen (N) cycling and the fate of fertilizer-N is well established, however, in the case of long term experimentation with perennial crops like citrus, coffee and rubber tree, there are still shortcomings mainly due to large plant size, sampling procedures, detection levels and interferences on the system. This report tries to contribute methodologically to the design and development of 15N labeled fertilizer experiments, using as an example a coffee crop fertilized with 15N labeled ammonium sulfate, which was followed for two years. The N of the plant derived from the fertilizer was studied in the different parts of the coffee plant in order to evaluate its distribution within the plant and the agronomic efficiency of the fertilizer application practice. An enrichment of the fertilizer-N of the order of 2% 15N abundance was sufficient to study N absorption rates and to establish fertilizer-N balances after one and two years of coffee cropping. The main source of errors in the estimated values lies in the inherent variability among field replicates and not in the measurements of N contents and 15N enrichments of plant material by mass-spectrometry.

  20. The {sup 15}N isotope to evaluate fertilizer nitrogen absorption efficiency by the coffee plant

    Energy Technology Data Exchange (ETDEWEB)

    Fenilli, Tatiele A.B. [Universidade Regional de Blumenau, (FURB), SC (Brazil); Reichart, Klaus; Bacchi, Osny O.S.; Trivelin, Paulo Cesar Ocheuze [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)]. E-mail: klaus@cena.usp.br; Dourado-Neto, Durval [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ)

    2007-12-15

    The use of the {sup 15}N label for agronomic research involving nitrogen (N) cycling and the fate of fertilizer-N is well established, however, in the case of long term experimentation with perennial crops like citrus, coffee and rubber tree, there are still shortcomings mainly due to large plant size, sampling procedures, detection levels and interferences on the system. This report tries to contribute methodologically to the design and development of {sup 15}N labeled fertilizer experiments, using as an example a coffee crop fertilized with {sup 15}N labeled ammonium sulfate, which was followed for two years. The N of the plant derived from the fertilizer was studied in the different parts of the coffee plant in order to evaluate its distribution within the plant and the agronomic efficiency of the fertilizer application practice. An enrichment of the fertilizer-N of the order of 2% {sup 15}N abundance was sufficient to study N absorption rates and to establish fertilizer-N balances after one and two years of coffee cropping. The main source of errors in the estimated values lies in the inherent variability among field replicates and not in the measurements of N contents and {sup 15}N enrichments of plant material by mass-spectrometry. (author)

  1. Challenge and Opportunity in Improving Fertilizer-nitrogen Use Efficiency of Irrigated Rice in China

    Institute of Scientific and Technical Information of China (English)

    PENG Shao-bing; Christian Witt; HUANG Jian-liang; ZHONG Xu-hua; YANG Jian-chang; WANG Guang-huo; ZOU Ying-bin; ZHANG Fu-suo; ZHU Qing-sen; Roland Buresh

    2002-01-01

    Today, about 30% of world nitrogen (N) fertilizer is consumed by China. Rice crops in China consume about 37% of the total N fertilizer used for rice production in the world. Average rate of N application for rice production in China is high and fertilizer-N use efficiency is low compared with other major rice growing countries. Research progresses have been made internationally and domestically on the application method, fertilizer-N sources, computer-based decision support systems, and real-time N management in order to reduce N losses and increase fertilizer-N use efficiency. In addition to continuous increase in N rate and lack of adoption of new knowledge and technology in N management by farmers, we hypothesize that high indigenous soil N supply, adoption of hybrid and super rice cultivars, improper timing of N application, and practice of mid-season drainage could be the causes for the low fertilizer-N use efficiency in China. Future research work on improving fertilizer-N use efficiency of rice crop in China should focus more on improving cultivar's N responsiveness, optimizing the timing and rate of N application based on crop N status, and achieving optimal soil N supply capacity.

  2. Identification of Soil Organic Nitrogen Substance Acting as Indicator of Response of Cocoa Plants to Nitrogen Fertilizer

    Directory of Open Access Journals (Sweden)

    John Bako Baon

    2008-07-01

    Full Text Available An indicator needed for estimating the presence of response of cocoa (Theobroma cacao trees to nitrogen (N fertilizer has been well understood, however there is still little progress on the work on identification of organic N fraction which regulates the response of cocoa to N fertilizer. The objective of this study is to identify a fraction of soil organic N which is very closely related with degree of cocoa response to N fertilizer. Hydrolyses were performed on soil samples derived from 23 sites of cocoa plantations distributed both in Banyuwangi district (12 sites and in Jember district (11 sites. Analysis of organic N fractions consisted of total hydrolysable N, ammonium N, amino sugar N, amino acid N and combinations of those fractions. To investigate the level of cocoa plants response to N fertilizer, seedlings of cocoa were planted in plastic pots treated with and without urea as source of N. Degree of response of cocoa plants to N fertilizer was measured based on growth parameters, such as plant height, leaf number, stem girth, fresh weight of stem, leaf and shoot; and dry weight of stem, leaf and shoot. Results of this study showed that biggest response of cocoa was shown by dry weight of leaf at the level of 29,22% (in the range of -17,43% – 95,98%, whereas the smallest response was shown by stem dry weight at the level of -1,04 (in the range of -26,16 – 47,54. From those of organic N fractions analyzed, only N ammonium did not show any significant correlations with all the growth parameters observed. Leaf dry weight was the most closely related parameter with nearly all organic N fractions followed by shoot dry weight and stem girth. The soil organic N fraction which had very significant relation with cocoa plant response was total hydrolysable N. Using the method of Cate-Nelson, it was revealed that cocoa gardens contain total hydrolysable N less than 1273 mg/kg were classified as responsive to N fertilizer.Key words: plant

  3. Nitrate-Nitrogen Content in Soil and Lysimeter Water under Different Nitrogen Fertilization Levels in Crop Production

    Directory of Open Access Journals (Sweden)

    Aleksandra Jurišić

    2014-03-01

    Full Text Available Production of biomass for energy, food or biomaterials requires certain agricultural practices. The increasing nitrogen loading due to inorganic fertilizers used in conventional agriculture is one of the major global environmental challenges. This research was conducted in central part of Croatia near Park of nature Lonjsko polje, on experimental field which was established 17 years ago in order to determine influence of mineral nitrogen fertilization on nitrate leaching. The soil type of trial site is drained distric Stagnosols and four different nitrogen fertilization levels are taken into consideration: 1. N0+P+K, 2. N100+P+K, 3. N200+P+K, 4. N300+P+K (kg N ha-1. Water samples were taken in periods with lysimeters discharge. Soil sampling (0-0.25 m was carried out four times in the investigated period from June 2007 to June 2008 during the vegetation of maize and winter wheat. Research results indicate that the soil NO3-N content significantly varied (27.3 kg ha–1 to 338.2 kg ha –1 depending on the treatment and sampling time. Compare to the winter sampling time (November 2007 and February 2008 significantly higher content of soil NO3-N was determined in the summer sampling (June 2007 and June 2008. Regarding to the water samples, results revealed that the total nitrate-nitrogen losses were in the range from 5.97 kg NO3-N ha-1 to 112.3 kg NO3-N ha-1. Lysimeter discharge varied in dependence on precipitation and crop type. Total amounts of precipitation during the investigation were 652.5 mm and 34.6 % of them were recorded in lysimeters. Average NO3-N concentration in lysimeter water varied from 2.4 mg L-1 (0 kg N ha-1 up to 54.5 mg L-1 (300 kg N ha-1.

  4. Influence of nitrogen loading and plant nitrogen assimilation on nitrogen leaching and N₂O emission in forage rice paddy fields fertilized with liquid cattle waste.

    Science.gov (United States)

    Riya, Shohei; Zhou, Sheng; Kobara, Yuso; Sagehashi, Masaki; Terada, Akihiko; Hosomi, Masaaki

    2015-04-01

    Livestock wastewater disposal onto rice paddy fields is a cost- and labor-effective way to treat wastewater and cultivate rice crops. We evaluated the influence of nitrogen loading rates on nitrogen assimilation by rice plants and on nitrogen losses (leaching and N2O emission) in forage rice fields receiving liquid cattle waste (LCW). Four forage rice fields were subjected to nitrogen loads of 107, 258, 522, and 786 kg N ha(-1) (N100, N250, N500, and N750, respectively) using basal fertilizer (chemical fertilizer) (50 kg N ha(-1)) and three LCW topdressings (each 57-284 kg N ha(-1)). Nitrogen assimilated by rice plants increased over time. However, after the third topdressing, the nitrogen content of the biomass did not increase in any treatment. Harvested aboveground biomass contained 93, 60, 33, and 31 % of applied nitrogen in N100, N250, N500, and N750, respectively. The NH4 (+) concentration in the pore water at a depth of 20 cm was less than 1 mg N L(-1) in N100, N250, and N500 throughout the cultivation period, while the NH4 (+) concentration in N750 increased to 3 mg N L(-1) after the third topdressing. Cumulative N2O emissions ranged from -0.042 to 2.39 kg N ha(-1); the highest value was observed in N750, followed by N500. In N750, N2O emitted during the final drainage accounted for 80 % of cumulative N2O emissions. This study suggested that 100-258 kg N ha(-1) is a recommended nitrogen loading rate for nitrogen recovery by rice plants without negative environmental impacts such as groundwater pollution and N2O emission.

  5. [Effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and quality and fertilizer nitrogen use efficiency].

    Science.gov (United States)

    Ma, Fu-Liang; Song, Fu-Peng; Gao, Yang; Zou, Peng

    2012-01-01

    A field experiment was conducted to study the effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and its quality, plow layer soil inorganic nitrogen (N) contents, and fertilizer N use efficiency. Compared with traditional urea fertilizer, both sulfur- and polymer-coated controlled release urea fertilizers increased the grain yield by 10.4%-16.5%, and the grain protein and starch contents by 5.8%-18.9% and 0.3%-1.4%, respectively. The controlled release urea fertilizers could maintain the topsoil inorganic N contents to meet the N requirement for the wheat, especially during its late growth stage. In the meantime, the fertilizer N use efficiency was improved by 58.2%-101.2%. Polymer-coated urea produced better wheat yield and higher fertilizer N use efficiency, compared with sulfur-coated controlled release urea.

  6. [Effects of water stress and nitrogen fertilization on peanut root morphological development and leaf physiological activities].

    Science.gov (United States)

    Ding, Hong; Zhang, Zhi-meng; Dai, Liang-xiang; Ci, Dun-wei; Qin, Fei-fei; Song, Wen-wu; Liu, Meng-juan; Fu, Xiao

    2015-02-01

    Taking 'Huayu 22' peanut as test material, effect of soil water content and nitrogen fertilization on the leaf physiological activities and root morphological characteristics of peanut plants were analyzed. Two levels of soil water condition were: (1) well-watered condition and (2) moderate water stress, and three levels of nitrogen were: (1) none nitrogen (N0), (2) moderate nitrogen (N1, 90 kg · hm(-2)) and (3) high nitrogen (N2, 180 kg · hm(-2)). The results showed that N1 significantly increased the peanut yield under two water conditions, but showed no significant effect on harvest index compared with N0. Under water stress condition, N1 had no significant effects on total root biomass and total root length, but the total root surface area was remarkably increased. The nitrogen fertilization significantly increased the root length and root surface area in 20-40 cm soil layer, and N2 significantly increased the root biomass and root surface area in the soil layer below 40 cm. The application of nitrogen remarkably increased CAT and POD activities in leaf, while MDA content was decreased with the increase of nitrogen level. Under well-watered condition, the root biomass, root length and root surface area in the soil layer below 40 cm and total root surface area were significantly reduced by nitrogen application, however, only N1 could increase leaf protective enzyme activities. Correlation analysis showed that the root length in 20-40 cm soil layer and SOD, CAT, POD activities in leaf were highly significantly related with peanut yield.

  7. BVOC responses to realistic nitrogen fertilization and ozone exposure in silver birch.

    Science.gov (United States)

    Carriero, G; Brunetti, C; Fares, S; Hayes, F; Hoshika, Y; Mills, G; Tattini, M; Paoletti, E

    2016-06-01

    Emission of BVOC (Biogenic Volatile Organic Compounds) from plant leaves in response to ozone exposure (O3) and nitrogen (N) fertilization is poorly understood. For the first time, BVOC emissions were explored in a forest tree species (silver birch, Betula pendula) exposed for two years to realistic levels of O3 (35, 48 and 69 ppb as daylight average) and N (10, 30 and 70 kg ha(-1) yr(-1), applied weekly to the soil as ammonium nitrate). The main BVOCs emitted were: α-pinene, β-pinene, limonene, ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and hexanal. Ozone exposure increased BVOC emission and reduced total leaf area. The effect on emission was stronger when a short-term O3 metric (concentrations at the time of sampling) rather than a long-term one (AOT40) was used. The effect of O3 on total leaf area was not able to compensate for the stimulation of emission, so that responses to O3 at leaf and whole-plant level were similar. Nitrogen fertilization increased total leaf area, decreased α-pinene and β-pinene emission, and increased ocimene, hexanal and DMNT emission. The increase of leaf area changed the significance of the emission response to N fertilization for most compounds. Nitrogen fertilization mitigated the effects of O3 exposure on total leaf area, while the combined effects of O3 exposure and N fertilization on BVOC emission were additive and not synergistic. In conclusion, O3 exposure and N fertilization have the potential to affect global BVOC via direct effects on plant emission rates and changes in leaf area.

  8. Effect of ureaformaldehyde on the agronomic efficiency of nitrogen fertilization in rice (Oryza sativa lin. flooded.

    Directory of Open Access Journals (Sweden)

    Pedro Meneses Dartayet

    2013-12-01

    Full Text Available The work was carried out during the years 2004 - 2011 in the international Center of Tsukuba, belonging to the International Agency of Cooperation of Japan and in the Territorial Station of Investigations of Grains "Sur del Jíbaro" in Sancti Spíritus with the objective value the employment of the nitrogenous fertilizer of Slow Liberation Ureaformaldehído on the index of agronomic efficiency in the use of the nitrogen and the increment of the agricultural yield for the production of rice; in the first one you study the speed of liberation of the nitrogen of the Ureaformaldehído and the conventional Urea to three temperatures (10; 17.5 and 25 ºC; in the second one studies effect of the fertilizer Ureaformaldehído on the agricultural yield and the index of agronomic efficiency in the use of the nitrogen, in the cultivation of the flooded rice. The main results showed the Ureaformaldehído reacted in a significant way in the measure the temperature was incremented, ending up being mineralized a percentage from 82 to the 100 days; on the other hand, the best yield was reached statistically, with the dose of 120 kg of N/ha, for the fertilizer Ureaformaldehído.

  9. Erratum to: Estimating the crop response to fertilizer nitrogen residues in long-continued field experiments

    DEFF Research Database (Denmark)

    Petersen, Jens; Thomsen, Ingrid Kaag; Mattson, L

    2012-01-01

    Knowledge of the cumulated effect of long-continued nitrogen (N) inputs is important for both agronomic and environmental reasons. However, only little attention has been paid to estimate the crop response to mineral fertilizer N residues. Before interpreting estimates for the crop response...... yield of spring barley decreased by an average of 5 kg DM/ha and the grain N offtake by 46 g N/ha for a decrease in the annual mineral N rate of 1 kg N/ha applied for more than three decades. Although statistically significant, the crop response to mineral fertilizer N residues was of minor importance...

  10. Grain, milling, and head rice yields as affected by nitrogen rate and bio-fertilizer application

    Directory of Open Access Journals (Sweden)

    Saeed FIROUZI

    2015-11-01

    Full Text Available To evaluate the effects of nitrogen rate and bio-fertilizer application on grain, milling, and head rice yields, a field experiment was conducted at Rice Research Station of Tonekabon, Iran, in 2013. The experimental design was a factorial treatment arrangement in a randomized complete block with three replicates. Factors were three N rates (0, 75, and 150 kg ha-1 and two bio-fertilizer applications (inoculation and uninoculation with Nitroxin, a liquid bio-fertilizer containing Azospirillum spp. and Azotobacter spp. bacteria. Analysis of variance showed that rice grain yield, panicle number per m2, grain number per panicle, flag leaves area, biological yield, grains N concentration and uptake, grain protein concentration, and head rice yield were significantly affected by N rate, while bio-fertilizer application had significant effect on rice grain yield, grain number per panicle, flag leaves area, biological yield, harvest index, grains N concentration and uptake, and grain protein concentration. Results showed that regardless of bio-fertilizer application, rice grain and biological yields were significantly increased as N application rate increased from 0 to 75 kg ha-1, but did not significantly increase at the higher N rate (150 kg ha-1. Grain yield was significantly increased following bio-fertilizer application when averaged across N rates. Grains N concentration and uptake were significantly increased as N rate increased up to 75 kg ha-1, but further increases in N rate had no significant effect on these traits. Bio-fertilizer application increased significantly grains N concentration and uptake, when averaged across N rates. Regardless of bio-fertilizer application, head rice yield was significantly increased from 56 % to 60 % when N rate increased from 0 to 150 kg ha-1. Therefore, this experiment illustrated that rice grain and head yields increased with increasing N rate, while bio-fertilizer application increased only rice grain

  11. Recent Trends and Recommendations for Nitrogen Fertilization in Intensive Agriculture in Eastern China

    Institute of Scientific and Technical Information of China (English)

    M. ROELCKE; HAN Yong; K. H. SCHLEEF; ZHU Jian-Guo; LIU Gang; CAI Zu-Cong; J. RICHTER

    2004-01-01

    The Taihu Region in eastern China is one of China's most intensive agricultural regions and also one of the economically most developed areas. High nitrogen balance surpluses in the summer rice-winter wheat double-cropping systems are leading to large-scale non-point source pollution of aquifers. In an interdisciplinary approach, four-year (1995-1998) field trials were carried out in two representative areas (Jurong County and Wuxi City) of the Taihu Region. Five farmers' field sites were chosen in each of the 2 locations, with each site divided into "standard" (farmers' practice) and "reduced" (by 30%-40%) N fertilization. For both fertilization intensities, N balance surpluses and monetary returns from grain sales minus fertilizer expenditures were calculated in an economic assessment. Based on the field trials, the mineral N fertilizer application rates reduced by about 10% for rice and 20%-30% for wheat were recommended in 1999. Since 1999, the research focused on the trends in N fertilizer application rates and changes in grain and agricultural commodities prices.Summer rice N fertilizer use, in Wuxi City as of 2001, dropped by roughly 25%, while for winter wheat it decreased by 10%-20%, compared to the 1995-1998 period. This has been achieved not only by grain policy and price changes, but also by an increased environmental awareness from government officials. Nitrogen balance surpluses in Anzhen Town (of Wuxi City) have consequently diminished by 50%-75% in rice and by up to 40% in wheat, with reductions being achieved without concomitant decreases in physical grain yields or returns from sales minus fertilizer costs.

  12. BIOMETRIC AND PHYSIOLOGICAL CHARACTERISTICS OF CHRYSANTHEMUM (CHRYSANTHEMUM INDICUM L. PLANTS GROWN AT DIFFERENT RATES OF NITROGEN FERTILIZATION

    Directory of Open Access Journals (Sweden)

    V IVANOVA

    2003-07-01

    Full Text Available A trial with large the flowered chrysanthemum cultivar Dark Westland was carried out in an unheated greenhouse. Three rates of nitrogen fertilization were studied: 0, 100 and 140 kgN/ha, as well as two modes of plant formation – single- and two-stemmed plants. Parameters of the biometric characteristics, leaf gasexchange and leaf pigment content were determined. The best results about growth and decorative behaviour were achieved at nitrogen fertilization level of 100 kgN/ha. It was established that nitrogen fertilization in rates of 100 and 140 kgN/ha enhances photosynthetic rate in both modes of plant formation.

  13. Nitrogen release, tree uptake, and ecosystem retention in a mid-rotation loblolly pine plantation following fertilization with 15N-enriched enhanced efficiency fertilizers.

    OpenAIRE

    Werner, Amy

    2013-01-01

    Nitrogen is the most frequently limiting nutrient in southern pine plantations.  Previous studies found that only 10 to 25% of applied urea fertilizer N is taken up by trees.  Enhanced efficiency fertilizers could increase tree uptake efficiency by controlling the release of N and/or stabilize N.  Three enhanced efficiency fertilizers were selected as a representation of fertilizers that could be used in forestry: 1) NBPT treated urea (NBPT urea), 2) polymer coated urea (PC urea), and 3) mono...

  14. Nitrogen release, tree uptake, and ecosystem retention in a mid-rotation loblolly pine plantation following fertilization with 15N-enriched enhanced efficiency fertilizers.

    OpenAIRE

    Werner, Amy

    2013-01-01

    Nitrogen is the most frequently limiting nutrient in southern pine plantations.  Previous studies found that only 10 to 25% of applied urea fertilizer N is taken up by trees.  Enhanced efficiency fertilizers could increase tree uptake efficiency by controlling the release of N and/or stabilize N.  Three enhanced efficiency fertilizers were selected as a representation of fertilizers that could be used in forestry: 1) NBPT treated urea (NBPT urea), 2) polymer coated urea (PC urea), and 3) mono...

  15. Use of anthropogenic nitrogen fertilizers in agriculture is associated with per capita ethanol consumption.

    Science.gov (United States)

    Fluegge, Keith; Fluegge, Kyle

    2017-09-01

    It has previously been demonstrated that emissions of the agricultural pollutant, nitrous oxide (N2O), may be a confounder to the relationship between herbicide use and psychiatric impairments, including ADHD. This report attempts to extend this hypothesis by testing whether annual use of anthropogenic nitrogen-based fertilizers in U.S. agriculture (thought to be the most reliable indicator of environmental N2O emissions) is associated with per capita ethanol consumption patterns, a behavior often comorbid with ADHD. State estimates of anthropogenic nitrogen fertilizers from the United States Geological Survey (USGS) were obtained for the years between 1987 and 2006. Our dependent variable was annual per capita ethanol consumption. Ethanol consumption was categorized as beer, wine, spirits, and all alcoholic beverages. Least squares dummy variable method using two-ways fixed effects was utilized. Among states above the 50th percentile in farm use of anthropogenic nitrogen for all years (i.e., agricultural states), a one log-unit increase in farm use of anthropogenic nitrogen fertilizers is associated with a 0.13 gallon increase in total per capita ethanol consumption (p<0.0125). No statistically significant association between farm use of anthropogenic nitrogen and per capita ethanol consumption was found in states below the 50th percentile in farm use of anthropogenic nitrogen. The new findings are in agreement with both behavioral human studies demonstrating a link between N2O preference and alcohol and drug use history as well as molecular studies elucidating shared mechanisms between trace N2O antinociception and alcohol-seeking related behaviors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Species-specific Response of Photosynthesis to Burning and Nitrogen Fertilization

    Institute of Scientific and Technical Information of China (English)

    Yanfang Zhang; Shuli Niu; Wenhua Xu; Yi Han

    2008-01-01

    The present study was conducted to examine photosynthetic characteristics of three dominant grass species (Agropyron cristatum, Leymus chinensis, and Cleistogenes squarrosa) and their responses to burning and nitrogen fertilization in a semiarid grassland in northern China. Photosynthetic rate (Pn), stomatal conductance (gs), and water use efficiency (WUE) showed strong temporal variability over the growing season. C. squarrosa showed a significantly higher Pn and WUE than A. cristatum and L. chinensis. Burning stimulated Pn of A. cristatum and L. chinensis by 24-59% (P<0.05) in the early growing season, but not during other time periods. Light-saturated photosynthetic rate (φmax) in A. cristatum C. squarrosa. The burning-induced changes in soil moisture could explain 51% (P=0.01) of the burning-induced changes The stimulation of Pn under N fertilization was mainly observed in the early growing season when the soil extractable N content was significantly higher in the fertilized plots. The N fertilization-induced changes in soil extractable N content could explain 66% (P=0.001) of the changes in Pn, under N fertilization. The photosynthetic responses of the three species indicate that burning and N fertilization will potentially change the community structure and ecosystem productivity in the semiarid grasslands of northern China.

  17. Growth and nutrition response of young sweetgum plantations to repeated nitrogen fertilization on two site types

    Energy Technology Data Exchange (ETDEWEB)

    Scott, D.A.D.A. [USDA Forest Service, Pineville, LA (United States); Burger, J.A. [Virginia Polytechnic Institute and State University, Blacksburg, VA (United States). Dept. of Forestry; Kaczmarek, D.J. [Mead Westvaco Forest Science and Technology, Summerville, SC (United States); Kane, M.B. [International Paper Corp., Ridgeland, MS (United States). Silviculture Research and Technology

    2004-10-01

    Short-rotation intensive tree culture is being investigated in the southern United States as a method of producing hardwood fiber, but little is known about the early productivity and nutritional needs of these systems, especially on different site types. We studied the growth and foliar nutrition response of two sweetgum (Liquidambar styraciflua L.) plantations on a converted agricultural field and a pine cutover site to biannual applications of three nitrogen (N) fertilizer rates: 0, 5 6, and 112 kg N ha{sup -1}. The trees did not respond to treatment at any age on the agricultural field site, but the fertilized trees on the cutover site had about 60% greater biomass at ages 5 and 6. Fertilization doubled foliar biomass on the cutover site in the years fertilizer was applied. Stem biomass was directly related to foliar biomass, but the relationship was age-specific at both sites. Stem biomass was also related to the foliar N concentration. Foliar critical values of N were about 18 g N kg{sup -1}. Foliage phosphorus (P) and potassium (K) contents were diluted by the N fertilization-induced growth responses at both sites. Fertilization of young intensive-culture sweetgum plantations is necessary for optimum foliar N concentrations and foliar and stem biomass production, but is site-specific. (author)

  18. Oxygen and nitrogen isotopic composition of nitrate in commercial fertilizers, nitric acid, and reagent salts.

    Science.gov (United States)

    Michalski, Greg; Kolanowski, Michelle; Riha, Krystin M

    2015-01-01

    Nitrate is a key component of synthetic fertilizers that can be beneficial to crop production in agro-ecosystems, but can also cause damage to natural ecosystems if it is exported in large amounts. Stable isotopes, both oxygen and nitrogen, have been used to trace the sources and fate of nitrate in various ecosystems. However, the oxygen isotope composition of synthetic and organic nitrates is poorly constrained. Here, we present a study on the N and O isotope composition of nitrate-based fertilizers. The δ(15)N values of synthetic and natural nitrates were 0 ± 2 ‰ similar to the air N2 from which they are derived. The δ(18)O values of synthetic nitrates were 23 ± 3 ‰, similar to air O2, and natural nitrate fertilizer δ(18)O values (55 ± 5 ‰) were similar to those observed in atmospheric nitrate. The Δ(17)O values of synthetic fertilizer nitrate were approximately zero following a mass-dependent isotope relationship, while natural nitrate fertilizers had Δ(17)O values of 18 ± 2 ‰ similar to nitrate produced photochemically in the atmosphere. These narrow ranges of values can be used to assess the amount of nitrate arising from fertilizers in mixed systems where more than one nitrate source exists (soil, rivers, and lakes) using simple isotope mixing models.

  19. Significant alteration of soil bacterial communities and organic carbon decomposition by different long-term fertilization management conditions of extremely low-productivity arable soil in South China.

    Science.gov (United States)

    Xun, Weibing; Zhao, Jun; Xue, Chao; Zhang, Guishan; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

    2016-06-01

    Different fertilization managements of red soil, a kind of Ferralic Cambisol, strongly affected the soil properties and associated microbial communities. The association of the soil microbial community and functionality with long-term fertilization management in the unique low-productivity red soil ecosystem is important for both soil microbial ecology and agricultural production. Here, 454 pyrosequencing analysis of 16S recombinant ribonucleic acid genes and GeoChip4-NimbleGen-based functional gene analysis were used to study the soil bacterial community composition and functional genes involved in soil organic carbon degradation. Long-term nitrogen-containing chemical fertilization-induced soil acidification and fertility decline and significantly altered the soil bacterial community, whereas long-term organic fertilization and fallow management improved the soil quality and maintained the bacterial diversity. Short-term quicklime remediation of the acidified soils did not change the bacterial communities. Organic fertilization and fallow management supported eutrophic ecosystems, in which copiotrophic taxa increased in relative abundance and have a higher intensity of labile-C-degrading genes. However, long-term nitrogen-containing chemical fertilization treatments supported oligotrophic ecosystems, in which oligotrophic taxa increased in relative abundance and have a higher intensity of recalcitrant-C-degrading genes but a lower intensity of labile-C-degrading genes. Quicklime application increased the relative abundance of copiotrophic taxa and crop production, although these effects were utterly inadequate. This study provides insights into the interaction of soil bacterial communities, soil functionality and long-term fertilization management in the red soil ecosystem; these insights are important for improving the fertility of unique low-productivity red soil.

  20. Combination of inoculation methods of Azospirilum brasilense with broadcasting of nitrogen fertilizer increases corn yield

    Directory of Open Access Journals (Sweden)

    Tânia Maria Müller

    2015-01-01

    Full Text Available Nitrogen (N is the most limiting nutrient for corn production. Thereby, the goal of the paper was to evaluate inoculation methods of Azospirillum brasilense in order to partially supply N required by the crop. The experiment was carried out in Guarapuava, PR, Brasil, in 2011/2012 growing season. Randomized blocks with factorial 3 inoculation methods (seed treatment, planting furrow and non-inoculated control x 5 doses of nitrogen (0, 75, 150, 225 and 300kg ha-1 x 8 replications was used as the experimental design. Leaf are index, foliar nitrogen content, total chlorophyll, grains per ear and yield were evaluated. There was significant interaction between inoculation methods and nitrogen fertilization to leaf area index, but not for yield. Inoculation with the diazotrophic bacteria provided yield increase of 702kg ha-1 for inoculation in seeding furrow and 432kg ha-1 for inoculation in seed treatment compared to the control, but both treatments did not differ between each other. Furthermore, total chlorophyll, grains per ear and yield were positively affected, with quadratic response, by the nitrogen fertilization in broadcasting

  1. Growth and yield of corn hybrids in response to association with Azospirillum brasilense and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Deniele Marini

    2015-02-01

    Full Text Available There is a growing interest in optimizing the positive effects of the association between Azospirillum bacteria and corn crop in order to reduce the use of nitrogen fertilizers. This study aimed to evaluate the inoculation efficiency of an A. brasilense-based commercial product in association with different rates of nitrogen fertilization in two corn genotypes. The experiment was arranged in a 2 x 2 x 5 factorial randomized block design, with four replications. The treatments consisted of two corn hybrids (30F53 and CD386; with and without inoculation with a commercial product based on A. brasilense and five nitrogen rates (0, 40, 80, 120 and 160 kg ha-1. The variables plant height, basal stem diameter, leaf area, shoot dry matter, leaf nitrogen content, length and diameter of the cob, weight of 100 grains and grain yield were evaluated. Inoculation with A. brasilense provided increases of 11 and 12% in leaf area and shoot dry matter, respectively. There were differences in the response of the corn hybrids for most variables and the increase in nitrogen supply provided increments in the growth and yield of corn.

  2. Morphogenetic characteristics of three Brachiaria brizantha cultivars submitted to nitrogen fertilization.

    Science.gov (United States)

    Silva, Marcos F; Porto, Edson M V; Alves, Dorismar D; Vitor, Cláudio M T; Aspiazú, Ignacio

    2013-03-01

    This study aims to evaluate the morphogenetic characteristics of three cultivars of Brachiaria brizantha subjected to nitrogen fertilization. The design was a randomized block in factorial arrangement 4x3; three cultivars of B. brizantha - Marandu, Piatã, Xaraés and four nitrogen levels - 0, 80, 160 and 240 kg/ha, with three replications. The experimental units consisted of plastic pots filled with 5 dm3 of soil. Thereupon the establishment fertilization, varieties were sowed directly in the pots, leaving, after thinning, five plants per pot. Forty-five days after planting, it was done a standardization cut at 10 cm tall. Nitrogen levels were distributed according to the treatments, divided in three applications. The morphogenetic characteristics were evaluated in three tillers per sampling unit and data were submitted to analysis of variance and regression. For all evaluated characteristics there was no interaction between factors cultivar and nitrogen levels, verifying only the effects of nitrogen on the variables leaf appearance rate and phyllochron. The dose 240 kg/ha of N corresponds to the greater leaf appearance rate. Cultivar Marandu shows the higher leaf blade: pseudostem and ratio of leaf elongation rate and elongation pseudostem, which favors higher forage quality.

  3. Reducing the reliance on nitrogen fertilizer for wheat production.

    Science.gov (United States)

    Hawkesford, Malcolm J

    2014-05-01

    All crops require nitrogen (N) for the production of a photosynthetically active canopy, whose functionality will strongly influence yield. Cereal crops also require N for storage proteins in the grain, an important quality attribute. Optimal efficiency is achieved by the controlled remobilization of canopy-N to the developing grain during crop maturation. Whilst N will always be required for crop production, targeting efficient capture and use will optimise consumption of this valuable macronutrient. Efficient management of N through agronomic practice and use of appropriate germplasm are essential for sustainability of agricultural production. Both the economic demands of agriculture and the need to avoid negative environmental impacts of N-pollutants, such as nitrate in water courses or release of N-containing greenhouse gases, are important drivers to seek the most efficient use of this critical agronomic input. New cultivars optimised for traits relating to N-use efficiency rather than yield alone will be required. Targets for genetic improvement involve maximising capture, partitioning and remobilization in the canopy and to the grain, and yield per se. Whilst there is existing genetic diversity amongst modern cultivars, substantial improvements may require exploitation of a wider germplasm pool, utilizing land races and ancestral germplasm.

  4. [Effects of nitrogen fertilization rate and planting density on cotton biomass and nitrogen accumulation in extremely early mature cotton region of Northeast China].

    Science.gov (United States)

    Wang, Zi-Sheng; Xu, Min; Zhang, Guo-Wei; Jin, Lu-Lu; Shan, Ying; Wu, Xiao-Dong; Zhou, Zhi-Guo

    2011-12-01

    Taking two cotton cultivars Liaomian 19 and NuCOTN 33B with different growth periods as test materials, a field experiment was conducted to study the effects of different nitrogen fertilization rates (0, 240 and 480 kg N x hm(-2)) and different planting densities (75000, 97500 and 120000 plants x hm(-2)) on the cotton biomass, nitrogen accumulation, and accumulative nitrogen utilization in the planting region of extremely early mature cotton in Northeast China. The dynamics of cotton biomass and nitrogen accumulation of the two cultivars with their growth process followed Logistic model. Both nitrogen fertilization rate and planting density had significant effects on the cotton nitrogen accumulation dynamics and the cotton yield and quality. In all treatments, the beginning time of rapid accumulation of nitrogen was about 13 d earlier than that of biomass. In treatment plant density 97500 plants x hm(-2) and nitrogen fertilization rate 240 kg x hm(-2), the eigenvalues of the dynamic accumulation models of nitrogen and biomass for the two cultivars were most harmonious, lint yield was the highest, fiber quality was the best, and accumulative nitrogen utilization efficiency was the highest. In the study region, the earlier beginning time of rapid accumulation of nitrogen and biomass and their higher accumulation rates were benefit to the formation of higher cotton yield.

  5. Available Nitrogen and Responses to Nitrogen Fertilizer in Brazilian Eucalypt Plantations on Soils of Contrasting Texture

    Directory of Open Access Journals (Sweden)

    Ana Paula Pulito

    2015-04-01

    Full Text Available Eucalyptus plantations have seldom responded to N fertilization in tropical and subtropical regions of Brazil. This implies that rates of N mineralization have been adequate to supply tree needs. However, subsequent crop rotations with low N fertilization may result in declining concentrations of organic and potentially mineralizable N (N0, and consequent loss of wood productivity. This study investigated (a in situ N mineralization and N0 in soils of eucalypt plantations in São Paulo state, Brazil; (b tree growth responses to N fertilizer applied 6–18 months after planting; and (c the relationships between N0, other soil attributes and tree growth. We established eleven N fertilizer trials (maximum 240 kg ha−1 of N in E. grandis and E. grandis x urophylla plantations. The soil types at most sites were Oxisols and Quartzipsamments, with a range of organic matter (18 to 55 g kg−1 and clay contents (8% to 67% in the 0–20 cm layer. Concentrations of N0 were measured using anaerobic incubation on soil samples collected every three months (different seasons. The samples collected in spring and summer had N0 140–400 kg ha−1 (10%–19% total soil N, which were best correlated with soil texture and organic matter content. Rates of in situ net N mineralization (0–20 cm ranged from 100 to 200 kg ha−1 year−1 and were not correlated with clay, total N, or N0. These high N mineralization rates resulted in a low response to N fertilizer application during the early ages of stand growth, which were highest on sandy soils. At the end of the crop rotation, the response to N fertilizer was negligible and non-significant at all sites.

  6. Effect Management Strategies Fertilizer Nitrogen and Biological on Morphological Traits, Yield and Quality Traits Corn (S.C. 704

    Directory of Open Access Journals (Sweden)

    eisa maghsoudi

    2014-09-01

    Full Text Available In recent years, surplus usage of chemical fertilizers and inattention the importance organic matter to improve soil fertility, leading to increasing use of chemical fertilizer, environmental pollution and etc. In order to study the different fertilizer levels (organic, chemical and combined on yield of grain corn (S.C.704 experiment was conducted at the Research Farm Faculty of Agriculture Tarbiat Modarres University 2010 growing season factorial treatment were arranged in manner based on randomized complete block design with three replications. One factor include of the five nutritional systems: 1- (8 ton ha-1 of organic fertilizer, 2- (6 ton ha-1 of organic fertilizer + 46 kg ha-1 nitrogen, 3- (4 ton ha-1 of organic fertilizer + 92 kg/ha nitrogen, 4- (2 ton ha-1 of organic fertilizer + 138 kg ha-1 nitrogen and 5- (184 kg ha-1 nitrogen and second factor consisting of: 1- (Seed inoculation with free living nitrogen fixation bacteria and 2- (Non-inoculated seed. The results showed that the experimental treatments had a significant effect on the traits measured. Maximum leaf area (7.7, grain yield (1000 g m-2, thousand grain weight (213 g and protein percent (11 percent of A3 fertilizer level and the highest plant height and biological yield amount 256 cm and 22 ton ha-1 of A4 fertilizer level, respectively. Also in seeds inoculated with biological fertilizer measured traits had greater extent than treatment control (no inoculation, so that the leaf area (7.7, plant height (252 cm, grain yield (978 g m-2, thousand grain weight (205 g, biological yield (22 ton ha-1 and protein percent (10 percent in the inoculated treatments (one. According to the results that obtained the usage from of bio-fertilizers and manure combined with chemical is considered as appropriate procedure for increasing the yield and quality of corn.

  7. Warming and nitrogen fertilization effects on winter wheat yields in northern China varied between four years

    DEFF Research Database (Denmark)

    Liu, Liting; Hu, Chunsheng; Olesen, Jørgen E

    2013-01-01

    per m2. This suggests that the wheat yield loss may be related to reduction of spike number, which was affected by decreased soil water content under warming. Warming tended to give larger yield reductions at higher nitrogen fertilizer rates, and this may be related to larger water consumption......Global warming is expected to affect wheat productivity significantly, but with large regional differences depending on current climatic conditions. We conducted a study that aimed to investigate how wheat growth and development as well as yield and yield components respond to warming combined...... with nitrogen fertilization. Infrared heaters were applied above the crop and soil to provide a warming of around 2 °C at 5 cm soil depth during the whole winter wheat growing season from 2008 to 2012 at a site near Shijiazhuang in the North China Plain. Two temperature levels (warming and ambient) for winter...

  8. Nitrogen Fertilizer Factory Effects on the Amino Acid and Nitrogen Content in the Needles of Scots Pine

    Directory of Open Access Journals (Sweden)

    Eugenija Kupsinskiene

    2001-01-01

    Full Text Available The aim of the research was to evaluate the content of amino acids in the needles of Pinus sylvestris growing in the area affected by a nitrogen fertilizer factory and to compare them with other parameters of needles, trees, and sites. Three young-age stands of Scots pine were selected at a distance of 0.5 km, 5 km, and 17 km from the factory. Examination of the current-year needles in winter of the year 2000 revealed significant (p

  9. Fertilization practices and soil variations control nitrogen oxide emissions from tropical sugar cane

    Science.gov (United States)

    Matson, P. A.; Billow, C.; Hall, S.; Zachariassen, J.

    1996-08-01

    Nitrogen (N) fertilization of agricultural systems is thought to be a major source of the increase in atmospheric N2O; NO emissions from soils have also been shown to increase due to N fertilization. While N fertilizer use is increasing rapidly in the developing world and in the tropics, nearly all of our information on gas emissions is derived from studies of temperate zone agriculture. Using chambers, we measured fluxes of N2O and NO following urea fertilization in tropical sugar cane systems growing on several soil types in the Hawaiian Islands, United States. On the island of Maui, where urea is applied in irrigation lines and soils are mollisols and inceptisols, N2O fluxes were elevated for a week or less after fertilization; maximum average fluxes were typically less than 30 ng cm-2 h-1. NO fluxes were often an order of magnitude less than N2O. Together, N2O and NO represented from 0.03 to 0.5% of the applied N. In fields on the island of Hawaii, where urea is broadcast on the surface and soils are andisols, N2O fluxes were similar in magnitude to Maui but remained elevated for much longer periods after fertilization. NO emissions were 2-5 times higher than N2O through most of the sampling periods. Together the gas losses represented approximately 1.1-2.5% of the applied N. Laboratory studies indicate that denitrification is a critical source of N2O in Maui, but that nitrification is more important in Hawaii. Experimental studies suggest that differences in the pattern of N2O/NO and the processes producing them are a result of both carbon availability and placement of fertilizer and that the more information-intensive fertilizer management practice results in lower emissions.

  10. Variation in riverine nitrate flux and fall nitrogen fertilizer application in East-central illinois.

    Science.gov (United States)

    Gentry, Lowell E; David, Mark B; McIsaac, Gregory F

    2014-07-01

    In east-central Illinois, fertilizer sales during the past 20 yr suggest that approximately half of the fertilizer nitrogen (N) applied to corn ( L.) occurs in the fall; however, fall fertilizer N sales were greatly reduced in 2009 as wet soil conditions restricted fall fieldwork, including fertilizer N applications. In 2010, we observed unusually low flow-weighted nitrate concentrations (approximately 40% below the long-term average) in two east-central Illinois rivers (5.7 mg N L in the Embarras River and 5.6 mg N L in the Lake Fork of the Kaskaskia River). Using long-term river nitrate data sets (1993-2012 for the Embarras and 1997-2012 for the Kaskaskia), we examined nitrate concentrations and developed regression models to estimate the association between fall fertilizer N application on riverine nitrate yields in these tile-drained watersheds. During these periods of record, annual riverine nitrate yields ranged from 8 to 57 kg N ha yr (30 kg N ha yr average) for the Embarras River and 2.6 to 59 kg N ha yr (32 kg N ha yr average) for the Kaskaskia. Multivariate linear regression relationships with the current and previous year's annual water yields, previous year's corn yield, and nine-county fall fertilizer sales accounted for 96% of the annual variation in nitrate yield in both watersheds. Running the regression models with fall fertilizer sales set to the 2009 amount suggests that the average reduction in nitrate yield (for the period of record) would be 17 and 20% for the Embarras and Kaskaskia Rivers, respectively. These data suggest that shifting fertilizer N application to the spring can be detected in watersheds as large as 481 km. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  11. Proteome changes in wheat subjected to different nitrogen and sulfur fertilizations.

    Science.gov (United States)

    Grove, Harald; Hollung, Kristin; Moldestad, Anette; Færgestad, Ellen Mosleth; Uhlen, Anne Kjersti

    2009-05-27

    Controlling the quality of wheat for breadmaking is a major concern for the milling and baking industry. Wheat flour quality depends on both the genetic background and environmental factors during growth and storage. Amount and timing of application of fertilizer are factors that affect wheat quality. This study investigated the effect of different levels of nitrogen and sulfur on the tris-soluble and glutenin protein fractions by 2D-electrophoresis. Multivariate analysis was performed to study changes in the proteome pattern. In the tris-soluble fraction 20 proteins were changed in abundance due to S fertilization, whereas 16 proteins were changed in the glutenin protein fraction. It was found that induced sulfur deficiency during growth resulted in the most pronounced effect on protein composition. Understanding which proteins are affected by varying levels of fertilizers may help tailor specific traits in various wheat varieties.

  12. Nitrogen and Crude Proteins in Beetroot (Beta vulgaris var. conditiva under Different Fertilization Treatments

    Directory of Open Access Journals (Sweden)

    Marko PETEK

    2012-11-01

    Full Text Available The research aim was to determine the influence of different organic and mineral fertilization treatments and post-harvest treatments on the content of nitrogen and crude proteins in the edible part of beetroot (Beta vulgaris var. conditiva. A field trial (2003-2005 was set up in a hilly part of Croatia according to the Latin square method with four types of fertilization (control, 50 t ha-1 stable manure, 500 and 1000 kg ha-1 NPK 5-20-30, while treatments involved harvested fresh beetroot and stored fresh beetroot. The highest dry weight (DW content was determined in climatologically favourable 2004 (average 14.8% DW and in the treatment with 1000 kg ha-1 NPK 5-20-30 (15.6% DW in harvested beetroot. In 2004 and 2005, the highest levels of nitrogen and crude proteins in harvested beetroot were determined in the treatment with 1000 kg ha-1 NPK 5-20-30 (2.41 and 2.43 g N kg-1 in fresh weight and 15.07 and 15.21 g crude proteins kg-1 in fresh weight, respectively. Regardless of fertilization treatment or studied year, nitrogen and crude protein contents were higher in stored than in harvested beetroot, by 12% on average. The lowest crude protein content was determined in treatment with stable manure what confirmed that protein content decreased by organic fertilization. It can be concluded that beetroot lost some water during the storage period, which increased its content of nitrogen and crude proteins in fresh weight and thus increased the nutritional quality of beetroot as a functional food.

  13. Surface runoff and nitrogen (N) loss in a bamboo (Phyllostachys pubescens) forest under different fertilization regimes.

    Science.gov (United States)

    Zhang, Qichun; Shamsi, Imran Haider; Wang, Jinwen; Song, Qiujin; Xue, Qiaoyun; Yu, Yan; Lin, Xianyong; Hussain, Sayed

    2013-07-01

    Nitrogen (N) losses from agricultural fields have been extensively studied. In contrast, surface runoff and N losses have rarely been considered for bamboo forests that are widespread in regions such as southern China. The thriving of bamboo industries has led to increasing fertilizer use in bamboo forests. In this study, we evaluated surface runoff and N losses in runoff following different fertilization treatments under field conditions in a bamboo (Phyllostachys pubescens) forest in the catchment of Lake Taihu in Jiangsu, China. Under three different fertilization regimes, i.e., control, site-specific nutrient management (SSNM), and farmer's fertilization practice (FFP), the water runoff rate amounted to 356, 361, and 342 m(3) ha(-1) and accounted for 1.91, 1.98, and 1.85% of the water input, respectively, from June 2009 to May 2010. The total N losses via surface runoff ranged from 1.2 to 1.8 kg ha(-1). Compared with FFP, the SSNM treatment reduced total nitrogen (TN) and dissolved nitrogen (DN) losses by 31 and 34%, respectively. The results also showed that variations in N losses depended mainly on runoff fluxes, not N concentrations. Runoff samples collected from all treatments throughout the year showed TN concentrations greater than 0.35 mg L(-1), with the mean TN concentration in the runoff from the FFP treatment reaching 8.97 mg L(-1). The loss of NO3(-)-N was greater than the loss of NH4(+)-N. The total loss of dissolved organic nitrogen (DON) reached 23-41% of the corresponding DN. Therefore, DON is likely the main N species in runoff from bamboo forests and should be emphasized in the assessment and management of N losses in bamboo forest.

  14. Soil carbon quality and nitrogen fertilization structure bacterial communities with predictable responses of major bacterial phyla

    OpenAIRE

    2014-01-01

    Agricultural practices affect the soil ecosystem in multiple ways and the soil microbial communities represent an integrated and dynamic measure of soil status. Our aim was to test whether the soil bacterial community and the relative abundance of major bacterial phyla responded predictably to long-term organic amendments representing different carbon qualities (peat and straw) in combination with nitrogen fertilization levels and if certain bacterial groups were indicative of specific treatm...

  15. Diazotrophic bacteria and nitrogen fertilization on the growth of micropropagated pineapple plantlets during acclimatization

    OpenAIRE

    2016-01-01

    ABSTRACT: This study examines the effect of inoculation with diazotrophic bacteria and nitrogen fertilization on the growth of micropropagated pineapple cv. 'Vitória' plantlets during the acclimatization period. The experiment was carried out in a greenhouse in Campos dos Goytacazes, in randomized blocks, using a 2x5x5 factorial scheme, with the factors being two types of inocula (absence or presence of a mixture of diazotrophic bacteria that contained Burkholderia sp. UENF 114111, Burkholder...

  16. Nitrate reductase activity in cabbage (Brassica oleracae var. capitata seedlings affected by the different nitrogen fertilizer forms

    Directory of Open Access Journals (Sweden)

    Metin Turan

    2013-12-01

    Full Text Available The effect of different nitrogen fertilizer (potassium nitrate, ammonium nitrate, ammonium sulphate, urea and farmyard manure on nitrate reductase activity in cabbage (Brassica oleracea var. capitata seedlings were studied. pH of the plant growth niedia was higher in the nitrate fertilizer treatment than the ammonium and other fertilizer forms. NO3--N application increased NRA in plant, but NH4+-N decreased NRA in plant. Harvesting date and different fertilizer doses increased NRA while NH4+-N decreased plant nitrate uptake. There was a significant relationship between NRA and fertilizer types.

  17. Sources of nitrogenous fertilizers and their effects in the growth of the castor bean plant

    Directory of Open Access Journals (Sweden)

    Joelma Sales dos Santos

    2008-12-01

    Full Text Available The main goal of this research was to verify and quantify the effects of doses (equivalent to nitrogen of fertilizers, manure from corral, residential sewage sludge, castor oil cake and urea, in the early growth of castor beans, BRS Nordestina in a greenhouse. The experiment was conducted in the Embrapa, at county of Campina Grande, state of Paraiba, Brazil, and it was used an experimental design of randomized with three replicates and 13 treatments, with a factorial 4 x 3 + 1, which factors were: types of organic fertilizers (manure from corral and manure, biosolids and castor bean cake and urea at rates of (85,170 and 255 kg N ha-¹, plus an additional treatment, which was the absolute witness without the fertilization. All the treatments witness received a mineral supplement P and K, at doses of 80 kg of P2O2 and K2O, applied in the foundation, with triple superphosphate and potassium chloride. Among the fertilizers, which further promoted the initial growth of castor beans was the pie of Euphorbia that, in addition to nutrients, especially of nitrogen, have much fiber, more than 35%, constituting themselves, thus a factor in improving soil physical environment.

  18. Brachiaria sp yield and nutrient contents after nitrogen and sulphur fertilization

    Directory of Open Access Journals (Sweden)

    Reges Heinrichs

    2013-08-01

    Full Text Available Among the production factors, adequate fertilization is an important tool to raise the productivity of pastoral systems and consequently increase the share of Brazil in the supply chain of primary agricultural products at the global level. The objective of this study was to evaluate the interaction of nitrogen and sulfur fertilization in BRACHIARIA DECUMBENS: Stapf. The experiment in pots with Dystrophic Oxisol was evaluated in a completely randomized design with four replications in a 5 x 3 factorial arrangement, involving five N doses (0, 100, 200, 400, and 800 mg dm-3 in the form of ammonium nitrate and three S doses (0, 20 and 80 mg dm-3 in the form of calcium sulfate, with a total of 15 treatments. In the treatments with low S dose, calcium was provided as calcium chloride, to ensure a homogeneous Ca supply in all treatments. The results showed that the tiller production and dry weight of green leaves and of stems + sheaths and total dry weight were favored by the combination of N and S fertilizer, while the proportion of dry leaves was reduced. Nitrogen fertilization raised the N contents in green leaves and stems + sheaths and reduced K contents in fresh and dry leaves. The response to S rates in the N content of green leaves was quadratic.

  19. Effects of nitrogen fertilizer and magnesium manipulation on the Cnaphalocrocis medinalis (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Ge, Lin-Quan; Wan, Don-Ju; Xu, Jie; Jiang, Li-Ben; Wu, Jin-Cai

    2013-02-01

    The rice leaffolder, Cnaphalocrocis medinalis Guenee (Lepidoptera: Pyralidae), is a rice pest that is prone to outbreaks when high levels of nitrogen (N) fertilizer are applied to rice. The larvae feed by scraping the mesophyll cells of leaves, which are mainly composed of chloroplasts containing significant levels of elemental magnesium (Mg). To determine the cause of N fertilizer-induced rice leaffolder outbreaks and the effects of Mg and Mg uptake on the rice leaffolder, the changes in the life history traits and biochemistry of C. medinalis larvae feeding on rice leaves treated with different Mg and N concentrations were investigated in this study. The results showed that foliar treatment using different Mg concentrations under hydroponic culture conditions significantly decreased the developmental duration (days) (DD) of the larvae and pupae but did not influence the pupation rate or adult emergence rate. The number of eggs laid by adult females and the protein content and total sugar content in the larvae and pupae significantly increased with increasing Mg concentrations. Under soil culture conditions, the DD for the larvae and number of eggs laid by adult females significantly increased with increasing nitrogen fertilizer levels, but the applied fertilizer did not influence the DD in the pupae, pupation rate, or adult emergence rate. In contrast, the DD for adults decreased with increased fertilizer levels. In hydroponic culture, Mg in the culture solution and Mg foliar sprays significantly increased the Mg content in rice leaves. In soil cultures, the use of N fertilizer and Mg foliar spray did not significantly increase the leaf Mg content, except at a concentration of 12.5 g/L, indicating that the leaf Mg content may be related to the root uptake of Mg.

  20. Impact of elevated CO(2) and nitrogen fertilization on foliar elemental composition in a short rotation poplar plantation.

    Science.gov (United States)

    Marinari, Sara; Calfapietra, Carlo; De Angelis, Paolo; Mugnozza, Giuseppe Scarascia; Grego, Stefano

    2007-06-01

    The experiment was carried out on a short rotation coppice culture of poplars (POP-EUROFACE, Central Italy), growing in a free air carbon dioxide enriched atmosphere (FACE). The specific objective of this work was to study whether elevated CO(2) and fertilization (two CO(2) treatments, elevated CO(2) and control, two N fertilization treatments, fertilized and unfertilized), as well as the interaction between treatments caused an unbalanced nutritional status of leaves in three poplar species (P. x euramericana, P. nigra and P. alba). Finally, we discuss the ecological implications of a possible change in foliar nutrients concentration. CO(2) enrichment reduced foliar nitrogen and increased the concentration of magnesium; whereas nitrogen fertilization had opposite effects on leaf nitrogen and magnesium concentrations. Moreover, the interaction between elevated CO(2) and N fertilization amplified some element unbalances such as the K/N-ratio.

  1. IMPACT OF NITROGEN FERTILIZATION ON THE CHEMICAL COMPOSITION OF CHARDONNAY, ITALIAN RIESLING AND WHITE RIESLING GRAPE CULTIVARS

    Directory of Open Access Journals (Sweden)

    Marko Karoglan

    2010-06-01

    Full Text Available Nitrogen fertilization is one of the common farming practices in vine production which may affect the increase in vegetative mass of vine and grape yield, but also the dynamics of maturation related primaryly to differences in the concentrations of sugar, total acidity, and content of organic acids in grapes. The experiment was conducted in 2006 – 2007 years on cultivars Chardonnay, Riesling and Italian Riesling, with three different intensities of nitrogen fertilization 23 kg, 70 kg and 117 kg N/ha. The concentrations of sugar, malic and citric acid have not been changed due to nitrogen fertilization. Differences were observed in the Riesling grapes from 2006th year with 23 kg and 70 kg N/ha fertilization, and in the Chardonnay grapes with 117 kg N / ha fertilization.

  2. Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

    Institute of Scientific and Technical Information of China (English)

    GAO Min-ling; DAI Shu-gui; MA Yong-min; ZHANG Pi

    2007-01-01

    Sorption of chlorotoluron in ammonium sulfate.urea and atrazine multi-solutes system was investigated by batch experiments.The results showed application of nitrogen fertilizers to the soil could affeCt the behavior of chlorotoluron.At the same concentration of N,sorption of chlorotoluron decreased as the concentration of atrazine increased on the day O and 6 in soil.respectively.The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water,ammonium sulfate and urea solution for 6 d.That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments.The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system,but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers.That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.

  3. Biomass and nutrients allocation in pot cultured beech seedlings:influence of nitrogen fertilizer

    Institute of Scientific and Technical Information of China (English)

    Ali Bagherzadeh; Rainer Brumme; Friedrich Beese

    2008-01-01

    Allocation of biomass and nutrient elements including Nitrogen to above and belowground compartments of beech seedlings (Fagus sylvatica L.) treated by labeled nitrogen fertilizer in the form of 15NH4 and 15NO3 were investigated at the end of two successive growing seasons.Pot cultured beech seedlings were grown at a green house on intact soil cores sampled from three adjacent stands including beech,Norway spruce and mixed beech-spruce cultures of Solling forest,Germany.Comparing biomass allocation and nutrients concentrations of the seedlings between the control and 15N-fertilized treatments revealed no significant effect of N fertilization on nutrients uptake by seedlings over the experiment.The form of N input influenced its movement into plant pools.It was demonstrated that beech seedlings take up nitrogen mainly in the form of nitrate,which is then reduced in the leaves,although the differences between the retention of NO3 ̄-N and NH4+-N in plants were not statistically significant.Percent recoveries of 15N in trees were typically greater after 15NO3 than after 15NH4 additions.It was indicated that immobilization of 15N tracer in fine roots was a slower process comparing other plant compartments such as stem and coarse roots,but a powerful sink for N during the course of study.

  4. Soil carbon and nitrogen affected by perennial grass, cover crop, and nitrogen fertilization

    Science.gov (United States)

    Soil C and N sequestration and the potential for N leaching can be influenced by the type of perennial grass, cover crop, and N fertilization due to differences in crop yields and the amount of residue returned to the soil. We evaluated the effects of the combinations of perennial grasses (energy ca...

  5. Does nitrogen fertilizer application rate to corn affect nitrous oxide emissions from the rotated soybean crop?

    Science.gov (United States)

    Iqbal, Javed; Mitchell, David C; Barker, Daniel W; Miguez, Fernando; Sawyer, John E; Pantoja, Jose; Castellano, Michael J

    2015-05-01

    Little information exists on the potential for N fertilizer application to corn ( L.) to affect NO emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects NO emissions during subsequent crops in rotation, we measured NO emissions for 3 yr (2011-2013) in an Iowa, corn-soybean [ (L.) Merr.] rotation with three N fertilizer rates applied to corn (0 kg N ha, the recommended rate of 135 kg N ha, and a high rate of 225 kg N ha); soybean received no N fertilizer. We further investigated the potential for a winter cereal rye ( L.) cover crop to interact with N fertilizer rate to affect NO emissions from both crops. The cover crop did not consistently affect NO emissions. Across all years and irrespective of cover crop, N fertilizer application above the recommended rate resulted in a 16% increase in mean NO flux rate during the corn phase of the rotation. In 2 of the 3 yr, N fertilizer application to corn (0-225 kg N ha) did not affect mean NO flux rates from the subsequent unfertilized soybean crop. However, in 1 yr after a drought, mean NO flux rates from the soybean crops that received 135 and 225 kg N ha N application in the corn year were 35 and 70% higher than those from the soybean crop that received no N application in the corn year. Our results are consistent with previous studies demonstrating that cover crop effects on NO emissions are not easily generalizable. When N fertilizer affects NO emissions during a subsequent unfertilized crop, it will be important to determine if total fertilizer-induced NO emissions are altered or only spread across a greater period of time.

  6. County-Level Estimates of Nitrogen and Phosphorus from Commercial Fertilizer for the Conterminous United States, 1987-2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains county-level estimates of nitrogen and phosphorus from fertilizer, for both farm and nonfarm uses, for the conterminous United States, for...

  7. Shifts in species composition constrain restoration of overgrazed grassland using nitrogen fertilization in Inner Mongolian steppe, China.

    Directory of Open Access Journals (Sweden)

    Qing Chen

    Full Text Available Long-term livestock over-grazing causes nitrogen outputs to exceed inputs in Inner Mongolia, suggesting that low levels of nitrogen fertilization could help restore grasslands degraded by overgrazing. However, the effectiveness of such an approach depends on the response of production and species composition to the interactive drivers of nitrogen and water availability. We conducted a five-year experiment manipulating precipitation (NP: natural precipitation and SWP: simulated wet year precipitation and nitrogen (0, 25 and 50 kg N ha(-1 yr(-1 addition in Inner Mongolia. We hypothesized that nitrogen fertilization would increase forage production when water availability was relatively high. However, the extent to which nitrogen would co-limit production under average or below average rainfall in these grasslands was unknown.Aboveground net primary production (ANPP increased in response to nitrogen when precipitation was similar to or higher than the long-term average, but not when precipitation was below average. This shift in limitation was also reflected by water and nitrogen use efficiency. Belowground live biomass significantly increased with increasing water availability, but was not affected by nitrogen addition. Under natural precipitation (NP treatment, the inter-annual variation of ANPP was 3-fold greater than with stable water availability (CV(ANPP = 61±6% and 17±3% for NP and SWP treatment, respectively and nitrogen addition increased CV(ANPP even more (89±14%. This occurred in part because fertilizer nitrogen left in the soil in dry years remained available for uptake during wet years and because of high production by unpalatable annual species in wet years in the NP treatment. In summary, plant growth by residual fertilizer nitrogen could lead to sufficient yields to offset lack of additional production in dry years. However, the utility of fertilization for restoration may be constrained by shifts in species composition and

  8. Shifts in species composition constrain restoration of overgrazed grassland using nitrogen fertilization in Inner Mongolian steppe, China.

    Science.gov (United States)

    Chen, Qing; Hooper, David U; Lin, Shan

    2011-03-01

    Long-term livestock over-grazing causes nitrogen outputs to exceed inputs in Inner Mongolia, suggesting that low levels of nitrogen fertilization could help restore grasslands degraded by overgrazing. However, the effectiveness of such an approach depends on the response of production and species composition to the interactive drivers of nitrogen and water availability. We conducted a five-year experiment manipulating precipitation (NP: natural precipitation and SWP: simulated wet year precipitation) and nitrogen (0, 25 and 50 kg N ha(-1) yr(-1)) addition in Inner Mongolia. We hypothesized that nitrogen fertilization would increase forage production when water availability was relatively high. However, the extent to which nitrogen would co-limit production under average or below average rainfall in these grasslands was unknown.Aboveground net primary production (ANPP) increased in response to nitrogen when precipitation was similar to or higher than the long-term average, but not when precipitation was below average. This shift in limitation was also reflected by water and nitrogen use efficiency. Belowground live biomass significantly increased with increasing water availability, but was not affected by nitrogen addition. Under natural precipitation (NP treatment), the inter-annual variation of ANPP was 3-fold greater than with stable water availability (CV(ANPP) = 61±6% and 17±3% for NP and SWP treatment, respectively) and nitrogen addition increased CV(ANPP) even more (89±14%). This occurred in part because fertilizer nitrogen left in the soil in dry years remained available for uptake during wet years and because of high production by unpalatable annual species in wet years in the NP treatment. In summary, plant growth by residual fertilizer nitrogen could lead to sufficient yields to offset lack of additional production in dry years. However, the utility of fertilization for restoration may be constrained by shifts in species composition and the lack of

  9. Effect of inorganic nitrogenous fertilizer on productivity of recently reclaimed saline sodic soils with and without biofertilizer.

    Science.gov (United States)

    Mehdi, S M; Sarfraz, M; Shabbir, G; Abbas, G

    2007-07-15

    Saline sodic soils after reclamation become infertile due to leaching of most of the nutrients along with salts from the rooting medium. Microbes can play a vital role in the productivity improvement of such soils. In this study a saline sodic field having EC, 6.5 dS m(-1), pH, 9.1 and gypsum requirement (GR) 3.5 tons acre(-1) was reclaimed by applying gypsum at the rate of 100% GR. Rice and wheat crops were transplanted/sown for three consecutive years. Inorganic nitrogenous fertilizer was used with and without biofertilizers i.e., Biopower (Azospirillum) for rice and diazotroph inoculums for wheat. Nitrogen was applied at the rate of 0, 75% of recommended dose (RD), RD, 125% of RD and 150% of RD. Recommended dose of P without K was applied to all the plots. Biopower significantly improved Paddy and straw yield of rice over inorganic nitrogenous fertilizer. In case of wheat diazotroph inoculum improved grain and straw yield significantly over inorganic nitrogenous fertilizer. Among N fertilizer rates, RD + 25% additional N fertilizer was found to be the best dose for rice and wheat production in recently reclaimed soils. Nitrogen concentration and its uptake by paddy, grain and straw were also increased by biopower and diazotroph inoculum over inorganic nitrogenous fertilizer. Among N fertilizer rates, RD + 25% additional N fertilizer was found to be the best dose for nitrogen concentration and its uptake by paddy, grain and straw. Total soil N, available P and extractable K were increased while salinity/sodicity parameters were decreased with the passage of time. The productivity of the soil was improved more by biofertilizers over inorganic N fertilizers.

  10. Phosphorus Characteristics with Controlled Nitrogen in Fertile Soils in Protected Vegetable Field

    Directory of Open Access Journals (Sweden)

    WANG Heng

    2014-06-01

    Full Text Available There is an unreasonable phenomenon of fertilization in vegetable facility cultivation, with the serious imbalance of soil nutrient. In purpose of understanding the absorption characteristics of phosphorus from nitrogen-rich soil, a long-term nitrogen-controlled experiment was carried from the year 2004 to 2007, and a split plot experiment of leaching was carried in winter-spring season of 2007. The results showed that the content of phosphorus varied with different nitrogen control. The TP was decreased with nitrogen supply of none(NN 、organic manure(MN 、organic manure and straw(MN+S, and the decreased range was NN>MN>MN+S, meanwhile the increase range of TP was traditional-nitrogen(CN >traditional-nitrogen+straw(CN+S >optimized-nitrogen+straw(SN+S >optimized-nitrogen(SN. The available P with CN and CN+S reached to 213.7 mg· kg -1 、225.4 mg·kg -1, which increased by 17.1 percent and 23.5 percent, which declared the phosphorus was accumulated; The available P with other nitrogen controlled decreased with the range of NN>MN>MN+S>SN+S>SN跃CN>CN+S, which showed that the supply reduction of nitrogen could slowdown the phosphorus accumulated and promote the utilization ratio of phosphorus. The organophosphorus was increased except NN, with obvious increase with CN、CN+S(308.4 mg·kg -1 、331.4 mg·kg -1 by 28.5 percent and 38.2 percent. The absorption coefficient of phosphorus with SN+S(P 2 O 5,mg· 100 g -1 reached to 1 571, increased by 143.6 percent; Otherwise the absorption coefficient of phosphorus with CN、CN+S showed negative growth, the CN dipped to 416(P 2 O 5,mg·100 g -1 by 35.5 percent. Adding wheat straw could greatly improved the capacity of absorption of phosphorus and slow down the accumulation of available phosphorus to some extent. The concentrations of total phosphorus in the filtrate with SN+S were less than SN, contrary to the concentration of organophosphorus, thus the straw returning had a certain effect on

  11. Effect of nitrogen and sulfur fertilization on accumulation characteristics and physicochemical properties of A- and B-wheat starch.

    Science.gov (United States)

    Li, Wenhao; Shan, Yulin; Xiao, Xinlong; Zheng, Jianmei; Luo, Qingui; Ouyang, Shaohui; Zhang, Guoquan

    2013-03-13

    The effects of nitrogen (N) fertilization at the rates of 0 and 230 kg hm(-2) combined with selected sulfur (S) fertilization rates of 0, 46, 56, 77, and 115 kg hm(-2) on A- and B-wheat starch granule accumulation, composition, and thermal and pasting properties were investigated. Scanning electron micrographs revealed that A- and B-starch granules accumulation during grain filling can be influenced significantly by N and S fertilization, and B-granules tend to be more sensitive to S fertilization than A-starch granules. The doses of nitrogen and sulfur fertilization on starch properties were not positively correlated; higher concentration of fertilizers failed to cause a higher effects. N230S46 and N230S56 treatment resulted in the higher peak viscosity, trough viscosity, breakdown viscosity, final and setback viscosity, and gelatinization temperature (To, Tp, Tc) according to differential scanning calorimeter (DSC) and rapid visco analyzer (RVA), respectively.

  12. Seabird nutrient subsidies benefit non-nitrogen fixing trees and alter species composition in South American coastal dry forests.

    Directory of Open Access Journals (Sweden)

    Gilles Havik

    Full Text Available Marine-derived nutrients can increase primary productivity and change species composition of terrestrial plant communities in coastal and riverine ecosystems. We hypothesized that sea nutrient subsidies have a positive effect on nitrogen assimilation and seedling survival of non-nitrogen fixing species, increasing the relative abundance of non-nitrogen fixing species close to seashore. Moreover, we proposed that herbivores can alter the effects of nutrient supplementation by preferentially feeding on high nutrient plants. We studied the effects of nutrient fertilization by seabird guano on tree recruitment and how these effects can be modulated by herbivorous lizards in the coastal dry forests of northwestern Peru. We combined field studies, experiments and stable isotope analysis to study the response of the two most common tree species in these forests, the nitrogen-fixing Prosopis pallida and the non-nitrogen-fixing Capparis scabrida. We did not find differences in herbivore pressure along the sea-inland gradient. We found that the non-nitrogen fixing C. scabrida assimilates marine-derived nitrogen and is more abundant than P. pallida closer to guano-rich soil. We conclude that the input of marine-derived nitrogen through guano deposited by seabirds feeding in the Pacific Ocean affects the two dominant tree species of the coastal dry forests of northern Peru in contrasting ways. The non-nitrogen fixing species, C. scabrida may benefit from sea nutrient subsidies by incorporating guano-derived nitrogen into its foliar tissues, whereas P. pallida, capable of atmospheric fixation, does not.

  13. Changes in fungal community composition in response to elevated atmospheric CO2 and nitrogen fertilization varies with soil horizon

    Directory of Open Access Journals (Sweden)

    Carolyn F Weber

    2013-04-01

    Full Text Available Increasing levels of atmospheric carbon dioxide (CO2 and rates of nitrogen (N-deposition to forest ecosystems are predicted to alter the structure and function of soil fungal communities, but the spatially heterogeneous distribution of soil fungi has hampered investigations aimed at understanding such impacts. We hypothesized that soil physical and chemical properties and fungal community composition would be differentially impacted by elevated atmospheric CO2 (eCO2 and N-fertilization in spatially separated field samples, in the forest floor, 0-2 cm, 2-5 cm and 5-10 cm depth intervals in a loblolly pine Free-Air-Carbon Dioxide Enrichment (FACE experiment. In all soils, quantitative PCR-based estimates of fungal biomass were highest in the forest floor. Fungal richness, based on pyrosequencing of the fungal ribosomal large subunit gene, increased in response to N-fertilization in 0-2 cm and forest floor intervals. Composition shifted in forest floor, 0-2 cm and 2-5 cm intervals in response to N-fertilization, but the shift was most distinct in the 0-2 cm interval, in which the largest number of statistically significant changes in soil chemical parameters (i.e phosphorus, organic matter, calcium, pH was also observed. In the 0-2 cm interval, increased recovery of sequences from the Thelephoraceae, Tricholomataceae, Hypocreaceae, Clavicipitaceae, and Herpotrichiellaceae families and decreased recovery of sequences from the Amanitaceae correlated with N-fertilization. In this same depth interval, Amanitaceae, Tricholomataceae and Herpotriciellaceae sequences were recovered less frequently from soils exposed to eCO2 relative to ambient conditions. These results demonstrated that vertical stratification should be taken into consideration in future efforts to elucidate environmental impacts on fungal communities and their feedbacks on ecosystem processes.

  14. Nitrogen fertilizer increases nitrous oxide, but not dinitrogen, emissions from moist tropical forest soils in Puerto Rico

    Science.gov (United States)

    Almaraz, M.; Porder, S.; Groffman, P. M.

    2015-12-01

    Nitrogen (N) deposition in tropical forests may increase substantially in coming decades, stimulating a concomitant increase of soil N gas emissions (dinitrogen (N2), nitrous (N2O) and nitric oxides). How N deposition might alter the relative emissions of these gases is unclear, and has ramifications for the global climate since N2O is a potent greenhouse gas. We used a small-scale fertilization study in the Luquillo Experimental Forest (LEF) of Puerto Rico to simulate the effects of N deposition on N gas emissions. Fertilizer was applied by placing mesh bags filled with ammonium saturated weak cation exchange resin directly on the mineral soil for two months. At that time, intact soil cores (0-10cm) were taken from below the bags. The cores were shipped to the Cary Institute of Ecosystem Studies, where they were incubated in a helium headspace with either 0 or 20% oxygen (O2), and analyzed for N2 and N2O emissions. N fertilization increased N2O emissions fourfold (p=0.03). N2O production was positively correlated with field soil moisture (r=0.45, p=0.002), and was higher under 20% than 0% atmospheric O2 (p=0.003). With the exception of a handful of samples, we detected no measureable N2 production from these soils, and fertilization did not influence N2 production. This may have been because our experiment occurred during a drought that reduced soil moisture in the field by ˜20%. We have found that N2 emissions correlate with soil moisture elsewhere in the LEF. While we conclude that N deposition may not influence the N2O:N2 of soil emissions under such conditions, it is still unclear whether this result would hold under higher rainfall.

  15. Autoregulation of nodulation interferes with impacts of nitrogen fertilization levels on the leaf-associated bacterial community in soybeans.

    Science.gov (United States)

    Ikeda, Seishi; Anda, Mizue; Inaba, Shoko; Eda, Shima; Sato, Shusei; Sasaki, Kazuhiro; Tabata, Satoshi; Mitsui, Hisayuki; Sato, Tadashi; Shinano, Takuro; Minamisawa, Kiwamu

    2011-03-01

    The diversities leaf-associated bacteria on nonnodulated (Nod(-)), wild-type nodulated (Nod(+)), and hypernodulated (Nod(++)) soybeans were evaluated by clone library analyses of the 16S rRNA gene. To analyze the impact of nitrogen fertilization on the bacterial leaf community, soybeans were treated with standard nitrogen (SN) (15 kg N ha(-1)) or heavy nitrogen (HN) (615 kg N ha(-1)) fertilization. Under SN fertilization, the relative abundance of Alphaproteobacteria was significantly higher in Nod(-) and Nod(++) soybeans (82% to 96%) than in Nod(+) soybeans (54%). The community structure of leaf-associated bacteria in Nod(+) soybeans was almost unaffected by the levels of nitrogen fertilization. However, differences were visible in Nod(-) and Nod(++) soybeans. HN fertilization drastically decreased the relative abundance of Alphaproteobacteria in Nod(-) and Nod(++) soybeans (46% to 76%) and, conversely, increased those of Gammaproteobacteria and Firmicutes in these mutant soybeans. In the Alphaproteobacteria, cluster analyses identified two operational taxonomic units (OTUs) (Aurantimonas sp. and Methylobacterium sp.) that were especially sensitive to nodulation phenotypes under SN fertilization and to nitrogen fertilization levels. Arbuscular mycorrhizal infection was not observed on the root tissues examined, presumably due to the rotation of paddy and upland fields. These results suggest that a subpopulation of leaf-associated bacteria in wild-type Nod(+) soybeans is controlled in similar ways through the systemic regulation of autoregulation of nodulation, which interferes with the impacts of N levels on the bacterial community of soybean leaves.

  16. INOCULATION OF DIAZOTROPHIC BACTERIA AND NITROGEN FERTILIZATION IN TOPDRESSING IN IRRIGATED CORN

    Directory of Open Access Journals (Sweden)

    VANESSA ZIRONDI LONGHINI

    2016-01-01

    Full Text Available Corn is a nitrogen-intensive crop, and the use of management practices such as inoculation of the seed with diazotrophic bacteria, which can maximize crop productivity and reduce the need of nitrogen fertilizers, may result in lower production costs. The present study aimed to evaluate the effect of inoculation of corn seed with Azospirillum brasilense and controlled addition of nitrogen to topdressing on the nutrition, production components, and productivity of crop grain. The experimental design was a randomized block design, with four replications in a 2 × 5 factorial scheme. The treatments consisted of inoculation or not of corn seed with A. brasilense (at 100 mL per 25 kg of seed and five nitrogen (N levels in topdressing (0, 30, 60, 90, and 120 kg N ha-1 from urea [45% N] were applied when the corn was in the phenological growth stage V6. Foliar macronutrients, foliar chlorophyll index (FCI, production components, and yield of corn grain were valuated. Inoculation of corn seeds with A. brasilense increased plant height and grain yield. Fertilization in topdressing, with N levels up to 120 kg ha-1, linearly increased the foliar nutrients and productivity of corn cultivated in the spring/summer in the low-altitude Cerrado region of Brazil.

  17. Effect of Irrigation and Preplant Nitrogen Fertilizer Source on Maize in the Southern Great Plains

    Directory of Open Access Journals (Sweden)

    Jacob T. Bushong

    2014-01-01

    Full Text Available With the demand for maize increasing, production has spread into more water limited, semiarid regions. Couple this with the increasing nitrogen (N fertilizer costs and environmental concerns and the need for proper management practices has increased. A trial was established to evaluate the effects of different preplant N fertilizer sources on maize cultivated under deficit irrigation or rain-fed conditions on grain yield, N use efficiency (NUE, and water use efficiency (WUE. Two fertilizer sources, ammonium sulfate (AS and urea ammonium nitrate (UAN, applied at two rates, 90 and 180 kg N ha−1, were evaluated across four site-years. Deficit irrigation improved grain yield, WUE, and NUE compared to rain-fed conditions. The preplant application of a pure ammoniacal source of N fertilizer, such as AS, had a tendency to increase grain yields and NUE for rain-fed treatments. Under irrigated conditions, the use of UAN as a preplant N fertilizer source performed just as well or better at improving grain yield compared to AS, as long as the potential N loss mechanisms were minimized. Producers applying N preplant as a single application should adjust rates based on a reasonable yield goal and production practice.

  18. Ammonia volatilization from nitrogen fertilizers in no-till wheat and maize in southern Brazil

    Directory of Open Access Journals (Sweden)

    Fernando Viero

    2014-10-01

    Full Text Available Crop residues on the soil surface of no-till systems can intensify ammonia volatilization from N fertilizers applied to cereal crops. This study assessed the magnitude of N losses through ammonia volatilization from urea applied to no-till winter (wheat and summer crops (maize on a Typic Hapludox in the south-central region of Paraná, southern Brazil. In addition, the potential of alternative N sources (urea with urease inhibitor, liquid fertilizer, ammonium nitrate and ammonium sulfate and different urea managements (fertilizer applied in the morning or afternoon were evaluated. Two experiments with maize and wheat were carried out for two years, arranged in a randomized block design with four replications. Nitrogen volatilization losses were assessed with a semi-open static collector until 21 days after fertilization. In winter, the losses were low (<5.5 % of applied N for all N sources, which were not distinguishable, due to the low temperatures. In the summer, volatilization rates from urea were higher than in the winter, but did not exceed 15 % of applied N. The main factor decreasing N losses in the summer was the occurrence of rainfall in the first five days after fertilization. Urea with urease inhibitor, nitrate and ammonium sulfate were efficient to decrease ammonia volatilization in maize, whereas the application time (morning or afternoon had no influence.

  19. Nitrogen and phosphorus fertilization negatively affects strigolactone production and exudation in sorghum.

    Science.gov (United States)

    Yoneyama, Kaori; Xie, Xiaonan; Kisugi, Takaya; Nomura, Takahito; Yoneyama, Koichi

    2013-11-01

    Strigolactones (SLs) are essential host recognition signals for both root parasitic plants and arbuscular mycorrhizal fungi, and SLs or their metabolites function as a novel class of plant hormones regulating shoot and root architecture. Our previous study indicated that nitrogen (N) deficiency as well as phosphorus (P) deficiency in sorghum enhanced root content and exudation of 5-deoxystrigol, one of the major SLs produced by sorghum. In the present study, we examined how N and P fertilization affects SL production and exudation in sorghum plants subjected to short- (5 days) or long-term (10 days) N or P deficiency and demonstrated their common and distinct features. The root contents and exudation of SLs in the N- or P-deficient sorghum plants grown for 6, 12 or 24 h with or without N or P fertilization were quantified by LC-MS/MS. In general, without fertilization, root contents and exudation of SLs stayed at similar levels at 6 and 12 h and then significantly increased at 24 h. The production of SLs responded more quickly to P fertilization than the secretion of SLs, while regulation of SL secretion began earlier after N fertilization. It is suggested that sorghum plants regulate SL production and exudation when they are subjected to nutrient deficiencies depending on the type of nutrient and degree of deficiency.

  20. Nitrogen fertilization of the host plant influences production and pathogenicity of Botrytis cinerea secondary inoculum.

    Science.gov (United States)

    Abro, Manzoor Ali; Lecompte, François; Bryone, Florian; Nicot, Philippe C

    2013-03-01

    The influence of nitrogen (N) nutrition on a plant's susceptibility to Botrytis spp. and other pathogens is well documented. However, little is known of possible effects on sporulation of the pathogen on diseased tissue and on the pathogenicity of resulting secondary inoculum. To address this question, sporulation by two strains of Botrytis cinerea was quantified on tomato plants produced under different N irrigation regimes with inputs of NO(3)- at 0.5 to 45 mmol liter(-1) (mM). Sporulation decreased significantly (P fertilization up to NO(3)- at 15 to 30 mM. The secondary inoculum was collected and used to inoculate pruning wounds on tomato plants produced under a standard fertilization regime. Pathogenicity of the spores was significantly influenced by the nutritional status of their production substrate. Disease severity was highest with spores produced on plants with very low or very high N fertilization (NO(3)- at 0.5 or 30 mM). It was lowest for inoculum from plants with moderate levels of N fertilization. These results suggest that it may be possible to find an optimum level of N fertilization to reduce the production of secondary inoculum and its pathogenicity to tomato.

  1. Role of integrated use of nitrogen fertilizer sources in improving seed quality of canola (Brassica napus L.

    Directory of Open Access Journals (Sweden)

    Ayman EL Sabagh

    2016-02-01

    Full Text Available It is necessary for developing strategies of integrated fertilization for crops to maximize production of crops and reducing the risk of pollution from chemical fertilizers. Therefore, the objectives of this study to evaluate the impact of bio-organic, chemical nitrogen on seed quality of canola. A study was conducted for two consecutive years (2005 to 2006 at the Farm of Faculty of Agriculture, Kafr El-Sheikh University, Egypt. Bio fertilizer (control and bio-fertilizer, compost (control, 6, 12 and 18 ton ha-1 and chemical nitrogen (control, 36, 72 and 108 kg N ha-1. The result indicated that, bio-fertilizer was significantly effects on protein % and iodine value except oil percent was decreased. On the other hand, the Maximum values oil and protein were recorded by using compost fertilizer at (18 ton ha-1. In respect to chemical fertilizer, adding nitrogen affected significantly on protein % and the maximum value was obtained at (108 N ha-1 while, oil percent and iodine value were decreased. Interestingly, it is clear that from results that cultivar belongs to canola (LEAR that contains < 2% erucic acid and a nitrogen source has almost slight effect on oil physical properties. Totally, the interaction among treatments application compost (6ton ha-1 and (72 N kg ha-1 with combined bio- fertilizer was achieved suitable oil percent and could be improve canola seed yield and quality and environment would have a better condition.

  2. Herbage and animal production responses to fertilizer nitrogen in perennial ryegrass swards. II. rotational grazing and cutting

    NARCIS (Netherlands)

    Lantinga, E.A.; Deenen, P.J.A.G.; Keulen, van H.

    1999-01-01

    The yield response of grass swards to fertilizer nitrogen (N) differs under cutting and grazing, as grazing cattle exert positive and negative effects on pasture production, with varying negative effects on different soil types. Nevertheless, current N fertilization recommendations in the Netherland

  3. Herbage and animal production responses to fertilizer nitrogen in perennial ryegrass swards. II. rotational grazing and cutting

    NARCIS (Netherlands)

    Lantinga, E.A.; Deenen, P.J.A.G.; Keulen, van H.

    1999-01-01

    The yield response of grass swards to fertilizer nitrogen (N) differs under cutting and grazing, as grazing cattle exert positive and negative effects on pasture production, with varying negative effects on different soil types. Nevertheless, current N fertilization recommendations in the

  4. Fertility profile of post Fourniers gangrene patients:Does neoscrotal environment alter fertility?

    Institute of Scientific and Technical Information of China (English)

    Zulqarnain Masoodi; Imran Ahmad; Fahad Khurram

    2012-01-01

    Objective:To ascertain changes in fertility in post Fournier’s gangrene patients on account of changed scrotal environment. Methods: Sixty post Fournier’s patients were as cases and 50 non Fournier’s individuals aptlyserved as controls. All subjects were followed up for 1 year. Aspects of fertility were investigated by means of a seminogram at 6 months and analysis for volume, viscosity, sperm concentration, motility and morphology according to WHO guidelines was done. Ability of the couples to conceive children in 1 year was also noted. The control group was investigated similarly and values were compared for significance. Results:The seminogram results were found out to be highly significant as there was marked difference in values (chi-square value 6.28, P-value< 0.012) whereas there was no significant association between attaining pregnancy at 1 year in two groups. Conclusions:A readily palpable difference in the seminogram values observed in Fournier’s patients is the most significant finding of this study. Also highlighted was that despite such seminogram changes the overall ability of the couple to achieve pregnancy remains unaltered.

  5. Synthetic nitrogen fertilizers deplete soil nitrogen: a global dilemma for sustainable cereal production.

    Science.gov (United States)

    Mulvaney, R L; Khan, S A; Ellsworth, T R

    2009-01-01

    Cereal production that now sustains a world population of more than 6.5 billion has tripled during the past 40 yr, concurrent with an increase from 12 to 104 Tg yr(-1) of synthetic N applied largely in ammoniacal fertilizers. These fertilizers have been managed as a cost-effective form of insurance against low yields, without regard to the inherent effect of mineral N in promoting microbial C utilization. Such an effect is consistent with a net loss of soil organic C recently observed for the Morrow Plots, America's oldest experiment field, after 40 to 50 yr of synthetic N fertilization that substantially exceeded grain N removal. A similar decline in total soil N is reported herein for the same site and would be expected from the predominantly organic occurrence of soil N. This decline is in agreement with numerous long-term baseline data sets from chemical-based cropping systems involving a wide variety of soils, geographic regions, and tillage practices. The loss of organic N decreases soil productivity and the agronomic efficiency (kg grain kg(-1) N) of fertilizer N and has been implicated in widespread reports of yield stagnation or even decline for grain production in Asia. A major global evaluation of current cereal production systems should be undertaken, with a view toward using scientific and technological advances to increase input efficiencies. As one aspect of this strategy, the input of ammoniacal N should be more accurately matched to crop N requirement. Long-term sustainability may require agricultural diversification involving a gradual transition from intensive synthetic N inputs to legume-based crop rotations.

  6. Effect of nitrogen fertilizer on distribution of starch granules in different regions of wheat endosperm

    Institute of Scientific and Technical Information of China (English)

    Fei; Xiong; Xurun; Yu; Liang; Zhou; Jing; Zhang; Yanping; Jin; Dongliang; Li; Zhong; Wang

    2014-01-01

    This study provided visual evidence of a nitrogen effect on starch granules(SGs) in wheat endosperm. Winter wheat(Titicum aestivum L.) cultivar Xumai 30 was cultured under no nitrogen(control) and 240 kg ha-1of nitrogen applied at the booting stage. The number, morphology, and size of Aand B-type SGs in subaleurone of dorsal endosperm(SDE), center of dorsal endosperm(CDE), modified aleurone(MA), subaleurone of ventral endosperm(SVE), and center of ventral endosperm(CVE) were observed under light and electron microscopes.(1) The distribution of SGs in SDE was similar to that in SVE, the distributions of SGs in CDE and CVE were similar, but the distribution of SGs in MA was different from those in the other four endosperm regions. The number of SGs in the five endosperm regions was in the order SDE > CDE > SVE > CVE > MA.(2) Nitrogen increased the number of Aand B-type SGs in SDE and SVE. Nitrogen also increased the number of B-type SGs but decreased the number of A-type SGs in CDE and CVE. Nitrogen decreased the numbers of A-type and B-type SGs in MA. The results suggest that increased N fertilizer application mainly increased the numbers of small SGs and decreased the numbers of large SGs, but that the results varied in different regions of the wheat endosperm.

  7. Effect of nitrogen fertilizer on distribution of starch granules in different regions of wheat endosperm

    Directory of Open Access Journals (Sweden)

    Fei Xiong

    2014-02-01

    Full Text Available This study provided visual evidence of a nitrogen effect on starch granules (SGs in wheat endosperm. Winter wheat (Titicum aestivum L. cultivar Xumai 30 was cultured under no nitrogen (control and 240 kg ha− 1 of nitrogen applied at the booting stage. The number, morphology, and size of A- and B-type SGs in subaleurone of dorsal endosperm (SDE, center of dorsal endosperm (CDE, modified aleurone (MA, subaleurone of ventral endosperm (SVE, and center of ventral endosperm (CVE were observed under light and electron microscopes. (1 The distribution of SGs in SDE was similar to that in SVE, the distributions of SGs in CDE and CVE were similar, but the distribution of SGs in MA was different from those in the other four endosperm regions. The number of SGs in the five endosperm regions was in the order SDE > CDE > SVE > CVE > MA. (2 Nitrogen increased the number of A- and B-type SGs in SDE and SVE. Nitrogen also increased the number of B-type SGs but decreased the number of A-type SGs in CDE and CVE. Nitrogen decreased the numbers of A-type and B-type SGs in MA. The results suggest that increased N fertilizer application mainly increased the numbers of small SGs and decreased the numbers of large SGs, but that the results varied in different regions of the wheat endosperm.

  8. Greenhouse gas emissions and reactive nitrogen releases from rice production with simultaneous incorporation of wheat straw and nitrogen fertilizer

    Science.gov (United States)

    Xia, Longlong; Xia, Yongqiu; Ma, Shutan; Wang, Jinyang; Wang, Shuwei; Zhou, Wei; Yan, Xiaoyuan

    2016-08-01

    Impacts of simultaneous inputs of crop straw and nitrogen (N) fertilizer on greenhouse gas (GHG) emissions and N losses from rice production are not well understood. A 2-year field experiment was established in a rice-wheat cropping system in the Taihu Lake region (TLR) of China to evaluate the GHG intensity (GHGI) as well as reactive N intensity (NrI) of rice production with inputs of wheat straw and N fertilizer. The field experiment included five treatments of different N fertilization rates for rice production: 0 (RN0), 120 (RN120), 180 (RN180), 240 (RN240), and 300 kg N ha-1 (RN300, traditional N application rate in the TLR). Wheat straws were fully incorporated into soil before rice transplantation. The meta-analytic technique was employed to evaluate various Nr losses. Results showed that the response of rice yield to N rate successfully fitted a quadratic model, while N fertilization promoted Nr discharges exponentially (nitrous oxide emission, N leaching, and runoff) or linearly (ammonia volatilization). The GHGI of rice production ranged from 1.20 (RN240) to 1.61 kg CO2 equivalent (CO2 eq) kg-1 (RN0), while NrI varied from 2.14 (RN0) to 10.92 g N kg-1 (RN300). Methane (CH4) emission dominated the GHGI with a proportion of 70.2-88.6 % due to direct straw incorporation, while ammonia (NH3) volatilization dominated the NrI with proportion of 53.5-57.4 %. Damage costs to environment incurred by GHG and Nr releases from current rice production (RN300) accounted for 8.8 and 4.9 % of farmers' incomes, respectively. Cutting N application rate from 300 (traditional N rate) to 240 kg N ha-1 could improve rice yield and nitrogen use efficiency by 2.14 and 10.30 %, respectively, while simultaneously reducing GHGI by 13 %, NrI by 23 %, and total environmental costs by 16 %. Moreover, the reduction of 60 kg N ha-1 improved farmers' income by CNY 639 ha-1, which would provide them with an incentive to change the current N application rate. Our study suggests that GHG

  9. Effects of nitrogen fertilizer rates and ratios of base and topdressing on wheat yield,soil nitrate content and nitrogen balance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Application of nitrogen (N) fertilizer is one of the most important measures that increases grain yield and improves grain quality in winter wheat (Triticum aestivum L.) production.Presently,there is a large number of investigations (experiments) in the field on different nitrogen fertilizer application regimes.However,there still exists a serious problem of low nitrogen use efficiency,especially in winter wheat high yield conditions:unsuitable nitrogen fertilizer,which often leads to lower yield and large accumulation of nitrate in the soil,bringing a potential risk to the environment.In order to explore the optimal regime of nitrogen fertilizer application suitable for environment and economy,a field experiment on the different rate and ratio of base and topdressing of nitrogen fertilizer at the different growth periods of winter wheat was conducted.The field experiment was undertaken from the fall of 2003 to the summer of 2004 in the village of Zhongcun in Longkou city,in the Shandong Province of China.The field experiment with three repeats for each treatment was designed in a split-plot.The major plot was applied with urea at a nitrogen fertilizer rate of three levels,namely,0 kg·hm-2 (CK),168 kg·hm-2 (A),and 240 kg·hm-2 (B).In the sub-plot,the ratios of base and topdressing nitrogen fertilizer at the different development periods of wheat were 1/2:1/2 (A1 and B1),1/3:2/3 (A2 and B2) and 0:1 (A3 and B3).Treatment B1 was under a regime used now in the local region.It was found that the amount of N accumulation in plants had no significant difference between treatments applied with nitrogen fertilizer.The grain yield and grain protein content were all elevated remarkably by applying nitrogen fertilizer compared with those of treatment CK.There was no significant difference in the grain yield and grain protein content between A2 and B2 and B3.However,when compared with those of B2 and B3,in A2 there was an increase in nitrogen use efficiency and residual soil

  10. Inhibition of methane oxidation by nitrogenous fertilizers in a paddy soil

    Directory of Open Access Journals (Sweden)

    M. Saiful Alam

    2012-07-01

    Full Text Available Nitrogenous fertilizers are generally thought to have an important role in regulating methane oxidation. In this study, the effect of ammonium on methane oxidation activity was investigated in a paddy soil using urea at concentrations of 0, 50, 100, 200 and 400 μg N per gram dry weight soil (N/g.d.w.s and ammonium sulfate at concentrations of 0, 50 and 200 μg N/g.d.w.s. The results of this study demonstrate that urea concentrations of 200 μg N/g.d.w.s. and above significantly inhibit methane oxidation activity, whereas no statistically significant difference was observed in methane oxidation activity among soil microcosms with urea concentrations of less than 200 μg N/g.d.w.s after incubation for 27 days. Similar results were obtained in a sense that methane oxidation activity was inhibited only when the ammonium sulfate concentration was 200 μg N/g.d.w.s in soil microcosms in this study. Phylogenetic analysis of pmoA genes showed that nitrogen fertilization resulted in apparent changes in the community composition of methane-oxidizing bacteria (MOB. Type I MOB displayed an increased abundance in soil microcosms amended with nitrogenous fertilizers, whereas type II MOB dominated the native soil. Furthermore, although no statistically significant relationship was observed between pmoA gene and amoA gene abundances, methane oxidation activity was significantly negatively correlated with nitrification activity in the presence of urea or ammonium sulfate. Our results indicate that the methane oxidation activity in paddy soils might be inhibited when the concentration of ammonium fertilizers is high and that the interactions between ammonia and methane oxidizers need to be further investigated.

  11. Rice rhizodeposition and its utilization by microbial groups depends on nitrogen fertilization

    Science.gov (United States)

    Ge, Tida; Zhu, Zhenke; Wu, Jinshui

    2016-04-01

    Rhizodeposited carbon (C) has received considerable attention because it plays an important role in regulating soil C sequestration and global C cycling, and represents the main C source for rhizosphere microorganisms. However, limited information exists on the utilization of rhizodeposited C by different microbial groups, its role in the turnover of soil organic matter (SOM) pools in rice paddies and how this is influenced by nitrogen (N) fertilization. Rice (Oryza sativa L.) was grown in soil at one of five N fertilization rates (0, 10, 20, 40, or 60 mg N kg-1 soil) and then continuously labeled by exposure to a 13CO2 atmosphere for 18 days. The utilization of root-derived C by microbial groups within the rhizosphere was assessed by following the incorporation of 13C into phospholipid fatty acids (PLFAs). Rice shoot and root biomass strongly increased with N fertilization rate. Rhizodeposition was greater, but total 13C incorporation into microorganisms was lower, in N-fertilized soils than in unfertilized soil. The contribution of root-derived 13C to SOM formation increased with root biomass. The roots tended to grow into large aggregates (0.25-2.0 mm diameter), and N fertilization stimulated incorporation of 13C into these macroaggregates, presumably due to the relatively high root biomass. The ratio of 13C in soil pools (SOM, microbial biomass) to 13C in roots decreased as a result of N fertilization. N fertilization increased 13C incorporation into fungi (18:2ω6, 9c, 18:1ω9c), AM fungi (16:1ω5c), and actinomycetes (10Me 16:0, 10Me 18:0), but decreased 13C incorporation into Gram-positive (i14:0, i15:0, a15:0, i16:0, i17:0, a17:0) and Gram-negative (16:1ω7c, 18:1ω7c, cy17:0, cy19:0) bacteria. Thus, the uptake and processing of root-derived C by microbial groups depended on soil N status. Relative to the unfertilized controls, the contribution of rhizodeposited-C to SOM and microorganisms was increased by low to intermediate N fertilization rates, but

  12. THE EFFECT OF NITROGEN FERTILIZATION OF MAIZE ON PROTEIN CONCENTRATION AND IN VITRO FEMENTABILITY OF GRAIN

    Directory of Open Access Journals (Sweden)

    D BABNIK

    2002-12-01

    Full Text Available The effect of nitrogen fertilization of maize on fermentability of maize grain in the rumen was studied by means of in vitro method based on the measurement of gas produced during the incubation of samples with rumen liquor. Gas production was recorded continuously up to 72 h incubation time and cumulative gas production was described by the Gompertz equation Y=A*exp(-exp(-d*(t-tm. Seven treatments, one of them unfertilized and others fertilized with 100 to 250 kg N ha–1, were compared. Grain yield and concentration of crude protein (CP in grain increased linearly with nitrogen fertilization. Grain yield increased for 25 kg dry matter (DM ha–1 and CP concentration for 0.13 g kg–1 DM per each additional kg of N. Concentration of CP in grain, which varied from 83 to 115 g kg–1 DM, was closely related to the dynamics of gas production. The maximal gas production rate (MPR was negatively related to CP concentration in the grain (R2 = 0.53; p < 0.10 and the time of MPR (tm was positively related to the amount of added N (R2 = 0.74; p < 0.05 and concentration of CP in the grain (R2 = 0.88; p < 0.01. It is likely that intensive N fertilization of maize limits ruminal digestion of maize starch. Due to the shift of starch digestion from the rumen to lower gastrointestinal tract better utilization of energy can be expected in maize grain of extensively fertilized maize than in the grain of maize, in which supply of N is sub-optimal.

  13. [Effects of phosphorus fertilization on yield of winter wheat and utilization of soil nitrogen].

    Science.gov (United States)

    Xing, Dan; Li, Shu-wen; Xia, Bo; Wen, Hong-da

    2015-02-01

    In order to evaluate the threshold of phosphorus (P) application rate and improve the utilization efficiency of fertilizers in Baoding region of Hebei Province, a field experiment was conducted to examine the impacts of P fertilization on wheat yield, soil NO(3-)-N and nitrogen use efficiency. Results showed that, compared with the CK (P0), all treatments with P application (P1, 120 kg · hm(-2); P2, 240 kg · hm(-2) and P3, 480 kg · hm(-2)) increased the plant height, flag leaf areas and total leaf areas per plant of winter wheat, which was conducive to the accumulation of photosynthetic products. In addition, P application increased the spike number, kernels per spike and yield of winter wheat but slightly decreased the grain mass per 1000 seeds. Of the P-fertilized treatments, P2 had the highest wheat yield of 6102 kg · hm(-2), which was similar to P1 but significantly greater than those of P0 and P3. Furthermore, P fertilization reduced the NO(3-)-N content in top soil layer although the total accumulation of NO3- was still rather high. The N grain production efficiencies (GPE(N)) and N uptake efficiencies (UE(N)) of P1 and P2 were similar but greater than the other treatments. The use efficiency (UR(P)) , agronomic efficiency (AE(P)) and partial productivity of P fertilizer (PFP(P)) in P1 were significantly greater than P2 and P3. In conclusion, the P application rate of 120 kg · hm(-2) (P1) in this study could be an appropriate threshold in Baoding, Hebei, from the aspects of wheat yield, nitrogen and phosphate use efficiencies and accumulation of soil NO3-.

  14. Nitrogen fertilization strategies, morphogenetic and structural features in Brachiaria decumbens deferred for 95 days

    Directory of Open Access Journals (Sweden)

    Fábio Andrade Teixeira

    2014-02-01

    Full Text Available The aim this work was to evaluate the morphogenic and structural characteristics of Brachiaria decumbens pastures to determine the most suitable nitrogen fertilization strategies, for pastures deferred for a period of 95 days. Four strategies of fertilization at the beginning and end of the summer (0-0, 100- 0, 50-50, 0-100 kg ha-1 N were studied, respectively, with four replications. The strategy of 100 kg ha-1 N applied at the end of the summer (0-100, followed the parceling strategy at the beginning and end of the summer (50-50 favored higher rates of leaf appearance and lower values of phyllochron. Greater rate of leaf elongation was observed for 0-100 strategy, resulting in 40% increase compared to pastures that were not fertilized. However, there was no effect of fertilization strategies on stem elongation rate, registering an average of 0.28 cm.dia-1. There was a higher blade:stem ratio for the stratum A (40 cm above the soil in all treatments, observing higher blade:stem ratio for strategies 0-100 and 50-50, at this stratum. There was no effect for the total number of leaves and final leaf length. However, greater stem lengths were observed in pastures with 0-100 fertilizer strategy, followed by the 50-50 strategy. The strategy of applying 100 kg ha-1 at the end of summer, followed by the strategy of 50 kg ha-1 nitrogen divided at the beginning and end of summer, promote greater influence on the morphogenic and structural traits, in pastures deferred for 95 days.

  15. Cultivar and nitrogen fertilizer rate affect yield and nitrogen use efficiency in irrigated durum wheat

    Science.gov (United States)

    Optimizing nitrogen (N) management and using cultivars with high N use efficiency (NUE) are of great importance for durum wheat (Triticum durum L.) producers in irrigated desert production systems. Field experiments with six durum wheat cultivars (Ocotillo, Orita, Kronos, Havasu, Duraking, and Toppe...

  16. Long-term reactive nitrogen loading alters soil carbon and microbial community properties in a subalpine forest ecosystem

    Science.gov (United States)

    Boot, Claudia M; Hall, Ed K.; Denef, Karolien; Baron, Jill S.

    2016-01-01

    Elevated nitrogen (N) deposition due to increased fossil fuel combustion and agricultural practices has altered global carbon (C) cycling. Additions of reactive N to N-limited environments are typically accompanied by increases in plant biomass. Soil C dynamics, however, have shown a range of different responses to the addition of reactive N that seem to be ecosystem dependent. We evaluated the effect of N amendments on biogeochemical characteristics and microbial responses of subalpine forest organic soils in order to develop a mechanistic understanding of how soils are affected by N amendments in subalpine ecosystems. We measured a suite of responses across three years (2011–2013) during two seasons (spring and fall). Following 17 years of N amendments, fertilized soils were more acidic (control mean 5.09, fertilized mean 4.68), and had lower %C (control mean 33.7% C, fertilized mean 29.8% C) and microbial biomass C by 22% relative to control plots. Shifts in biogeochemical properties in fertilized plots were associated with an altered microbial community driven by reduced arbuscular mycorrhizal (control mean 3.2 mol%, fertilized mean 2.5 mol%) and saprotrophic fungal groups (control mean 17.0 mol%, fertilized mean 15.2 mol%), as well as a decrease in N degrading microbial enzyme activity. Our results suggest that decreases in soil C in subalpine forests were in part driven by increased microbial degradation of soil organic matter and reduced inputs to soil organic matter in the form of microbial biomass.

  17. Nitrogen split dose fertilization, plant age and frost effects on phytochemical content and sensory properties of curly kale (Brassica oleracea L. var. sabellica).

    Science.gov (United States)

    Groenbaek, Marie; Jensen, Sidsel; Neugart, Susanne; Schreiner, Monika; Kidmose, Ulla; Kristensen, Hanne L

    2016-04-15

    We investigated how concentrations of sensory relevant compounds: glucosinolates (GLSs), flavonoid glycosides, hydroxycinnamic acid derivatives and sugars in kale responded to split dose and reduced nitrogen (N) fertilization, plant age and controlled frost exposure. In addition, frost effects on sensory properties combined with N supply were assessed. Seventeen week old kale plants showed decreased aliphatic GLSs at split dose N fertilization; whereas reduced N increased aliphatic and total GLSs. Ontogenetic effects were demonstrated for all compounds: sugars, aliphatic and total GLSs increased throughout plant development, whereas kaempferol and total flavonoid glycosides showed higher concentrations in 13 week old plants. Controlled frost exposure altered sugar composition slightly, but not GLSs or flavonoid glycosides. Reduced N supply resulted in less bitterness, astringency and pungent aroma, whereas frost exposure mainly influenced aroma and texture. N treatment explained most of the sensory variation. Producers should not rely on frost only to obtain altered sensory properties.

  18. Nitrogen fluxes at the root-soil interface show a mismatch of nitrogen fertilizer supply and sugarcane root uptake capacity

    Science.gov (United States)

    Inselsbacher, Erich; Schmidt, Susanne; Näsholm, Torgny; Robinson, Nicole; Guillou, Stéphane; Vinall, Kerry; Lakshmanan, Prakash; Brackin, Richard

    2016-04-01

    Nitrogen (N) uptake by agricultural crops is a key constituent of the global N cycle, as N captured by roots has a markedly different fate than N remaining in the soil. Global evidence indicates that only approximately 50% of applied N fertilizer is captured by crops, and the remainder can cause pollution via runoff and gaseous emissions. This inefficiency is of global concern, and requires innovation based on improved understanding of which N forms are available for and ultimately taken up by crops. However, current soil analysis methods based on destructive soil sampling provide little insight into delivery and acquisition of N forms by roots. Here, we present the results of a study in sugarcane fields receiving different fertilizer regimes comparing soil N supply rates with potential root N uptake rates. We applied microdialysis, a novel technique for in situ quantification of soil nutrient fluxes, to measure flux rates of inorganic N and amino acid N, and analyzed N uptake capacities of sugarcane roots using 15N labelled tracers. We found that in fertilized sugarcane soils, fluxes of inorganic N exceed the uptake capacities of sugarcane roots by several orders of magnitude. Contrary, fluxes of organic N closely matched roots' uptake capacity. These results indicate root uptake capacity constrains plant acquisition of inorganic N. This mismatch between soil N supply and root N uptake capacity is a likely key driver for low N efficiency in the studied crop system. Our results also suggest that the relative contribution of inorganic N for plant nutrition may be overestimated when relying on soil extracts as indicators for root-available N, and organic N may contribute more to crop N supply than is currently assumed. Overall, we show a new approach for examining in situ N relations in soil in context of crop N physiology, which provides a new avenue towards tailoring N fertilizer supply to match the specific uptake abilities and N demand of crops over the growth

  19. Effects of Long-Term Fertilization on Distribution of Organic Matters and Nitrogen in Cinnamon Soil Macro-Aggregates

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Soil samples collected from a 25-year long-term fertilizer experiment carried out on the Earth-cumulic-Orthic Anthrosols in semi-humid farmland ecological system, were used to study the distribution of soil organic matters, total nitrogen, nitrate nitrogen, and ammoniate nitrogen in different grades of soil macro-aggregates in order to study the effects of long-term application of organic manures in combination with chemical fertilizers. It is showed that the percentage of mass of the soil macro-aggregates with long-term application of fertilizers with sizes of 5-2 mm is increased compared with that of the samples with no fertilizer. It is easier to form lager size soil macro-aggregates by the long-term application of organic manures in combination with chemical fertilizers. The contents of organic matters, total nitrogen and nitrate nitrogen are all higher after treatments with different combinations of fertilizers, while there is a little effect on the contents of ammoniate nitrogen. The contents of organic matters, total nitrogen in the grades of soil macro-aggregates from the plough layers of the treated farmland exhibited significant difference. Moreover, the contents of organic matters and total nitrogen in the soil macro-aggregates with the size of 1-0.25 mm is the highest in all treated soil samples. The contents of nitrate nitrogen in soil macro-aggregates increased with the increasing of soil macro-aggregate size except those applied with chemical fertilizer and lower amount of corn stover. The results of correlation analysis revealed that there exists a significantly positive correlation between the percentage of mass of soil macro-aggregates with the size of 5-2 mm and the contents of organic matters, total nitrogen and nitrate nitrogen in the soil samples. However, the correlation between the percentage of mass of soil macro-aggregates with the size of 1-0.25 mm and the contents of total nitrogen and nitrate nitrogen is significantly negative. The

  20. Comparison of split nitrogen appliacation strategies in leek (Allium porrum) to reduce N fertilization on sandy soils in the Netherlands

    NARCIS (Netherlands)

    Geel, van W.C.A.; Meurs, E.J.J.; Radersma, S.; Grashoff, C.

    2006-01-01

    High nitrogen (N) fertilization to maximize production of leek (Allium porrum L.) combined with low N recovery can lead to considerable nitrogen pollution of the environment. A field trial was conducted in 2002 and 2003 on a sandy soil in the Netherlands. To synchronize N supply and N demand, two st

  1. Use of the analysis of plant growth and nutrient uptake for nitrogen fertilizer recommendations in open air vegetable growing.

    NARCIS (Netherlands)

    Titulaer, H.H.H.; Slangen, J.H.G.

    1990-01-01

    The plant growth and nitrogen uptake pattern of a crop with a short production period (iceberg lettuce) grown at two different periods in the growing season and a crop with a long growth period (gherkins) are analyzed in order to formulate an improved nitrogen fertilizer recommendation. A split

  2. Effect of zeolite on the nitrogen fertilizer efficiency in rice crop.

    Directory of Open Access Journals (Sweden)

    José Ezequiel Villarreal-Núñez

    2015-06-01

    Full Text Available The objective of this work was to evaluate the effect of zeolite on the efficiency of nitrogen fertilizer in rice crop. The experiment was conducted in Cacao, Tonosi, Los Santos, Panama, between August and December 2012 and 2013 under rainfed conditions.The Rice variety used was IDIAP FL 106-11 with seeding density of 110 kg/ha in a medium- fertility vertic Fluvisol. This study consisted of five treatments with four replications, following a completely randomized block design using N rate of 80 kg/ha mixed with different percentages of zeolite (0; 15; 25; 35 and 45%. The isotopic technique 15N 3% excess to determine the nitrogen fertilizer use efficiency (EUNF was used. Each experimental unit consisted of 15 m2 with three micro-plots of 1 m2 where 15N-labeled urea was applied at different times of the crop cycle to determine EUNF in each application. Top grain yields were obtained with 80 kg N + 45% zeolite/ha and 80 kg N + 15% zeolite/ha. A 7% EUNF increase was achieved with the addition of natural zeolite. Small doses of 12 kg/ha (15% of zeolite can improve EUNF; after subsequent experiments, it is recommended to reduce the amount of N applied in soils with similar soil and climatic conditions suitable for growing rice.

  3. Upland rice under no-tillage preceded by crops for soil cover and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Edemar Moro

    2013-12-01

    Full Text Available The grain yield of upland rice under no-tillage has been unsatisfactory and one reason could be the nitrate/ammonium balance in the soil. Cover crops and nitrogen fertilization can be used to change the nitrate/ammonium relation in the soil and improve conditions for the development of upland rice in the no-tillage (NT system. The aim was to study the effect of cover crops and nitrogen sources on grain yield of upland rice under no tillage. The study was carried out on the Fazenda Experimental Lageado, in Botucatu, State of São Paulo, Brazil, in an Oxisol area under no-tillage for six years. The experiment was arranged in a randomized block split-plot design with four replications. The plots consisted of six cover crop species (Brachiaria brizantha, B. decumbens, B. humidicola, B. ruziziensis, Pennisetum americanum, and Crotalaria spectabilis and the split-plots of seven forms of N fertilizer management. Millet is the best cover crop to precede upland rice under NT. The best form of N application, as nitrate, is in split rates or total rate at topdressing or an ammonium source with or without a nitrification inhibitor, in split doses. When the cover crops C. spectabilis, B. brizantha, B. decumbens, B. humidicola, and B. ruziziensis preceded rice, they induced the highest grain yield when rice was fertilized with N as ammonium sulfate source + nitrification inhibitor in split rates or total dose at topdressing.

  4. Effects of nitrogen fertilization on the acidity and salinity of greenhouse soils.

    Science.gov (United States)

    Han, Jiangpei; Shi, Jiachun; Zeng, Lingzao; Xu, Jianming; Wu, Laosheng

    2015-02-01

    A greenhouse pot experiment was conducted to study the effects of conventional nitrogen fertilization on soil acidity and salinity. Three N rates (urea; N0, 0 kg N ha(-1); N1, 600 kg N ha(-1); and N2, 1,200 kg N ha(-1)) were applied in five soils with different greenhouse cultivation years to evaluate soil acidification and salinization rate induced by nitrogen fertilizer in lettuce production. Both soil acidity and salinity increased significantly as N input increased after one season, with pH decrease ranging from 0.45 to 1.06 units and electrolytic conductivity increase from 0.24 to 0.68 mS cm(-1). An estimated 0.92 mol H(+) was produced for 1 mol (NO2 (-) + NO3 (-))-N accumulation in soil. The proton loading from nitrification was 14.3-27.3 and 12.1-58.2 kmol H(+) ha(-1) in the center of Shandong Province under N1 and N2 rate, respectively. However, the proton loading from the uptake of excess bases by lettuces was only 0.3-4.5 % of that from nitrification. Moreover, the release of protons induced the direct release of base cations and accelerated soil salinization. The increase of soil acidity and salinity was attributed to the nitrification of excess N fertilizer. Compared to the proton loading by lettuce, nitrification contributed more to soil acidification in greenhouse soils.

  5. Responses of Nitrogen and related enzyme Activities to Fertilization in Rhizosphere of Wheat

    Institute of Scientific and Technical Information of China (English)

    YUANLING; YUSHANGQI; 等

    1997-01-01

    In the present experiment,wheat seedlings(Trticucum aestivum L.)were grown on a purple soil with various fertilizer treatments in order to investigate the responses of nitrogen and related enzyme activities in the rhizosphere,The results revealed the increments of both organic matter and total N in the soil with the proximity to the growing roots,especially in treatment of supplying pig manure in combination with chemical fertilizer,suggesting that they could ome from root and microorganism exudation which could be intensified by inorganic-organic fertiliztion,being of benefit to improving the physical and bilogical envi-ronment in the rhizosphere of wheat.Much more inorganic N was observed in the fertilized soils surrounding wheat roots than in the CK treatment ,indicating ,the improvement of crop N supply in the rhizosphere of wheat by fertilization. The activities of invertase,urease and protease in the root zone were greatly enhanced as compared to those in the other parts of soil except that the urease activities were similar in the rhizospher and nonrhi-zosphere of the CK and pig manure treatments,indicating that invertase and protese could be produced by growing roots and rhizosphere microorganisms,in contrast to urease which could be stimulated by urea,Also,significant increment of chemical fertilizer combined with pig manure,suggested that fertilization not only accelerated the renewal of organic matter bu also enhanced bioavailability of organic N in that soil zone .This could be the reason why the total amount of inorganic N available for plants was increased more obviously in the rhizosphere of wheat of the fertilizaton treatments than in taht of the CK treatment.

  6. Nitrogen Use Efficiency of Coffee at the Vegetative Stage as Influenced by Fertilizer Application Method.

    Science.gov (United States)

    Salamanca-Jimenez, Alveiro; Doane, Timothy A; Horwath, William R

    2017-01-01

    Nitrogen (N) is the most limiting nutrient for coffee production in Colombia. An adequate supply is especially important during the vegetative period of growth, since any deficiency during this short period is known to have lasting effects on subsequent coffee bean production. Urea fertilizer is commonly applied on the soil surface since steep slopes hamper incorporation into soil, a practice which increases the risk of N volatilization. Little information is available on N recovery during early growth stages under different fertilizer application practices. The aim of this study was therefore to provide a comparison of (15)N uptake during the early vegetative growth stage under surface-applied and incorporation practices at two contrasting locations. The highest proportion of plant N derived from fertilizer (Ndff) occurred 60 days following application at the site with greater precipitation and soil organic matter, where surface application also increased the Ndff in roots and stems after 120 days. Although fertilizer N supplied approximately 20-29% of total plant N after 4 months, this fertilizer-derived N corresponded on average to only 5% of the total application, indicating that very little fertilizer (relative to how much is applied) reaches plants during this time. Apart from the difference in Ndff observed at the wetter site, there was no effect of application method on dry weight and macronutrient content in different plant components, root to shoot ratio, and leaf (13)C content. However, site effects were registered for most of these measurements, with the exception of total nutrient uptake. Similarly to Ndff trends, lower root/shoot ratio and higher concentrations of N, K, and Mg in aboveground biomass were found in the site with higher rainfall and soil organic matter, likely resulting from higher soil water and N availability. These findings provide new information useful as a direction for further research looking toward increasing NUE during the

  7. Nitrogen Use Efficiency of Coffee at the Vegetative Stage as Influenced by Fertilizer Application Method

    Science.gov (United States)

    Salamanca-Jimenez, Alveiro; Doane, Timothy A.; Horwath, William R.

    2017-01-01

    Nitrogen (N) is the most limiting nutrient for coffee production in Colombia. An adequate supply is especially important during the vegetative period of growth, since any deficiency during this short period is known to have lasting effects on subsequent coffee bean production. Urea fertilizer is commonly applied on the soil surface since steep slopes hamper incorporation into soil, a practice which increases the risk of N volatilization. Little information is available on N recovery during early growth stages under different fertilizer application practices. The aim of this study was therefore to provide a comparison of 15N uptake during the early vegetative growth stage under surface-applied and incorporation practices at two contrasting locations. The highest proportion of plant N derived from fertilizer (Ndff) occurred 60 days following application at the site with greater precipitation and soil organic matter, where surface application also increased the Ndff in roots and stems after 120 days. Although fertilizer N supplied approximately 20–29% of total plant N after 4 months, this fertilizer-derived N corresponded on average to only 5% of the total application, indicating that very little fertilizer (relative to how much is applied) reaches plants during this time. Apart from the difference in Ndff observed at the wetter site, there was no effect of application method on dry weight and macronutrient content in different plant components, root to shoot ratio, and leaf 13C content. However, site effects were registered for most of these measurements, with the exception of total nutrient uptake. Similarly to Ndff trends, lower root/shoot ratio and higher concentrations of N, K, and Mg in aboveground biomass were found in the site with higher rainfall and soil organic matter, likely resulting from higher soil water and N availability. These findings provide new information useful as a direction for further research looking toward increasing NUE during the

  8. Reducing Nitrogen Pollution while Decreasing Farmers' Costs and Increasing Fertilizer Industry Profits.

    Science.gov (United States)

    Kanter, David R; Zhang, Xin; Mauzerall, Denise L

    2015-03-01

    Nitrogen (N) pollution is emerging as one of the most important environmental issues of the 21st Century, contributing to air and water pollution, climate change, and stratospheric ozone depletion. With agriculture being the dominant source, we tested whether it is possible to reduce agricultural N pollution in a way that benefits the environment, reduces farmers' costs, and increases fertilizer industry profitability, thereby creating a "sweet spot" for decision-makers that could significantly increase the viability of improved N management initiatives. Although studies of the economic impacts of improved N management have begun to take into account farmers and the environment, this is the first study to consider the fertilizer industry. Our "sweet spot" hypothesis is evaluated via a cost-benefit analysis of moderate and ambitious N use efficiency targets in U.S. and China corn sectors over the period 2015-2035. We use a blend of publicly available crop and energy price projections, original time-series modeling, and expert elicitation. The results present a mixed picture: although the potential for a "sweet spot" exists in both countries, it is more likely that one occurs in China due to the currently extensive overapplication of fertilizer, which creates a greater potential for farmers and the fertilizer industry to gain economically from improved N management. Nevertheless, the environmental benefits of improving N management consistently dwarf the economic impacts on farmers and the fertilizer industry in both countries, suggesting that viable policy options could include incentives to farmers and the fertilizer industry to increase their support for N management policies.

  9. Effect of nitrogen fertilization and residue management practices on ammonia emissions from subtropical sugarcane production

    Science.gov (United States)

    mudi, Sanku Datta; Wang, Jim J.; Dodla, Syam Kumar; Arceneaux, Allen; Viator, H. P.

    2016-08-01

    Ammonia (NH3) emission from soil is a loss of nitrogen (N) nutrient for plant production as well as an issue of air quality, due to the fact that it is an active precursor of airborne particulate matters. Ammonia also acts as a secondary source of nitrous oxide (N2O) emission when present in the soil. In this study, the impacts of different sources of N fertilizers and harvest residue management schemes on NH3 emissions from sugarcane production were evaluated based on an active chamber method. The field experiment plots consisting of two sources of N fertilizer (urea and urea ammonium nitrate (UAN)) and two common residue management practices, namely residue retained (RR) and residue burned (RB), were established on a Commerce silt loam. The NH3 volatilized following N fertilizer application was collected in an impinger containing diluted citric acid and was subsequently analyzed using ion chromatography. The NH3 loss was primarily found within 3-4 weeks after N application. Average seasonal soil NH3 flux was significantly greater in urea plots with NH3-N emission factor (EF) twice or more than in UAN plots (2.4-5.6% vs. 1.2-1.7%). The RR residue management scheme had much higher NH3 volatilization than the RB treatment regardless of N fertilizer sources, corresponding to generally higher soil moisture levels in the former. Ammonia-N emissions in N fertilizer-treated sugarcane fields increased with increasing soil water-filled pore space (WFPS) up to 45-55% observed in the field. Both N fertilizer sources and residue management approaches significantly affected NH3 emissions.

  10. Soil pH Dynamics and Nitrogen Transformations Under Long-Term Chemical Fertilization in Four Typical Chinese Croplands

    Institute of Scientific and Technical Information of China (English)

    MENG Hong-qi; XU Ming-gang; L Jia-long; HE Xin-hua; LI Jian-wei; SHI Xiao-jun; PENG Chang; WANG Bo-ren; ZHANG Hui-min

    2013-01-01

    Long-term fertilization experiment provides the platform for understanding the proton budgets in nitrogen transformations of agricultural ecosystems. We analyzed the historical (1990-2005) observations on four agricultural long-term experiments in China (Changping, Chongqing, Gongzhuling and Qiyang) under four different fertilizations, i.e., no-fertilizer (control), sole chemical nitrogen fertilizer (FN), sole chemical phosphorous and potassium fertilizers (FPK) and chemical nitrogen, phosphorous and potassium fertilizers (FNPK). The significant decline in topsoil pH was caused not only by chemical N fertilization (0.29 and 0.89∆pH at Gongzhuling and Qiyang, respectively) but also by chemical PK fertilization (0.59∆pH at Gongzhuling). The enhancement of available nutrients in the topsoil due to long-term direct nutrients supply with chemical fertilizers was in the descending order of available P (168-599%)>available K (16-189%)>available N (9-33%). The relative rate of soil pH decline was lower under long-term judicious chemical fertilization (-0.036-0.034 ∆pH yr-1) than that under long-term sole N or PK fertilization (0.016-0.086 ∆pH yr-1). Long-term judicious chemical fertilization with N, P and K elements decreases the nutritional limitation to normal crop growth, under which more N output was distributed in biomass removal rather than the loss via nitrate leaching. We concluded that the N distribution percentage of nitrate leaching to biomass removal might be a suitable indicator to the sensitivity of agricultural ecosystems to acid inputs.

  11. Nitrogen fertilization of fall panicum cultivars (Panicum dichotomiflorum Michx.: biochemical and agronomical aspects

    Directory of Open Access Journals (Sweden)

    Soratto Rogério Peres

    2004-01-01

    Full Text Available Information on improved fall panicum cultivars and agronomical pratices is scarce because of the relatively small importance of this crop in Brazil. The present study aimed to evaluate levels of nitrogen sidedressing on plant development and biochemical characteristics of two fall panicum cultivars. The experiment was set up under plastic tunnel conditions in Botucatu, São Paulo, Brazil, with plants growing inside asbestos-cement boxes. The experimental design was a randomized block setup and treatments consisted of six levels of nitrogen fertilization (0, 40, 80, 120, 160, and 200 mg L-1 applied at the onset of tillering on two fall panicum cultivars (AL Mogi and AL Tibagi. The application of increasing levels of nitrogen to fall panicum plants increased chlorophyll content, total amino acids, plant dry matter nitrogen content, plant height, tillering and grain yield, and decreased plant dry matter sugar content. The cultivars had similar performances in relation to the evaluated variables, as a response to nitrogen sidedressing.

  12. Key ecological responses to nitrogen are altered by climate change

    Science.gov (United States)

    Here we review the effects of nitrogen and climate (e.g. temperature and precipitation) on four aspects of ecosystem structure and function including hydrologic-coupled nitrogen cycling, carbon cycling, acidification and biodiversity.

  13. Effect of nitrogen fertilization and seedling density on fine rice yield in Faisalabad, Pakistan

    Directory of Open Access Journals (Sweden)

    Ehsanullah, Khawar Jabran, Ghulam Asghar

    2012-11-01

    Full Text Available Rice seedlings density per hill and optimal nitrogen fertilization exercises a strong influence on rice growth and grain yield due to competitive effects both on the vegetative and reproductive development. Present study was conducted to explore the possible role of nitrogen fertilizer and seedlings density on rice kernel yield and yield contributing factors. Three nitrogen (N rates viz. 75, 100 and 125 kg ha-1 and four seedling densities (1, 2, 3 and 4 seedlings hill-1 were tested in the study. Panicle length, number of branches per panicle and kernels per panicle remained unaffected at varying levels of N and rice seedlings per hill. Two, 3 and 4 seedlings per hill along with 100 and 125 kg N ha-1 resulted in maximum rice kernel yield and harvest index due to enhanced number of panicle bearing tillers and 1000-kernel weight. While application of N at 75 kg ha-1 along with one seedling per hill revealed the poorest results with respect to 1000-kernel weight, panicle bearing tillers per hill and the kernel yield of rice. In crux, two seedlings hill-1 at 100 kg N ha-1 proved to be the best combination for maximizing the rice yield in the Faisalabad area of Pakistan.

  14. Carotenoid Accumulation by Carrot Storage Roots in Relation to Nitrogen Fertilization Level

    Directory of Open Access Journals (Sweden)

    Marek GAJEWSKI

    2010-06-01

    Full Text Available The accumulation of carotenoid compounds in carrot (Daucus carota L. roots of five cultivars, in relation to different nitrogen fertilization levels was investigated. The experiment was carried out at the Warsaw University of Life Sciences. Carrot cultivars ‘Karotan’ F1, ‘Trafford’ F1, ‘Krakow’ F1, ‘Komarno’ F1 and ‘HY 7842’ were used in the study. Nitrogen fertilization was applied as urea form, in doses ranging from 0 to 120 kg N ha–1, and on two terms: pre-sowing and in the middle of the growing season. The carrot seeds were sown at the beginning of May and the roots were harvested in mid-October at maturity. Total carotenoids and β-carotene contents in the carrot roots were determined after the harvest by means of the standard spectrophotometric method. CIE L*a*b* colour parameters of the roots and the juice, as well as dry matter in the roots were determined. Results of the experiment showed that carotenoid accumulation in the roots was significantly affected by carrot genotype. ‘HY7842’ carrot showed the highest accumulation of total carotenoids and β-carotene. Nitrogen in the rates applied, did not significantly influence carotenoid content in the roots. Moderate correlation between carotenoid content and colour a* parameter (redness intensity of the roots and the juice was found.

  15. [Effects of nitrogen fertilization on soil respiration during maize growth season].

    Science.gov (United States)

    Li, Jian-Min; Ding, Wei-Xin; Cai, Zu-Cong

    2010-08-01

    In order to understand how nitrogen (N) fertilization affects soil respiration, a pot experiment with splitting-root compartment and by root-cutting was conducted in a greenhouse. The experiment had four treatments, i. e., unplanted and N-unfertilized (CKO), unplanted but fertilized with 150 mg N x kg(-1) CKN), planted maize (Zea mays L.) but N-unfertilized (MO), and planted maize and fertilized with 150 mg N x kg(-1) (MN). Soil respiration, soil basal respiration, root respiration, and rhizospheric microbial respiration were measured simultaneously. In unplanted soils (treatments CKO and CKN), soil respiration rate (soil basal respiration) ranged from 13.41 to 77.27 mg C x m(-2) x h(-1), and N fertilization had less effect; while in planted soils, the averaged soil respiration rate in treatment MN amounted to 138.54 mg C x m(-2) x h(-1), and was 17.7% higher (P < 0.05) than that in treatment MO. This increment mainly occurred at tasselling and flowering stages. During maize growth season, the contribution of soil basal respiration, root respiration, and rhizospheric microbial respiration to soil respiration in treatments MN and MO was 36.2%, 45.9%, and 17.9%, and 35.5%, 36.9%, and 37.6%, respectively.

  16. Nitrogen fluxes from irrigated common‑bean as affected by mulching and mineral fertilization

    Directory of Open Access Journals (Sweden)

    Márcia Thaís de Melo Carvalho

    2013-05-01

    Full Text Available The objective of this work was to measure the fluxes of N2O‑N and NH3‑N throughout the growing season of irrigated common‑bean (Phaseolus vulgaris, as affected by mulching and mineral fertilization. Fluxes of N2O‑N and NH3‑N were evaluated in areas with or without Congo signal grass mulching (Urochloa ruziziensis or mineral fertilization. Fluxes of N were also measured in a native Cerrado area, which served as reference. Total N2O‑N and NH3‑N emissions were positively related to the increasing concentrations of moisture, ammonium, and nitrate in the crop system, within 0.5 m soil depth. Carbon content in the substrate and microbial biomass within 0.1 m soil depth were favoured by Congo signal grass and related to higher emissions of N2O‑N, regardless of N fertilization. Emission factors (N losses from the applied mineral nitrogen for N2O‑N (0.01-0.02% and NH3‑N (0.3-0.6% were lower than the default value recognized by the Intergovernmental Panel on Climate Change. Mulch of Congo signal grass benefits N2O‑N emission regardless of N fertilization.

  17. Effect of Nitrogen Fertilizer on Combined Forms and Transformation of Fluorine in Tea Garden Soil

    Directory of Open Access Journals (Sweden)

    ZHANG Yong-li

    2015-10-01

    Full Text Available In order to investigate the effect of nitrogen fertilizer on combined forms and transformation of fluorine in tea garden soil, soil pot experiment was carried out. The research object was red-yellow soil in Shizipu tea plantation in the south of Anhui Province. Five treatments were N0P0K0 (CK, N0P1K1 (N0, N1P1K1 (N1, N2P1K1 (N2, N3P1K1 (N3. Water-soluble fluorine content, exchangeable fluorine content, Fe/Mn oxide-bound fluorine content, organic matter-bound fluorine content, ammonium nitrogen content and soil pH value in 0~15 cm soil layer were analyzed in 10, 20, 30, 50, 70, 90 days after fertilization. The results showed that compared with CK, in the short term (10 or 20 days after applying NPK, the content of water-soluble fluorine in 0~15 cm soil layer was decreased and the content of exchangeable fluorine, Fe/Mn oxide-bound fluorine and organic matter-bound fluorine were increased. After 20 days, the content of soil water-soluble fluorine was increased and the content of soil exchangeable fluorine, Fe/Mn oxide-bound fluorine and organic matter-bound fluorine were reduced. The effect on water-soluble fluorine and exchangeable fluorine increased with time and the application rate of nitrogen. The content of water-soluble fluorine in tea garden soil had a moderately positive correlation with the application rate of nitrogen while the content of exchangeable fluorine had a moderately or highly negative correlation with the application rate of nitrogen. The content of water-soluble fluorine had a quite highly negative correlation with the soil pH (P<0.01, but the content of exchangeable fluorine had a moderately or highly negative correlation with the soil pH (P<0.01. Therefore, nitrogen fertilizer changed the soil pH during its form transformation and thus affected the transformation and the availability of fluorine in soil.

  18. Morphophysiological characteristcs and nutrition of aries grass (Panicum maximum, jacq. with nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Marcia Atauri Cardeli de Lucena

    2013-12-01

    Full Text Available Low availability of nitrogen (N is a factor that limits forage production. Pastures are mostly formed of grasses, which need large N amounts to sustain high yields. Additionally, the availability of this nutrient affects the persistence and quality of the forage produced. However, when applying fertilizers containing nitrogen up to 50% can be lost, making their use costly for farmers. N is a highly volatile gas, and urea, widely used in agriculture, contains 46% N. When urea comes in contact with moisture in the soil, hydrolysis occurs due to the precipitation of the enzyme urease, accelerating the transformation of urea into ammonia, which can be lost by volatilization. One of the techniques to increase the efficiency of using urea is application of nitrogen fertilizers along with urease inhibitors, to retard the breakdown of urea so that it becomes incorporated in the soil slowly. One of the inhibitors used is N-(n-butyl phosphate triamide (NBPT. This study aimed to assess the effect of nitrogen sources and doses on some productive characteristics of Áries grass (Panicum maximum, Jacq to find ways to improve the effectiveness of nitrogen application. The tests were performed at Centro Nutrição Animal e Pastagens – Instituto de Zootecnia in Nova Odessa, São Paulo, from March to August 2012. The experimental design was randomized blocks, with five replications in 2 x 3 factorial setup, where we studied the use of urea and urea containing urease inhibitor (NPBT, in pottery vessels (3.34 dm3. The treatments involved the following rates of N application: 0, 75.0 and 150.0 kg ha-1. The traits analyzed were dry biomass, leaf dry weight, dry weight of pseudostems, number of tillers, leaf area, nitrogen concentration and accumulation, and concentrations of chlorophyll and flavonoids. The data were analyzed using de GLM procedure of the SAS program. The results showed that nitrogen promoted considerable improvements in the plants, contributing to

  19. Effect of Nitrogen Fertilizer on Light Interception and Light Extinction Coefficient in Different Wheat Cultivars

    Directory of Open Access Journals (Sweden)

    F Samadiyan

    2016-07-01

    Full Text Available Introduction Wheat (Triticum aestivum is a cereal grain, originated from the levant region of the near east and Ethiopian highlands, currently cultivated worldwide. Light extinction coefficient K is a coefficient that represents the amount of light reduced by the plant. Light or radiation extinction coefficient is a concept that expresses the light penetration decrease into the canopy in the way the upper leaves of the canopy with less angles have lower amount of K in comparison with the horizontal leaves. Green et al., (2003 stated that nitrogen fertilizer increased light absorption by plant leaves; and affects the yield. The distribution patterns of nitrogen allocation in leaves are more exposed therefore photosynthesis rate per unit leaf area and canopy were optimized. Differences in canopy structure by the light extinction coefficient (k of the Act Lambert - Beer is described, along LAI differing due to different species and genotypes which are important factors in absorption and light use efficiency. This experiment was performed to evaluate the maximum light absorption and light extinction coefficient in different levels of nitrogen usage and wheat cultivars. Materials and Methods An experiment was conducted during 2011-2012 on a research farm of Islamic Azad University, Isfahan Branch, located in Khatoon Abad Village (northern latitude of 320 and 40´ and eastern longitude of 510 and 48´ with altitude of 1555 m above sea level. A split plot layout within randomized complete block design was used with three replications. Main plots were consisted in four levels of N fertilizer (0, 50, 100 and 150 kg ha-1 from an urea source in main plots and different cultivars of wheat included Pishtaz, Sepahan and SW-486 in sub plots. Planting was performed on 14 November 2011 and at a density of 400 plants per square meter. In order to strengthen the land and required elements for plant regarding soil test and treatments based on the test plan, the

  20. Effects of Nitrogen Fertilization of Boreal Forest Land on Greenhouse Gas Flows

    Science.gov (United States)

    Gustavsson, L.; Sathre, R. C.

    2011-12-01

    Forest growth on mineral soils in boreal regions is often limited by a low availability of nitrogen (N), and fertilization has shown particular promise in increasing yields in productive boreal forests. In this study we analyze the greenhouse gas (GHG) implications of increasing forest biomass production through N fertilization and using the increased production for bioenergy and biomaterials in place of non-renewable fuels and materials. We begin with a stand-level analysis of the radiative forcing implications of forest fertilization and biomass substitution, with explicit consideration of the temporal patterns of GHG emissions to and removals from the atmosphere. We model and compare the production and use of biomass from a hectare of fertilized and non-fertilized forest land in northern Sweden. We calculate the annual net emissions of CO2, N2O and CH4 for each system, over a 225-year period with 1-year time steps. We calculate the annual atmospheric concentration decay of each of these emissions, and calculate the resulting annual changes in instantaneous and cumulative radiative forcing. We find that forest fertilization can significantly increase biomass production, which increases the potential for material and energy substitution. The average carbon stock in tree biomass, forest soils and wood products all increase when fertilization is used. The additional GHG emissions due to fertilizer production and application are small compared to increases in carbon stock and substitution benefits. By the end of the 225-year simulation period, the cumulative radiative forcing reduction of the fertilized stand is over twice that of the non-fertilized stand. We then consider a steady-state landscape-level scenario where 10% of Swedish forest land is fertilized. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net GHG benefits

  1. A nitrogen fertilization field study of carbon-13 and nitrogen-15 transfers in ectomycorrhizas of Pinus sabiniana.

    Science.gov (United States)

    Albarracín, María Victoria; Six, Johan; Houlton, Benjamin Z; Bledsoe, Caroline S

    2013-12-01

    Ectomycorrhizal (EM) fungi form relationships with higher plants; plants transfer C to fungi, and fungi transfer nutrients to their host. While evidence indicates that this interaction is largely mutualistic, less is known about how nutrient supply and EM associates may alter C and nutrient exchanges, especially in intact plant-soil-microbe systems in the field. In a dual-labeling experiment with N fertilization, we used C and N stable isotopes to examine in situ transfers in EM pine trees in a Pinus sabiniana woodland in northern California. We added (15)NH4SO2 and (13)CO2 to track (13)C transfer from pine needles to EM roots and (15)N transfer from soil to EM roots and pine needles. Transfers of (13)C and (15)N differed with EM morphotype and with N fertilization. The brown morphotype received the least C per unit of N transferred (5:1); in contrast red and gold morphotypes gained more C and transferred less N (17:1 and 25:1, respectively). N fertilization increased N retention by ectomycorrhizas (EMs) but did not increase N transfer from EMs to pine needles. Therefore N fertilization positively affected both nutrient and C gains by EMs, increasing net C flows and N retention in EMs. Our work on intact and native trees/EM associations thereby extends earlier conclusions based on pot studies with young plants and culturable EM fungi; our results support the concept that EM-host relationships depend on species-level differences as well as responses to soil resources such as N.

  2. Productivity of irrigated beans due to sources of stabilized nitrogen fertilizer and controlled release

    OpenAIRE

    Tatiely Gomes Bernardes; Pedro Marques da Silveira; Marcia Thaís de Melo Carvalho; Beáta Emöke Madari; Maria da Conceição Santana Carvalho

    2015-01-01

    ABSTRACT New nitrogen fertilizers are available in the market actually, however, does not have results on the efficiency of the Cerrado conditions. With that objective of this study was to evaluate the effect of urea including stabilized and controlled release urea on yield of irrigated common beans (Phaseolus vulgaris L) in no-tillage system. The experiment was conducted in the winter crop, at Embrapa Arroz e Feijão, in Santo Antônio de Goiás, State of Goiás, Brazil. The experimental design ...

  3. Effect of Long-Term Fertilization on Organic Nitrogen Forms in a Calcareous Alluvial Soil on the North China Plain

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to illustrate the change of nitrogen (N) supply capacity after long-term application of manure and chemical fertilizer, as well as to properly manage soil fertility through fertilizer application under the soil-climatic conditions of the North China Plain, organic N forms were quantified in the topsoil with different manure and chemical fertilizer treatments in a 15-year fertilizer experiment in a Chinese calcareous alluvial soil Soil total N (TN) and various organic N forms were significantly influenced by long-term application of chemical fertilizer and manure. TN, total hydrolysable N, acid-insoluble N, amino acid N and ammonium N in the soil increased significantly (P < 0.05) with increasing manure and fertilizer N rates, but were not influenced by increasing P rates. Also, application of manure or N fertilizer or P fertilizer did not significantly influence either the quantity of amino sugar N or its proportion of TN. Application of manure significantly increased (P < 0.05) hydrolysable unknown N, but adding N or P did not. In addition, application of manure or N fertilizer or P fertilizer did not significantly influence the proportions of different soil organic N forms.

  4. Comparison of plasma generated nitrogen fertilizer to conventional fertilizers ammonium nitrate and sodium nitrate for pre-emergent and seedling growth

    Science.gov (United States)

    Andhavarapu, A.; King, W.; Lindsay, A.; Byrns, B.; Knappe, D.; Fonteno, W.; Shannon, S.

    2014-10-01

    Plasma source generated nitrogen fertilizer is compared to conventional nitrogen fertilizers in water for plant growth. Root, shoot sizes, and weights are used to examine differences between plant treatment groups. With a simple coaxial structure creating a large-volume atmospheric glow discharge, a 162 MHz generator drives the air plasma. The VHF plasma source emits a steady state glow; the high drive frequency is believed to inhibit the glow-to-arc transition for non-thermal discharge generation. To create the plasma activated water (PAW) solutions used for plant treatment, the discharge is held over distilled water until a 100 ppm nitrate aqueous concentration is achieved. The discharge is used to incorporate nitrogen species into aqueous solution, which is used to fertilize radishes, marigolds, and tomatoes. In a four week experiment, these plants are watered with four different solutions: tap water, dissolved ammonium nitrate DI water, dissolved sodium nitrate DI water, and PAW. Ammonium nitrate solution has the same amount of total nitrogen as PAW; sodium nitrate solution has the same amount of nitrate as PAW. T-tests are used to determine statistical significance in plant group growth differences. PAW fertilization chemical mechanisms are presented.

  5. Nitrogen deposition alters soil chemical properties and bacterial communities in the Inner Mongolia grassland

    Institute of Scientific and Technical Information of China (English)

    Ximei Zhang; Xingguo Han

    2012-01-01

    Nitrogen deposition has dramatically altered biodiversity and ecosystem functioning on the earth; however,its effects on soil bacterial community and the underlying mechanisms of these effects have not been thoroughly examined.Changes in ecosystems caused by nitrogen deposition have traditionally been attributed to increased nitrogen content.In fact,nitrogen deposition not only leads to increased soil total N content,but also changes in the NH4+-N content,NO3--N content and pH,as well as changes in the heterogeneity of the four indexes.The soil indexes for these four factors,their heterogeneity and even the plant community might be routes through which nitrogen deposition alters the bacterial community.Here,we describe a 6-year nitrogen addition experiment conducted in a typical steppe ecosystem to investigate the ecological mechanism by which nitrogen deposition alters bacterial abundance,diversity and composition.We found that various characteristics of the bacterial community were explained by different environmental factors.Nitrogen deposition decreased bacterial abundance that is positively related to soil pH value.In addition,nitrogen addition decreased bacterial diversity,which is negatively related to soil total N content and positively related to soil NO3--N heterogeneity.Finally,nitrogen.addition altered bacterial composition that is significantly related to soil NH4+-N content.Although nitrogen deposition significantly altered plant biomass,diversity and composition,these characteristics of plant community did not have a significant impact on processes of nitrogen deposition that led to alterations in bacterial abundance,diversity and composition.Therefore,more sensitive molecular technologies should be adopted to detect the subtle shifts of microbial community structure induced by the changes of plant community upon nitrogen deposition.

  6. The effects of chronic nitrogen fertilization on alpine tundra soil microbial communities: implications for carbon and nitrogen cycling.

    Science.gov (United States)

    Nemergut, Diana R; Townsend, Alan R; Sattin, Sarah R; Freeman, Kristen R; Fierer, Noah; Neff, Jason C; Bowman, William D; Schadt, Christopher W; Weintraub, Michael N; Schmidt, Steven K

    2008-11-01

    Many studies have shown that changes in nitrogen (N) availability affect primary productivity in a variety of terrestrial systems, but less is known about the effects of the changing N cycle on soil organic matter (SOM) decomposition. We used a variety of techniques to examine the effects of chronic N amendments on SOM chemistry and microbial community structure and function in an alpine tundra soil. We collected surface soil (0-5 cm) samples from five control and five long-term N-amended plots established and maintained at the Niwot Ridge Long-term Ecological Research (LTER) site. Samples were bulked by treatment and all analyses were conducted on composite samples. The fungal community shifted in response to N amendments, with a decrease in the relative abundance of basidiomycetes. Bacterial community composition also shifted in the fertilized soil, with increases in the relative abundance of sequences related to the Bacteroidetes and Gemmatimonadetes, and decreases in the relative abundance of the Verrucomicrobia. We did not uncover any bacterial sequences that were closely related to known nitrifiers in either soil, but sequences related to archaeal nitrifiers were found in control soils. The ratio of fungi to bacteria did not change in the N-amended soils, but the ratio of archaea to bacteria dropped from 20% to less than 1% in the N-amended plots. Comparisons of aliphatic and aromatic carbon compounds, two broad categories of soil carbon compounds, revealed no between treatment differences. However, G-lignins were found in higher relative abundance in the fertilized soils, while proteins were detected in lower relative abundance. Finally, the activities of two soil enzymes involved in N cycling changed in response to chronic N amendments. These results suggest that chronic N fertilization induces significant shifts in soil carbon dynamics that correspond to shifts in microbial community structure and function.

  7. Nitrogen Fertilization for Optimizing the Quality and Yield of Shade Grown Cuban Cigar Tobacco: Required Nitrogen Amounts, Application Schedules, Adequate Leaf Nitrogen Levels, and Early Season Diagnostic Tests

    Directory of Open Access Journals (Sweden)

    Borges A

    2014-12-01

    Full Text Available Nitrogen (N fertilizers have a decisive influence on the yield and quality of tobacco. Yield, percentage of plant N, wrapper leaf quality, and nicotine content are all important quality characteristics in tobacco growing. This work is an attempt to provide a tool for optimizing mineral N nutrition for Cuban cigar tobacco, using a strategy that links N supply with leaf N concentration and wrapper yield. Similar approaches developed worldwide have mainly involved Virginia and Burley tobacco types but not Cuban cigar tobacco. The objective of the current work is to identify the effects of fertilizer N levels and timing of application on each of the mentioned quality factors for shade grown Cuban cigar tobacco. Another purpose is to explore the usefulness of a quick method of assessing the N status of plants based on measuring leaf transmission at two different wavelengths (650 and 940 nm. The experiments were done in the main tobacco growing area of Cuba (Vueltabajo. In each experiment, nine separate treatments were used covering different levels and times of fertilizer N application. The same experiment was carried out in three different years (2005-2006, 2006-2007, 2007-2008 but as the results were similar only one set of data is described (2006-2007. The patterns of response to N fertilizer of all four quality measurements, including yield and wrapper leaf quality, were similar in the different replications of the experiments. The optimal fertilizer level was 140-190 kg N/ha (40% applied on days 8-10 after transplanting and 60% on days 18-20 after transplanting. The optimal N concentration of leaves taken at the central foliar level of the middle stalk position was 4.3-4.7% at harvest time. Leaf transmission measurements by means of the SPAD-502 Chlorophyll Meter in the early stages of growth were correlated with leaf chlorophyll and N concentration and provide an excellent guide for predicting Cuban cigar tobacco wrapper leaf yield.

  8. Autoregulation of Nodulation Interferes with Impacts of Nitrogen Fertilization Levels on the Leaf-Associated Bacterial Community in Soybeans ▿ †

    OpenAIRE

    2011-01-01

    The diversities leaf-associated bacteria on nonnodulated (Nod−), wild-type nodulated (Nod+), and hypernodulated (Nod++) soybeans were evaluated by clone library analyses of the 16S rRNA gene. To analyze the impact of nitrogen fertilization on the bacterial leaf community, soybeans were treated with standard nitrogen (SN) (15 kg N ha−1) or heavy nitrogen (HN) (615 kg N ha−1) fertilization. Under SN fertilization, the relative abundance of Alphaproteobacteria was significantly higher in Nod− an...

  9. Effects of different levels of nitrogen fertilizer and sowing dates on

    Directory of Open Access Journals (Sweden)

    korosh ehteramian

    2009-06-01

    Full Text Available The purpose of this research was to determine the optimal level of nitrogen fertilizer and planting date for cumin (Cuminum cyminum L. planting in Kooshkak region located in Doroodzan Dam Areas which represents a typical semiarid region. This research was carried out in the fall and winter 2000 and using a factorial experiment with two factors based on completely randomized block design with nitrogen fertilizer at three rates (0, 30, and 60 kg N ha-1 and sowing date (Nov. 6th, Dec. 21th, Feb. 6th, and March 6th in four replications. The effects of different nitrogen rates were significant on plant height, number of umbrella per plant and number of seed per umbrella, but it was not significant on number of seeds per plant, 1000-seed weight, biological yield, seed yield and harvest index. The effects of sowing dates were significant on number of seeds per umbrella, number of seeds per plant; 1000-seed weight, biological yield and seed yield; but it was not significant on plant height and harvest index. The interaction of nitrogen rates and sowing dates were significant on plant height, number of umbrella per plant and seed yield, but it was not significant on number of seeds per umbrella, number of seeds per plant, 1000-seed weight, biological yield and harvest index. It was concluded that for obtaining the high cumin yield, application of 30 kg N ha-1 and the late planting date (February 6th and March 6th due to probable winter cold, are recommended for this region.

  10. HOW DOES BIOCHAR AND BIOCHAR WITH NITROGEN FERTILIZATION INFLUENCE SOIL REACTION?

    Directory of Open Access Journals (Sweden)

    Vladimír Šimanský

    2017-09-01

    Full Text Available Biochar usually has a neutralizing effect therefore it is recommended for application to acid soils due to its potential to increase a soil pH. The aims of this study were (1. to quantify the role of different rates of biochar and biochar in combination with N fertilization on change of soil pH, and (2. to evaluate the dynamic changes of soil pH in relation with doses of biochar and biochar with N fertilization. A field experiment was conducted with different biochar application rates: B0 control (0 t ha-1, B10 (10 t ha-1 and B20 (20 t ha-1 and 0, 40 and 80 kg N ha–1 of nitrogen fertilizer (N0, N40, N80 on silt loam Haplic Luvisol at the locality of Dolná Malanta (Slovakia in 2014. Their effects were investigated after vegetation season of spring barley and spring wheat (once a month: from April to July in 2014 and 2016, respectively. Experimental results indicate that the soil pHH2O in B0N0, B10N0, B20N0, B10N40, B20N40, B10N80 and B20N80 were 6.23, 6.45, 6.60, 6.77, 6.48, 6.36 and 6.60, respectively. The results of LSD test showed statistically significant differences between soil pH in control treatment and treatments with biochar and biochar with N fertilization. The most significant effect on increase of soil pH was observed in B10N40. During whole period, after application of biochar and biochar with N fertilization the values of pHKCl were gradually decreased in all treatments.

  11. Modeling the impacts of alternative fertilization methods on nitrogen loading in rice production in Shanghai.

    Science.gov (United States)

    Zhao, Zheng; Sha, Zhimin; Liu, Yibo; Wu, Shuhang; Zhang, Hanlin; Li, Changsheng; Zhao, Qi; Cao, Linkui

    2016-10-01

    Nitrogen (N) loss from paddy fields is an important source of agricultural non-point source pollution that leads to eutrophication of water bodies and degradation of water quality. The impacts of alternative N fertilizer management practices on N loading (N loss through runoff and leaching) from paddy fields in Shanghai were assessed using a process-based biogeochemical model, DNDC. The results indicated that the current fertilization rate in paddy fields of Shanghai (300kgN/ha) exceeds the actual rice demand and has led to substantial N loading of 1142±276kg. The combined application of urea at 150kgN/ha and organic manure at 100kgN/ha was identified as the best fertilization method for rice cultivation in Shanghai; this application maintained optimal rice yields and significantly reduced N loading to 714±151kg in comparison with the current fertilization rate. A sensitivity test was conducted with various input parameters, and the results indicated that fertilization, precipitation and soil properties were the most sensitive factors that regulate N loss from paddy fields. The variability of soil properties, especially SOC led to high uncertainties in the simulated results. Therefore, the local climate conditions and soil properties should be taken into account in the identification of the best management practice (BMP) for rice cultivation, given the high spatially heterogeneous N loading values across all towns used in the simulation. The DNDC model is an effective approach for simulating and predicting N loading in paddy fields under alternative agricultural management practices.

  12. Can nitrogen fertilization aid restoration of mature tree productivity in degraded dryland riverine ecosystems?

    Science.gov (United States)

    Andersen, Douglas C.; Adair, Elizabeth Carol; Nelson, Sigfrid Mark; Binkley, Dan

    2014-01-01

    Restoration of riparian forest productivity lost as a consequence of flow regulation is a common management goal in dryland riverine ecosystems. In the northern hemisphere, dryland river floodplain trees often include one or another species of Populus, which are fast-growing, nutrient-demanding trees. Because the trees are phreatophytic in drylands, and have water needs met in whole or in part by a shallow water table, their productivity may be limited by nitrogen (N) availability, which commonly limits primary productivity in mesic environments. We added 20 g N m−2 in a 2-m radius around the base of mature Populus fremontii along each of a regulated and free-flowing river in semiarid northwest Colorado, USA (total n = 42) in order to test whether growth is constrained by low soil N. Twelve years after fertilization, we collected increment cores from these and matched unfertilized trees and compared radial growth ratios (growth in the 3-year post-fertilization period/growth in the 3-year pre-fertilization period) in paired t tests. We expected a higher mean ratio in the fertilized trees. No effect from fertilization was detected, nor was a trend evident on either river. An alternative test using analysis of covariance (ANCOVA) produced a similar result. Our results underscore the need for additional assessment of which and to what extent factors other than water control dryland riverine productivity. Positive confirmation of adequate soil nutrients at these and other dryland riparian sites would bolster the argument that flow management is necessary and sufficient to maximize productivity and enhance resilience in affected desert riverine forests.

  13. County-level estimates of nitrogen and phosphorus from commercial fertilizer for the Conterminous United States, 1987–2006

    Science.gov (United States)

    Gronberg, Jo Ann M.; Spahr, Norman E.

    2012-01-01

    The U.S. Geological Survey’s National Water-Quality Assessment program requires nutrient input for analysis of the national and regional assessment of water quality. Detailed information on nutrient inputs to the environment are needed to understand and address the many serious problems that arise from excess nutrients in the streams and groundwater of the Nation. This report updates estimated county-level farm and nonfarm nitrogen and phosphorus input from commercial fertilizer sales for the conterminous United States for 1987 through 2006. Estimates were calculated from the Association of American Plant Food Control Officials fertilizer sales data, Census of Agriculture fertilizer expenditures, and U.S. Census Bureau county population. A previous national approach for deriving farm and nonfarm fertilizer nutrient estimates was evaluated, and a revised method for selecting representative states to calculate national farm and nonfarm proportions was developed. A national approach was used to estimate farm and nonfarm fertilizer inputs because not all states distinguish between farm and nonfarm use, and the quality of fertilizer reporting varies from year to year. For states that distinguish between farm and nonfarm use, the spatial distribution of the ratios of nonfarm-to-total fertilizer estimates for nitrogen and phosphorus calculated using the national-based farm and nonfarm proportions were similar to the spatial distribution of the ratios generated using state-based farm and nonfarm proportions. In addition, the relative highs and lows in the temporal distribution of farm and nonfarm nitrogen and phosphorus input at the state level were maintained—the periods of high and low usage coincide between national- and state-based values. With a few exceptions, nonfarm nitrogen estimates were found to be reasonable when compared to the amounts that would result if the lawn application rates recommended by state and university agricultural agencies were used. Also

  14. The Comparison of Different Fertilizer Technologies on Nitrogen Leaching Losses and Nitrogen Use Efficiency in Rice Production——Taking Ningxia Irrigation Region as an Example

    Directory of Open Access Journals (Sweden)

    ZHANG Ai-ping

    2015-04-01

    Full Text Available High N fertilizer and flooding irrigation applied to rice in anthropogenic-alluvial soil often result in N leaching and low use efficiency of applied fertilizer N from the rice field in Ningxia irrigation region in the upper reaches of the Yellow River. Sound N management practices need to be established to improve N use efficiency while sustain high grain yield levels and minimize fertilizer N loss to the environment. We investigated the effects of different fertilizer technologies on N leaching, N use efficiency and rice yield. The four fertilizer N treatments were CK (No nitrogen fertilizer application treatment; FP (Farmer's practice of application rate of urea at 300 kg N·hm-2, 60% used as base fertilizer, 20% as tillering fertilizer and 20% as booting fertilizer; SD (Controlled-release nitrogen fertilizer at 120 kg N·hm-2, all controlled-release fertilizer was applied as base fertilizer while transplant rice seedlings and NB (Controlled-release nitrogen fertilizer at 120 kg N·hm-2, all controlled-release fertilizer was applied as base fertilizer in the seeding soil. The results showed that the SD and NB treatments could reduce the amount of nitrogen applied by 60% compared to FP but still maintain crop yields while substantially reducing N losses to the environment. The SD could significantly decrease the N leaching losses from the paddy field. Under the FP treatment, the leaching losses of TN, NO3-N and NH4+-N were 39.89, 26.22 kg·hm-2 and 5.49 kg·hm-2, respectively. Compared with FP treatment, the SD treatment could decrease the leaching losses of TN, NO3-N and NH4+-N by 18.97, 11.18 kg·hm-2 and 2.27 kg·hm-2. The nitrogen use efficiency of SD treatment was 55.7% which increased by 21.4% compared with FP treatment. NB treatment also could decrease nitrogen leaching losses TN, NO3-N and NH4+-N by 14.36, 10.14 kg·hm-2 and 1.84 kg·hm-2 and increase the N use efficiency by 15.7% compared with FP, but it increased nitrogen leaching

  15. Effect of soil heating, severity of powdery mildew and nitrogen fertilization on yield of winter wheat

    Energy Technology Data Exchange (ETDEWEB)

    Buschhaus, H.; Werning, L.

    1981-01-01

    Field studies were conducted to determine the effect of different levels of nitrogen and severity of powdery mildew on yield of winter wheat grown in soil heated with waste heat from power plants. Soil heating reduced yield depending on efficiency of mildew control and nitrogen level from 12 to 37%. Disease severity showed a linear increase with intensity of heating corresponding with a decrease in yield reduction. In the non-heated plot, 0.8% of the flag leaves were diseases. Increase soil temperatures by 2-3/sup 0/C caused a 2% rise in mildew severity and at 5-6/sup 0/C 3%, respectively. Control of powdery mildew increased yield on the unheated plot about 5,2 dt/ha, on the moderately heated about 8,7 dt/ha and on the plots with highest temperature about 11,1 dt/ha over that of untreated plots. Nitrogen fertilizers increased yield on non-heated plots, in heated plots with diseased plants, only. Nitrogen did not increases yield of healthy plants on heated plots.

  16. Nitrogen fertilization in corn with urea coated with different sources of polymers

    Directory of Open Access Journals (Sweden)

    Márcio Valderrama

    2014-02-01

    Full Text Available In view of theoretic increase in efficiency of nitrogen fertilizers for controlled release, this study aimed to evaluate the effect of nitrogen, using conventional urea and ureas coated by different polymers, in the leaf N content, leaf chlorophyll index, components production and grain yield of irrigated corn in growing season and second crop in the savannah region. The experiments were conducted at experimental area belonging to UNESP – Ilha Solteira, located in Selvíria – MS in a dystrophic Red Latosol (Haplustox, clayey texture. The statistical design was randomized blocks, with four repetitions, in a 4 x 4 factorial arrangement, being four nitrogen doses (0, 40, 80 and 120 kg ha-1 applied at sidedressing and four urea sources (a conventional urea and three coated with polymers in different compositions and concentrations. The coated ureas are not efficient under the soil and climate conditions studied of the savanna, because they provided results similar to the conventional urea for the production components and grain yield of corn in the first and second crop. The increment of nitrogen doses increase linearly the leaf N content and grain yield of corn in the first and second crop.

  17. Effects of nitrogen fertilization on synthesis of primary and secondary metabolites in three varieties of Kacip Fatimah (Labisia pumila Blume).

    Science.gov (United States)

    Ibrahim, Mohd Hafiz; Jaafar, Hawa Z E; Rahmat, Asmah; Rahman, Zaharah Abdul

    2011-01-01

    A split plot 3 by 4 experiment was designed to examine the impact of 15-week variable levels of nitrogen fertilization (0, 90, 180 and 270 kg N/ha) on the characteristics of total flavonoids (TF), total phenolics (TP), total non structurable carbohydrate (TNC), net assimilation rate, leaf chlorophyll content, carbon to nitrogen ratio (C/N), phenyl alanine lyase activity (PAL) and protein content, and their relationships, in three varieties of Labisia pumila Blume (alata, pumila and lanceolata). The treatment effects were solely contributed by nitrogen application; there was neither varietal nor interaction effect observed. As nitrogen levels increased from 0 to 270 kg N/ha, the production of TNC was found to decrease steadily. Production of TF and TP reached their peaks under 0 followed by 90, 180 and 270 kg N/ha treatment. However, net assimilation rate was enhanced as nitrogen fertilization increased from 0 to 270 kg N/ha. The increase in production of TP and TF under low nitrogen levels (0 and 90 kg N/ha) was found to be correlated with enhanced PAL activity. The enhancement in PAL activity was followed by reduction in production of soluble protein under low nitrogen fertilization indicating more availability of amino acid phenyl alanine (phe) under low nitrogen content that stimulate the production of carbon based secondary metabolites (CBSM). The latter was manifested by high C/N ratio in L. pumila plants.

  18. Impact of Organic and Inorganic Fertilizers on Nematode Reproduction and Biochemical Alterations on Tomato

    Directory of Open Access Journals (Sweden)

    Ahmed A. FARAHAT

    2012-02-01

    Full Text Available The organic amendments, compost, neem and poultry as well as inorganic fertilizer, N P K and nematicide Nemacur 10% G applied singly at two different doses were effective in reducing M. incognita number of galls, nematode reproduction and fecundity. Also, they ameliorated growth criteria of treated tomato plants. The effectiveness seemed to be material origin and concentration dependent. Neem, compost 1, 3 at higher doses (5 g/pot gave the best results. Yet, achieved results were less than those of nemacur 10% G which overmatched all the organic and inorganic fertilizers. Nematode infection reduced total soluble sugars in roots but the opposite was the case in all treatments. Nematode infection supported root contents of amino acids, total phenols and tannins but they were diminished as a result of almost all treatments. Total soluble sugars and total carbohydrates in shoots decreased as a result of nematode infection but they were regained only by application of inorganic fertilizer. Total amino acids increased in shoots of infected plants and more increase was observed in almost all treatments. Nematode infection impaired tomato uptake of N P K; organic and inorganic fertilizers provoked plants up take, however nemacur improved plants up take of nitrogen only.

  19. Biomass, chlorophyll and nitrogen content of leaves of two chili pepper varieties (Capsicum annum in different fertilization treatments

    Directory of Open Access Journals (Sweden)

    SUTARNO

    2009-03-01

    Full Text Available Suharja, Sutarno. 2009. Biomass, chlorophyll and nitrogen content of leaves of two chili pepper varieties (Capsicum annum in different fertilization treatments. Nusantara Bioscience 1: 9-16. This study aims to determine the influence of various fertilization treatments on biomass, chlorophyll and nitrogen content of leaves from two varieties of chili, Sakti (large chili and Fantastic (curly chili. The study was conducted in the village of Gatak, Karangnongko sub-district, Klaten District, Central Java in September 2006 to March 2007. The study used a complete block design with two factorial of chili varieties and fertilizer treatment. Fertilization treatments includes no fertilizer (control (P1; manure 2 kg/plant (P2, manure (1 kg/plant + chemical fertilizer (ZA, SP-36, KCl = 2: 1: 1 + NPK (P3; and manure (1 kg/plant + chemical fertilizer (SP-36: KCl = 1:1 + liquid organic fertilizer (P4. Chlorophyll content was measured refers to Harborne (1987, whereas leaf nitrogen concentration was measured with Kjeldahl method. Data were analyzed using ANOVA followed by DMRT. The results showed that on the Fantastic chili fertilizer treatment affected the biomass and chlorophyll a, but gave no effect on chlorophyll b, total chlorophyll and leaf nitrogen. On the curly chili fertilizer treatment effected plant fresh weight, chlorophyll a and total chlorophyll, but gave no effect on dry weight, fresh fruit weight, chlorophyll b and leaf nitrogen. It is, therefore, recommended to use the formulation of manure + chemical fertilizer (SP-36: KCl = 1: 1 + liquid organic fertilizer in the cultivation of chili.Key words: biomass, chlorophyll, leaf nitrogen, chili, Capsicum annum, fertilizing.Abstrak. Suharja, Sutarno. 2009. Biomassa, kandungan klorofil dan nitrogen daun dua varietas cabai (Capsicum annum pada berbagai perlakuan pemupukan. Nusantara Bioscience 1: 9-16. Penelitian ini bertujuan untuk mengetahui pengaruh berbagai perlakuan pemupukan terhadap biomassa

  20. Abundance and Community Composition of Ammonia-Oxidizers in Paddy Soil at Different Nitrogen Fertilizer Rates

    Institute of Scientific and Technical Information of China (English)

    SONG Ya-na; LIN Zhi-min

    2014-01-01

    Ammonia oxidation, the ifrst and rate-limiting step of nitriifcation, is carried out by both ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). However, the relative importance of AOB and AOA to nitriifcation in terrestrial ecosystems is not well understood. The aim of this study was to investigate the effect of the nitrogen input amount on abundance and community composition of AOB and AOA in red paddy soil. Soil samples of 10-20 cm (root layer soil) and 0-5 cm (surface soil) depths were taken from a red paddy. Rice in the paddy was fertilized with different rates of N as urea of N1 (75 kg N ha-1 yr-1), N2 (150 kg N ha-1 yr-1), N3 (225 kg N ha-1 yr-1) and CK (without fertilizers) in 2009, 2010 and 2011. Abundance and community composition of ammonia oxidizers was analyzed by real-time PCR and denaturing gradient gel electrophoresis (DGGE) based on amoA (the unit A of ammonia monooxygenase) gene. Archaeal amoA copies in N3 and N2 were signiifcantly (P<0.05) higher than those in CK and N1 in root layer soil or in surface soil under tillering and heading stages of rice, while the enhancement in bacterial amoA gene copies with increasing of N fertilizer rates only took on in root layer soil. N availability and soil NO3--N content increased but soil NH4+-N content didn’t change with increasing of N fertilizer rates. Otherwise, the copy numbers of archaeal amoA gene were higher (P<0.05) than those of bacterial amoA gene in root lary soil or in surface soil. Redundancy discriminate analysis based on DGGE bands showed that there were no obvious differs in composition of AOA or AOB communities in the ifeld among different N fertilizer rates. Results of this study suggested that the abundance of ammonia-oxidizers had active response to N fertilizer rates and the response of AOA was more obvious than that of AOB. Similarity in the community composition of AOA or AOB among different N fertilizer rates indicate that the community composition of ammonia

  1. [Influences of biochar and nitrogen fertilizer on soil nematode assemblage of upland red soil].

    Science.gov (United States)

    Lu, Yan-yan; Wang, Ming-wei; Chen, Xiao-vun; Liu, Man-qiang; Chen, Xiao-min; Cheng, Yan-hong; Huang, Qian-ru; Hu, Feng

    2016-01-01

    The use of biochar as soil remediation amendment has received more and more concerns, but little attention has been paid to its effect on soil fauna. Based on the field experiment in an upland red soil, we studied the influences of different application rates of biochar (0, 10, 20, 30, 40 t · hm⁻²) and nitrogen fertilizer (60, 90, 120 kg N · hm⁻²) on soil basic properties and nematode assemblages during drought and wet periods. Our results showed that the biochar amendment significantly affect soil moisture and pH regardless of drought or wet period. With the increasing of biochar application, soil pH significantly increased, while soil moisture increased first and then decreased. Soil microbial properties (microbial biomass C, microbial biomass N, microbial biomass C/N, basal respiration) were also significantly affected by the application of biochar and N fertilizer. Low doses of biochar could stimulate the microbial activity, while high doses depressed microbial activity. For example, averaged across different N application rates, biochar amendment at less than 30 t · hm⁻² could increase microbial activity in the drought and wet periods. Besides, the effects of biochar also depended on wet or drought period. When the biochar application rate higher than 30 t · hm⁻², the microbial biomass C was significantly higher in the drought period than the control, but no differences were observed in the wet period. On the contrary, microbial biomass N showed a reverse pattern. Dissolved organic matter and mineral N were affected by biochar and N fertilizer significantly in the drought period, however, in the wet period they were only affected by N fertilizer rather than biochar. There was significant interaction between biochar and N fertilizer on soil nematode abundance and nematode trophic composition independent of sampling period. Combined high doses of both biochar and N fertilization promoted soil nematode abundance. Moreover, the biochar amendment

  2. Effect of Nitrogen Fertilization on Leaf Chlorophyll Fluorescence in Field-Grown Winter Wheat Under Rainfed Conditions

    Institute of Scientific and Technical Information of China (English)

    SHANGGUAN Zhou-ping; ZHENG Shu-xia; ZHANG Lei-ming; XUE Qing-wu

    2005-01-01

    The effect of nitrogen fertilization on leaf chlorophyll fluorescence was studied in field-grown winter wheat during grain filling under rainfed conditions in Loess Plateau. Results showed that the actual photochemical efficiency of PS Ⅱ reaction center (Ф PS Ⅱ) decreased significantly as leaf water stress progressed, however, the Ф PS was increased by nitrogen fertilization. The Ф PS Ⅱ of 0, 90 and 180 kg ha-1 nitrogen treatments at noon were 0.197, 0.279 and 0.283, respectively, which decreased by 57.7, 56.4 and 40.2% as compared was even higher than that in the moming. Application of nitrogen fertilizer significantly increased maximum photochemical efficiency (Fv/Fm), photochemical quenching coefficient (qP) and non-photochemical quenching coefficient (qNP). These results indicated that application of nitrogen fertilizer could increase the light energy conversion efficiency, the potential activity of photosynthetic reaction center, and the non-photochemical dissipation of excess light energy, which can prevent leaf photosynthetic apparatus from damage of treatments, indicating that the excess nitrogen was unfavorable to photosynthesis.

  3. Dry matter accumulation and mineral nutrition of arracacha in response to nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Luis Augusto Magolbo

    2015-08-01

    Full Text Available Abstract:The objective of this work was to evaluate the effect of nitrogen fertilization on the growth and yield of arracacha (Arracacia xanthorrhiza, as well as on the plant's nutrient uptake, distribution, and removal. The experiment was carried out in a typical Oxisol, with sandy texture. A randomized complete block design was used, with four replicates. The treatments consisted of five N rates: 0, 50, 100, 200, and 400 kg ha-1. The plots were composed of three 8-m-length rows, spaced at 0.60 m between rows and 0.40 m between plants. The plants were harvested after an 8-month cycle. Nitrogen fertilization significantly increased the proportion of N and S accumulated in stems, and of Ca, Mg, Fe, and Mn in leaves. N supply increased Zn distribution to stems and leaves, whereas high N rates increased Cu allocation to stems more than to the rootstock. High N rates increase plant dry matter (DM production and nutrient uptake and removal, but do not result in the greatest yield due to the greater development of leaves and stems, and to the lower allocation of DM in storage roots.

  4. Optimizing Nitrogen Fertilizer Application for Rice Production in the Taihu Lake Region, China

    Institute of Scientific and Technical Information of China (English)

    DENG Mei-Hua; SHI Xiao-Jun; TIAN Yu-Hua; YIN Bin; ZHANG Shao-Lin; ZHU Zhao-Liang; S. D. KIMURA

    2012-01-01

    To determine the optimal amount of nitrogen (N) fertilizer for achieving a sustainable rice production at the Taihu Lake region of China,two-year on-farm field experiments were performed at four sites using various N application rates.The results showed that 22%-30% of the applied N was recovered in crop and 7%-31% in soils at the rates of 100-350 kg N ha-1.Nitrogen losses increased with N application rates,from 44% of the applied fertilizer N at the rate of 100 kg N ha-1 to 69% of the N applied at 350 kg N ha-1.Ammonia volatilization and apparent denitrification were the main pathways of N losses.The N application rate of 300 kg N ha-1,which is commonly used by local farmers in the study region,was found to lead to a significant reduction in economic and environmental efficiency.Considering the cost for mitigating environmental pollution and the maximum net economic income,an application rate of 100-150 kg N ha-1 would be recommended.This recommended N application rate could greatly reduce N loss from 199 kg N ha-1 occurring at the N application rate of 300 kg N ha-1 to 80-110 kg N ha-1,with the rice grain yield still reaching 7300-8300 kg DW ha-1 in the meantime.

  5. Symbiosome-like intracellular colonization of cereals and other crop plants by nitrogen-fixing bacteria for reduced inputs of synthetic nitrogen fertilizers.

    Science.gov (United States)

    Cocking, Edward C; Stone, Philip J; Davey, Michael R

    2005-12-01

    It has been forecast that the challenge of meeting increased food demand and protecting environmental quality will be won or lost in maize, rice and wheat cropping systems, and that the problem of environmental nitrogen enrichment is most likely to be solved by substituting synthetic nitrogen fertilizers by the creation of cereal crops that are able to fix nitrogen symbiotically as legumes do. In legumes, rhizobia present intracellularly in membrane-bound vesicular compartments in the cytoplasm of nodule cells fix nitrogen endosymbiotically. Within these symbiosomes, membrane-bound vesicular compartments, rhizobia are supplied with energy derived from plant photosynthates and in return supply the plant with biologically fixed nitrogen, usually as ammonia. This minimizes or eliminates the need for inputs of synthetic nitrogen fertilizers. Recently we have demonstrated, using novel inoculation conditions with very low numbers of bacteria, that cells of root meristems of maize, rice, wheat and other major non-legume crops, such as oilseed rape and tomato, can be intracellularly colonized by the non-rhizobial, non-nodulating, nitrogen fixing bacterium, Gluconacetobacter diazotrophicus that naturally occurs in sugarcane. G. diazotrophicus expressing nitrogen fixing (nifH) genes is present in symbiosome-like compartments in the cytoplasm of cells of the root meristems of the target cereals and non-legume crop species, somewhat similar to the intracellular symbiosome colonization of legume nodule cells by rhizobia. To obtain an indication of the likelihood of adequate growth and yield, of maize for example, with reduced inputs of synthetic nitrogen fertilizers, we are currently determining the extent to which nitrogen fixation, as assessed using various methods, is correlated with the extent of systemic intracellular colonization by G. diazotrophicus, with minimal or zero inputs.

  6. Symbiosome-like intracellular colonization of cereals and other crop plants by nitrogen-fixing bacteria for reduced inputs of synthetic nitrogen fertilizers

    Institute of Scientific and Technical Information of China (English)

    Edward C. Cocking; Philip J. Stone; Michael R. Davey

    2005-01-01

    It has been forecast that the challenge of meeting increased food demand and protecting environmental quality will be won or lost in maize, rice and wheat cropping systems,and that the problem of environmental nitrogen enrichment is most likely to be solved by substituting synthetic nitrogen fertilizers by the creation of cereal crops that are able to fix nitrogen symbiotically as legumes do. In legumes, rhizobia present intraceliularly in membrane-bound vesicular compartments in the cytoplasm of nodule cells fix nitrogen endosymbiotically. Within these symbiosomes, membrane-bound vesicular compartments, rhizobia are supplied with energy derived from plant photosynthates and in return supply the plant with biologically fixed nitrogen, usually as ammonia. This minimizes or eliminates the need for inputs of synthetic nitrogen fertilizers. Recently we have demonstrated, using novel inoculation conditions with very low numbers of bacteria, that cells of root meristems of maize, rice, wheat and other major non-legume crops, such as oilseed rape and tomato, can be intracellularly colonized by the non-rhizobial, non-nodulating, nitrogen fixing bacterium, Gluconacetobacter diazotrophicus that naturally occurs in sugarcane. G. diazotrophicus expressing nitrogen fixing (nifH) genes is present in symbiosome-like compartments in the cytoplasm of cells of the root meristems of the target cereals and non-legume crop species, somewhat similar to the intracellular symbiosome colonization of legume nodule cells by rhizobia. To obtain an indication of the likelihood of adequate growth and yield, of maize for example, with reduced inputs of synthetic nitrogen fertilizers,we are currently determining the extent to which nitrogen fixation, as assessed using various methods, is correlated with the extent of systemic intracellular colonization by G. diazotrophicus,with minimal or zero inputs.

  7. Nitrogen translocation in wheat inoculated with Azospirillum and fertilized with nitrogen

    Directory of Open Access Journals (Sweden)

    RODRIGUES OSMAR

    2000-01-01

    Full Text Available The productivity and the translocation of assimilates and nitrogen (N were compared after inoculation of wheat (Triticum aestivum L., cv. BR-23 seeds with two strains of Azospirillum brasilense (strains 245 and JA 04 under field conditions. The inoculation of wheat seeds was done with a peat inoculant at sowing time. Plant material for evaluations were collected at anthesis and maturity. No differences in grain yield and in the translocation of assimilates resulting from inoculation were detected. Differences were observed in relation to N rates (0, 15, and 60 kg ha-1. N content in the grain increased significantly in the bacteria-inoculated treatments in which N was not added. This increase in N content in the grain with inoculation was probably due to higher N uptake after anthesis without any significant contribution on the grain yield. Such increment was of 8.4 kg ha-1 of N representing 66% more N than in no inoculated treatment. Regardless of the inoculation and the rate of N applied, it was observed that about 70% of the N accumulated at anthesis was translocated from vegetative parts to the grain.

  8. Carbohydrates Concentration in leaves of potato plants affected by nitrogen fertilization rates

    Directory of Open Access Journals (Sweden)

    Heder Braun

    2016-04-01

    Full Text Available ABSTRACT At poor conditions of nitrogen (N in the soil, potato plants may accumulate starch in leaves and be indicative of N nutritional stress. The objective of this work was to determine the effects of N rates (0, 50, 100, 200 and 300 kg ha-1 of N on the concentrations of carbohydrates (total soluble sugars-TSS, reducing sugars-RS, non-reducing sugars-NRS and starch in the fourth leaf (FL of two potato cultivars (Asterix and Atlantic and their critical levels (CL associated to the N fertilization rate necessary to obtain the maximum physical (MPE and economic (MEE efficiency of tubers. A randomized block design with four replications was used in both experiments. On day 21 after plant emergence, four FL were collected from four plants. Potatoes plants fertilized with low rates of N accumulated less TSS in leaves than those properly fertilized. The opposite occurred with content of starch. The cultivars showed similar responses to five doses of N in relation to contents of starch and TSS. However, the response to the increase in doses of N for RS, NRS and Starch/NRS is cultivar-specific. The correlations between contents of RS, NRS and Starch/NRS with the starch and TSS were dependent on the potato cultivar.

  9. Stalk and sucrose yield in response to nitrogen fertilization of sugarcane under reduced tillage

    Directory of Open Access Journals (Sweden)

    Caio Fortes

    2013-01-01

    Full Text Available The objective of this work was to evaluate the agroindustrial production of sugarcane (millable stalks and sucrose yield after successive nitrogen fertilizations of plant cane and ratoons in a reduced tillage system. The experiment was carried out at Jaboticabal, SP, Brazil, on a Rhodic Eutrustox soil, during four consecutive crop cycles (March 2005 to July 2009. Plant cane treatments consisted of N-urea levels (control, 40, 80, and 120 kg ha-1 N + 120 kg ha-1 P2O5 and K2O in furrow application. In the first and second ratoons, the plant cane plots were subdivided in N-ammonium nitrate treatments (control, 50, 100, and 150 kg ha-1 N + 150 kg ha-1 K2O as top dressing over rows. In the third ratoon, N fertilization was leveled to 100 kg ha-1 in all plots, including controls, to detect residual effects of previous fertilizations on the last crop's cycle. Sugarcane ratoon was mechanically harvested. A weighing truck was used to evaluate stalk yield (TCH, and samples were collected in the field for analysis of sugar content (TSH. Increasing N doses and meteorological conditions promote significant responses in TCH and TSH in cane plant and ratoons, in the average and accumulated yield of the consecutive crop cycles.

  10. Residual recovery and yield performance of nitrogen fertilizer applied at sugarcane planting

    Directory of Open Access Journals (Sweden)

    Henrique Coutinho Junqueira Franco

    2015-12-01

    Full Text Available ABSTRACTThe low effectiveness of nitrogen fertilizer (N is a substantial concern that threatens global sugarcane production. The aim of the research reported in this paper was to assess the residual effect of N-fertilizer applied at sugarcane planting over four crop seasons in relation to sugarcane crop yield. Toward this end three field experiments were established in the state of São Paulo, Brazil, during February of 2005 and July of 2009, in a randomized block design with four treatments: 0, 40, 80 and 120 kg ha−1 of N applied as urea during sugarcane planting. Within each plot, a microplot was established to which 15N-labeled urea was applied. The application of N at planting increased plant cane yield in two of the three sites and sucrose content at the other, whereas the only residual effect was higher sucrose content in one of the following ratoons. The combined effect was an increase in sugar yield for three of the 11 crop seasons evaluated. Over the crop cycle of a plant cane and three ratoon crops, only 35 % of the applied N was recovered, split 75, 13, 7 and 5 % in the plant cane, first, second and third ratoons, respectively. These findings document the low efficiency of N recovery by sugarcane, which increases the risk that excessive N fertilization will reduce profitability and have an adverse effect on the environment.

  11. Fertilizer residence time affects nitrogen uptake efficiency and growth of sweet corn.

    Science.gov (United States)

    Zotarelli, L; Scholberg, J M; Dukes, M D; Muñoz-Carpena, R

    2008-01-01

    Understanding plant N uptake dynamics is critical for increasing fertilizer N uptake efficiency (FUE) and minimize the risk of N leaching. The objective of this research was to determine the effect of residence time of N fertilizer on N uptake and FUE of sweet corn. Plants were grown in 25 L columns during the fall and spring to mimic short-term N uptake dynamics. Nitrogen was applied either 1, 3, or 7 d before a weekly leaching event, using KNO3 solution (total of 393 kg N ha(-1)). Residence times (tR) were tR-1, tR-3, and tR-7 d before weekly removal of residual soil N. Plant N uptake was calculated by comparing weekly N recovery from planted with non-planted columns. During the fall, N uptake values at 70 d after emergence were 59, 73, and 126 kg N ha(-1). During the spring, corresponding values were 54, 108, and 159 kg N ha(-1). A linear response of plant growth and yield to the tR was observed under cooler conditions, whereas a quadratic response occurred under warmer conditions. There was correlation between root length density and yield. It is concluded that increasing N fertilizer residence time, which is indicative of better irrigation practices, enhanced overall sweet corn growth, yield, N uptake, and FUE, consequently reduced the risk of N being leached below the root zone before complete N uptake.

  12. Nitrogen fertilizer use efficiency, recovery and leaching of an alexandergrass pasture

    Directory of Open Access Journals (Sweden)

    Laércio Ricardo Sartor

    2011-06-01

    Full Text Available Nitrogen usually determines the productive potential of forage crops, although it is highly unstable in the environment. Studies on recovery rates and use efficiency are important for more reliable fertilizer recommendations to reduce costs and avoid environmental pollution. The purpose of this study was to evaluate N use efficiency and recovery rate of Alexandergrass pasture (Brachiaria - Syn. Urochloa plantaginea as well as N-NO3- and N-NH4+ soil concentrations using different levels of N fertilization under two grazing intensities. The experiment was arranged in a randomized block design in a factorial scheme with three replications. Treatments consisted of three N rates (0, 200 and 400 kg ha-1 N and two grazing intensities termed low mass (LM; forage mass of 2,000 kg ha-1 of DM and high mass (HM; forage mass of 3,600 kg ha-1 of DM under continuous stocking and variable stocking rates. Results of N fertilization with 200 kg ha-1 were better than with 400 kg ha-1 N. There was a significant effect of N rates on soil N-NO3-concentration with higher levels in the first layer of the soil profile in the treatment with 400 kg ha-1 N. Grazing intensity also affected soil N-NO3- concentration, by increasing the levels under the higher stocking rate (lower forage mass.

  13. Nitrogen recovery in soil and needle biomass after fertilization of a Scots pine stand, and growth responses obtained

    OpenAIRE

    Nömmik, Hans; Möller, Göran

    1981-01-01

    The distribution of fertilizer nitrogen in soil and needle biomass of an 120-year-old stand of Scots pine was studied over a period of six years. The nitrogen was applied as ammonium nitrate or urea and at rates of 150,300 and 600 kg N per hectare. The soil investigations showed that, at the lowest nitrogen application rate, 21 % of the ammonium nitrate and 49% of the urea nitrogen were immobilized in the soil in nonexchangeable form. For the corresponding treatments the losses by leaching we...

  14. Nitrogen uptake during one year in subarctic plant functional groups and in microbes after long-term warming and fertilization

    DEFF Research Database (Denmark)

    Sørensen, Pernille Lærkedal; Michelsen, Anders; Jonasson, Sven Evert

    2008-01-01

    For the first time in an arctic long-term warming and fertilization experiment, the short-term (days) and longer-term (month and year) nitrogen (N) uptake and allocation in plants, microbes, and soil pools were studied, with 15N-labeling of an organic nitrogen form, glycine. The long-term warming...... and fertilization had no marked effect on soil inorganic N content, but both dissolved organic N (DON) and plant biomass did increase after fertilization. Soil microbes initially immobilized most of the added 15N, but in the following months, they lost two-thirds, while label concentration in plants increased....... After a year, however, the 15N recovered in microbes was still 10-fold higher than that in the plant biomass, showing the high importance of soil microbes in nutrient retention in arctic ecosystems, irrespective of the impact of long-term warming or fertilization. The effects of the treatments...

  15. [Effects of nitrogen fertilization and straw amendment on soil microbial biomass and soil functions after heat stress].

    Science.gov (United States)

    Chen, Xiao-Yun; Chen, Shi; Liu, Man-Qiang; Jiao, Jia-Guo; Li, Hui-Xin; Hu, Feng

    2013-02-01

    A 60-day incubation experiment was conducted to study the effects of nitrogen fertilization (N), rice straw amendment (R), and their combination (RN) on the changes of soil microbial biomass and soil functions (basal respiration, substrate-induced respiration, and straw decomposition) after heat stress (40 degrees C for 18 h). Heat stress tended to promote the soil microbial biomass and soil functions, but the effects were weak and transient. Either with or without heating, treatment R and especially RN could greatly stimulate soil microbial biomass, basal respiration, substrate-induced respiration and straw decomposition, as compared to no straw amendment and with nitrogen fertilization alone, but the parameters in treatment N had less change, and even, presented a decreasing trend. It was suggested that straw amendment and its combination with nitrogen fertilization could improve soil functions in natural conditions or after environmental stress.

  16. Evaluation of Different Levels of Nitrogen and Phosphorus Fertilizers on Shoot and Root Characteristics of Echinacea purpurea

    Directory of Open Access Journals (Sweden)

    morteza Goldani

    2017-02-01

    Full Text Available Introduction: Purple coneflower with scientific name Echinacea purpurea (L. is an herbaceous perennial plant native to North America and is the one of the most important medicinal plants in the world. Root of Echinacea purpurea is commonly used around the world for stimulation of immune system. It is used as herbal medicine in respiratory infections, against malignant tumors and several inflammatory conditions However, nitrogen and phosphorus are the main elements that make up the proteins in plants and herbs for natural growth, especially is necessary in their productive organs. The results showed that nitrogen and phosphorus are important in continuation of flowering, the flowers fresh and dry weight and in essential oil. Fertilization of E. purpurea plants indicated that in absence or at low levels of nitrogen fertilization (0 and 100 kg acre-1, the addition of 50 and 100 kg acre-1 of potassium increased aerial parts, flower heads and root yield. Another report indicated that highest aerial biomass and root yield in E. purpurea was obtained with 100 kg ha-1 of nitrogen at constant rates of phosphorus and potassium. Polyphenol content was not influenced by nitrogen fertilization and values fluctuated between 2.4 and 5.4 % in the aerial part at flowering and between 1.6 and 3.5 % in the roots. Fertilization with nitrogen caused a decrease in the concentrations of echinoside. Echinoside content was 1.16 % without nitrogen fertilization, and 0.94 % with nitrogen fertilization. Materials and Methods: To evaluate the effect of different levels of nitrogen and phosphorus on growth and yield of coneflower, a factorial experiment in a completely randomized design with three replications was conducted in Ferdowsi University of Mashhad. Treatments were included three levels of nitrogen (0, 1 and 2 gr urea per kilogram of soil and three levels of phosphate fertilizer (0, 0.75 and 1.5 gr of phosphate (P2O5 per kg of soil. Nitrogen fertilizer was applied

  17. Organic and nitrogen fertilization of soil under Syrah grapevine: effects on soil chemical properties and nitrate concentration.

    OpenAIRE

    Davi José Silva; Luís Henrique Bassoi; Marlon Gomes da Rocha; Alexsandro Oliveira da Silva; Magnus Dall’Igna Deon

    2016-01-01

    ABSTRACT Viticulture is an activity of great social and economic importance in the lower-middle region of the São Francisco River valley in northeastern Brazil. In this region, the fertility of soils under vineyards is generally poor. To assess the effects of organic and nitrogen fertilization on chemical properties and nitrate concentrations in an Argissolo Vermelho-Amarelo (Typic Plinthustalf), a field experiment was carried out in Petrolina, Pernambuco, on Syrah grapevines. Treatments cons...

  18. Organic and Nitrogen Fertilization of Soil under ‘Syrah’ Grapevine: Effects on Soil Chemical Properties and Nitrate Concentration

    OpenAIRE

    Silva,Davi José; Bassoi,Luís Henrique; Rocha,Marlon Gomes da; Silva, Alexsandro Oliveira da [UNESP; Deon,Magnus Dall'Igna

    2016-01-01

    ABSTRACT Viticulture is an activity of great social and economic importance in the lower-middle region of the São Francisco River valley in northeastern Brazil. In this region, the fertility of soils under vineyards is generally poor. To assess the effects of organic and nitrogen fertilization on chemical properties and nitrate concentrations in an Argissolo Vermelho-Amarelo (Typic Plinthustalf), a field experiment was carried out in Petrolina, Pernambuco, on Syrah grapevines. Treatments cons...

  19. Towards Growing Bario Rice on Lowland Soils: A Preliminary Nitrogen and Potassium Fertilization Trial

    Directory of Open Access Journals (Sweden)

    Muyang T. S. Kevin

    2007-01-01

    Full Text Available A pot study was carried with the following objectives: (i To investigate N and K uptake of Bario rice on Bekenu series (Tipik Tualemkuts, and (ii To investigate N and K use efficiency of Bario rice on Bekenu series. Treatments evaluated were: (i Bario rice under fertilized condition (T1, and (ii Bario rice under unfertilized condition (T0. The experiment was conducted in a glasshouse at Universiti Putra Malaysia Bintulu Campus, Sarawak, Malaysia. Altogether 18 pots were used. The experimental design was completely randomized design (CRD with 9 replications. Nitrogen and K were applied in the forms of urea (46 % N and muriate of potash (60 % K2O at the rates of 0.52 g N g and 0.60 g K2O per pot respectively at specific times. The fertilizers applications were done 20 and 45 days after seeding (for T1 only. However, P was applied to T1 pots only in the form of Christmas Island Rock Phosphate (36 % P2O5 at a rate of 0.54 g P2O5 per pot. At 65 days after planting, the Bario rice plants were sampled and partitioned into roots and stem. Their dry weight, N, and K concentrations determined using standard procedures. Soil sampling was done before and after fertilization stages. Soil total N was determined using the Kjeldahl method while exchangeable K, Ca, Na, and Mg were extracted using the double acid method and their concentrations determined using atomic absorption spectrophotometry. Dry ashing method was used for the determination of K, Ca, Na, and Mg concentrations in plant tissues while the Kjeldahl method was used to determine total N in plant tissues. The concentrations multiplied by the oven dried weight of roots and stem provided N, K, Ca, Na, and Mg uptake in these plant parts. The N and K use efficiency were then calculated using the subtraction method. With the exception of Ca, urea and KCl (MOP application significantly increased soil N, K, Mg, and Na concentrations. Total dry weight for both stem and roots showed no significant

  20. Carbon rhizodeposition by plants of contrasting strategies for resource acquisition: responses to various nitrogen fertility regimes

    Science.gov (United States)

    Baptist, Florence; Aranjuelo, I.; Lopez-Sangil, L.; Rovia, P.; Nogués, S.

    2010-05-01

    Rhizodeposition by plants is one of the most important physiological mechanisms related to carbon and nitrogen cycling which is also believed to vary along the acquisition-conservation continuum. However, owing to methodological difficulties (i.e. narrow zone of soil around roots and rapid assimilation by soil microbes), root exudation and variations between species are one of the most poorly understood belowground process. Although previous approaches such as hydroponic culture based system, permit the chemical analysis of exudates, the fact that this protocol is qualitative, conditions its utility (see review in Phillips et al. 2008). Others techniques based on pulse-labelling approach have been developed to quantify rhizodeposition but are rarely sufficient to uniformly label all plant inputs to soil. Consequently with this typical pulse chase methods, recent assimilates are labeled but the recalcitrant carbon will not be labeled and therefore the contribution of this carbon will not be considered. Hence, traditional pulse labelling is not a quantitative means of tracing carbon due to inhomogeneous labelling and so limits greatly comparative studies of rhizodeposition fluxes at the interspecific level. In this study we developped a new protocole based on a long-term (3 months) steady state 13C labelling in order (1) to quantify rhizodeposition fluxes for six graminoid species caracterized by contrasted nutrient acquisition strategies and (2) to investigate to what extent various level of nitrogen fertility regimes modulate rhizodeposition fluxes. This method will enable to quantify under natural soil conditions both the accumulation of 13C in the soil but also the quantity that has been respired by the microorganisms during a given time and so will give an integrated picture of rhizodeposition fluxes for each species under each nitrogen fertility level. Results are currently being processed and will be presented at the conference. References: Phillips RP, Erlitz

  1. Fertilizer-Induced Advances in Corn Growth Stage and Quantitative Definitions of Nitrogen Deficiencies

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Evidence that nitrogen(N)fertilization tends to accelerate maturation as well as increase rates of growth has received little attention when diagnosing N deficiencies in corn(Zea mays L.).Such a tendency could be a potential source of errors when the diagnosis is solely based on comparing plants with different rates of growth.Whether N fertilization could accelerate rates of growth and maturation was tested in a field study with 12 paired plots representing relatively large variability in soil properties and landscape positions.The plots were located under conditions where preplant N fertilization reduced or avoided temporary N shortages for some plants but did not reduce for other plants early in the season.We measured corn heights to the youngest leaf collar,stages of growth and chlorophyll meter readings(CMRs).The added N advanced growth stages as well as increased corn heights and CMRs at any given time.Fertilization effects on corn heights,growth stages and ear weights were statistically significant(P<0.05)despite substantial variability associated with landscape.Reductions in growth due to a temporary shortage of N within a growth stage might be partially offset by longer periods of growth within that stage to physiological maturity.Temporary shortages of N,therefore,may produce symptoms of N deficiency in situations where subsequent additions of N should not be expected to increase yields.Recognition of these two somewhat different effects(i.e.,increase growth rates and advance growth stages)on corn growth could help to define N deficiency more precisely and to improve the accuracy of diagnosing N status in production agriculture.

  2. Soil Organic Carbon Response to Cover Crop and Nitrogen Fertilization under Bioenergy Sorghum

    Science.gov (United States)

    Sainju, U. M.; Singh, H. P.; Singh, B. P.

    2015-12-01

    Removal of aboveground biomass for bioenergy/feedstock in bioenergy cropping systems may reduce soil C storage. Cover crop and N fertilization may provide additional crop residue C and sustain soil C storage compared with no cover crop and N fertilization. We evaluated the effect of four winter cover crops (control or no cover crop, cereal rye, hairy vetch, and hairy vetch/cereal rye mixture) and two N fertilization rates (0 and 90 kg N ha-1) on soil organic C (SOC) at 0-5, 5-15, and 15-30 cm depths under forage and sweet sorghums from 2010 to 2013 in Fort Valley, GA. Cover crop biomass yield and C content were greater with vetch/rye mixture than vetch or rye alone and the control, regardless of sorghum species. Soil organic C was greater with vetch/rye than rye at 0-5 and 15-30 cm in 2011 and 2013 and greater with vetch than rye at 5-15 cm in 2011 under forage sorghum. Under sweet sorghum, SOC was greater with cover crops than the control at 0-5 cm, but greater with vetch and the control than vetch/rye at 15-30 cm. The SOC increased at the rates of 0.30 Mg C ha-1 yr-1 at 0-5 cm for rye and the control to 1.44 Mg C ha-1 yr-1 at 15-30 cm for vetch/rye and the control from 2010 to 2013 under forage sorghum. Under sweet sorghum, SOC also increased linearly at all depths from 2010 to 2013, regardless of cover crops. Nitrogen fertilization had little effect on SOC. Cover crops increased soil C storage compared with no cover crop due to greater crop residue C returned to the soil under forage and sweet sorghum and hairy vetch/cereal rye mixture had greater C storage than other cover crops under forage sorghum.

  3. Plant growth-promoting bacteria associated with nitrogen fertilization at topdressing in popcorn agronomic performance

    Directory of Open Access Journals (Sweden)

    Leandro Teodoski Spolaor

    2016-03-01

    Full Text Available ABSTRACT The use of plant growth-promoting bacteria is a promising alternative with low environmental impact to increase the efficiency of use of chemical fertilizers, ensuring high yield with better cost-effective ratio. In maize crops, several studies have demonstrated an increased yield when Azospirillum-based inoculants are used. In the case of popcorn, there are no available studies related to use of inoculation and its response on yield parameters. Thus, the aim of this study was to evaluate the field performance of popcorn when inoculated with the commercial product Masterfix L (A. brasilense Ab-V5 and A. brasilense Ab-V6 and the non-commercial inoculant UEL (A. brasilense Ab-V5 + Rhizobium sp. 53GRM1 associated with nitrogen fertilization. The trials were conducted in Londrina and Maringá, Paraná State, Brazil, in a randomized block design with four replications, in a split plot design with the inoculation treatments located in the plots (uninoculated, Masterfix L, and UEL and the different N rates located in the subplots where ammonium sulphate was applied in the topdressing at the V6 stage (0, 50, 100, and 150 kg∙ha–1. The variance analysis showed significant effects (p < 0.05 of inoculation (Londrina environment and N rates (both environments only for grain yield. There was no inoculation effect in the grain yield when inoculants were applied together with N-fertilization at topdressing. In the absence of N-fertilization at topdressing, the inoculants Masterfix L. and UEL promoted higher grain yield as compared to the uninoculated plants, with resulting increases of 13.21 and 26.61% in yield, respectively.

  4. Impact of elevated CO{sub 2} and nitrogen fertilization on foliar elemental composition in a short rotation poplar plantation

    Energy Technology Data Exchange (ETDEWEB)

    Marinari, Sara [Department of Agrochemistry and Agrobiology (DABAC), Universita degli Studi della Tuscia, Via S. Camillo de Lellis, I.01100 Viterbo (Italy)]. E-mail: marinari@unitus.it; Calfapietra, Carlo [Department of Forest Environment and Resources (DISAFRI), Universita degli Studi della Tuscia, Via S. Camillo de Lellis, I-01100 Viterbo (Italy); De Angelis, Paolo [Department of Forest Environment and Resources (DISAFRI), Universita degli Studi della Tuscia, Via S. Camillo de Lellis, I-01100 Viterbo (Italy); Mugnozza, Giuseppe Scarascia [Department of Forest Environment and Resources (DISAFRI), Universita degli Studi della Tuscia, Via S. Camillo de Lellis, I-01100 Viterbo (Italy); Grego, Stefano [Department of Agrochemistry and Agrobiology (DABAC), Universita degli Studi della Tuscia, Via S. Camillo de Lellis, I.01100 Viterbo (Italy)

    2007-06-15

    The experiment was carried out on a short rotation coppice culture of poplars (POP-EUROFACE, Central Italy), growing in a free air carbon dioxide enriched atmosphere (FACE). The specific objective of this work was to study whether elevated CO{sub 2} and fertilization (two CO{sub 2} treatments, elevated CO{sub 2} and control, two N fertilization treatments, fertilized and unfertilized), as well as the interaction between treatments caused an unbalanced nutritional status of leaves in three poplar species (P. x euramericana, P. nigra and P. alba). Finally, we discuss the ecological implications of a possible change in foliar nutrients concentration. CO{sub 2} enrichment reduced foliar nitrogen and increased the concentration of magnesium; whereas nitrogen fertilization had opposite effects on leaf nitrogen and magnesium concentrations. Moreover, the interaction between elevated CO{sub 2} and N fertilization amplified some element unbalances such as the K/N-ratio. - CO{sub 2} enrichment reduced foliar nitrogen and increased the magnesium concentration in poplar.

  5. Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China

    Science.gov (United States)

    Tian, Di; Li, Peng; Fang, Wenjing; Xu, Jun; Luo, Yongkai; Yan, Zhengbing; Zhu, Biao; Wang, Jingjing; Xu, Xiaoniu; Fang, Jingyun

    2017-07-01

    Reactive nitrogen (N) increase in the biosphere has been a noteworthy aspect of global change, producing considerable ecological effects on the functioning and dynamics of the terrestrial ecosystems. A number of observational studies have explored responses of plants to experimentally simulated N enrichment in boreal and temperate forests. Here we investigate how the dominant trees and different understory plants respond to experimental N enrichment in a subtropical forest in China. We conducted a 3.4-year N fertilization experiment in an old-aged subtropical evergreen broad-leaved forest in eastern China with three treatment levels applied to nine 20 m × 20 m plots and replicated in three blocks. We divided the plants into trees, saplings, shrubs (including tree seedlings), and ground-cover plants (ferns) according to the growth forms, and then measured the absolute and relative basal area increments of trees and saplings and the aboveground biomass of understory shrubs and ferns. We further grouped individuals of the dominant tree species, Castanopsis eyrei, into three size classes to investigate their respective growth responses to the N fertilization. Our results showed that the plot-averaged absolute and relative growth rates of basal area and aboveground biomass of trees were not affected by N fertilization. Across the individuals of C. eyrei, the small trees with a DBH (diameter at breast height) of 5-10 cm declined by 66.4 and 59.5 %, respectively, in N50 (50 kg N ha-1 yr-1) and N100 fertilized plots (100 kg N ha-1 yr-1), while the growth of median and large trees with a DBH of > 10 cm did not significantly change with the N fertilization. The growth rate of small trees, saplings, and the aboveground biomass of understory shrubs and ground-cover ferns decreased significantly in the N-fertilized plots. Our findings suggested that N might not be a limiting nutrient in this mature subtropical forest, and that the limitation of other nutrients in the forest

  6. 氮利用率和氮转化率评价氮肥肥效比较研究%Comparative research of evaluation nitrogen fertilizer efficiency be- tween nitrogen use efficiency and fertilizer yield method

    Institute of Scientific and Technical Information of China (English)

    侯彦林; 周燕; 周炜

    2013-01-01

    external N; using N fertilizer yield and external N was the method of scientific evaluation N fertilizer efficiency; ③ using N fertilizer relative conversion to evaluate fertilizer efficiency and guide fertilization not considering external N when concrete practicing fertilization;guidance fertilization semi-quantitatively can be realized by referencing optimum nitrogen application rate of long-term experiment even without determining soil N using N fertilizer yield.

  7. INFLUENCE OF IRRIGATION AND NITROGEN FERTILIZATION ON YIELD AND QUALITY OF (Zea mays L. MAIZE GRAIN

    Directory of Open Access Journals (Sweden)

    Monika Marković

    2014-06-01

    Full Text Available The three years’ research (from 2010 to 2012, conducted on a trial field of the Institute of Agriculture in Osijek, is a part of a long stationary experiment. The objective of the research was the impact of irrigation (main factor, A, nitrogen fertilization (second factor, B, and the genotype (third factor, C on the grain yield and the quality of maize hybrids (Zea mays L. The irrigation scheduling was the main factor where A1 treatment was the control, rain-fed plot. In A2 treatment the soil water content was 60-100% of the field water capacity (FWC, while in the A3 treatment the soil water content was 80 to 100% FWC. Nitrogen fertilization as a sub factor, consisted of the three levels where B1 was the control treatment (0 kg N ha-1. In B2 treatment 100 kg N ha-1 was added, while in B3 treatment 200 kg N ha-1. Fall application (1/3 of all nitrogen was in the form of UREA. The same amount of nitrogen was applied in the pre-sowing period. During the vegetation period, two side dressings with CAN were carried out. The first side dressing (1/6 of nitrogen was done by cultivating the maize in 6-8 leaves phase, while the second one in 8 to 10 leaves phase (1/6 of nitrogen. Four maize hybrids (FAO 500 and 600 were used in the research, C1=OSSK596, C2=OSSK617, C3=OSSK602 and C4=OSSK552. The maize was irrigated by a traveling sprinkler system. The moment of irrigation was set by measuring soil moisture with the Watermark sensor (gypsum block. During the period of the research the weather conditions significantly varied, especially concerning the amount of precipitation. The year 2010 stands out as extremely wet (rainy, when a natural disaster of flood was proclaimed, due to high amount of precipitation, which had an influence on the results of the research. Analysis of variance showed statistically significant differences in yield in all three years of the research. Grain yield was higher as amount of irrigation water was higher, with an exception of

  8. Growth evaluation of spondias tuberosa rootsctocks in the substrate fertilization with nitrogen and boron.

    Directory of Open Access Journals (Sweden)

    Cleiton José de Oliveira

    2009-08-01

    Full Text Available The main goal of this works was evaluate the effect of nitrogen and boron doses, in the rootstocks ‘umbu’ (Spondias tuberosa Arruda Câmara. The experiment it was led at CCA/UFPB-Campus II, located in the Areia city, state of Paraiba in Brazil. The treatments were five levels of nitrogen (0 to 4,50 g dm-3 as ureia (45% N, and five boron doses (0 to 3,0 mg dm-3, as borax (11% B, applied in the subtract constituted by the mixture of 75% of soil and 25% of manure bovine, in the randomized blocks design, with four repetitions. The experimental unit was constituted of three recipient containing three seedlings. It was evaluated height and the diameter of the stem of the seedlings, besides the mass of the matter evaporates and the areas of the root system and aerial part. The increase of the levels of nitrogen resulted in smaller growth of the seedlings. The application of 3 mg dm-3 of the boron provided the largest growth of the aerial parts and root.Key-words: Spondias tuberosa, mixture, fertilization

  9. Regional distribution of nitrogen fertilizer use and N-saving potential for improvement of food production and nitrogen use efficiency in China.

    NARCIS (Netherlands)

    Wang Xiaobin,; Cai Diangxiong,; Hoogmoed, W.B.; Oenema, O.

    2011-01-01

    BACKGROUND: An apparently large disparity still exists between developed and developing countries in historical trends of the amounts of nitrogen (N) fertilizers consumed, and the same situation holds true in China. The situation of either N overuse or underuse has become one of the major limiting f

  10. Energy assessment of nitrogen variable rate fertilization on wheat; Analise energetica da aplicacao de nitrogenio em taxa variavel em trigo

    Energy Technology Data Exchange (ETDEWEB)

    Colaco, A.F.; Karam, E.H.; Romanelli, T.L.; Molin, J.P. [Escola Superior de Agricultura Luiz Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Engenharia de Biossistemas], Email: andrecolaco@usp.br; Povh, F.P. [Fundacao ABC Pesquisa e Desenvolvimento Agropecuario, Castro, PR (Brazil)

    2011-07-01

    Precision Agriculture (PA) is a technique that can reduce the inputs utilization in agriculture production, including the nitrogen fertilizer consume. Great importance is given to this fertilizer, due to its contribution on energy input in agriculture. Methodologies based on the calculation of energy flow of agriculture systems are capable to identify management practices that use energy more efficiently. So, this study's objective is to evaluate the variable-rate nitrogen fertilization on wheat, using energy assessment. This study was carried on in two wheat fields, in which the fertilization was done adopting strips alternated by conventional method (single nitrogen dose) and by nitrogen variable-rate technology. Thus, the input and output energy in the system, energy balance, energy return on investment (EROI) and incorporated energy were determined for each geo-referenced point within the fields. Results showed that less energy was demanded when using variable-rate technology, due to the nitrogen saving, providing greater energy balance, EROI and lower incorporated energy on the areas managed using PA. The energy assessment showed to be an important tool to evaluate systems that use PA, because it is capable of monitoring crops energy potential. (author)

  11. The effect of different nitrogen fertilization rates on yield and quality of marigold (Calendula officinalis L. 'Tokaj' raw material

    Directory of Open Access Journals (Sweden)

    Beata Król

    2012-12-01

    Full Text Available Pot marigold (Calendula officinalis L. is an annual ornamental plant which is also grown for herbal raw material (flower heads used in the pharmaceutical and cosmetic industries. A field experiment was carried out in the years 2006-2008 in the Experimental Farm of the University of Life Sciences in Lublin. The study was conducted on loess soil with the granulometric composition of silt loam. The aim of the experiment was to determine the effect of different nitrogen rates (0, 40, 80, 120, 160 kg N × ha-1 on some morphological features of flower heads as well as on yield and quality of pot marigold raw material. Flowering of pot marigold was shortest in the control treatment (32 days and longest (43 days in the plot where nitrogen fertilization had been applied at the highest rate (160 kg N × ha-1. Nitrogen fertilization had a significant influence on the number of flower heads per plant, but no significant difference was found in diameter as well as in ligulate flowers and tubular flowers in the flower head. It was found to increase significantly raw material yield after the application of 80 kg N × ha-1, compared to the control treatment. Yield of flower heads did not differ markedly for fertilization rates from 80 to 160 kg N × ha-1. Nitrogen fertilization modified slightly essential oil content (this content increased with increasing nitrogen rates, but at the same time it decreased the percentage of flavonoid compounds.

  12. Effects of Water Volume and Nitrogen Fertilization on Yield and Quality Traits of Air-cured Burley Tobacco (Nicotianatabacum L.

    Directory of Open Access Journals (Sweden)

    Ascione S

    2014-12-01

    Full Text Available Based on a two-year field trial in the region of Campania (Southern Italy the effects of water volume and nitrogen fertilization on the yield and quality of Burley tobacco (Nicotianatabacum L. were investigated with reference to the following traits: cured leaf yield, price index, yield value, leaf area, specific leaf weight, burning capacity, color parameters, total alkaloid, nitrate and chloride leaf content. The experimental design was a factorial comparison among three water volumes (40, 80 and 120% evapotranspiration (ET, four nitrogen fertilization levels (0, 80, 160 and 240 kg ha-1 and two genotypes (cv TN86 and the hybrid R7-11. The yield of cured leaves rose with the increase in water and nitrogen availability, albeit at a decreasing rate. With the increase in water volume, the price index, burning capacity, specific leaf weight, total alkaloid and nitrate content decreased, while leaf area and chloride content increased. Up to a rate of 160 kg ha-1, nitrogen fertilization increased the price index, yield value, burning capacity, leaf area, specific leaf weight, total alkaloid and nitrates, and reduced leaf chloride content especially at 40% ET water volume. Both, nitrogen fertilization and water volume had little influence on leaf color. The year had considerable effects on yield, leaf area and color parameters, with higher values in the rainier season. In the two years, genotype TN86 showed higher stability for yield and yield value, lower alkaloid and higher nitrate content in the leaf than the R7-11 hybrid.

  13. Emersion induces nitrogen release and alteration of nitrogen metabolism in the intertidal genus Porphyra.

    Directory of Open Access Journals (Sweden)

    Jang K Kim

    Full Text Available We investigated emersion-induced nitrogen (N release from Porphyra umbilicalis Kütz. Thallus N concentration decreased during 4 h of emersion. Tissue N and soluble protein contents of P. umbilicalis were positively correlated and decreased during emersion. Growth of P. umbilicalis did not simply dilute the pre-emersion tissue N concentration. Rather, N was lost from tissues during emersion. We hypothesize that emersion-induced N release occurs when proteins are catabolized. While the δ(15N value of tissues exposed to emersion was higher than that of continuously submerged tissues, further discrimination of stable N isotopes did not occur during the 4 h emersion. We conclude that N release from Porphyra during emersion did not result from bacterial denitrification, but possibly as a consequence of photorespiration. The release of N by P. umbilicalis into the environment during emersion suggests a novel role of intertidal seaweeds in the global N cycle. Emersion also altered the physiological function (nitrate uptake, nitrate reductase and glutamine synthetase activity, growth rate of P. umbilicalis and the co-occurring upper intertidal species P. linearis Grev., though in a seasonally influenced manner. Individuals of the year round perennial species P. umbilicalis were more tolerant of emersion than ephemeral, cold temperate P. linearis in early winter. However, the mid-winter populations of both P. linearis and P. umbilicalis, had similar temporal physiological patterns during emersion.

  14. Long-term incorporation of manure with chemical fertilizers reduced total nitrogen loss in rain-fed cropping systems

    Science.gov (United States)

    Duan, Yinghua; Xu, Minggang; Gao, Suduan; Liu, Hua; Huang, Shaomin; Wang, Boren

    2016-09-01

    Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization are essential for sustainable agriculture. Quantifying the contribution of various fertilization regimes to soil N storage and loss has been lacking in a wide range of spatiotemporal scales. Based on data collected from field experiments at three typical agricultural zones in China, soil N dynamics and N changes in soil profile (0–100 cm) were examined during 1990–2009 under chemical fertilization, manure incorporation with fertilizer, and fertilizer with straw return treatments. We employed a mass balance approach to estimate the N loss to the environment after taking into account soil N change. Results showed a significant increase in soil N storage under manure incorporation treatments, accompanied with the lowest N loss (ave.20–24% of total N input) compared to all other treatments (ave.35–63%). Both soil N distribution and mass balance data suggested higher leaching risk from chemical fertilization in acidic soil of southern China with higher precipitation than the other two sites. This research concludes that manure incorporation with chemical fertilizer not only can achieve high N use efficiency and improve soil fertility, but also leads to the lowest total N loss or damage to the environment.

  15. Long-term incorporation of manure with chemical fertilizers reduced total nitrogen loss in rain-fed cropping systems

    Science.gov (United States)

    Duan, Yinghua; Xu, Minggang; Gao, Suduan; Liu, Hua; Huang, Shaomin; Wang, Boren

    2016-01-01

    Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization are essential for sustainable agriculture. Quantifying the contribution of various fertilization regimes to soil N storage and loss has been lacking in a wide range of spatiotemporal scales. Based on data collected from field experiments at three typical agricultural zones in China, soil N dynamics and N changes in soil profile (0–100 cm) were examined during 1990–2009 under chemical fertilization, manure incorporation with fertilizer, and fertilizer with straw return treatments. We employed a mass balance approach to estimate the N loss to the environment after taking into account soil N change. Results showed a significant increase in soil N storage under manure incorporation treatments, accompanied with the lowest N loss (ave.20–24% of total N input) compared to all other treatments (ave.35–63%). Both soil N distribution and mass balance data suggested higher leaching risk from chemical fertilization in acidic soil of southern China with higher precipitation than the other two sites. This research concludes that manure incorporation with chemical fertilizer not only can achieve high N use efficiency and improve soil fertility, but also leads to the lowest total N loss or damage to the environment. PMID:27650801

  16. Long-term fertilization alters chemically-separated soil organic carbon pools: Based on stable C isotope analyses

    Science.gov (United States)

    Dou, Xiaolin; He, Ping; Cheng, Xiaoli; Zhou, Wei

    2016-01-01

    Quantification of dynamics of soil organic carbon (SOC) pools under the influence of long-term fertilization is essential for predicting carbon (C) sequestration. We combined soil chemical fractionation with stable C isotope analyses to investigate the C dynamics of the various SOC pools after 25 years of fertilization. Five types of soil samples (0–20, 20–40 cm) including the initial level (CK) and four fertilization treatments (inorganic nitrogen fertilizer, IN; balanced inorganic fertilizer, NPK; inorganic fertilizer plus farmyard manure, MNPK; inorganic fertilizer plus corn straw residue, SNPK) were separated into recalcitrant and labile fractions, and the fractions were analysed for C content, C:N ratios, δ13C values, soil C and N recalcitrance indexes (RIC and RIN). Chemical fractionation showed long-term MNPK fertilization strongly increased the SOC storage in both soil layers (0–20 cm = 1492.4 gC m2 and 20–40 cm = 1770.6 gC m2) because of enhanced recalcitrant C (RC) and labile C (LC). The 25 years of inorganic fertilizer treatment did not increase the SOC storage mainly because of the offsetting effects of enhanced RC and decreased LC, whereas no clear SOC increases under the SNPK fertilization resulted from the fast decay rates of soil C.

  17. Long-term fertilization alters chemically-separated soil organic carbon pools: Based on stable C isotope analyses.

    Science.gov (United States)

    Dou, Xiaolin; He, Ping; Cheng, Xiaoli; Zhou, Wei

    2016-01-01

    Quantification of dynamics of soil organic carbon (SOC) pools under the influence of long-term fertilization is essential for predicting carbon (C) sequestration. We combined soil chemical fractionation with stable C isotope analyses to investigate the C dynamics of the various SOC pools after 25 years of fertilization. Five types of soil samples (0-20, 20-40 cm) including the initial level (CK) and four fertilization treatments (inorganic nitrogen fertilizer, IN; balanced inorganic fertilizer, NPK; inorganic fertilizer plus farmyard manure, MNPK; inorganic fertilizer plus corn straw residue, SNPK) were separated into recalcitrant and labile fractions, and the fractions were analysed for C content, C:N ratios, δ(13)C values, soil C and N recalcitrance indexes (RIC and RIN). Chemical fractionation showed long-term MNPK fertilization strongly increased the SOC storage in both soil layers (0-20 cm = 1492.4 gC m(2) and 20-40 cm = 1770.6 gC m(2)) because of enhanced recalcitrant C (RC) and labile C (LC). The 25 years of inorganic fertilizer treatment did not increase the SOC storage mainly because of the offsetting effects of enhanced RC and decreased LC, whereas no clear SOC increases under the SNPK fertilization resulted from the fast decay rates of soil C.

  18. Effects of altering dietary fatty acid composition on prostaglandin synthesis and fertility.

    Science.gov (United States)

    Abayasekara, D R; Wathes, D C

    1999-11-01

    Several studies over the past 20 years have demonstrated that subjects on diets composed of substances with high levels of n-3 polyunsaturated fatty acids (PUFAs) (e.g. fish) have a decreased incidence of heart disease. On this basis, a recent report from the Department of Health has advised UK consumers to decrease the proportion of saturated as opposed to unsaturated fats in their diet and to increase the ratio of n-3 to n-6 PUFAs. This could be achieved by altering the amounts of these constituents in milk and meat. n-3 Fatty acids can most easily be added to animal feed as either fish oil or linseed oil and can be increased in the blood and milk of ruminants following protection to avoid hydrogenation in the rumen. In western countries the ratio of consumption of n-6 to n-3 PUFAs is greater than 10 and current evidence tends to suggest that a ratio nearer 5 would be more desirable and compatible with cardiovascular well being. As fertility in the UK dairy herd is already poor, it is important to establish whether alterations in dietary n-3 and n-6 PUFAs affects herd fertility before widespread changes in animal diets are recommended. Therefore, this review considers the role played by PUFAs and eicosanoids in fertility, with particular reference to the implications for farm livestock production. The evidence reviewed shows that alteration of the concentration and ratio of n-6 and n-3 PUFAs in feeds can influence prostaglandin synthesis/metabolism in a number of mammalian systems. The changed patterns of prostaglandin synthesis can as a consequence, affect the diverse functions (e.g. hormone secretion) that are normally mediated via prostaglandins. Similarly, changes in prostaglandin synthesis effected through manipulation of PUFAs has a major bearing on fertility (as PGs affect many reproductive parameters, e.g. ovulation). Several studies in cattle and other mammals, show that feeding or infusing different types of fat with varying PUFA content to females can

  19. [Effects of nitrogen fertilization rate and planting density on cotton boll biomass and nitrogen accumulation in extremely early maturing cotton region of Northeast China].

    Science.gov (United States)

    Wang, Zi-Sheng; Wu, Xiao-Dong; Gao, Xiang-Bin; Xu, Min; Shen, Dan; Jin, Lu-Lu; Zhou, Zhi-Guo

    2012-02-01

    Taking cotton cultivars Liaomian 19 and NuCoTN 33B as test materials, a field experiment was conducted to study the effects of nitrogen fertilization rate (0, 240 and 480 kg x hm(-2)) and planting density (75000, 97500 and 120000 plants x hm(-2)) on the boll biomass and nitrogen accumulation in the extremely early maturing cotton region of Northeast China. With the growth and development of cotton, the biomass and nitrogen accumulation of cotton boll, cotton seed, and cotton fiber varied in 'S' shape. Both nitrogen fertilization rate and planting density had significant effects on the dynamic characteristics of boll biomass and nitrogen accumulation, and on the fiber yield and quality. In treatment 240 kg x hm(-2) and 97500 plants x hm(-2), the biomass of single boll, cotton seed and cotton fiber was the maximum, the starting time and ending time of the rapid accumulation period of the biomass and nitrogen were earlier but the duration of the accumulation was shorter, the rapid accumulation speed of the biomass was the maximum, and the distribution indices of the biomass and nitrogen were the lowest in boll shell but the highest in cotton seed and cotton fiber.

  20. Leaching and Transformation of Nitrogen Fertilizers in Soil After Application of N with Irrigation: A Soil Column Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A soil column method was used to compare the effect of drip fertigation (the application of fertilizer through drip irrigation systems, DFI) on the leaching loss and transformation of urea-N in soil with that of surface fertilization combined with flood irrigation (SFI), and to study the leaching loss and transformation of three kinds of nitrogen fertilizers (nitrate fertilizer, ammonium fertilizer, and urea fertilizer) in two contrasting soils after the fertigation. In comparison to SFI,DFI decreased leaching loss of urea-N from the soil and increased the mineral N (NH4+-N + NO3--N) in the soil. The N leached from a clay loam soil ranged from 5.7% to 9.6% of the total N added as fertilizer, whereas for a sandy loam soil they ranged between 16.2% and 30.4%. Leaching losses of mineral N were higher when nitrate fertilizer was used compared to urea or ammonium fertilizer. Compared to the control (without urea addition), on the first day when soils were fertigated with urea, there were increases in NH4+-N in the soils. This confirmed the rapid hydrolysis of urea in soil during fertigation. NH4+-N in soils reached a peak about 5 days after fertigation, and due to nitrification it began to decrease at day 10. After applying NH4+-N fertilizer and urea and during the incubation period, the mineral nitrogen in the soil decreased. This may be related to the occurrence of NH4+-N fixation or volatilization in the soil during the fertigation process.

  1. Evaluation of interspecific hybrids and cultivars of Brachiaria spp. submitted to sourcers and levels of nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Márcia Atauri Cardelli Lucena

    2012-12-01

    evaluated were positively influenced by N fertilization, which can alter growth patterns and canopy structure. The hybrids H69 and H12 showed structural features in relation to all variables evaluated that positively validate as options for pasture. The ammonium nitrate was more effective than urea for dry matter production in hybrids H69 and H12 in the first cut, and for regrowth of cultivars Piata and Marandu. The results showed that nitrogen is a good tool which in turn contributes positively to increases the growth-related variables, such as dry matter (total, leaves and pseudostems. The hybrids H69 and H12 showed morphological, structural features and production of dry matter that validate them as positive options for pasture use.

  2. Carbon and nitrogen allocations in corn grown in Central and Northeast China:different responses to fertilization treatments

    Institute of Scientific and Technical Information of China (English)

    MIAO Hui-tian; L Jia-long; XU Ming-gang; ZHANG Wen-ju; HUANG Shao-min; PENG Chang; CHEN Li-ming

    2015-01-01

    In order to reveal the impact of various fertilization strategies on carbon (C) and nitrogen (N) accumulation and al ocation in corn (Zea mays L.), corn was grown in the ifelds where continuous fertilization management had been lasted about 18 years at two sites located in Central and Northeast China (Zhengzhou and Gongzhuling), and biomass C and N contents in different organs of corn at harvest were analyzed. The fertilization treatments included non-fertilizer (control), chemical fertilizers of either nitrogen (N), or nitrogen and phosphorus (NP), or phosphorus and potassium (PK), or nitrogen, phospho-rus and potassium (NPK), NPK plus manure (NPKM), 150%of the NPKM (1.5NPKM), and NPK plus straw (NPKS). The results showed that accumulated C in aboveground ranged from 2 550–5 630 kg ha–1 in the control treatment to 9 300–9 610 kg ha–1 in the NPKM treatment, of which 57–67%and 43–50%were al ocated in the non-grain organs, respectively. Accumulated N in aboveground ranged from 44.8–55.2 kg ha–1 in the control treatment to 211–222 kg ha–1 in the NPKM treatment, of which 35–48% and 33–44% were al ocated in the non-grain parts, respectively. C al ocated to stem and leaf for the PK treatment was 65 and 49%higher than that for the NPKM treatment at the both sites, respectively, while N al ocated to the organs for the PK treatment was 18 and 6%higher than that for the NPKM treatment, respectively. This study demonstrated that responses of C and N al ocation in corn to fertilization strategies were different, and C al ocation was more sensitive to fertilization treatments than N al ocation in the area.

  3. Fertilizer performance of liquid fraction of digestate as synthetic nitrogen substitute in silage maize cultivation for three consecutive years.

    Science.gov (United States)

    Sigurnjak, I; Vaneeckhaute, C; Michels, E; Ryckaert, B; Ghekiere, G; Tack, F M G; Meers, E

    2017-12-01

    Following changes over recent years in fertilizer legislative framework throughout Europe, phosphorus (P) is taking over the role of being the limiting factor in fertilizer application rate of animal manure. This results in less placement area for spreading animal manure. As a consequence, more expensive and energy demanding synthetic fertilizers are required to meet crop nutrient requirements despite existing manure surpluses. Anaerobic digestion followed by mechanical separation of raw digestate, results in liquid fraction (LF) of digestate, a product poor in P but rich in nitrogen (N) and potassium (K). A 3-year field experiment was conducted to evaluate the impact of using the LF of digestate as a (partial) substitute for synthetic N fertilizer. Two different fertilization strategies, the LF of digestate in combination with respectively animal manure and digestate, were compared to the conventional fertilization regime of raw animal manure with synthetic fertilizers. Results from the 3-year trial indicate that the LF of digestate may substitute synthetic N fertilizers without crop yield losses. Through fertilizer use efficiency assessment it was observed that under-fertilization of soils with a high P status could reduce P availability and consequently the potential for P leaching. Under conditions of lower K application, more sodium was taken up by the crop. In arid regions, this effect might reduce the potential risk of salt accumulation that is associated with organic fertilizer application. Finally, economic and ecological benefits were found to be higher when LF of digestate was used as a synthetic N substitute. Future perspectives indicate that nutrient variability in bio-based fertilizers will be one of the greatest challenges to address in the future utilization of these products. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Effects of a controlled release fertilizer on the nitrogen dynamics of mid-rotation loblolly pine plantation in the Piedmont, Virginia

    Science.gov (United States)

    J. Rob Elliot; Thomas R. Fox

    2006-01-01

    Nitrogen deficiency is characteristic of many mid-rotation loblolly pine (Pinus taeda L.) plantations in the Piedmont region of the Southeast. Fertilization with urea is the most common method used to correct this deficiency. Previous studies show that urea fertilization produces a rapid pulse of available nitrogen (N) with only a portion being...

  5. Effect of Preplant Irrigation, Nitrogen Fertilizer Application Timing, and Phosphorus and Potassium Fertilization on Winter Wheat Grain Yield and Water Use Efficiency

    Directory of Open Access Journals (Sweden)

    Jacob T. Bushong

    2014-01-01

    Full Text Available Preplant irrigation can impact fertilizer management in winter wheat. The objective of this study was to evaluate the main and interactive effects of preplant irrigation, N fertilizer application timing, and different N, P, and K fertilizer treatments on grain yield and WUE. Several significant two-way interactions and main effects of all three factors evaluated were observed over four growing seasons for grain yield and WUE. These effects could be described by differences in rainfall and soil moisture content among years. Overall, grain yield and WUE were optimized, if irrigation or adequate soil moisture were available prior to planting. For rain-fed treatments, the timing of N fertilizer application was not as important and could be applied before planting or topdressed without much difference in yield. The application of P fertilizer proved to be beneficial on average years but was not needed in years where above average soil moisture was present. There was no added benefit to applying K fertilizer. In conclusion, N and P fertilizer management practices may need to be altered yearly based on changes in soil moisture from irrigation and/or rainfall.

  6. Structural characteristics signal-grass under continuois stoking and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Rodrigo Vieira de Morais

    2010-01-01

    Full Text Available From February to November 2003, the mass and morphological composition of forage from Brachiaria decumbens cv. Basilisk pastures under four different doses of nitrogen (75, 150, 225 and 300 kg/ha/year were evaluated. The pastures were managed under continuous stocking with growing cattle. The data were grouped within three periods: February to April, May to August and September to November. Randomized block design with subdivided plots and two repetitions was used. The plots correspond to the nitrogen (N doses, while the subplots to the time of the evaluation. In the period from May to August, the forage mass in the B. decumbens pasture increased linearly related to the N dose. The percentage of green leaf blade (GLB was lower in the May/August period if compared to the other periods. The highest percentage values for green stem (GS ocorred February/April. The relation between LFV masses and CV were influenced by the period of evaluation, reaching higher values in September/November. When 75 kg ha-1 of N was applied, the senescent tissue (ST participation in the pasture did not vary throughout the months of the year. However, when whith doses of 150 kg ha-1 of N were applied, the percentage of ST was lower for February/April in comparison to the other periods. The percentages of GFB and GS increased linearly and positively as the N doses increased in the February/April. The structure of the B. decumbens pasture under continuous stocking is influenced interactively by the nitrogen doses and time of the year. Nitrogen fertilization improves the structure of the B. decumbens pasture under continuous stocking managed with the same mean height.

  7. The effect of plant density and nitrogen fertilizer on light interception and dry matter yield in hemp (Cannabis sativa L.

    Directory of Open Access Journals (Sweden)

    mohamad reza asghari poor

    2009-06-01

    Full Text Available The effect of plant density and nitrogen fertilizer on canopy light interception and on flowering was investigated in hemp (Cannabis sativa L. cv. ‘Kompolti’ Crop grown at initial densities of 50, 150 and 250 plants/m2 at the Mashhad and 30, 90 and 150 plants/m2 at the Shirvan. Nitrogen fertilizer was applied before and 45 days after sowing at a rates of 50 and 200 kg/ha at the Mashhad, and 50, 150 and 250 kg/ha at the Shirvan. Rate of canopy development increased with increasing plant density and nitrogen fertilizer in both sites. At the Mashhad, interception of 90% of light was attained at 380 to 665 degree days (base 2°C from emergence for the crop grown at different densities. At Shirvan, rate of canopy development was slower. Interception of 90% of light was attained at 586 degree days from emergence for the crop grown at 30 plants/m2 and at 712 degree days for the crop grown at 150 plants/m2, probably as a result of cold weather. Nitrogen fertilizer in a similar way as plant density increased light interception. Maximum light interception did not depend on plant density and nitrogen fertilizer and was about 95%. In both sites, the flowering date was later with increasing plant density. Dates of 75% flowering for the initial densities of 50, 150 and 250 plants/m2 in Mashhad and 30, 90 and 150 plants/m2 in Shirvan were, respectively 26 August, 1, 6, 6, 11 and 12 September. Independent of plant density, canopy light interception started to decline at about 150 degree days after flowering, reaching 58 to 75% at about 700 degree days post-flowering. Morphological characteristics at both sites were highly correlated with plant sexual, plant population and nitrogen fertilizer. Highest stem, leaf and inflorescence yield were obtained in Mashhad at 250 plant/m-2 and in Shirvan at 150 plant m-2 when 200 kg N ha-1 in Mashhad and 250 kg N/ha in Shirvan was used. Above ground dry matter increased at both sites with increasing plant density and

  8. Soil microbial community structure is unaltered by plant invasion, vegetation clipping, and nitrogen fertilization in experimental semi-arid grasslands

    Directory of Open Access Journals (Sweden)

    Chelsea J Carey

    2015-05-01

    Full Text Available Global and regional environmental changes often co-occur, creating complex gradients of disturbance on the landscape. Soil microbial communities are an important component of ecosystem response to environmental change, yet little is known about how microbial structure and function respond to multiple disturbances, or whether multiple environmental changes lead to unanticipated interactive effects. Our study used experimental semi-arid grassland plots in a Mediterranean-climate to determine how soil microbial communities in a seasonally variable ecosystem respond to one, two, or three simultaneous environmental changes: exotic plant invasion, plant invasion + vegetation clipping (to simulate common management practices like mowing or livestock grazing, plant invasion + nitrogen (N fertilization, and plant invasion + clipping + N fertilization. We examined microbial community structure 5-6 years after plot establishment via sequencing of >1 million 16S rRNA genes. Abiotic soil properties (soil moisture, temperature, pH, and inorganic N and microbial functioning (nitrification and denitrification potentials were also measured and showed treatment-induced shifts, including altered NO3- availability, temperature, and nitrification potential. Despite these changes, bacterial and archaeal communities showed little variation in composition and diversity across treatments. Even communities in plots exposed to three interacting environmental changes were similar to those in restored native grassland plots. Historical exposure to large seasonal and inter-annual variations in key soil properties, in addition to prior site cultivation, may select for a functionally plastic or largely dormant microbial community, resulting in a microbial community that is structurally robust to single and multiple environmental changes.

  9. Soil carbon dioxide emission from intensively cultivated black soil in Northeast China. Nitrogen fertilization effect

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Kang [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Graduate University of Chinese Academy of Sciences, Beijing (China); Ding, Weixin; Cai, Zucong [Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Wang, Yufeng; Zhang, Xilin; Zhou, Baoku [Heilongjiang Academy of Agricultural Sciences, Harbin (China). Inst. of Soil and Fertilizer

    2012-08-15

    Purpose: The aim of this study was to understand the effect of nitrogen fertilization on soil respiration and native soil organic carbon (SOC) decomposition and to identify the key factor affecting soil respiration in a cultivated black soil. Materials and methods: A field experiment was conducted at the Harbin State Key Agroecological Experimental Station, China. The study consisted of four treatments: unplanted and N-unfertilized soil (U0), unplanted soil treated with 225 kg N ha{sup -1} (UN), maize planted and N-unfertilized soil (P0), and planted soil fertilized with 225 kg N ha{sup -1} (PN). Soil CO{sub 2} and N{sub 2}O fluxes were measured using the static closed chamber method. Results and discussion: Cumulative CO{sub 2} emissions during the maize growing season with the U0, UN, P0, and PN treatments were 1.29, 1.04, 2.30 and 2.27 Mg C ha{sup -1}, respectively, indicating that N fertilization significantly reduced the decomposition of native SOC. However, no marked effect on soil respiration in planted soil was observed because the increase of rhizosphere respiration caused by N addition was counteracted by the reduction of native SOC decomposition. Soil CO{sub 2} fluxes were significantly affected by soil temperature but not by soil moisture. The temperature sensitivity (Q{sub 10}) of soil respiration was 2.16-2.47 for unplanted soil but increased to 3.16-3.44 in planted soil. N addition reduced the Q{sub 10} of native SOC decomposition possibly due to low labile organic C but increased the Q{sub 10} of soil respiration due to the stimulation of maize growth. The estimated annual CO{sub 2} emission in N-fertilized soil was 1.28 Mg C ha{sup -1} and was replenished by the residual stubble, roots, and exudates. In contrast, the lost C (1.53 Mg C ha{sup -1}) in N-unfertilized soil was not completely supplemented by maize residues, resulting in a reduction of SOC. Although N fertilization significantly increased N{sub 2}O emissions, the global warming potential

  10. Nitrogen utilization and transformation in red soil fertilized with urea and ryegrass

    Institute of Scientific and Technical Information of China (English)

    WuGang; HeZhen-Li

    1998-01-01

    The influence of fertilization with urea and ryegrass on nitrogen utilization and transformation in red soil has been studied by using 15N tracer method.When urea and ryegrass were applied alone or in combination,the percentage of N uptaken by ryegrass from labelled urea was 3 and 1.7 times that from labelled ryegrass for the application rate of 200mgN.kg-1 and 100mgN.kg-1,respectively;combining application of ryegrass and ureareduced uptake of urea N and increased uptake of ryegrass N by ryegrass plant,but the percentage of N residued in soil increased for urea and decreased for ryegrass.when urea and ryegrass were applied alone,the percentage of N residued in soil from labelled ryegrass was more than 69% while that from labelled urea was less than 25%,and much more ryegrass N was incorporated into humus than urea N.

  11. Growth of castor bean BRS-149 nordestina fertilized with nitrogen, phosphorus and potassium

    Directory of Open Access Journals (Sweden)

    Diva Lima de Araujo

    2009-12-01

    Full Text Available A trial was carried out in a greenhouse located at the Federal University of Campina Grande, in Campina Grande, Paraiba State, Brazil, with castor bean plants (Ricinus communis L., cv BRS Nordestina, in order to evaluate the effects of nitrogen, phosphorus and potassium on the growth. A completely randomized design with three replications and 15 treatments originated from a baconian matrix was adopted. Reference doses were 40:90:60 kg ha-1 of N:P2O5:K2O, respectively. Plant height, stem diameter, number and length of leaves were measured at 20, 40, 60, 80, 100, 120 and 140 days after planting (DAP. The unbalanced fertilization affected the development and seed production of castor bean, and the best response of the plants was observed at levels of 200 kg ha-1 de N; 150 kg ha-1 de P2O5 and 150 kg ha-1 de K2O.

  12. Productivity of irrigated beans due to sources of stabilized nitrogen fertilizer and controlled release

    Directory of Open Access Journals (Sweden)

    Tatiely Gomes Bernardes

    2015-12-01

    Full Text Available ABSTRACT New nitrogen fertilizers are available in the market actually, however, does not have results on the efficiency of the Cerrado conditions. With that objective of this study was to evaluate the effect of urea including stabilized and controlled release urea on yield of irrigated common beans (Phaseolus vulgaris L in no-tillage system. The experiment was conducted in the winter crop, at Embrapa Arroz e Feijão, in Santo Antônio de Goiás, State of Goiás, Brazil. The experimental design was randomized blocks, with five replicates. Treatments consisted of five N sources (urea, urea + NBPT, urea + polymer, ammonium sulphate, and ammonium nitrate and a control (without N being applied 20 kg ha-1 of N at sowing and 80 kg ha-1 onf N in topdressing. We evaluated the chlorophyll content in leaves of common beans, the leaf N content and dry mass weight (MSPA in the flowering of common beans, the number of pods per plant, number of grains per pod, mass of 100 grains, grain yield and final stand of the common beans. The sources of nitrogen fertilizer did not influence, leaf N content, the mass of MSPA and the relative chlorophyll index of common beans. The use of polymerized urea and urea with urease inhibitor, did not produce increases in the number of grains per pod, number of pods per plant, mass of 100 grains and common beans yield compared to traditional sources of N, urea, ammonium sulfate and ammonium nitrate.

  13. Impact of DNA mismatch repair system alterations on human fertility and related treatments.

    Science.gov (United States)

    Hu, Min-hao; Liu, Shu-yuan; Wang, Ning; Wu, Yan; Jin, Fan

    2016-01-01

    DNA mismatch repair (MMR) is one of the biological pathways, which plays a critical role in DNA homeostasis, primarily by repairing base-pair mismatches and insertion/deletion loops that occur during DNA replication. MMR also takes part in other metabolic pathways and regulates cell cycle arrest. Defects in MMR are associated with genomic instability, predisposition to certain types of cancers and resistance to certain therapeutic drugs. Moreover, genetic and epigenetic alterations in the MMR system demonstrate a significant relationship with human fertility and related treatments, which helps us to understand the etiology and susceptibility of human infertility. Alterations in the MMR system may also influence the health of offspring conceived by assisted reproductive technology in humans. However, further studies are needed to explore the specific mechanisms by which the MMR system may affect human infertility. This review addresses the physiological mechanisms of the MMR system and associations between alterations of the MMR system and human fertility and related treatments, and potential effects on the next generation.

  14. ROW METHOD OF SUGAR BEET (BETA VULGARIS L. FERTILIZATION WITH MULTICOMPONENT FERTILIZER BASED ON UREA-AMMONIUM NITRATE SOLUTION AS A WAY TO INCREASE NITROGEN EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Przemysław BARŁÓG

    2010-12-01

    Full Text Available Sugar beet is the main crop commonly cultivated for sugar production in temperate regions of the World. Actual yields in main Central Europe producing countries are much lower, due to many limiting factors. Among them, nutrients supply is of great value, especially referring to efficiency of nitrogen, which is generally low. In the conducted study two methods of nitrogen application were compared (i broadcast of calcium saltpeter and (ii row application of the multicomponent fertilizer based on urea-ammonium-nitrate (UAN solution. The basic amount of the applied N was 75 kg ha-1. The highest yields of both taproots and refined sugar were harvested on the plot receiving 75 kg N-1 as UAN liquid multicomponent fertilizer and 50% of the recommended P and K rates. The positive effects of row application of liquid N fertilizer on taproot and sugar yields were also corroborated by high values of indices of agronomic efficiency for both N as well as P and K. However this method of sugar beets fertilization has some possibilities, as indicated by still high contents of melassogenic substances.

  15. Nitrogen and potassium fertilization in yield and macronutrients contents of heliconia cv. Golden Torch

    Directory of Open Access Journals (Sweden)

    Márkilla Z. Beckmann-Cavalcante

    2016-04-01

    Full Text Available ABSTRACT This study aimed to evaluate the effect of nitrogen (N and potassium (K fertilization in yield and contents of macronutrients in heliconia plants (Heliconia psittacorum x Heliconia spathocircinata Aristeguieta cv. Golden Torch. The experiment was set in a randomized block design, in a 4 x 4 factorial, corresponding to N doses (0, 120, 180 and 240 g of N hole-1 and K doses (0, 120, 180 and 240 g of K2O hole-1 with four replicates and five rhizomes per plot, under field conditions. After one year of cultivation, yield (number of flower stems per square meter and the leaf contents of N, P, K, Ca, Mg and S were determined. The applied N doses did not influence either yield or the leaf contents of the evaluated macronutrients. K fertilization favored the increase in leaf K content and the decrease in the contents of P, Ca and Mg in leaves of heliconias. Under the conditions of this experiment, it is recommended to apply 161.46 g of K2O hole-1 for a maximum yield of 9.89 stems m-2 per month.

  16. [Effects of nitrogen fertilization, soil moisture and soil temperature on soil respiration during summer fallow season].

    Science.gov (United States)

    Zhang, Fang; Guo, Sheng-Li; Zou, Jun-Liang; Li, Ze; Zhang, Yan-Jun

    2011-11-01

    On the loess plateau, summer fallow season is a hot rainy time with intensive soil microbe activities. To evaluate the response of soil respiration to soil moisture, temperature, and N fertilization during this period is helpful for a deep understanding about the temporal and spatial variability of soil respiration and its impact factors, then a field experiment was conducted in the Changwu State Key Agro-Ecological Experimental Station, Shaanxi, China. The experiment included five N application rates: unfertilized 0 (N0), 45 (N45), 90 (N90), 135(N135), and 180 (N180) kg x hm(-2). The results showed that at the fallow stage, soil respiration rate significantly enhanced from 1.24 to 1.91 micromol x (m2 x s)(-1) and the average of soil respiration during this period [6.20 g x (m2 x d)(-1)] was close to the growing season [6.95 g x (m2 x d)(-1)]. The bivariate model of soil respiration with soil water and soil temperature was better than the single-variable model, but not so well as the three-factor model when explaining the actual changes of soil respiration. Nitrogen fertilization alone accounted for 8% of the variation soil respiration. Unlike the single-variable model, the results could provide crucial information for further research of multiple factors on soil respiration and its simulation.

  17. Diazotrophic bacteria and nitrogen fertilization on the growth of micropropagated pineapple plantlets during acclimatization

    Directory of Open Access Journals (Sweden)

    Aurilena de Aviz Silva

    Full Text Available ABSTRACT: This study examines the effect of inoculation with diazotrophic bacteria and nitrogen fertilization on the growth of micropropagated pineapple cv. 'Vitória' plantlets during the acclimatization period. The experiment was carried out in a greenhouse in Campos dos Goytacazes, in randomized blocks, using a 2x5x5 factorial scheme, with the factors being two types of inocula (absence or presence of a mixture of diazotrophic bacteria that contained Burkholderia sp. UENF 114111, Burkholderia silvatlantica UENF 11711, and Herbaspirillum seropedicae HRC 54, five levels of urea (0, 2, 5, 7, and 10g L-1, and five evaluation periods (30, 60, 90, 120, and 150 days following the planting of plantlets in trays, and with four replications of each treatment. An increase in the dried weight of shoots and roots of micropropagated pineapple cv. 'Vitória' plants depended on inoculation with diazotrophic bacteria, and plantlets acclimatization could be reduced by up to 57 days, depending on the concentration of urea fertilizer.

  18. Nitrogen Fertilization Modifies the Phenology of Ground CO2 Efflux in a Boreal Scots Pine Forest

    Science.gov (United States)

    Marshall, J. D.; Näsholm, T.; Linder, S.; Tarvainen, L.; Peichl, M.; Lundmark, T.

    2015-12-01

    Problems with the extraction of ecosystem respiration rates from eddy covariance data have led to renewed interest in chamber-based estimates of CO2 efflux from near the ground surface. However, chamber measurements frequently have their own issues. Here we describe the results of a study using large (≈2 m radius), transparent chambers over intact ground vegetation to describe the net efflux of CO2 and its environmental controls during the growing season at Rosinedal, a research site in northern Sweden. Measurements were made at thirty-minute intervals over the course of three growing seasons in a heavily fertilized and an unfertilized Scots pine stand. Ammonium nitrate was added at rates of 100 kg N ha-1 for the first five years, after which the rate was halved but the additions continued. The CO2 efflux results were simultaneously fitted to a nonlinear model describing the exponential increase in dark efflux with temperature, the Michaelis-Menten saturation of light-driven CO2 uptake in photosynthesis, the reduction in efflux due to soil drying, and a residual term that we ascribe to weekly shifts in the photosynthate partitioning of canopy trees to belowground processes. We found the expected exponential increase in dark efflux with temperature, however the net efflux in daytime was often negative, reflecting the high GPP of the ground vegetation, especially in dense canopies of bilberry (Vaccinium myrtillus L.). There was a clear reduction in dark efflux under dry conditions. The empirical phenology parameters increased sharply in early July, around the time that leaf expansion and rapid cambial growth were completed. This increase was more pronounced on the control plot than on the fertilized plot, consistent with expectations based on the notion that N fertilization should favor aboveground partitioning. The empirical "partitioning coefficient" shifted net efflux by nearly as much as the seasonal temperature range. Dark efflux of CO2 was nearly halved as a

  19. Modelling of catchment nitrogen concentrations response to observed varying fertilizer application intensities

    Science.gov (United States)

    Jomaa, Seifeddine; Jiang, Sanyuan; Yang, Xiaoqiang; Rode, Michael

    2016-04-01

    Eutrophication is a serious environmental problem. Despite numerous experimental and modelling efforts, understanding of the effect of land use and agriculture practices on in-stream nitrogen fluxes is still not fully achieved. This study combined intensive field monitoring and numerical modelling using 30 years of surface water quality data of a drinking water reservoir catchment in central Germany. The Weida catchment (99.5 km2) is part of the Elbe river basin and has a share of 67% of agricultural land use with significant changes in agricultural practices within the investigation period. The geology of the Weida catchment is characterized by clay schists and eruptive rocks, where rocks have low permeability. The semi-distributed hydrological water quality HYPE (Hydrological Predictions for the Environment) model was used to reproduce the measured data. First, the model was calibrated for discharge and nitrate-N concentrations (NO3-N) during the period 1997-2000. Then, the HYPE model was validated successfully for three different periods 1983-1987, 1989-1996 and 2000-2003, which are charaterized by different fertilizer application rates (with lowest discharge prediction performance of NSE = 0.78 and PBIAS = 3.74%, considering calibration and validation periods). Results showed that the measured as well as simulated in-stream nitrate-N concentration respond quickly to fertilizer application changes (increase/decrease). This rapid response can be explained with short residence times of interflow and baseflow runoff components due to the hardrock geological properties of the catchment. Results revealed that the surface runoff and interflow are the most dominant runoff components. HYPE model could reproduce reasonably well the NO3-N daily loads for varying fertilizer application, when detailed input data in terms of crop management (field-specific survey) are considered.

  20. Carbon and carbon dioxide accumulation by marandu grass under nitrogen fertilization and irrigation

    Directory of Open Access Journals (Sweden)

    Elisângela Dupas

    2016-06-01

    Full Text Available ABSTRACT Nitrogen (N is the most limiting nutrient for growth of forage grasses, especially in conditions of low water availability. Therefore, it is important to evaluate the effect of N fertilization and irrigation on the accumulation of carbon (C and carbon dioxide (CO2 by marandu grass in the Cerrado Paulista, in the rainy and dry seasons. Experiments were conducted to evaluate N fertilization in each season, with and without irrigation. Five N rates were used (0, 50, 100, 150 and 200 kg ha-1 per cutting, using urea as N source, totaling 0, 300, 600, 900 and 1200 kg ha-1 in the rainy season and 0, 100, 200, 300 and 400 kg ha-1 in the dry season. The experiments were arranged in a split-plot randomized block design. There was no significant interaction (p > 0.05 between N and time of fertilization in the irrigated experiment. However, N promoted a quadratic effect in organic matter production (OMP, accumulation of C and CO2 by marandu grass, while there was no influence of the seasons. In the non-irrigated experiment, the interaction between N rates and seasons was significant (p < 0.05 only for the rainy season. Organic matter production and C and CO2 accumulation was greater in the rainy season than in the dry season. Irrigation provided increases of approximately 20% in C and CO2 accumulation. The use of N and irrigation increases the accumulation of C and CO2 by marandu grass, and this increase is higher during the rainy season.

  1. Management of irrigation frequency and nitrogen fertilization to mitigate GHG and NO emissions from drip-fertigated crops

    NARCIS (Netherlands)

    Abalos, D.; Sanchez-Martin, L.; Garcia-Torres, L.; Groenigen, van J.W.; Vallejo, A.

    2014-01-01

    Drip irrigation combined with split application of fertilizer nitrogen (N) dissolved in the irrigation water (i.e. drip fertigation) is commonly considered best management practice for water and nutrient efficiency. As a consequence, its use is becoming widespread. Some of the main factors (water-fi

  2. INFLUENCE OF ORGANIC AND MINERAL FERTILIZATION ON GERMINATION, LEAF NITROGEN, NITRATE ACCUMULATION AND YIELD OF VEGETABLE AMARANTH

    NARCIS (Netherlands)

    Kooten, Olaf van

    2012-01-01

    The influence of manure and diammonium phosphate (DAP) mineral fertilizer on germination, leaf nitrogen content, nitrate accumulation and yield of vegetable amaranth (Amaranthus hypochondriacus) was investigated. Field trials were set up at the University of Nairobi Field Station at the Upper Kabete

  3. Influence of organic and mineral fertilization on germination, leaf nitrogen, nitrate accumulation and yield of vegetable amaranth

    NARCIS (Netherlands)

    Onyango, Cecilia M.; Kooten, Olaf van

    2012-01-01

    The influence of manure and diammonium phosphate (DAP) mineral fertilizer on germination, leaf nitrogen content, nitrate accumulation and yield of vegetable amaranth (Amaranthus hypochondriacus) was investigated. Field trials were set up at the University of Nairobi Field Station at the Upper Kabete

  4. Effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to post-harvest proliferation of Salmonella enterica.

    Science.gov (United States)

    Marvasi, Massimiliano; George, Andrée S; Giurcanu, Mihai; Hochmuth, George J; Noel, Jason T; Gause, Elizabeth; Teplitski, Max

    2014-10-01

    Fresh fruits and vegetables are increasingly recognized as vehicles of salmonellosis. Pre- and post-harvest environmental conditions, and physiological, and genetic factors are thought to contribute to the ability of human pathogens to persist in the production environment, attach to, colonize and proliferate in and on raw produce. How field production conditions affect the post-harvest food safety outcomes is not entirely understood. This study tested how varying nitrogen and potassium fertilization levels affected the "susceptibility" of tomatoes to Salmonella infections following the harvest of fruits. Two tomato varieties grown over three seasons under high, medium, and low levels of nitrogen and potassium fertilization in two locations were inoculated with seven strains of Salmonella. Even though the main effects of nitrogen and potassium fertilization on the susceptibility of tomatoes to infections with Salmonella enterica were not statistically significant overall, differences in nitrogen concentrations in plant tissues correlated with the susceptibility of partially ripe tomatoes (cv. Solar Fire) to Salmonella. Tomato maturity and the season in which tomatoes were produced had the strongest effect on the ability of Salmonella to multiply in tomatoes. Tomato phenolics, accumulation of which is known to correlate with rates of the N fertilization, did not inhibit growth of Salmonella in vitro.

  5. [Effects of drought stress and nitrogen fertilization rate on the accumulation of osmolytes in Jatropha curcas seedlings].

    Science.gov (United States)

    Yin, Li; Liu, Yong-An; Xie, Cai-Yong; Jiang, Xue; Wang, Yong-Jie; Li, Yin-Hua; Yan, Zhen; Hu, Ting-Xing

    2012-03-01

    A pot experiment with controlled water supply was conducted to study the effects of different drought stress degree (80% FC, 60% FC, 40% FC, and 20% FC) and nitrogen fertilization rate (0 g x pot(-1), 1.2 g x pot(-1), 3.6 g x pot(-1), and 6.0 g x pot(-1)) on the accumulation of osmolytes in different organs of Jatropha curcas seedlings. Under drought stress, the soluble protei and free proline in seedling shoots and roots and the soluble sugar in seedling shoots had a great accumulation, and the free proline content in seedling leaves had a great increase with increasing drought stress degree. Also under drought stress, the Na+, Ca2+, and Mg2+ all highly accumulated in seedling various organs, while K only accumulated greatly in shoots but slightly in leaves and roots. The effects of nitrogen fertilization on the accumulation of osmolytes in seedlings depended on drought stress degree and nitrogen fertilization rate. At 80% FC and 60% FC, increasing nitrogen fertilization rate could markedly promote the accumulation of osmolytes in the organs of J. curcas seedlings; at 40% FC, applying 6.0 g x pot(-1) weakened the promotion effect on the osmolytes accumulation; whereas at 20%, applying 1.2 g x pot(-1) made the plants have a higher capability in osmoregulation, but applying 3.6 g x pot(-1) and 6.0 g x pot(-1) had less promotion effect, and even, inhibited osmolytes accumulation.

  6. Runoff, nitrogen (N) and phosphorus (P) losses from purple slope cropland soil under rating fertilization in Three Gorges Region.

    Science.gov (United States)

    Bouraima, Abdel-Kabirou; He, Binghui; Tian, Taiqiang

    2016-03-01

    Soil erosion along with soil particles and nutrients losses is detrimental to crop production. We carried out a 5-year (2010 to 2014) study to characterize the soil erosion and nitrogen and phosphorus losses caused by rainfall under different fertilizer application levels in order to provide a theoretical evidence for the agricultural production and coordinate land management to improve ecological environment. The experiment took place under rotation cropping, winter wheat-summer maize, on a 15° slope purple soil in Chongqing (China) within the Three Gorges Region (TGR). Four treatments, control (CK) without fertilizer, combined manure with chemical fertilizer (T1), chemical fertilization (T2), and chemical fertilizer with increasing fertilization (T3), were designed on experimental runoff plots for a long-term observation aiming to study their effects on soil erosion and nutrients losses. The results showed that fertilization reduced surface runoff and nutrient losses as compared to CK. T1, T2, and T3, compared to CK, reduced runoff volume by 35.7, 29.6, and 16.8 %, respectively and sediment yield by 40.5, 20.9, and 49.6 %, respectively. Regression analysis results indicated that there were significant relationships between soil loss and runoff volume in all treatments. The combined manure with chemical fertilizer (T1) treatment highly reduced total nitrogen and total phosphorus losses by 41.2 and 33.33 %, respectively as compared with CK. Through this 5-year experiment, we can conclude that, on the sloping purple soil, the combined application of manure with fertilizer is beneficial for controlling runoff sediments losses and preventing soil erosion.

  7. Do polyamines alter the sensitivity of lichens to nitrogen stress?

    Science.gov (United States)

    Pirintsos, S A; Munzi, S; Loppi, S; Kotzabasis, K

    2009-07-01

    The sensitivity of lichens measuring photosynthetic efficiency and polyamines as modulator of nitrogen stress tolerance was investigated. Two lichen species with a markedly different tolerance to nitrogen compounds, namely Evernia prunastri (L.) Ach. and Xanthoria parietina (L.) Th.Fr., were incubated with deionized water (control) and solutions of KNO(3), NH(4)NO(3) and (NH(4))(2)SO(4) and then exposed to different light conditions. The F(v)/F(m) parameter (maximum quantum efficiency of photosystem II) was used as stress indicator. The results showed that F(v)/F(m) values, in the produced experimental conditions, were independent from the light gradient. Photosynthetic efficiency of E. prunastri was impaired by high ammonium concentrations, while nitrate had no effect; X. parietina was hardly influenced by nitrogen compounds. External supply of polyamines reduced the sensitivity of E. prunastri, while polyamine inhibitors reduced the tolerance of X. parietina to NH(4)(+), suggesting that polyamines play an important role in modulating the sensitivity/tolerance to nitrogen stress.

  8. Reconstruction of spatially detailed global map of NH4+ and NO3- application in synthetic nitrogen fertilizer

    Science.gov (United States)

    Nishina, Kazuya; Ito, Akihiko; Hanasaki, Naota; Hayashi, Seiji

    2017-02-01

    Currently, available historical global N fertilizer map as an input data to global biogeochemical model is still limited and existing maps were not considered NH4+ and NO3- in the fertilizer application rates. This paper provides a method for constructing a new historical global nitrogen fertilizer application map (0.5° × 0.5° resolution) for the period 1961-2010 based on country-specific information from Food and Agriculture Organization statistics (FAOSTAT) and various global datasets. This new map incorporates the fraction of NH4+ (and NO3-) in N fertilizer inputs by utilizing fertilizer species information in FAOSTAT, in which species can be categorized as NH4+- and/or NO3--forming N fertilizers. During data processing, we applied a statistical data imputation method for the missing data (19 % of national N fertilizer consumption) in FAOSTAT. The multiple imputation method enabled us to fill gaps in the time-series data using plausible values using covariates information (year, population, GDP, and crop area). After the imputation, we downscaled the national consumption data to a gridded cropland map. Also, we applied the multiple imputation method to the available chemical fertilizer species consumption, allowing for the estimation of the NH4+ / NO3- ratio in national fertilizer consumption. In this study, the synthetic N fertilizer inputs in 2000 showed a general consistency with the existing N fertilizer map (Potter et al., 2010) in relation to the ranges of N fertilizer inputs. Globally, the estimated N fertilizer inputs based on the sum of filled data increased from 15 to 110 Tg-N during 1961-2010. On the other hand, the global NO3- input started to decline after the late 1980s and the fraction of NO3- in global N fertilizer decreased consistently from 35 to 13 % over a 50-year period. NH4+-forming fertilizers are dominant in most countries; however, the NH4+ / NO3- ratio in N fertilizer inputs shows clear differences temporally and geographically. This

  9. The 15N isotope to evaluate fertilizer nitrogen absorption efficiency by the coffee plant

    Directory of Open Access Journals (Sweden)

    Tatiele A.B. Fenilli

    2007-12-01

    Full Text Available The use of the 15N label for agronomic research involving nitrogen (N cycling and the fate of fertilizer-N is well established, however, in the case of long term experimentation with perennial crops like citrus, coffee and rubber tree, there are still shortcomings mainly due to large plant size, sampling procedures, detection levels and interferences on the system. This report tries to contribute methodologically to the design and development of 15N labeled fertilizer experiments, using as an example a coffee crop fertilized with 15N labeled ammonium sulfate, which was followed for two years. The N of the plant derived from the fertilizer was studied in the different parts of the coffee plant in order to evaluate its distribution within the plant and the agronomic efficiency of the fertilizer application practice. An enrichment of the fertilizer-N of the order of 2% 15N abundance was sufficient to study N absorption rates and to establish fertilizer-N balances after one and two years of coffee cropping. The main source of errors in the estimated values lies in the inherent variability among field replicates and not in the measurements of N contents and 15N enrichments of plant material by mass-spectrometry.O uso do traçador 15N em pesquisas agronômicas que envolvem o ciclo do nitrogênio (N e o destino do N do fertilizante está bem estabelecido, entretanto, para o caso de experimentação com plantas perenes como citrus, café e seringueira, ainda existem limitações devidas ao porte das plantas, à amostragem, aos níveis de detecção e à interferência no sistema. Este estudo procura contribuir metodologicamente no delineamento experimental e no desenvolvimento desse tipo de experimentação, em condições de campo, fazendo uso, por dois anos, do experimento de uma cultura de café adubada com fertilizante marcado com 15N. O N da planta derivado do fertilizante foi estudado nas diferentes partes da planta de café para determinar sua

  10. Nitrogen dynamics in soils cultivated with maize and fertilized with pig slurry

    Directory of Open Access Journals (Sweden)

    Maria Emília Borges Alves

    2012-04-01

    Full Text Available The proper disposal of pig manure is of great importance because, when mishandled, it can contaminate water resources. This study aimed to evaluate the nitrogen dynamics in a Cerrado Oxisol and its absorption, over time, by a maize crop managed with pig slurry associated with mineral fertilization (N P K. The study was conducted at a private farm, in the region of Sete Lagoas, Minas Gerais, Brazil. The maize crop was able to recover 62% of the mineral nitrogen that entered the soil-plant system, while 9% leached as nitrate and, to a lesser amount, as ammonium. The maximum average content of nitrate and ammonium of 92 kg ha-1 and 43 kg ha-1, respectively, was observed in the 0 to 0.3 m soil layer during the early crop development stage. A minimum content of 5.8 kg ha-1 of nitrate and 9.0 kg ha-1 of ammonium, respectively, was measured at the end of the cycle. In addition, the nitrate content at that soil layer, at the end of the maize cycle, remained below the values measured at the native Cerrado, indicating that the agricultural use of the land poses no additional risk to the nitrate accumulation and leaching into the soil profile.

  11. Evolution of Nitrogen, Phosphorus and Potassium Fertilizer Application Rates in Cotton Fields and lts lnfluences on Cotton Yield in the Yangtze River Valley

    Institute of Scientific and Technical Information of China (English)

    Naiyin XU; Jian Ll

    2014-01-01

    Objective] The historical evolution pattern of nitrogen (N), phosphorus (P) and potassium (K) fertilizer application rate and its effects on lint cotton yield were explored to provide the theoretical basis for reasonable fertilizer management strate-gy in the cotton planting region of the Yangtze River Val ey. [Method] GGE biplot analysis method was adopted to analyze the correlation among N, P and K fertilizer application rate and lint cotton yield with the dataset of national cotton regional trials of the Yangtze River Val ey during 1991-2013. The linear and nonlinear regression analysis method was used to reveal the evolution of the fertilizer applying patterns, and analyze the effects of N, P, K application rates on cotton lint yield. [Result] The application rates of N, P and K fertilizer presented highly significant positive corre-lation with lint cotton yield, among which the potassium fertilizer was the strongest relative factor with lint cotton yield, fol owed by phosphorus fertilizer, while nitrogen fertilizer was the weakest factor. The application rate of nitrogen fertilizer was relat-ed with the test year in the pattern of a quadratic function, while phosphate and potassium had progressive increase linear relation with the test year in the cotton planting region of the Yangtze River Val ey. Meanwhile, cotton lint yield was in re-sponse to nitrogen fertilizer content increase with a quadratic parabola function, and increased with the applying phosphate fertilizer and potassium fertilizer content with linearly increasing function. [Conclusion] The increasing application amount of N, P and K fertilizer was general y beneficial to cotton yield improvements, however, ex-orbitant applying nitrogen fertilizer was unfavorable for cotton production, and a reasonable mixture formula of N, P and K fertilizer was better in terms of cotton yield-increasing effect.

  12. Responses of leaf nitrogen concentration and leaf area of Populus sibirica seedlings to nitrogen fertilization in a semi-arid area, Mongolia

    Science.gov (United States)

    Chang, H.; Han, S. H.; Son, Y.

    2016-12-01

    We investigate the effects of three rates of nitrogen fertilization on Populus sibirica seedlings in a semi-arid area, Elsentasarkhai, Mongolia. In May 2015, 2-year-old P. sibirica seedlings were planted in the control and three fertilized plots. Urea was applied to each seedling with 5 g (N1), 15 g (N2) and 30 g (N3) in May 2015 and 2016. Leaf nitrogen concentration, total chlorophyll content, leaf area and specific leaf area (SLA) were measured in July 2016 and the differences were analyzed using one-way ANOVA (PSLA, however, leaf area in the N2 plot (3109.9 cm2) was significantly higher than that in the control (494.0 cm2). The N3 treatment significantly increased leaf nitrogen concentration and total chlorophyll content, however, it did not change leaf area. The N2 treatment seems to be suitable for leaf growth of P. sibirica seedlings in the study site. To determine the optimal rate of nitrogen fertilization, the growth and biomass of seedlings after treatments also need to be examined. * This study was supported by Korea Forest Service (S211216L030120).

  13. [Effects of nitrogen fertilization and root separation on the plant growth and grain yield of maize and its rhizosphere microorganisms].

    Science.gov (United States)

    Zhang, Xiang-Qian; Huang, Guo-Qin; Bian, Xin-Min; Zhao, Qi-Guo

    2012-12-01

    A field experiment with root separation was conducted to study the effects of root interaction in maize-soybean intercropping system on the plant growth and grain yield of maize and its rhizosphere microorganisms under different nitrogen fertilization levels (0.1, 0.3, 0.5, and 0.7 g x kg(-1)). Root interaction and nitrogen fertilization had positive effects on the plant height, leaf length and width, and leaf chlorophyll content of maize. Less difference was observed in the root dry mass of maize at maturing stage between the treatments root separation and no root separation. However, as compared with root separation, no root separation under the nitrogen fertilization levels 0.1, 0.3, 0.5, and 0.7 g x kg(-1) increased the biomass per maize plant by 8.8%, 6.3%, 3.6%, and 0.7%, and the economic yield per maize plant by 17.7%, 10.0%, 8.2%, and 0.9%, respectively. No root separation increased the quantity of rhizosphere fungi and azotobacteria significantly, as compared with root separation. With increasing nitrogen fertilization level, the quantity of rhizosphere bacteria, fungi, and actinomycetes presented an increasing trend, while that of rhizosphere azotobacteria decreased after an initial increase. The root-shoot ratio of maize at maturing stage was significantly negatively correlated with the quantity of rhizosphere bacteria, fungi, and actinomycetes, but less correlated with the quantity of rhizosphere azotobacteria. It was suggested that the root interaction in maize-soybean intercropping system could improve the plant growth of maize and increase the maize yield and rhizosphere microbial quantity, but the effect would be decreased with increasing nitrogen fertilization level.

  14. Nitrogen Fertilization of Corn: Plant Biochemistry Effects and Carbon Cycle Implications

    Science.gov (United States)

    Gallagher, M. E.; Hockaday, W. C.; Masiello, C. A.; McSwiney, C. P.; Robertson, G. P.; Baldock, J. A.

    2008-05-01

    Atmospheric carbon dioxide (CO2) concentrations are rising due to anthropogenic CO2 emissions (Alley et al. 2007; Prentice et al. 2001). About half of the anthropogenic CO2 emitted during the 1990s was absorbed by the terrestrial biosphere and ocean (Prentice et al. 2001). It is possible to estimate the size of terrestrial and oceanic carbon sinks individually using atmospheric CO2 and O2 measurements (Keeling et al. 1996). To best estimate the sizes of these carbon sinks, we need to accurately know the oxidative ratio (OR) of the terrestrial biosphere (Randerson et al. 2006). OR is the ratio of the moles of O2 released per moles of CO2 consumed in gas fluxes between the terrestrial biosphere and atmosphere. Though it is likely that the net OR of the biosphere varies with ecosystem type and nutrient status, OR is assumed constant in carbon sink apportionment calculations (e.g. Prentice et al. 2001). Small shifts in OR can lead to large variations in the calculated sizes of the terrestrial biosphere and ocean carbon sinks (Randerson et al. 2006). OR likely shifts with changes in climate, nutrient status, and land use. These shifts are due, in part, to shifts in plant biochemistry. We are measuring ecosystem OR in corn agricultural ecosystems under a range of nitrogen fertilization treatments at the Kellogg Biological Station-Long Term Ecological Research Site (KBS-LTER) in Michigan. We measure OR indirectly, through its relationship with organic carbon oxidation state (Cox) (Masiello et al. in press 2008). Cox can be measured through elemental analysis and, with basic knowledge of plant nitrogen use patterns, Cox values can be converted to OR values. Cox can also be measured through 13C nuclear magnetic resonance spectroscopy (NMR), which can be combined with a molecular mixing model to determine Cox, OR, and plant biochemical composition (i.e. percentage carbohydrates, lignin, lipids, and proteins) (Baldock et al. 2004). Here we present data showing the effects of

  15. The Effects of Source and Rate of Nitrogen Fertilizer and Irrigation on Nitrogen Uptake of Silage Corn and Residual Soil Nitrate

    Directory of Open Access Journals (Sweden)

    M. A. Khodshenas

    2016-09-01

    Full Text Available Introduction: Growing irrigation demand for corn production, along side with draws of ground water from stressed water sources, should be limited due to scarce resources and environmental protection aspects. Nitrogen fertilizer applied at rates higher than the optimum requirement for crop production may cause an increase in nitrate accumulation below the root zone and pose a risk of nitrate leaching. Improving nitrogen management for corn production has a close relation with soil water content. In this study, we investigated the effects of source and rate of nitrogen fertilizer and irrigation on silage corn production and nitrogen concentration, nitrogen uptake and residual soil nitrate in two depths. Materials and Methods: This experiment carried out as split spli- plot in a Randomized Complete Block design (RCBD with three replications, in Arak station (Agricultural research center of markazi province, 34.12 N, 49.7 E; 1715 m above mean sea level during three years. The soil on the site was classified as a Calcaric Regosols (loamy skeletal over fragmental, carbonatic, thermic, calcixerollic xerochrepts. Main plots were irrigation treatments based on 70, 100 and 130 mm cumulative evaporation from A class Pan. Sub plots were two kinds of nitrogen fertilizers (Urea and Ammonium nitrate and sub sub-plots were five levels of nitrogen rates (0, 100, 200, 300 and 400 kgN.ha-1. Nitrogen fertilizer rates were split into three applications: 1/3 was applied at planting, 1/3 at 7-9 leaf stage and 1/3 remainder was applied before tasseling as a banding method. Phosphorus was applied at a rate of 150 kg.ha-1in each season and potassium at a rate of 30kg.ha-1 (only in first growth season based on soil testing as triple super phosphate and potassium sulfate, respectively. The corn variety of single cross 704 was planted at 20 m2 plots. The plants were sampled at dough stage from the two rows and weighted in each plot. Plant samples were dried in a forced air

  16. Potential soil cleanup objectives for nitrogen-containing fertilizers at agrichemical facilities

    Science.gov (United States)

    Roy, W.R.; Krapac, I.G.

    2006-01-01

    Accidental and incidental chemical releases of nitrogen-containing fertilizers occur at retail agrichemical facilities. Because contaminated soil may threaten groundwater quality, the facility may require some type of site remediation. The purpose of this study was to apply the concepts of the Soil Screening Levels of the U.S. Environmental Protection Agency to derive soil cleanup objectives (SCO) that are protective of groundwater quality in Illinois for nitrogen as nitrate and as ammonium. The Soil Screening Levels are based on the solute transport mechanisms of sorption, volatilization, and groundwater dilution, and the contaminant-specific groundwater cleanup objective used to derive the SCO. Because nitrate is relatively unreactive, only groundwater dilution could be taken into account in the derivation of a SCO. Using a default groundwater objective for potable groundwater, an SCO of 38 mg N-NO3/kg was derived. For ammonium, however, the extent of sorption was measured using an uncontaminated, surface-soil sample (0 to 15 cm) of 10 different soil types that occur in Illinois and three gravel-fill samples from three different agrichemical facilities. Using a default groundwater objective, an SCO was derived for each soil type. The median SCO was 989 mg N-NH4/kg. The SCO calculated for each of the 10 soil and 3 fill samples was positively correlated with cation exchange capacity, clay content, and surface area. It was concluded that this approach can be used to derive either default of site-specific SCOs for nitrogen as nitrate and as ammonium for chemical releases. Copyright ?? Taylor & Francis Group, LLC.

  17. Growth index in massai grass under different levels of nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Marcos Neves Lopes

    2011-12-01

    Full Text Available This study aimed to evaluate the growth index of massai grass during two regrowth cycles in a greenhouse under five levels of nitrogen (0, 150, 300, 450 and 600 mg N/dm³ of soil and eight growth ages (5, 8, 11, 14, 17, 20, 23 and 26 days in a split-plot design with five replications. The following variables were evaluated: net assimilation rate, herbage growth rate, relative growth rate, leaf area ratio, leaf weight ratio and specific leaf area. The effect of nitrogen was detected on the variables net assimilation rate (regrowths 1 and 2, leaf area ratio (regrowth 1, leaf weight ratio (regrowths 1 and 2, specific leaf area (regrowths 1 and 2 and herbage growth rate (regrowths 1 and 2. The growth ages influenced the relative growth rate (regrowth 2 and the net assimilation rate (regrowth 2. The net assimilation rate presented linear effect, estimated in 0.70 and 2.86 g/m² leaf.day-1 for the 0 and 600 mg N/dm³ soil, respectively (regrowth 1. For each milligram of N/dm³ added, the leaf area ratio was reduced in 0.0000258 m² leaf/g plant (regrowth 1. The herbage growth rate was estimated in 1.38 and 37.02 g/m².day-1 (regrowth 1, and 4.37 and 32.20 g/m².day-1 (regrowth 2 for the 0 and 600 mg N/dm³ soil, respectively. The massai grass' growth is favored by nitrogen fertilization, and little do the growth ages affect the growth index of the plants.

  18. Variation in forest canopy nitrogen and albedo in response to N fertilization and elevated CO2

    Science.gov (United States)

    Wicklein, H. F.; Ollinger, S. V.; Martin, M.; Hollinger, D. Y.; Collatz, G. J.

    2009-12-01

    It is important to understand how high levels of nitrogen (N) deposition, through changes in N status, could influence a forest’s albedo and photosynthetic rates, and therefore the forest’s overall feedback (positive or negative) to global warming. Foliar N and albedo have recently been shown to covary at the canopy level across temperate and boreal forests. The purpose of this study is to examine the nature of this relationship from leaf to canopy scales and how it might change in response N and CO2 fertilization. Research was conducted at two long-term forest experimental sites. The chronic N amendment site at Harvard Forest in Petersham, MA includes three treatments: high N (fertilized with 150 kg N ha-1 yr-1), low N (50 kg N ha-1 yr-1), and ambient deposition (around 8 kg N ha-1 yr-1). The Oak Ridge National Environmental Research Park in Oak Ridge, TN includes a Free Air CO2 Enrichment (FACE) site where plots receive either ambient and elevated CO2 (540 ppm), and an N amendment site where plots are either fertilized with N (200 kg N ha-1 yr-1) or receive ambient deposition (10-15 kg N ha-1 yr-1). At Harvard Forest we measured seven black oak (Quercus velutina) and five red maple (Acer rubrum) trees in each treatment plot. At Oak Ridge we measured five sweetgum (Liquidambar styraciflua) trees in each FACE treatment plot, and four sweetgum trees in each N amendment treatment plot. Leaves were collected from two to three canopy heights from trees in each treatment plot. For each tree height we measured reflectance and transmittance spectra for stacks of 1, 2, 4, and 8 leaves, both abaxial and adaxial sides. We also measured N concentration, water content, and leaf mass per unit area (LMA) of the leaves. Canopy-level reflectance was modeled using the Scattering by Arbitrarily Inclined Leaves (SAIL-2) radiative transfer model. Preliminary results show significant differences in average leaf-level reflectance in the N fertilized treatments, with higher NIR

  19. Use of Stable Isotopes to Trace the Fate of Applied Nitrogen in Forest Plantations to Evaluate Fertilizer Efficiency and Ecosystem Impacts

    OpenAIRE

    Raymond, Jay E.

    2016-01-01

    This study assessed five fertilizer treatments (control – no fertilizer, urea, urea treated with N-(n-butyl) thiophosphoric triamide (NBPT), coated urea + NBPT (CUF), polymer coated urea (PCU) ) during two application seasons (spring, summer) to: 1) compare fertilizer nitrogen (N) losses (see Chapter 2); 2) evaluate temporal N uptake patterns of loblolly pine (see Chapter 3); and 3) evaluate fertilizer N cycling and partitioning in a loblolly pine ecosystem (see Chapter 4). Chapter 2 results ...

  20. Interactive effects between nitrogen fertilization and elevated CO2 on growth and gas exchange of papaya seedling

    Science.gov (United States)

    Elevation of CO2 in the atmosphere will change requirements for minerals, mainly nitrogen, altering the relationship between nutrients demand and growth of the plants. We evaluated the interacting effects between CO2 concentrations (390 or 750 µL L-1) and nitrogen levels (3mM or 8mM) on the growth, ...

  1. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

    Science.gov (United States)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

    2016-01-15

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings.

  2. [Change characteristics of rice yield and soil organic matter and nitrogen contents under various long-term fertilization regimes].

    Science.gov (United States)

    Huang, Jing; Gao, Ju-Sheng; Zhang, Yang-Zhu; Qin, Dao-Zhu; Xu, Ming-Gang

    2013-07-01

    A long-term (1982-2010) field experiment was conducted in the Red Soil Experiment Station of Chinese Academy of Agricultural Sciences in Qiyang County of Hunan Province, South-central China to investigate the dynamic changes of rice yield and soil organic matter (OM) and nitrogen contents under different fertilization treatments. The treatments included NPK, NPKM (M: manure), NPM, NKM, PKM, M, and CK. Fertilization increased the soil OM, total N, and alkaline-hydrolysable N contents and the rice yield. In treatment NPKM, the rice yield across the 28 years maintained at the highest level; while in treatment NPK, the yield showed a decreasing trend, being lower than that in other fertilization treatments. In the treatments applied with manure only or in combining with chemical fertilizers, the soil OM content increased rapidly in the first 16 years, and then fluctuated around a constant level (29.42-39.32 g x kg(-1)). In the treatments of chemical fertilization, the soil OM content only had a quicker increase in the first 8 years, and then fluctuated within a relatively stable range. Fertilization with manure increased the soil OM significantly, as compared to fertilization with chemical fertilizers only. The soil total N content in all fertilization treatments showed a rapid increase in the first 8 years, and the increment was the highest in treatment NPKM. The soil alkaline-hydrolysable N content in all fertilization treatments had a slower increase in the first 12 years, with an average annual increment of 0.66-2.25 mg x kg(-1) x a(-1). In 1994-1998, the soil alkaline-hydrolysable N content in fertilization treatments had a quicker increase, with an average annual increment of 6.45-32.45 mg x kg(-1) x a(-1); but after 1998, the soil alkaline-hydrolysable N content had a slight decrease. It was concluded that organic fertilization was the key measure to stably improve the physical and chemical properties and the productivity of red paddy soils by increasing their

  3. Exploring a suitable nitrogen fertilizer rate to reduce greenhouse gas emissions and ensure rice yields in paddy fields

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yiming; Wang, Xiaopeng; Yang, Jingping, E-mail: jpyang@zju.edu.cn; Zhao, Xing; Ye, Xinyi

    2016-09-15

    The application rate of nitrogen fertilizer was believed to dramatically influence greenhouse gas (GHG) emissions from paddy fields. Thus, providing a suitable nitrogen fertilization rate to ensure rice yields, reducing GHG emissions and exploring emission behavior are important issues for field management. In this paper, a two year experiment with six rates (0, 75, 150, 225, 300, 375 kg N/ha) of nitrogen fertilizer application was designed to examine GHG emissions by measuring carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O) flux and their cumulative global warming potential (GWP) from paddy fields in Hangzhou, Zhejiang in 2013 and 2014. The results indicated that the GWP and rice yields increased with an increasing application rate of nitrogen fertilizer. Emission peaks of CH{sub 4} mainly appeared at the vegetative phase, and emission peaks of CO{sub 2}, and N{sub 2}O mainly appeared at reproductive phase of rice growth. The CO{sub 2} flux was significantly correlated with soil temperature, while the CH{sub 4} flux was influenced by logging water remaining period and N{sub 2}O flux was significantly associated with nitrogen application rates. This study showed that 225 kg N/ha was a suitable nitrogen fertilizer rate to minimize GHG emissions with low yield-scaled emissions of 3.69 (in 2013) and 2.23 (in 2014) kg CO{sub 2}-eq/kg rice yield as well as to ensure rice yields remained at a relatively high level of 8.89 t/ha in paddy fields. - Highlights: • Exploiting co-benefits of rice yield and reduction of greenhouse gas emission. • Global warming potential and rice yield increased with nitrogen fertilizer rate up. • Emission peaks of CH{sub 4,} CO{sub 2} and N{sub 2}O appeared at vegetative and reproductive phase. • 225 kg N/ha rate benefits both rice yields and GWP reduction.

  4. Effects of inorganic fertilizers on biological nitrogen fixation and seedling growth of some agroforestry trees in Bangladesh

    Institute of Scientific and Technical Information of China (English)

    Mohammad Belal Uddin; Mohammed Abu Sayed Arfin Khan; Sharif Ahmed Mukul; Mohammed Kamal Hossain

    2008-01-01

    The effects of different inorganic fertilizers (Urea and Triple Super Phosphate (TSP)) on seedling growth and nodulation capabilities of four agroforestry tree species (Albizia chinensis,A.saman,Acacia nilotica and Sesbania sesban) were compared.The nodulation of these seedlings were treated with different fertilizer treatments (at the rate of urea 40 kg(hm-2,urea 80 kg(hm-2,TSP 40 kg(hm-2,TSP 80 kg(hm-2,(urea+TSP) 40 kg(hm-2-and (urea+TSP) 80 kg(hm-2) after one month of seed germination.The results revealed that the seedling growth was enhanced significantly with moderate fertilizer treatment.In some cases,the higher levels of fertilizers reduced the seedling growth.The study also revealed that the nodulation in nodule number and size was significantly inhibited by the application of N fertilizer (Urea),while it was increased significantly with the application of P fertilizer (TSP).This study improved our understanding and provided insights that would be useful to the farmers in their efforts to amend the soil with inorganic fertilizers in order to enhance plant growth and biological nitrogen fixation.

  5. Influence of Bacillus subtilis on the physiological state of wheat and the microbial community of the soil under different rates of nitrogen fertilizers

    Science.gov (United States)

    Pishchik, V. N.; Vorobyev, N. I.; Moiseev, K. G.; Sviridova, O. V.; Surin, V. G.

    2015-01-01

    The effects of inoculation with bacteria Bacillus subtilis strain No. 2 (hereinafter, B. subtilis 2) and of the physical properties of the soil on the physiological state of wheat ( Triticum aestivum L.) plants and the soil microbial community under different rates of nitrogen fertilizers are studied. In the field, the physiological state of wheat was evaluated using the optical vegetation index. It was found that (1) the impact of B. subtilis 2 on plants decreases with an increase in the rate of fertilizers and soil bulk density, (2) the inoculation of wheat with bacteria enhances the resistance of the plant-microbial system to the adverse impact of high rates of nitrogen fertilizers due to the rearrangement of bacteria in rhizosphere ecological niches, and (3) the highest agronomic efficiency of nitrogen fertilizers is observed in wheat inoculation with B. subtilis 2 at the rate of nitrogen fertilization of 120 kg/ha.

  6. Economic viability of production of Nellore heifers on Urochloa brizantha cv. Marandu pastures deferred and fertilized with nitrogen

    Directory of Open Access Journals (Sweden)

    Poliana Batista de Aguilar

    2016-01-01

    Full Text Available The objective of this study was to evaluate the effect of different levels of nitrogen on deferred pastures of Urochloa brizantha cv. Marandu, and the implications on the economic viability of production of Nellore heifers. This was a completely randomized design with four treatments (T1 = deferred pasture without nitrogen fertilization; T2 = deferred pasture fertilized with 50 kg N ha-1, T3 = deferred pasture with 100 kg N ha-1, T4 = deferred pasture with 150 kg N ha-1 and four replications (16 fertilized paddocks. First, there were used 48 Nellore heifers, average eight months of age and initial body weight of 178.69 ± 26.67 kg, with three heifers in each paddock, in all treatments, in a continuous grazing system, with variable stocking rate. Only the treatment the without nitrogen fertilization showed negative monetary values of R$ -181.96, R$ ha-1 -72.79 and R$ @-1 -32.11. The treatment with 50 kg N ha-1 achieved the highest positive monetary values of R$ 756.02, R$ ha-1 302.40 and R$ @-1 50.52. Economic viability data in beef heifer production demonstrate that the treatment with 50 kg N ha-1 is the most financially viable under the conditions of this study.

  7. External Costs and Optimum Use of Nitrogen Fertilizer Based on the Balance of Economic and Ecological Benefits in the Paddy Field System of the Dongting Lake Area, China

    Institute of Scientific and Technical Information of China (English)

    XIANG Ping-an; ZHOU Yan; JIANG Ju-ao; ZHENG Hua; YAN Hui-min; HUANG Huang

    2007-01-01

    The external costs and the optimum use of nitrogen fertilizer based on the balance of economic and ecological benefits was studied with the paddy field system of Dongting Lake area, one of the main food production regions in China. The environmental impact was economically evaluated using methods of the environmental impact economical evaluation.The optimum use of nitrogen fertilizer was calculated based on the exterior diseconomy theory and by using the production function model. Both ecological benefits and farmers' economic benefits were considered. It was calculated on the data from 2002 that the losses caused by inappropriate utilization of nitrogen fertilizer in the process of food production were fishery, 0.1 × 107 RMB yuan; water treatment, 1.02 × 108 RMB yuan; tour business, 0.11 × 108 RMB yuan, and habitation environment, 0.3 × 107 RMB yuan, totally equivalent to 0.41 RMB yuan kg-1 N. The economically satisfactory and the ecological agronomic nitrogen fertilizer dose for current production was 138 and 137 kg ha-1, respectively. The research showed that the actual nitrogen fertilizer application amount in the paddy field system of the Dongting Lake area already reached or exceeded the farmers' economic satisfaction and the ecological agronomic nitrogen fertilizer dose for current production. An environmental tax is suggested to impose on over-use of nitrogen fertilizer.

  8. Comparative effects of nitrogen fertigation and granular fertilizer application on growth and availability of soil nitrogen during establishment of highbush blueberry

    Directory of Open Access Journals (Sweden)

    David eBryla

    2011-09-01

    Full Text Available A 2-year study was done to compare the effects of nitrogen (N fertigation and granular fertilizer application on growth and availability of soil N during establishment of highbush blueberry (Vaccinium corymbosum L. ‘Bluecrop’. Treatments included four methods of N application (weekly fertigation, split fertigation, and two non-fertigated controls and four levels of N fertilizer (0, 50, 100, and 150 kg•ha-1 N. Fertigation treatments were irrigated by drip and injected with a liquid urea solution; weekly fertigation was applied once a week from leaf emergence to 60 d prior to the end of the season while split fertigation was applied as a triple split from April to June. Non-fertigated controls were fertilized with granular ammonium sulfate, also applied as a triple split, and irrigated by drip or microsprays. Weekly fertigation produced the smallest plants among treatments at 50 kg•ha-1 N in year 1 but the highest canopy cover at 150 kg•ha-1 N in both years 1 and 2. The other application methods required less N to maximize growth but were less responsive than weekly fertigation to additional N fertilizer applications. In fact, 44-50% of the plants died when granular fertilizer was applied at 150 kg•ha-1 N. By comparison, none of the plants died with weekly fertigation. Plant death with granular fertilizer was associated with high ammonium ion concentrations (up to 650 mg•L-1 and electrical conductivity (>3 dS•m-1 in the soil solution. Early results indicate that fertigation may be less efficient (i.e., less plant growth per unit of N applied at lower N rates than granular fertilizer application but is also safer (i.e., less plant death and promotes more growth when high amounts of fertilizer is applied.

  9. Short term responses of nitrogen trace gas emissions to nitrogen fertilization in tropical sugar cane: Variations due to soils and management practices

    Science.gov (United States)

    Matson, P. A.; Billow, C.; Hall, S.; Zachariassen, J.

    1994-01-01

    Nitrogen (N) fertilization of agricultural systems is thought to be a major source of the increase in atmospheric N2O; NO emissions from soils have also been shown to increase due to N fertilization. While N fertilizer use is increasing rapidly in the developing world and in the tropics, nearly all of our information on gas emissions is derived from studies of temperate zone agriculture. Using chambers, we measured fluxes of N2O and NO following urea fertilization in tropical sugar cane systems growing on a variety of soil types in the Hawaiian Islands, USA. On the island of Maui, where urea is applied in irrigation lines and soils are mollisols and inceptisols, N2O fluxes were elevated for a week or less following fertilization; maximum average fluxes were typically less than 30 ng cm(exp -2)/ h. NO fluxes were often an order of magnitude less than N2O. Together, N2O and NO represented from 0.01 - 0.5% of the applied N. In fields on the island of Hawaii, where urea is broadcast on the surface and soils are andisols, N2O fluxes were similar in magnitude to Maui but remained elevated for much longer periods after fertilization. NO emissions were 2-5 times higher than N2O through most of the sampling periods. Together the gases loss represented approximately 1. 1 - 3% of the applied N. Laboratory studies indicate that denitrification is a critical source of N2O in Maui, but that nitrification is more important in Hawaii. Experimental studies suggest that differences in the pattern of N2O/NO and the processes producing them are a result of both carbon availability and placement of fertilizer, and that the more information-intensive fertilizer management practice results in lower emissions.

  10. Forest defoliator pests alter carbon and nitrogen cycles

    Science.gov (United States)

    Grüning, Maren; Simon, Judy; Reinhardt, Annett-Barbara; Lamersdorf, Norbert; Thies, Carsten

    2016-01-01

    Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests (Quercus petraea L.) that were heavily infested by the leaf herbivores winter moth (Operophtera brumata L.) and mottled umber (Erannis defoliaria L.). In infested forests, total net canopy-to-soil fluxes of C and N deriving from insect faeces, leaf litter and throughfall were 30- and 18-fold higher compared with uninfested oak forests, with 4333 kg C ha−1 and 319 kg N ha−1, respectively, during a pest outbreak over 3 years. In infested forests, C and N levels in soil solutions were enhanced and C/N ratios in humus layers were reduced indicating an extended canopy-to-soil element pathway compared with the non-infested forests. In a microcosm incubation experiment, soil treatments with insect faeces showed 16-fold higher fluxes of carbon dioxide and 10-fold higher fluxes of dissolved organic carbon compared with soil treatments without added insect faeces (control). Thus, the deposition of high rates of nitrogen and rapidly decomposable carbon compounds in the course of forest pest epidemics appears to stimulate soil microbial activity (i.e. heterotrophic respiration), and therefore, may represent an important mechanism by which climate change can initiate a carbon cycle feedback. PMID:27853551

  11. Effects of Nitrogen Fertilizer Level on Chlorophyll Fluorescence Characteristics in Flag Leaf of Super Hybrid Rice at Late Growth Stage

    Institute of Scientific and Technical Information of China (English)

    LONG Ji-rui; MA Guo-hui; WAN Yi-zheng; SONG Chun-fang; SUN Jian; QIN Rui-jun

    2013-01-01

    To compare the effects of slow-release nitrogen fertilizer at six different levels on the flag leaf chlorophyll fluorescence characteristics of super hybrid rice,a field fertilization experiment was conducted with super hybrid rice Y Liangyou 1 as a test material.The photosynthetic electron transport rate (ETR),effective quantum yield (EQY),photochemical quenching coefficient (qp),and non-photochemical quenching coefficient (NPQ) of flag leaves were measured at the initial heading,full heading,10 d after full heading and 20 d after full heading stages.Results showed that the values of ETR,EQY and qp increased with rice development from initial heading to 20 d after full heading,whereas the NPQ decreased.During the measured stages,ETR,EQY and qp increased initially and then decreased as nitrogen application amount increased,but they peaked at different nitrogen fertilizer levels.The maximum ETR and EQY values appeared at the treatment of 135 kg/hm2 N.In conclusion,the optimum nitrogen amount for chlorophyll fluorescence characteristics of super hybrid rice was 135-180 kg/hm2.

  12. Nitrogen use efficiency and life cycle of nodules in alfalfa after different mineral fertilization and soil cultivation

    Directory of Open Access Journals (Sweden)

    V. Vasileva

    2015-09-01

    Full Text Available Nitrogen use efficiency and life cycle of root nodules in alfalfa after different mineral fertilization and soil cultivation practices were studied. Field trial was conducted in the Institute of Forage Crops, Pleven, Bulgaria on leached chernozem subsoil type and no irrigation. The next treatments were tested: i for fertilization as follows: N0P0K0 (control; N60P100K80 (an accepted technology; N23P100K35 (nitrogen was applied 1/2 in first year of growing and 1/2 in third year; N23P100K35 (nitrogen was supplied pre-sowing; N35P80K50, and Аmophose - 250 kg/ha, calculated at fertilizing rates N27P120K0; ii for soil cultivation as follows: soil loosing 10-12 cm, plough at depth 12-15 cm, 22-24 cm (an accepted technology, 18-22 cm and 30-35 cm. It was found that soil cultivation and mineral fertilization had effect on nitrogen use efficiency and life cycle of root nodules in Alfalfa. Nitrogen use efficiency was found to be highest at N23P100K35 and plough at the depth of 22-24 cm. Life cycle of root nodules was the longest at N35P80K50 and plough at the depth of 18-22 cm. The better root mass to nodule number ratio was found at N23P100K35 and plough at the depth of 22-24 cm.

  13. Evaluation of a 15N plot design for estimating plant recovery of fertilizer nitrogen applied to sugar cane

    OpenAIRE

    1994-01-01

    Two experiments were conducted on commercial sugar cane fields cropped with the variety SP70-1143, with the objective of evaluating a single row microplot design to determine plant recovery of 15N fertilizer nitrogen. One of them used 15N-aqua ammonia and 15N-urea applied to two linear meter microplots of a ratoon crop (four replicates). The second used one linear meter microplots (three replicates) which received 15N-aqua ammonia only. The fertilizers were applied on 15cm deep furrows, locat...

  14. 控失氮肥技术应用及发展总结%Use of Technology for Leach-Control Nitrogenous Fertilizers and Development Summary

    Institute of Scientific and Technical Information of China (English)

    薛宏光; 黄滨; 徐文峰; 李刚

    2013-01-01

    控失氮肥是在对原有高塔造粒装置进行技术升级改造的基础上,将粉状氯化铵或硫酸铵及尿液与可降低其溶解性或改变其流失特性的化肥养分控失剂充分混合后制备的无膜型缓释脲铵氮肥,适合于大田作物.概述了控失氮肥的形成机理、技术路线及创新点、产品特点及质量标准,并就存在的问题提出了今后的努力方向.%On the basis of the original high-tower prilling unit renovated with technological upgrade, powdery ammonium chloride or ammonium sulfate and melted urea are intimately mixed with nutrient leach-control agents able to reduce the solubility or alter the leach properties, to prepare filmless slow-release urea-ammonium nitrogenous fertilizers, suitable for field crops. An outline is given of the formation mechanism of leach-control nitrogenous fertilizers, technological routes and innovation point, product characteristics and quality standards, and the direction for further efforts for solving the remaining problems.

  15. Synergy and Transition of Recovery Efficiency of Nitrogen Fertilizer in Various Rice Genotypes under Organic Farming

    Directory of Open Access Journals (Sweden)

    Lifen Huang

    2016-08-01

    Full Text Available Despite the growing demand for organic products, research on organic farming (OF such as genotype screening, fertilizer application and nutrition uptake remains limited. This study focused on comparisons of the apparent recovery efficiency of nitrogen fertilizer (REN in rice grown under OF and conventional farming (CF. Thirty-two representative conventional Japonica rice varieties were field grown under five different treatments: control check (CK; organic farming with low, medium and high levels of organic fertilizer (LO, MO and HO, respectively; and CF. Comparisons of REN between OF and CF classified the 32 genotypes into four types: high REN under both OF and CF (type-A; high REN under OF and low REN under CF (type-B; low REN under OF and high REN under CF (type-C; and low REN under both OF and CF (type-D. Though the yield and REN of all the rice varieties were higher with CF than with OF, organic N efficient type-A and B were able to maintain relatively high grain yield under OF. Physiological activities in flag leaves of the four types from booting to maturity were subsequently investigated under OF and CF. Under OF, high values of soil and plant analyzer development (SPAD and N were observed in type-B varieties, while in contrast, both indexes slowly decreased in type-C varieties under CF. Moreover, the decline in N content in type-C and D varieties was greater under OF than CF. The decrease in glutamine synthetase (GS, glutamic-pyruvic transaminase (GPT and glutamic oxaloacetic transaminase (GOT activity in flag leaves was smaller under OF than CF in type-A and B varieties, while in contrast, type-C and D varieties showed an opposite trend. The findings suggest that OF slows the decline in key enzymes of N metabolism in organic N-efficient type rice, thus maintaining a relatively high capacity for N uptake and utilization and increasing yield during the late growth period. Accordingly, we were able to screen for varieties of rice with

  16. Effects of fertilization and drought on substrate decomposition and inorganic nitrogen concentration in a managed loblolly pine forest

    Science.gov (United States)

    Zhang, Y.; West, J. B.; Will, R. E.; Vogel, J. G.

    2013-12-01

    The productivity of managed pine forests in the southeastern US has been improved in part through nutrient management over the past 50 years. Although significant uncertainty exists, climate change may drive a reduction of rainfall of 10%-30% by 2080 for the region. This reduced precipitation may interact with fertilization to affect forest productivity and carbon balance. In this study, we analyzed the decomposition of southern pine wood and the accumulation of soil NH4+ and NO3- under a factorial combination of two treatments: soil moisture (30% throughfall removal) and nitrogen addition (386 lbs. /ac N fertilizer). We also studied the relationship between the distance from the trees and wood substrate decomposition. Our results showed that after 6 months the substrate decomposition rate (mass loss) under throughfall removal, irrespective of fertilization treatment, was lower compared to the decomposition rate under control (1.64% versus 2.35%). Although reduced precipitation did lower decomposition rates, local spatial pattern was also important, as the substrate in the middle location of a row of trees (regardless of throughfall treatment; 2.62%) decomposed faster than those near the tree (2.13%) and far from the tree (1.86%), likely reflecting small-scale variation in soil moisture. The effect of increased fertilization on inorganic soil N pools depended strongly on precipitation. While N pools increased as a result of fertilization, the relative increase was greater under throughfall removal for both NH4+ and NO3-. The possible mechanisms to explain this effect of precipitation include 1) reduced plant uptake of inorganic nitrogen due to soil moisture limitation; 2) drought reduced the activity of soil nitrifying and denitrifying microorganisms; and 3) less NO3- leaching after fertilization under drought. Our results indicate that future drought may cause slower substrate decomposition and will interact with fertilization to affect forest N dynamics.

  17. Effects of Film-Degraded Rice Controlled Release Fertilizer on the Nitrogen Uptake and Yield of the Hybrid Rice

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Field experiment was carried out to nitrogen release characteristics of rice controlled release fertilizer (RCRF) coated with natural and half natural high molecular materials, and to thereof effects on the nitrogen uptake and yield of early and late hybrid rice from 1999 to 2000, with urea as control.In experimental fields regardless of early and late seasons, the amount of N in the plants increased exponentially at the early growth stage (y=abx) and nonlinearly at the middle and late growth stages (y=a+bx+cx2).Rice controlled release fertilizer lengthened the exponential phase and increased the parameter -b/c during the nonlinear phase. Although the N amount of plants was less in rice controlled release fertilizer plots than in urea plots within 20 days after transplanting, at the heading and maturity stages, the N amount of plants in rice controlled release fertilizer plots was above two times greater than in the urea plots due to the higher N recovery, and the high absorption density of N in the nonlinear phase. Tillers pattern and achievement of the maximum tillering stage varied with fertilizer types. The maximum tillering stage in the urea plots occurred a week earlier than in the rice controlled release fertilizer plots. Yield sink size and potential sink size of the plants reflected the N absorption pattern and the amount of N in the plants. The yields of early and late rice with 90 kg N ha-1of rice controlled release fertilizer were respectively increased by 832.7 kg ha-1 and 412.8 kg ha-1 than those with 90 kg N ha-1 of urea, almost equivalent to the yield of early and late hybrid rice with 180 kg N ha-1 of urea.

  18. Nitrogen Limitation Along The Kalahari Transect: Preliminary Results From A Stable Isotope Fertilization Experiment

    Science.gov (United States)

    Wang, L.; Macko, S.; D'Odorico, P.; Ries, L.

    2005-12-01

    Globally, savannas cover ~ 20% of the Earth's land area. Nutrients and soil moisture interactively control vegetation dynamics in many savannas although it is unclear how the relative importance of water and nutrient limitations (especially nitrogen) change with the mean climatic conditions. The Kalahari Transect (KT) in southern Africa traverses a dramatic aridity gradient (from ~ 200 mm to more than 1000 mm of mean annual precipitation (MAP), through the Republic of South Africa, Botswana, Namibia and Zambia), on relatively homogenous soils (deep Kalahari sands). This transect offers the ideal setting to study nutrient and vegetation dynamics without confounding soil effects. To improve the understanding of nitrogen and water controls on savanna vegetation, this study tested the hypothesis that the savannas in the Kalahari switch from conditions of water limitation in the dry areas to nutrient limitation in the wet areas. To this end, we conducted a large-scale stable isotope fertilization experiment using four study sites with different MAP. The transect included sites in Mongu, Zambia (MAP ~950mm), Pandamatenga, Ghanzi, and Tshane, Botswana with MAP ranging between 700 mm and 300 mm. The experimental design consisted of a randomized block design with four 21 m x 13 m plots at each site. Each plot was divided into four 10 m x 6 m subplots with 1 m buffer zone between each subplot. Four treatments (N addition, P addition, N+P addition and control) were randomly applied to the subplots. The experiment began during the dry season, in August, 2004, when 39g/m2 of Ca(NO3)2 (3.3g-N/ m2 ) was evenly applied to the N and N+P subplots, and 7.5g/m2 of Ca(H2PO4)2 (1.7g-P/m2) was applied to the P and N+P subplots, while the control subplots were left with no treatment. The N and N+P additions were enriched with 15N (Ca(15NO3)2 ) to a signature of 10.3 ‰. Before application, soil samples from two different layers (0cm and 50cm) outside the plots and foliar samples of the

  19. Comparison of greenhouse gas emissions from rice paddy fields under different nitrogen fertilization loads in Chongming Island, Eastern China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xianxian [School of Agriculture and Biology, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Research Centre for Low Carbon Agriculture, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Key Laboratory for Urban Agriculture (South), Ministry of Agriculture, PR China, Dongchuan Rd. 800, Shanghai 200240 (China); Yin, Shan, E-mail: yinshan@sjtu.edu.cn [School of Agriculture and Biology, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Research Centre for Low Carbon Agriculture, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Key Laboratory for Urban Agriculture (South), Ministry of Agriculture, PR China, Dongchuan Rd. 800, Shanghai 200240 (China); Li, Yinsheng [School of Agriculture and Biology, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Research Centre for Low Carbon Agriculture, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Zhuang, Honglei [School of Agriculture and Biology, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Research Centre for Low Carbon Agriculture, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Key Laboratory for Urban Agriculture (South), Ministry of Agriculture, PR China, Dongchuan Rd. 800, Shanghai 200240 (China); Li, Changsheng [School of Agriculture and Biology, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Research Centre for Low Carbon Agriculture, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai 200240 (China); Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Morse Hall, College Road, NH 03824-3525 (United States); and others

    2014-02-01

    Rice is one of the major crops of southern China and Southeast Asia. Rice paddies are one of the largest agricultural greenhouse gas (GHG) sources in this region because of the application of large quantities of nitrogen (N) fertilizers to the plants. In particular, the production of methane (CH{sub 4}) is a concern. Investigating a reasonable amount of fertilizers to apply to plants is essential to maintaining high yields while reducing GHG emissions. In this study, three levels of fertilizer application [high (300 kg N/ha), moderate (210 kg N/ha), and low (150 kg N/ha)] were designed to examine the effects of variation in N fertilizer application rate on carbon dioxide (CO{sub 2}), methane (CH{sub 4}), and nitrous oxide (N{sub 2}O) emissions from the paddy fields in Chongming Island, Shanghai, China. The high level (300 kg N/ha) represented the typical practice adopted by the local farmers in the area. Maximum amounts of CH{sub 4} and N{sub 2}O fluxes were observed upon high-level fertilizer application in the plots. Cumulative N{sub 2}O emissions of 23.09, 40.10, and 71.08 mg N{sub 2}O/m{sup 2} were observed over the growing season in 2011 under the low-, moderate-, and high-level applications plots, respectively. The field data also indicated that soil temperatures at 5 and 10 cm soil depths significantly affected soil respiration; the relationship between Rs and soil temperature in this study could be described by an exponential model. Our study showed that reducing the high rate of fertilizer application is a feasible way of attenuating the global-warming potential while maintaining the optimum yield for the studied paddy fields. - Highlights: • In Chongming Island, Shanghai, GHG emissions were measured under different nitrogen fertilizer rates from the paddy. • Low nitrogen fertilizer application reduced CH{sub 4} and N{sub 2}O emissions. • The study showed that 210 kg N/ha was the suitable fertilizer application rate.

  20. Nitrogen fertilization (15NH4NO3 of palisadegrass and residual effect on subsequent no-tillage corn

    Directory of Open Access Journals (Sweden)

    Emerson Borghi

    2014-10-01

    Full Text Available Nitrogen is required in large amounts by plants and their dinamics in corn and perennial forages intercropped is little known. This study analyzed the efficiency of nitrogen fertilization (15NH4NO3 applied after corn grain harvest to palisadegrass (Brachiaria brizantha cv. Marandu in intercrops sown at two times, as well as the N residual effect on the subsequent corn crop. The field experiment was performed in Botucatu, São Paulo State, in southeastern Brazil, on a structured Alfisol under no-tillage. The experiment was arranged in a randomized block design in a split plot scheme with four replications. The main plots consisted of two intercropping systems (corn and palisadegrass sown together and palisadegrass sown later, at corn top-dressing fertilization. The subplots consisted of four N rates (0, 30, 60, and 120 kg ha-1 N. The subplots contained microplots, in which enriched ammonium nitrate (15NH4NO3 was applied at the same rates. The time of intercrop sowing affected forage dry matter production, the amount of fertilizer-derived N in and the N use efficiency by the forage plants. Nitrogen applied in autumn to palisadegrass intercropped with corn, planted either at corn sowing or at N top-dressing fertilization, increased the forage yield up to a rate of 60 kg ha-1. The amount of fertilizer-derived N by the forage plants and the fertilizer use efficiency by palisadegrass were highest 160 days after fertilization for both intercrop sowing times, regardless of N rates. Residual N did not affect the N nutrition of corn plants grown in succession to palisadegrass, but increased grain yield at rates of 60 and 120 kg ha-1 N, when corn was grown on palisadegrass straw from the intercrop installed at corn fertilization (top-dressing. Our results indicated that the earlier intercropping allowed higher forage dry matter production. On the other hand, the later intercrop allowed a higher corn grain yield in succession to N-fertilized palisadegrass.

  1. Corn Yield and Foliar Diagnosis Affected by Nitrogen Fertilization and Inoculation with Azospirillum brasilense

    Directory of Open Access Journals (Sweden)

    Fernando Shintate Galindo

    2016-01-01

    Full Text Available ABSTRACT The biological nitrogen fixation (BNF process in grasses is caused by diazotrophic bacteria, particularly Azospirillum brasilense. However, studies are lacking on BNF efficiency to define how much mineral nitrogen (N can be applied to achieve more sustainable high yields. Furthermore, there should be an analysis of whether urea with the urease enzyme inhibitor NBPT is less harmful, benefiting BNF in grasses. The objective of this study was to evaluate the effect of N sources and N rates associated with inoculation with Azospirillum brasilense regarding foliar diagnosis and leaf chlorophyll index (LCI, agronomic efficiency (AE, and corn grain yield in the Cerrado (Brazilian tropical savanna region. The experiment was conducted in a no-tillage system in a Latossolo Vermelho Distroférrico (Oxisol. A randomized block experimental design was used with four replications in a 2 × 5 × 2 factorial arrangement as follows: two N sources - urea and Super N, urea with urease enzyme inhibitor NBPT [N - (n-butyl thiophosphoric triamide]; five N rates (0, 50, 100, 150, and 200 kg ha-1 applied in topdressing; and two seed inoculation treatments, one with and one without A. brasilense. N rate positively influenced the LCI and concentrations of N, S, and Mn in leaves, and may increase the concentrations of P, Cu, and Fe; however, higher N rates can reduce AE. The N sources had similar effects, and therefore urea is recommended for N fertilization. Inoculation with A. brasilense decreased leaf concentration of Fe and increased LCI, leaf concentration of P, AE, and corn grain yield; the use of this diazotrophic bacterium is therefore viable even when high rates of N are applied.

  2. Application of herbicides as growth regulators of emerald Zoysia grass fertilized with nitrogen

    Directory of Open Access Journals (Sweden)

    Raíssa Pereira Dinalli

    2015-07-01

    Full Text Available Nitrogen (N is essential for nutrition and for the maintenance of the intense green color of lawns. However, this element affects shoot growth and, therefore, mowing frequency, which is a key factor of lawn-maintenance costs. Accordingly, this study aimed to evaluate the use of nitrogen fertilization in combination with the use of potential herbicides as growth regulators to promote the maintenance of the high visual (intense green and nutritional quality of lawns of emerald Zoysia (Zoysia japonica Steud. grown in Ultisol soil while reducing their leaf growth. The experiment was conducted at the Teaching, Research and Extension Education Farm (Fazenda de Ensino, Pesquisa e Extensão of São Paulo State University (Universidade Estadual Paulista Júlio de Mesquita Filho, UNESP, Ilha Solteira Campus/ São Paulo (SP, from June/2012 to June/2013. The experimental design consisted of randomized blocks with 20 treatments established in a 5 x 4 factorial arrangement with four replicates, including four herbicides (glyphosate, imazaquin, imazethapyr, and metsulfuron-methyl, applied at doses of 200, 420, 80, and 140 g ha-1 active ingredient (a.i., respectively and a control (without herbicide, and four N doses (0, 5, 10, and 20 g m-2, split into five applications delivered throughout the year. The following items were evaluated: length, LCI (leaf chlorophyll index, leaf dry matter production and leaf N concentration and the percentage of phytotoxicity on lawn grass shoots. Doses from 10 to 20 g m-2 N provided sufficient N concentrations to maintain the emerald Zoysia. The herbicides metsulfuron-methyl and glyphosate were superior in the control of lawn leaf growth. While the former was phytotoxic, the latter had no effect on the aesthetic quality of the lawn, standing out as an herbicide that may be used at a dose of 200 g ha-1 toregulate the growth of emerald Zoysia.

  3. Effects of split nitrogen fertilization on post-anthesis photoassimilates, nitrogen use efficiency and grain yield in malting barley

    DEFF Research Database (Denmark)

    Cai, Jian; Jiang, Dong; Liu, Fulai

    2011-01-01

    . The remobilization of pre-anthesis stored assimilates from vegetative organs into grains was hardly significantly affected by fractions of topdressed nitrogen. Grain yield was the highest for fraction of topdressed nitrogen of 30%, which coincided with the highest plant nitrogen uptake and physiological...

  4. Effect of Vermicompost Alone and Its Combination with Recommended Dose of Fertilizers on Available Nitrogen, Phosphorus, Potassium in Rice Field.

    Science.gov (United States)

    Shwetha, S; Narayana, J

    2014-01-01

    Rice variety KMP101 was treated with both organic and inorganic manure. The field and experimental studies were conducted, before applying organic and inorganic manures.The values obtained for available nitrogen, phosphorous and potassium were 360 kg/ha, 12 kg/ha and 166 kg/ha respectively. After treatment and harvest there was a gradual increase in available nitrogen, phosphorus and potassium ranging between 335-415, 14 -23 and 173- 235 kg/ha respectively among the treatments. Applying 15 t of vermicompost /ha and 10 t of vermicompost /ha and recommended dose of fertilizer showed a greater availability of nitrogen and phosphorus. It is revealed that after addition of organics into the soil year-wise, the soil became more stable. Also, the biological activity increased in the soil and was influenced to maintain the available nitrogen in the soil. Therefore, it is evident that vermicompost significantly increases the availability of available nutrients.

  5. Effect of nitrogen fertilizer with mushroom compost of varied C:N ratio on nitrogen use efficiency, carbon sequestration and rice yield

    Directory of Open Access Journals (Sweden)

    Shahnawaz R. Dar

    2009-04-01

    Full Text Available Integrating fertilizer nitrogen (N with organic manures can foster a sustainable agricultural system in subtropical soils low in organic matter. A two year field experiment was conducted on a sandy loam soil at Allahabad, India to evaluate the effect of incorporating spent white button mushroom compost (WB-SMC with a narrow C:N ratio (15.18 and spent oyster mushroom compost (OY-SMC of a wider C:N ratio (37.58 with and without fertilizer N on rice crop production, N use efficiency and soil carbon (C sequestration. A higher paddy, straw yield and total dry matter production of 5.00, 6.24 and 11.24 t ha-1 in WB-SMC at 5 t ha-1 with fertilizer N at 90 kg ha-1 and 5.26, 6.80 and 12.05 t ha-1 in WB-SMC at 5 t ha-1 with fertilizer N at 120 kg ha-1 confirmed the superiority of the WB-SMC over OY-SMC, which produced 3.57, 4.62 and 8.18 t ha-1 with fertilizer N at 90 kg ha-1 and 4.17, 5.32 and 9.48 t ha-1 with fertilizer N at 120 kg ha-1 respectively. When WB-SMC was applied at 5 t ha-1 it enhanced the recovery efficiency of 19.62 and 15.56 % compared to fertilizer N at 90 and 120 kg ha-1 respectively. Physiological efficiency due to luxury uptake of N with the use of WB-SMC and fertilizer N at 120 kg ha-1 gave evidence that N addition through the combined use of WB-SMC and fertilizer N was excessive. Agronomic efficiency of added N by the rice crop was improved by the incorporating WB-SMC at 5 t ha-1 and fertilizer N at 90 kg ha-1. Despite a wider C:N ratio, OY-SMC gave higher soil C sequestration in flooded rice than WB-SMC in the presence or absence of fertilizer N.

  6. Alterations in the nitrogen dynamics of European beech trees infested by the woolly beech aphid

    Science.gov (United States)

    Levia, D. F.; Michalzik, B.

    2012-12-01

    Insects are a major stressor in wooded ecosystems, triggering profound changes in the hydrology, biogeochemistry, and net primary productivity of infested forests. The influence of woolly beech aphids (Phyllaphis fagi L.) on nitrogen cycling via throughfall, stemflow, and litter leachates is not well understood. Employing a combination of field sampling, X-ray photoelectron spectroscopy, and scanning electron microscopy, we examined and compared the alterations and partitioning of nitrogen (particulate, dissolved, organic, inorganic) between control (uninfested) and infested trees. Preliminary results suggest that the amount of nitrogen routed to the soil is much lower in throughfall and stemflow of infested trees than control trees. Preliminary X-ray photoelectron spectroscopy and scanning electron microscopy measurements on the abaxial surface of sample leaves have demonstrated that the surface microbiology and nitrogen chemistry of control, lightly infested, and heavily infested leaves are notably different. These observations suggest that the aphids alter the phyllosphere ecology to such an extent that they trigger nitrogen uptake by microbes on the leaf surface in the presence of easily available carbon from aphid excretions (i.e., honeydew). A better understanding of nitrogen cycling in stressed forests would advance theories of nitrogen cycling.

  7. Effects of single basal application of coated compound fertilizer on yield and nitrogen use efficiency in double-cropped rice

    Directory of Open Access Journals (Sweden)

    Jiana Chen

    2017-06-01

    Full Text Available Fertilizer plays an important role in increasing rice yield. More than half of all fertilizer applied to the field is not taken up, resulting in environmental damage and substantial economic losses. To address these concerns, a low-cost, coated compound fertilizer named “Xiang Nong Da” (XND, requiring only a single basal application, was studied. A two-year field experiment was conducted to test the effects of XND application on rice yield and nitrogen fertilizer use efficiency. An ordinary uncoated compound fertilizer (UNCF, with 20% more nutrients and split application was selected as the control. The yield of XND-treated rice was only 3.1% lower than that of the control, an insignificant difference. There were no significant differences between N use efficiency indices of the two fertilizer treatments except for N partial factor productivity (PFPN. PFPN of XND treatment was 19.7%–23.2% higher than the control, a significant difference. This result indicates that a 20% decrease in N application rate is possible with XND without yield reduction and with savings in both labor and time.

  8. The effect of nitrogen and sulphur fertilization on the yield and content of sulforaphane and nitrates in cauliflower

    Directory of Open Access Journals (Sweden)

    Nina Čekey

    2011-01-01

    Full Text Available In the field experiment with cauliflower, we investigated the effect of four different variants of nitrogen and suplhur fertilization on quantity and quality of cauliflower in the term of sulforaphane content and nitrate accumulation. The influence of fertilization was statistically significant between control variant and fertilization variants and in both experimental years within all parameters of cauliflower yield. The highest yield of cauliflower was reached at the variant 4 when it was fertilized on the level of nutrients N:S = 250:60 kg.ha−1. The increase of yield against control variant represented value 26.6%. The applied fertilization positively affected on the accumulation sulforaphane in the cauliflower. Its highest content was determined at the variant 4 (N:S = 250:60 kg.ha−1. In comparison with control variant, the sulforaphane content was increased about 18.4%. On the other side, applied nutrition resulted in increased accumulation of nitrates in the cauliflower. The most increase of nitrate content, compared to the control variant, was also ascertained at the variant 4 (about 31.4%.The gathered data point towards to the possibility and way how we could effect on the increased accumulation of sulforaphane in cauliflower florets. This sphere of fertilization effect on the sulforaphane content is not sufficiently explored well. Our aim is to continue in this research subject and to find way how to cultivate vegetables with higher content of health-promoting compounds.

  9. Temperature Sensitivity of Soil Respiration to Nitrogen Fertilization: Varying Effects between Growing and Non-Growing Seasons

    Science.gov (United States)

    Liu, Qingfang; Wang, Rui; Li, Rujian; Hu, Yaxian; Guo, Shengli

    2016-01-01

    Nitrogen (N) fertilization has a considerable effect on food production and carbon cycling in agro-ecosystems. However, the impacts of N fertilization rates on the temperature sensitivity of soil respiration (Q10) were controversial. Five N rates (N0, N45, N90, N135, and N180) were applied to a continuous winter wheat (Triticum aestivum L.) crop on the semi-arid Loess Plateau, and the in situ soil respiration was monitored during five consecutive years from 2008 to 2013. During the growing season, the mean soil respiration rates increased with increasing N fertilization rates, peaking at 1.53 μmol m−2s−1 in the N135 treatment. A similar dynamic pattern was observed during the non-growing season, yet on average with 7.3% greater soil respiration rates than the growing season. In general for all the N fertilization treatments, the mean Q10 value during the non-growing season was significantly greater than that during the growing season. As N fertilization rates increased, the Q10 values did not change significantly in the growing season but significantly decreased in the non-growing season. Overall, N fertilization markedly influenced soil respirations and Q10 values, in particular posing distinct effects on the Q10 values between the growing and non-growing seasons. PMID:27992576

  10. Effects of Nitrogen Fertilization on Potato Leafhopper (Hemiptera: Cicadellidae) and Maple Spider Mite (Acari: Tetranychidae) on Nursery-Grown Maples.

    Science.gov (United States)

    Prado, Julia; Quesada, Carlos; Gosney, Michael; Mickelbart, Michael V; Sadof, Clifford

    2015-06-01

    Although leaf nitrogen (N) has been shown to increase the suitability of hosts to herbivorous arthropods, the responses of these pests to N fertilization on susceptible and resistant host plants are not well characterized. This study determined how different rates of N fertilization affected injury caused by the potato leafhopper (Empoasca fabae Harris) and the abundance of maple spider mite (Oligonychus aceris (Shimer)) on 'Red Sunset' red maple (Acer rubrum) and 'Autumn Blaze' Freeman maple (Acer×freemanii) during two years in Indiana. N fertilization increased leaf N concentration in both maple cultivars, albeit to a lesser extent during the second year of the study. Overall, Red Sunset maples were more susceptible to E. fabae injury than Autumn Blaze, whereas Autumn Blaze maples supported higher populations of O. aceris. Differences in populations of O. aceris were attributed to differences between communities of stigmaeid and phytoseiid mites on each cultivar. Injury caused by E. fabae increased with N fertilization in a dose-dependent manner in both cultivars. Although N fertilization increased the abundance of O. aceris on both maple cultivars, there was no difference between the 20 and 40 g rates. We suggest the capacity of N fertilization to increase O. aceris on maples could be limited at higher trophic levels by the community of predatory mites.

  11. Dryland Winter Wheat Yield, Grain Protein, and Soil Nitrogen Responses to Fertilizer and Biosolids Applications

    Directory of Open Access Journals (Sweden)

    Richard T. Koenig

    2011-01-01

    Full Text Available Applications of biosolids were compared to inorganic nitrogen (N fertilizer for two years at three locations in eastern Washington State, USA, with diverse rainfall and soft white, hard red, and hard white winter wheat (Triticum aestivum L. cultivars. High rates of inorganic N tended to reduce yields, while grain protein responses to N rate were positive and linear for all wheat market classes. Biosolids produced 0 to 1400 kg ha−1 (0 to 47% higher grain yields than inorganic N. Wheat may have responded positively to nutrients other than N in the biosolids or to a metered N supply that limited vegetative growth and the potential for moisture stress-induced reductions in grain yield in these dryland production systems. Grain protein content with biosolids was either equal to or below grain protein with inorganic N, likely due to dilution of grain N from the higher yields achieved with biosolids. Results indicate the potential to improve dryland winter wheat yields with biosolids compared to inorganic N alone, but perhaps not to increase grain protein concentration of hard wheat when biosolids are applied immediately before planting.

  12. Effects of Seeding Density and Nitrogen Fertilizer on the Productivity of Egyptian Clover

    Directory of Open Access Journals (Sweden)

    Jwan G. Rafaat

    2013-11-01

    Full Text Available The study was carried out to show the effect of different levels of nitrogen fertilizer 0, 20, 40 and 60 kg urea/ha, and two seeding rates 15 and 30 kg/ha. The study was conducted at Bakrajo research field during the winter season 2011-2012 to some growth characteristics of Egyptian clover, such as plant height, dry leaf weight percent, dry stem weight percent, leave stem ratio, fresh yield t/ha, dry yield t/ha and dry matter percent. The experiment was designed as (R.C.B.D. The results can be summarized as follow; significant differences were observed between all three cuts, and the third cut was superior in almost characters especially in the forage yield. The application of 40 and 60 kg urea gave maximum yield. Using 15 kg seeds/ha showed superior value due to fresh yield in compare to 30 kg for all cutting, while the dry yield responded non-significantly to seeding rates.

  13. Effects of Nitrogen Fertilizer,Soil Moisture and Temperature on Methane Oxidation in Paddy Soil

    Institute of Scientific and Technical Information of China (English)

    YANXIAOYUAN; CAIZUCONG

    1996-01-01

    Effects of nitrogen fertilizer,soil mosture and temperature and temperature on methane oxidation in paddy soil were investigated under laboratory conditions.Addition of 0.05 g N kg-1 soil as NH4Cl strongly inhibited methane oxidation and addition of the same rate of KCl also inhibited the oxidation but with more slight effect,suggesting that the inhibitory effect was partly caused by increase in osmotic potential in microorganism cell,Not only NH4+ but also NO3- greatly affected methane oxidation.Urea did not affect methane oxidation in paddy soil in the first two days of incubation,but strong inhibitory effect was observed afterwards.Methane was oxidized in the treated soil with an optimum moisture of 280 g kg-1 ,and air-drying inhibited methane oxidation entirely.The optimum temperature of methane oxidation was about 30℃ in paddy soil.while no methane oxidation was observed at 5℃or 50℃。

  14. Cultivation of cherry tomato under irrigation with saline water and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Ianne G. S. Vieira

    2016-01-01

    Full Text Available ABSTRACT The study was carried out from August 2013 to January 2014 to evaluate growth and production of cherry tomato cultivated under irrigation with water of different salinity levels and fertilized with different nitrogen (N doses, in experiment conducted in drainage lysimeters under greenhouse conditions, at the Center for Agrifood Science and Technology of the Federal University of Campina Grande. The statistical design was randomized blocks in a 5 x 4 factorial scheme, with three replicates, and the treatments consisted of five levels of electrical conductivity of water (0.3, 1.5, 2.5, 3.5 and 4.5 dS m-1 and four N doses (60, 100, 140 and 180 mg kg-1. Growth and production variables of cherry tomato decrease linearly from the irrigation water salinity of 0.3 dS m-1 on. The longer exposure of plants to salt stress caused the highest reductions, and the root dry matter, leaf area and the number of clusters are the most sensitive variables. The highest value of plant height at 125 days after transplantation was obtained with the N dose of 139 mg kg-1 of soil. Increasing N doses reduced the effect of salinity on cherry tomato growth at 125 days after transplantation.

  15. The role of stoichiometric flexibility in modelling forest ecosystem responses to nitrogen fertilization.

    Science.gov (United States)

    Meyerholt, Johannes; Zaehle, Sönke

    2015-12-01

    The response of the forest carbon (C) balance to changes in nitrogen (N) deposition is uncertain, partly owing to diverging representations of N cycle processes in dynamic global vegetation models (DGVMs). Here, we examined how different assumptions about the degree of flexibility of the ecosystem's C : N ratios contribute to this uncertainty, and which of these assumptions best correspond to the available data. We applied these assumptions within the framework of a DGVM and compared the results to responses in net primary productivity (NPP), leaf N concentration, and ecosystem N partitioning, observed at 22 forest N fertilization experiments. Employing flexible ecosystem pool C : N ratios generally resulted in the most convincing model-data agreement with respect to production and foliar N responses. An intermediate degree of stoichiometric flexibility in vegetation, where wood C : N ratio changes were decoupled from leaf and root C : N ratio changes, led to consistent simulation of production and N cycle responses to N addition. Assuming fixed C : N ratios or scaling leaf N concentration changes to other tissues, commonly assumed by DGVMs, was not supported by reported data. Between the tested assumptions, the simulated changes in ecosystem C storage relative to changes in C assimilation varied by up to 20%.

  16. Yield components and water use efficiency in coriander under irrigation and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Karoline P. Angeli

    2016-05-01

    Full Text Available ABSTRACT Among the determining factors of yield, nitrogen (N fertilization and the correct supply of water play an important role in the quality and yield aspects of coriander. Therefore, the aim of this study was to evaluate the yield components and the water use efficiency (WUE in coriander subjected to different depths and N doses. A completely randomized design in split plot was used. Water depths were applied in the plots at the rates of 25, 50, 75, 100 and 125% of the Required Real Irrigation (RRI. N doses were distributed within the subplots at the following proportions: 50, 100 and 150% of the recommendation for the crop (70 kg ha-1. The N dose of 94 kg ha-1 and irrigation depth of 115% of RRI promoted the greatest yield (29.0 t ha-1 and number of bunches (29 bunches m-2. The highest number of leaves per plant was obtained with the N dose of 103.2 kg ha-1 and irrigation depth of 68% of the RRI. The maximum plant height (43 cm was obtained with N dose of 105 kg ha-1 and irrigation depth of 121% of RRI. The highest WUE in coriander (71 kg m-3 occurred at the irrigation depth of 26% of RRI and N dose of 105 kg ha-1.

  17. Maize responds to Azotobacter sp and Burkholderia sp inoculation at reduced dose of nitrogen fertilizer

    Directory of Open Access Journals (Sweden)

    Juan Manuel Sánchez-Yáñez

    2014-03-01

    Full Text Available The positive maize response to inoculation with plant growth promoting bacteria (PGPB as Azotobacter sp and Burkholderia sp an endophytic type, are an alternative to reduced and optimize nitrogen fertilizer (NF dose, recommended for this plant, without adversely affect its growth. The aim of this study was to analyze maize respond to inoculation with Azotobacter sp and Burkholderia sp at the dose 50% of FN. Used an experimental design of randomized blocks. By response variables: percent germination (%, the shoot and root phenology: plant height (PH, root length (RL and biomass: shoot fresh weight (SFW and root fresh weight (RFW, the shoot dry weight (SDW and root dry weight (RDW. The results indicated a positive maize respond to PGPB inoculation at germination, seedling and flowering level, reached a RDW of 7.03 g, statistically significant value compared with 2.60 g of RDW non inoculated maize feed with NF dose recommended regard as relative control (RC. This suggests a synergistic interaction among these PGPB in synthesis of plant growth promoting substances (PGPS on maize, to optimize the reduced NF dose.

  18. Plant hydraulic responses to long-term dry season nitrogen deposition alter drought tolerance in a Mediterranean-type ecosystem.

    Science.gov (United States)

    Pivovaroff, Alexandria L; Santiago, Louis S; Vourlitis, George L; Grantz, David A; Allen, Michael F

    2016-07-01

    Anthropogenic nitrogen (N) deposition represents a significant N input for many terrestrial ecosystems. N deposition can affect plants on scales ranging from photosynthesis to community composition, yet few studies have investigated how changes in N availability affect plant water relations. We tested the effects of N addition on plant water relations, hydraulic traits, functional traits, gas exchange, and leaf chemistry in a semi-arid ecosystem in Southern California using long-term experimental plots fertilized with N for over a decade. The dominant species were Artemisia california and Salvia mellifera at Santa Margarita Ecological Reserve and Adenostoma fasciculatum and Ceanothus greggii at Sky Oaks Field Station. All species, except Ceanothus, showed increased leaf N concentration, decreased foliar carbon to N ratio, and increased foliar N isotopic composition with fertilization, indicating that added N was taken up by study species, yet each species had a differing physiological response to long-term N addition. Dry season predawn water potentials were less negative with N addition for all species except Adenostoma, but there were no differences in midday water potentials, or wet season water potentials. Artemisia was particularly responsive, as N addition increased stem hydraulic conductivity, stomatal conductance, and leaf carbon isotopic composition, and decreased wood density. The alteration of water relations and drought resistance parameters with N addition in Artemisia, as well as Adenostoma, Ceanothus, and Salvia, indicate that N deposition can affect the ability of native Southern California shrubs to respond to drought.

  19. T-1, a mitotic arrester, alters centrosome configurations in fertilized sea urchin eggs.

    Science.gov (United States)

    Itoh, T J; Schatten, H; Schatten, G; Mazia, D; Kobayashi, A; Sato, H

    1990-01-01

    T-1 induces modifications in the shape of the centrosome at division in fertilized eggs of the North American sea urchin, Lytechinus pictus. Phase contrast microscopy observations of mitotic apparatus isolated from T-1-treated (1.7-8.5 microM) eggs at first division shows that the centrosomes already begin to spread or to separate by prophase and that the mitotic spindle is barrel-shaped. When eggs are fertilized with sperm that have been preteated with T-1, the centrosomes become flattened; the spindles are of normal length. Immunofluorescence microscopy using an anti-centrosomal monoclonal antibody reveals that T-1 modifies the structure of the centrosome so that barrel-shaped spindles with broad centrosomes are observed at metaphase, rather than the expected focused poles and fusiform spindle. Higher concentrations of T-1 induce fragmentation of centrosomes, causing abnormal accumulation of microtubules in polar regions. These results indicate that T-1 directly alters centrosomal configuration from a compact structure to a flattened or a spread structure. T-1 can be classified as a new category of mitotic drugs that may prove valuable in dissecting the molecular nature of centrosomes.

  20. Status of Technology in Domestic Nitrogenous Fertilizer Industry%我国氮肥工业技术状况

    Institute of Scientific and Technical Information of China (English)

    曹占高; 凌晓东; 常怀春

    2012-01-01

    分析了国外、国内氮肥工业生产装置的技术状况,罗列了大、中、小型合成氨装置和尿素装置的消耗情况.介绍了我国氮肥生产装置关键部位具有国内或国际水平的新技术的开发与应用情况.%An analysis is made of the status of technology used in the production units of foreign and domestic nitrogenous fertilizer industry, and consumption levels are listed for large-, medium- and small-scale ammonia and urea units. A presentation is given of the development and application of new technology at domestic or international level used in key locations of domestic nitrogenous fertilizer production units.

  1. Influence of different fertilization on the dissolved organic carbon, nitrogen and phosphorus accumulation in acid and limed soils

    Directory of Open Access Journals (Sweden)

    Ieva Jokubauskaite

    2015-04-01

    Full Text Available Soil quality has become an important issue in soil science. Dissolved organic carbon (DOC is believed to play an important role in soil processes and in the C, N and P balances, their supplies to plants in all types of soils. It is much more sensitive to soil management than is soil organic matter as a whole, and can be used as a key indicator of soil natural functions. This study aimed to assess the influence of different organic fertilizers on DOC and N, P accumulation. The study was carried out on a moraine loam soil at the Vezaiciai Branch of Lithuanian Research Centre for Agriculture and Forestry in 2012. Farmyard manure (FYM (60 t ha -1 and alternative organic fertilizers (wheat straw, rape residues, roots, stubble, perennial grasses were applied on two soil backgrounds - acid and limed. DOC was analysed using an ion chromatograph SKALAR. Application of organic amendments resulted in a significant increase of soil organic carbon (SOC content, which demonstrates a positive role of organic fertilizers in SOC conservation. The combination of different organic fertilizers and liming had a significant positive effect on DOC concentration in the soil. The highest DOC content (0.241 g kg-1 was established in the limed soil fertilized with farmyard manure. The most unfavourable status of DOC was determined in the unlimed, unfertilized soil. The limed and FYM-applied soil had the highest nitrogen (1.47 g kg-1 and phosphorus (0.84 g kg-1 content compared to the other treatments. Organic fertilizers gave a significant positive effect on SOC and DOC content increase in the topsoil. This immediate increase is generally attributed to the presence of soluble materials in the amendments. Application of organic fertilizers in acid and limed soil increased the nutrient stocks and ensured soil chemical indicato