WorldWideScience
 
 
1

Simulated crop rotation systems control swede midge, Contarinia nasturtii  

UK PubMed Central (United Kingdom)

Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), a common insect pest in Europe and a new invasive pest in North America, causes severe damage to cruciferous crops. Many counties in Canada and the USA, in which C. nasturtii has not been previously reported, are at risk of being infested by C. nasturtii. Effectiveness of chemical control is limited, especially under high population pressure in fields. Alternative management strategies against C. nasturtii are sorely needed in order to protect crucifers. Under controlled laboratory conditions, the effectiveness on C. nasturtii control by 11 simulated cauliflower-sweet corn and cauliflower-kidney bean crop rotation systems was evaluated, with and without the presence of cruciferous weeds as alternative hosts. Our results indicated that when soil was infested with C. nasturtii pupae, the emergence pattern from the soil was very similar regardless whether the soil was later planted to host or non-host plants. As emergence was not affected, we examined whether manipulating host availability for oviposition through crop rotation would be effective. Our results indicated that the simulated cauliflower-sweet corn and cauliflower-kidney bean rotation systems provided full control of C. nasturtii. The effectiveness of one cycle of non-host crop rotation was reduced when cruciferous weeds were present. However, the C. nasturtii population in a one-cycle non-host rotation system with cruciferous weeds present was significantly lower than that in a non-rotation system. Two consecutive cycles (simulating a cropping season) of non-host plant crop rotations provided full control of C. nasturtii, regardless of the presence of the cruciferous weeds. The importance of cruciferous weed management and how to implement a successful crop rotation in fields to control C. nasturtii are discussed.

Chen Mao; Li Weiwei; Shelton AnthonyM

2009-10-01

2

Recycling of crop residues for sustainable crop production in a maize-groundnut rotation system  

International Nuclear Information System (INIS)

[en] A long-term field experiment, which was established to investigate the contribution of crop residues to the N-economy of a maize-groundnut rotation system, consisted of three treatments: (i) T1, the recommended rate of chemical fertilizer with residue, (ii) T2, the recommended rate of chemical fertilizer without residue, and (iii) T3, a combination of organic fertilizer (chicken manure) and chemical fertilizer with residue. In order to investigate the N contribution from residues of the first crop (maize) to subsequent crops, the maize was labelled with 15N in the T1 and T2 treatments. Fertilizer N (15N-ammonium sulphate, 9.82% a.e.) was applied (60 kg N ha-1) to microplots within each yield plot, to generate labelled maize residue. At the same time 90 kg N ha-1 unlabelled N fertilizer was applied to provide the recommended rate for maize of 150 kg Nha-1. Uptake of N and K by subsequent crops was significantly higher in crop-residue treatments, whereas uptake of P, Ca and Mg was not significantly affected. Soil pH, organic C, cation-exchange capacity, soil resistance, water content and bulk density were not significantly changed after four crop-residue applications. Soil organic matter size and density fractions seemed to increase, with application of residues, but without statistical significance. Soil available P and exchangeable K were significantly higher in plots with crop residues. Recovery of fertilizer 15N by the first crop ranged from 19 to 22%. In the following crop, the recoveries were only 5.1% and 5.6% in plants of T1 and T2 treatment and only trace recoveries of 15N occurred in the subsequent crop. Fertilizer 15N retained in the soil after harvest of the first crop was 35 to 44%, whereas after the second crop 33% was present in crop-residue treated plots and 26% in plots where crop residues had been removed. Nitrogen mineralization from maize residues was quite rapid from 4 to 8 weeks after incorporation due to the hot, humid conditions. Thus, for good synchrony of release of N from residues and uptake of N by the crop, sowing should be 4 to 6 weeks after residue incorporation. However, in a rain-fed area it is sometimes inevitable that fallow periods are long, i.e. more than 6 weeks, depending on the rainfall, as in this study. Contributions of crop residues to economic yields were not significant, even after six crop cycles. (author)

2003-01-01

3

[Nutrient management strategy of paddy rice-upland crop rotation system].  

UK PubMed Central (United Kingdom)

Paddy rice-upland crop rotation system is a major cropping system in China, and practiced widely along the Yangtze River basin. A unique feature of this system is the annual conversion of soil from aerobic to anaerobic and then back to aerobic condition, which can result in the changes of soil physical, chemical, and biological prosperities among seasons, making a special agroecosystem. The major challenges faced by this system include declining or stagnating productivity, increasing shortage of irrigation water, improper management of nutrients, low efficiency of resource utilization, and environmental pollution. Based on an overview of the characteristics and problems of paddy rice-upland crop rotation system, this paper put forward a strategy of practicing integrated nutrient management to solve the contradictions between nutrient input, crop production and environmental risk. The key points of this strategy included nutrient management from the whole rotation system perspective, integrated use of nutrients from various sources (chemical fertilizers, organic fertilizers, and nutrients from the environment), synchronization of nutrient supply and crop nutrient demand, application of different management technologies based on the characteristics of different nutrient resources, and integration of nutrient management with other cropping system technologies like water saving and high-yielding cultivation, etc.

Fan MS; Jiang RF; Zhang FS; Lü SH; Liu XJ

2008-02-01

4

Evaluation of soil quality indicators in paddy soils under different crop rotation systems  

Science.gov (United States)

Evaluation of soil quality indicators in paddy soils under different crop rotation systems Soil quality, by definition, reflects the capacity to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Soil quality assessment is an essential issue in soil management for agriculture and natural resource protection. This study was conducted to detect the effects of four crop rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) on soil quality indicators (soil moisture, porosity, bulk density, water-filled pore space, pH, extractable P, CEC, OC, OM, microbial respiration, active carbon) in paddy soils of Verona area, Northern Italy. Four adjacent plots which managed almost similarly, over five years were selected. Surface soil samples were collected from each four rotation systems in four times, during growing season. Each soil sample was a composite of sub-samples taken from 3 points within 350 m2 of agricultural land. A total of 48 samples were air-dried and passed through 2mm sieve, for some chemical, biological, and physical measurements. Statistical analysis was done using SPSS. Statistical results revealed that frequency distribution of most data was normal. The lowest CV% was related to pH. Analysis of variance (ANOVA) and comparison test showed that there are significant differences in soil quality indicators among crop rotation systems and sampling times. Results of multivariable regression analysis revealed that soil respiration had positively correlation coefficient with soil organic matter, soil moisture and cation exchange capacity. Overall results indicated that the rice rotation with legumes such as bean and soybean improved soil quality over a long time in comparison to rice-fallow rotation, and this is reflected in rice yield. Keywords: Soil quality, Crop Rotation System, Paddy Soils, Italy

Nadimi-Goki, Mandana; Bini, Claudio; Haefele, Stephan; Abooei, Monireh

2013-04-01

5

Are many little hammers effective? Velvetleaf (Abutilon theophrasti) population dynamics in two- and four-year crop rotation systems.  

UK PubMed Central (United Kingdom)

To improve understanding of relationships between crop diversity, weed management practices, and weed population dynamics, we used data from a field experiment and matrix models to examine how contrasting crop rotations affect velvetleaf. We compared a 2-yr rotation system (corn-soybean) managed with conventional rates of herbicides with a 4-yr rotation (corn-soybean-triticale + alfalfa-alfalfa) that received 82% less herbicide. In November 2002, a pulse of velvetleaf seeds (500 seeds m(-2)) was added to 7- by 7-m areas within replicate plots of each crop phase-rotation system combination. Velvetleaf seed, seedling, and reproductive adult population densities, seed production, and seed losses to predators were measured during the next year. Velvetleaf seed production was greater in the 4-yr rotation than in the 2-yr rotation (460 vs. 16 seeds m(-2)). Averaged over 12 sampling periods from late May to mid-November 2003, loss of velvetleaf seeds to predators also was greater in the 4-yr rotation than in the 2-yr rotation (32 vs. 17% per 2 d). Modeling analyses indicated that velvetleaf density in the 4-yr rotation should decline if cumulative losses of seeds produced in the soybean phase exceeded 40%. Achieving such a level of predation appears possible, given the observed rates of velvetleaf seed predation. In addition, no tillage occurs in the 4-yr rotation for 26 mo after soybean harvest, thus favoring seed exposure on the soil surface to predators. Models that included estimates of seed predation indicated that to prevent increases in velvetleaf density, weed control efficacy in soybean must be greater than or equal to 93% in the 2-yr rotation, but could drop to 86% in the 4-yr rotation. These results support the hypothesis that diverse rotations that exploit multiple stress and mortality factors, including weed seed predation, can contribute to effective weed suppression with less reliance on herbicides.

Westerman PR; Liebman M; Menalled FD; Heggenstaller AD; Hartzler RG; Dixon PM

2005-05-01

6

Influence of conservation tillage and crop rotation on the resilience of an intensive long-term potato cropping system: Restoration of soil biological properties after the potato phase  

UK PubMed Central (United Kingdom)

Conservation tillage in potato (Solanum tuberosum L.) systems, in cool-humid climatic regions, can benefit soil physical and biological properties. However, insight is needed on how the combination of conservation tillage and crop rotation enhances the resilience of intensive short-term potato cropping systems, specifically the restoration of the soil condition after the perturbations that occur in the potato phase. A long-term 3-year rotation (potato-barley-red clover) and conservation tillage study was initiated in 1994 on a fine sandy loam in Prince Edward Island, eastern Canada. Over a 3-year period (2004-2006), soil physical (bulk density) and biological (C and N fractions, structural stability; densities of plant parasitic and bacterial-feeding nematodes, and micro-arthropod abundance and diversity) properties were monitored over each phase of the crop rotation cycle to assess the restoration or rejuvenation of the surface (0-10cm) soil condition. Conservation compared to conventional tillage, increased soil organic C, large water-stable macro-aggregates, and soil particulate C and N in the potato year only. After the potato phase, rotation crops were associated with the further restoration of all soil C and N fractions and soil structural stability indices; and also increases in soil microbial biomass C and microbial activity indices, and soil Collembola abundance. Soil nematode densities showed some incidences of treatment differences but no clear trends. The study indicated that conservation tillage has a positive influence on soil biological properties and that the 3-year rotation successfully restored many of the soil parameters that had declined in the potato year.

Carter MR; Noronha C; Peters RD; Kimpinski J

2009-09-01

7

Recycling of crop-residue N for sustainable production in a maize-groundnut rotation system  

International Nuclear Information System (INIS)

[en] To investigate the contribution of crop residues to the N-economy of a maize-groundnut rotation, a long-term field experiment was established in February 1997. It consisted of the following treatments: (i) T1 - the recommended rate of chemical fertilizer plus residues, (ii) T2 - the recommended rate of chemical fertilizer without residues, and (iii) T3 - a combination of organic fertilizer (chicken dung), chemical fertilizer, and residues. In order to investigate the possible contribution of residue N to subsequent crops, the first maize crop was labelled with 15N. The first crop was sown in March 1997 and 15N-labelled ammonium sulphate was applied at 60 kg N ha-1 to the T1 and T2 treatments, in microplots within yield plots, to generate labelled maize residues. At the same time, 90 kg N ha-1 unlabelled N fertilizer was applied to provide the locally recommended rate for maize of 150 kg N ha-1. Treatment T3 was included for comparison of yields and appraisal of effects on soil properties. After the first crop was harvested, the labelled aboveground residues in T1 were applied to a different microplot so that the fate of the labelled residue-N could be followed. Groundnut was grown in rotation with maize, and, after each harvest, the labelled aboveground residues in the microplots of T1 and T2 were removed and unlabelled residues were added to T1. Because variability between replicates was high in the treatment T2, the average yields in plots with residues, T1 and T3, in the second and third crop cycles were not significantly different from those without residues. Maize yields were similar in the first and second years

2002-01-01

8

Recycling of crop-residue N for sustainable production in maize-groundnut rotation system  

International Nuclear Information System (INIS)

[en] To investigate the contribution of crop residues to the N-economy of a maize-groundnut rotation, a long-term field experiment was established in February 1997. It consisted of the following treatments: (i) T1 - the recommended rate of chemical fertilizer plus residues, (ii) T2 - the recommended rate of chemical fertilizer without residues, and (iii) T3 - a combination of organic fertilizer (chicken dung), chemical fertilizer, and residues. In order to investigate the possible contribution of residue N to subsequent crops, the first maize crop was labelled with 15N. The first crop was sown in March 1997 and 15N-labelled ammonium sulphate was applied at 60 kg N ha-1 to the T1 and T2 treatments, in microplots within yield plots, to generate labelled maize residues. At the same time, 90 kg N ha-1 unlabelled N fertilizer was applied to provide the locally recommended rate for maize of 150 kg N ha-1. Treatment T3 was included for comparison of yields and appraisal of effects on soil properties. After the first crop was harvested, the labelled aboveground residues in T1 were applied to a different microplot so that the fate of the labelled residue-N could be followed. Groundnut was grown in rotation with maize, and, after each harvest, the labelled aboveground residues in the microplots of T1 and T2 were removed and unlabelled residues were added to T1. Because variability between replicates was high in the treatment T2, the average yields in plots with residues, T1 and T3, in the second and third crop cycles were not significantly different from those without residues. Maize yields were similar in the first and second years

2002-01-01

9

Fluxes of nitrous oxide from soil under different crop rotations and tillage systems in the South of Brazil  

UK PubMed Central (United Kingdom)

The zero tillage (ZT) system is used in a large area (>24 Mha) of crop production in Brazil. This management system can contribute to soil C sequestration, but many studies in other countries have registered greater nitrous oxide emissions under ZT compared to conventional tillage (CT), which may reduce greenhouse gas mitigation benefits. The aim of this study was to estimate the emission of N?O from cropping systems under conventional and zero tillage in an 18-year-old experiment conducted on a Rhodic Ferralsol in the South of Brazil. Fluxes of N?O were measured over two years using static-closed chambers in the two tillage systems with three crop rotations. Soil water filled pore space (%WFPS) and soil mineral N were monitored along with rainfall and air temperature. Estimates of N?O emissions were obtained by integrating the fluxes with time and also by applying the IPCC direct emission factor (EF1 = 1%) to the amounts of N added as fertilisers and returned as crop residues. Fluxes of N?O were relatively low, apart from a short period at the beginning of measurements. No relationship between N?O fluxes and %WFPS or mineral N were observed. Nitrous oxide emissions were not influenced either by tillage system or crop rotation. For the crop rotation receiving high rates of N fertiliser in the second year, field-measured N?O emissions were significantly underestimated by the IPCC emission factor 1 (EF1). For the other treatments measured N?O emissions fell within the EF1 uncertainty range, but always considerably lower than the EF1 estimate, which suggests IPCC EF1 overestimates true N?O emissions for the Ferralsol under evaluation.

Jantalia ClaudiaP; dos Santos HenriqueP; Urquiaga Segundo; Boddey RobertM; Alves BrunoJR

2008-10-01

10

Crop rotation impact on soil quality  

International Nuclear Information System (INIS)

Management systems influence soil quality over time. A study was carried out on Van meter farm of the Ohio State University South Centers at Piketon Ohio, USA to evaluate the impact of crop rotations on soil quality from 2002 to 2007. The crop rotations comprised of continuous corn (CC), corn-soybean (CS) and corn-soybean-wheat-cowpea (CSW). Ten soil cores were collected at 0-7.5, 7.5-15, 15-22.5 and 22.5-30 cm, and sieved. The soils were analyzed for total microbial biomass (C/sub mic/), basal respiration (BR) and specific maintenance respiration (qCO/sub 2/) rates as biological quality indicators; total organic carbon (TC), active carbon (AC) and total nitrogen (TN) as chemical quality indicators; and aggregate stability (AS), particulate organic matter (POM) and total porosity (ft) as physical quality parameters at different depths of soil. The inductive additive approach based on the concept of 'higher value of any soil property except ft, a better indicator of soil quality' was used to calculate the biological (SBQ), chemical (SCQ), physical (SPQ) and composite soil quality (SQI) indices. The results showed that crop rotation had significant impact on C/sub mic/, BR, qCO/sub 2/, TC, AC, TN, AS and POM except ft at different depths of soil. The CSW had higher soil quality values than CC and CS. The values of selected soil quality properties under the given crop rotation significantly decreased except ft with increasing soil depth. The SBQ (23%), SCQ (16%), SPQ (7%) and SQI (15%) improved under CSW over time. The results imply that multiple cropping systems could be more effective for maintaining and enhancing soil quality than sole-cropping systems. (author)

2011-01-01

11

Short rotation Wood Crops Program  

Energy Technology Data Exchange (ETDEWEB)

This report synthesizes the technical progress of research projects in the Short Rotation Woody Crops Program for the year ending September 30, 1989. The primary goal of this research program, sponsored by the US Department of Energy's Biofuels and Municipal Waste Technology Division, is the development of a viable technology for producing renewable feedstocks for conversion to biofuels. One of the more significant accomplishments was the documentation that short-rotation woody crops total delivered costs could be $40/Mg or less under optimistic but attainable conditions. By taking advantage of federal subsidies such as those offered under the Conservation Reserve Program, wood energy feedstock costs could be lower. Genetic improvement studies are broadening species performance within geographic regions and under less-than-optimum site conditions. Advances in physiological research are identifying key characteristics of species productivity and response to nutrient applications. Recent developments utilizing biotechnology have achieved success in cell and tissue culture, somaclonal variation, and gene-insertion studies. Productivity gains have been realized with advanced cultural studies of spacing, coppice, and mixed-species trials. 8 figs., 20 tabs.

Wright, L.L.; Ehrenshaft, A.R.

1990-08-01

12

Short Rotation Crops in the United States  

Energy Technology Data Exchange (ETDEWEB)

The report is based primarily on the results of survey questions sent to approximately 60 woody and 20 herbaceous crop researchers in the United States and on information from the U.S. Department of Energy?s Bioenergy Feedstock Development Program. Responses were received from 13 individuals involved in woody crops research or industrial commercialization (with 5 of the responses coming from industry). Responses were received from 11 individuals involved in herbaceous crop research. Opinions on market incentives, technical and non-technical barriers, and highest priority research and development areas are summarized in the text. Details on research activities of the survey responders are provided as appendices to the paper. Woody crops grown as single-stem systems (primarily Populus and Eucalyptus species) are perceived to have strong pulp fiber and oriented strand board markets, and the survey responders anticipated that energy will comprise 25% or less of the utilization of single-stem short-rotation woody crops between now and 2010. The only exception was a response from California where a substantial biomass energy market does currently exist. Willows (Salix species) are only being developed for energy and only in one part of the United States at present. Responses from herbaceous crop researchers suggested frustration that markets (including biomass energy markets) do not currently exist for the crop, and it was the perception of many that federal incentives will be needed to create such markets. In all crops, responses indicate that a wide variety of research and development activities are needed to enhance the yields and profitability of the crops. Ongoing research activities funded by the U.S. Department of Energy?s Bioenergy Feedstock Development Program are described in an appendix to the paper.

Wright, L.L.

1998-06-04

13

Maize response to different straw management and tillage systems under cereal crop rotation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this study was to determine the effect of various straw management and tillage systems on the emergence, grain yield and cob characteristics of maize (Zea mays L.) under different cereal rotations on two soils (Orthic Luvisols) of loamy sand and sandy loam textures. The study was conducte...

J. Pabin; J. Lipiec; S. Włodek; A. Biskupski

14

Carbon footprints of organic crops from arable crop rotations - using a life cycle assessment approach  

DEFF Research Database (Denmark)

Many current organic arable agriculture systems are challenged by a dependency on imported livestock manure from conventional agriculture. At the same time organic agriculture aims at being climate friendly. A life cycle assessment is used in this paper to compare the carbon footprints of different organic arable crop rotations with different sources of N supply. Data from long-term field experiments at three different locations in Denmark were used to analyse three different organic cropping systems (‘Slurry’, ‘Biogas’ and ‘Mulching’), one conventional cropping system (‘Conventional’) and a “No input” system as reference systems. The ‘Slurry’ and ‘Conventional’ rotations received slurry and mineral fertilizer, respectively, whereas the ‘No input’ was unfertilized. The ‘Mulching’ and ‘Biogas’ rotations had one year of grass-clover instead of a faba bean crop. The grass-clover biomass was incorporated in the soil in the ‘Mulching’ rotation and removed and used for biogas production in the ‘Biogas’ rotation (and residues from biogas production were simulated to be returned to the field). A method was suggested for allocating effects of fertility building crops in life cycle assessments. The results showed significantly lower carbon footprint of the crops from the ‘Biogas’ rotation (assuming that biogas replaces fossil gas) whereas the remaining crop rotations had comparable carbon footprints per kg cash crop. The study showed considerable contributions caused by the green manure crop (grass-clover) and highlights the importance of analysing the whole crop rotation and including soil carbon changes when estimating carbon footprints of organic crops especially where green manure crops are included.

Knudsen, Marie Trydeman; Meyer-Aurich, A

2013-01-01

15

Short rotation crops in Estonia  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the activities in Estonia to increase the use of biomass in power and heat generation. The main emphasis so far lies in using abandoned farmland for short rotation forestry. The biomass plantations concentrate on willows (Salix spp.), while the natural short rotation forestry is focused on grey alder.

Koppel, A. [Estonian Agricultural Univ., Tartu (Estonia). Inst. of Zoology and Botany

1999-07-01

16

Water erosion during a 17-year period under two crop rotations in four soil management systems on a Southbrazilian Inceptisol  

Science.gov (United States)

Soil erosion still remains a persistent issue in the world, and this in spite of the efforts to ameliorate soil management systems taken into account the point of view of environmental protection against soil losses. In South Brazil water erosion is mainly associated to rainfall events with a great volume and high intensity, which are more or less evenly distributed all over the year. Nowadays, direct drilling is the most widely soil management system used for the main crops of the region. However, some crops still are grown on conventionally tilled soils, which means mainly ploughing and harrowing and less frequently chisel ploughing. In Lages-Santa Catarina State, Brazil, a plot experiment under natural rain was started in 1992 on an Inceptisol with the aim of quantifying soil and water losses. Treatments included bare and vegetated plots. The crop succession was: oats (Avena strigosa), soybean (Glycine max), vetch (Vicia sativa), maize (Zea mays), fodder radish (Raphanus sativus) and beans (Phaseolus vulgaris). Soil tillage systems investigated in this study were: i) conventional tillage (CT), ii) reduced tillage (MT), iii) no tillage (NT) under crop rotation and iv) conventional tillage on bare soil (BS). Treatments CT and BS involved ploughing plus twice harrowing, whereas MT involved chisel ploughing plus harrowing. Rainfall erosivity from January 1 1992 to December 31 2009 was calculated. Soil losses from the BS treatment along the 17 year study period were higher than 1200 Mg ha-1. Crop cover significantly reduced erosion, so that under some crops soil losses in the CT treatment were 80% lower than in the BS treatment. In turn soil losses in the MT treatment, where tillage was performed by chiselling and harrowing, were on average about 50% lower than in the CT treatment. No tillage was the most efficient soil management system in reducing soil erosion, so that soil losses in the NT treatment were about 98% lower than in the BS treatment. The three vegetated treatments, CT, MT and NT showed a lower efficiency in reducing water losses than soil losses. Water losses by runoff during a number of events were of the same order of magnitude for all the management systems studied here; which was mainly true when the volume of rainfall was high and the lag between successive events was small. In general, soil losses in the autumn-winter seasons were lower than under the spring-summer seasons. Soil losses showed a positive correlation with rainfall erosivity. However, the degree of dependence between these two variables decreased as the efficiency of soil management in controlling soil erosion increased. The large soil and water losses in the BS and CT treatments suggest that there is a need to implement soil conservation measures in the study region. In this context soil conservation would take advantage from soil cover by previous crop residue as well as from terrace building. Acknowledgement: This work was partly supported by Spanish Ministry of Education (Project CGL2005-08219-C02).

Bertol, Ildegardis; Vidal Vázquez, Eva; Paz Ferreiro, Jorge

2010-05-01

17

ECONOMIC VIABILITY OF CROPS ROTATION AND GREEN MANURING PRECEDING THE CULTIVATION OF NO-TILL SYSTEM CORN IN THE CERRADO  

Directory of Open Access Journals (Sweden)

Full Text Available In search of minimizing the environmental impacts of agricultural production it is necessary the use of techniques which make larger production sustainability possible and bring economic return to the producer. In this context, the present work had the objective to evaluate, in a typical Cerrado soil, the economic viability of crops rotation and green manure (Cajanus cajan (L.) Millsp; Crotalaria juncea (L.); Eleusine coracana (L.); Pennisetum americanum (L.)) or fallow land in the yield of corn cultivated in notill system. The production information used were collected in the 2003/2004 harvest, in a test carried out in Selvíria, Mato Grosso do Sul, and the costs of farm inputs and production price were obtained in September 2004. The method used was the Total Operational Cost. To determine the profit of the activity for each treatment were considered the gross revenue, the operational profit, the profitability index and the balance price. The corn in rotation system with soybean obtained larger grains yield and higher profitability. The use of green manure preceding the cultivation of the corn was proven economically viable, and the use of the C. juncea allowed larger economic return, without showing significant difference between the E. coracana and the P. americanumt.

AGUINALDO JOSÉ FREITAS LEAL; EDSON LAZARINI; MARIA APARECIDA ANSELMO TARSITANO; MARCO EUSTÁQUIO DE SÁ; FRANCISCO GUILHIEN GOMES JÚNIOR

2005-01-01

18

Ecophysiology of short rotation forest crops  

Energy Technology Data Exchange (ETDEWEB)

An understanding of ecophysiology of the crop is critical to the effective management of short rotation forest crops. There are many interacting ecophysiological factors such as canopy structure and development, water and nutrient use efficiency, root architecture and function, sustainability of coppicing, which, through a deeper understanding, can be manipulated through genetic improvement and silvicultural practice. These complex factors are discussed, and areas requiring further research to elucidate the nature of the processes are highlighted. (author).

Mitchell, C.P. (Aberdeen Univ. (United Kingdom). Dept. of Forestry)

1992-01-01

19

Effects of crop rotation and management system on water-extractable organic matter concentration, structure, and bioavailability in a chernozemic agricultural soil.  

UK PubMed Central (United Kingdom)

Water-extractable organic matter (WEOM) in soil affects contaminant mobility and toxicity, heterotrophic production, and nutrient cycling in terrestrial and aquatic ecosystems. This study focuses on the influences of land use history and agricultural management practices on the water extractability of organic matter and nutrients from soils. Water-extractable organic matter was extracted from soils under different crop rotations (an annual rotation of wheat-pea/bean-wheat-flax or a perennial-based rotation of wheat-alfalfa-alfalfa-flax) and management systems (organic or conventional) and examined for its concentration, composition, and biodegradability. The results show that crop rotations including perennial legumes increased the concentration of water-extractable organic carbon (WEOC) and water-extractable organic nitrogen (WEON) and the biodegradability of WEOC in soil but depleted the quantity of water-extractable organic phosphorus (WEOP) and water-extractable reactive phosphorus. The 30-d incubation experiments showed that bioavailable WEOC varied from 12.5% in annual systems to 22% for perennial systems. The value of bioavailable WEOC was found to positively correlate with WEON concentrations and to negatively correlate with C:N ratio and the specific ultraviolet absorbance of WEOM. No significant treatment effect was present with the conventional and organic management practices, which suggested that WEOM, as the relatively labile pool in soil organic matter, is more responsive to the change in crop rotation than to mineral fertilizer application. Our results indicated that agricultural landscapes with contrasting crop rotations are likely to differentially affect rates of microbial cycling of organic matter leached to soil waters.

Xu N; Wilson HF; Saiers JE; Entz M

2013-01-01

20

Carbon footprints of crops from organic and conventional arable crop rotations – using a life cycle assessment approach  

DEFF Research Database (Denmark)

Many current organic arable agriculture systems are challenged by a dependency on imported livestock manure from conventional agriculture. At the same time organic agriculture aims at being climate friendly. A life cycle assessment is used in this paper to compare the carbon footprints of different organic arable crop rotations with different sources of N supply. Data from long-term field experiments at three different locations in Denmark were used to analyse three different organic cropping systems (‘Slurry’, ‘Biogas’ and ‘Mulching’), one conventional cropping system (‘Conventional’) and a “No input” system as reference systems. The ‘Slurry’ and ‘Conventional’ rotations received slurry and mineral fertilizer, respectively, whereas the ‘No input’ was unfertilized. The ‘Mulching’ and ‘Biogas’ rotations had one year of grass-clover instead of a faba bean crop. The grass-clover biomass was incorporated in the soil in the ‘Mulching’ rotation and removed and used for biogas production in the ‘Biogas’ rotation (and residues from biogas production were simulated to be returned to the field). A method was suggested for allocating effects of fertility building crops in life cycle assessments. The results showed significantly lower carbon footprint of the crops from the ‘Biogas’ rotation (assuming that biogas replaces fossil gas) whereas the remaining crop rotations had comparable carbon footprints per kg cash crop. The study showed considerable contributions caused by the green manure crop (grass-clover) and highlights the importance of analysing the whole crop rotation and including soil carbon changes when estimating carbon footprints of organic crops especially where green manure crops are included.

Knudsen, Marie Trydeman; Meyer-Aurich, A

2013-01-01

 
 
 
 
21

Optimal weed management in crop rotations: incorporating economics is crucial  

UK PubMed Central (United Kingdom)

Optimal weed management in crop rotations: incorporating economics is crucial. Weed Research50, 413-424. Although the effects of crop rotation sequence and length on weed population dynamics have been studied, it is not clear whether or not the best strategy, from a weed population dynamics point of view, is also the economic optimal strategy. It is also not clear which biological and economic parameters are most important in determining this optimal strategy. We use a density-dependent periodic matrix model, integrated with an economic model, to study the effect of rotation length and weed control on the average annual net profit (ANP). The system of the weed Persicaria maculosa in carrots (crop A) and spring wheat (crop B) is used as an example case study. The bio-economic model shows that income is roughly constant with rotation length, apart from the shortest rotation sequence. These results are in agreement with a previous model study, which was restricted to biological dynamics. However, where the purely biological model suggests that weeding effort should be focussed on spring wheat years in the rotation, our bio-economic model shows that this is not a viable economic strategy. In fact, the mean ANP over a rotation is mainly determined by the ANP in carrot years (where the gross margin is high) and depends on the balance between the increase in seed population density in carrot years and its decrease in wheat years, in combination with weeding costs. The model can easily be extended to incorporate other damaging organisms, making the model broadly suitable for analysing a range of weed management strategies from an economic perspective.

VAN DEN BERG F; GILLIGAN CA; GERDESSEN JC; GREGOIRE LAH; VAN DEN BOSCH F

2010-10-01

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Lucratividade e risco de sistemas de manejo de solo e de rotação e sucessão de culturas Profitability and risk of soil tillage and crop rotation and succession systems  

Directory of Open Access Journals (Sweden)

Full Text Available Sistemas de rotação e de sucessão de culturas reduzem o nível de risco pela diversificação da produção. De 1994/95 a 1997/98, foram avaliados sistemas de manejo de solo e de rotação e sucessão de culturas, em Passo Fundo, RS. Os tratamentos consistiram em quatro sistemas de manejo de solo - 1) plantio direto, 2) cultivo mínimo, 3) preparo convencional de solo com arado de discos e 4) preparo convencional de solo com arado de aivecas - em três sistemas de rotação e sucessão de culturas: sistema I (trigo/soja), sistema II (trigo/soja e ervilhaca/sorgo ou milho) e sistema III (trigo/soja, ervilhaca/sorgo ou milho e aveia branca/soja). O delineamento experimental foi em blocos ao acaso, com parcelas subdivididas e três repetições. A parcela principal foi constituída pelos sistemas de manejo de solo e as subparcelas pelos sistemas de rotação e sucessão de culturas. Foram aplicados à receita líquida nos sistemas de manejo de solo e de rotação e sucessão de culturas dois tipos de análise: análise da média variância e análise de risco. Pela análise da média variância, foi possível separar o plantio direto e o cultivo mínimo como as melhores alternativas a serem oferecidas ao agricultor, por apresentarem maior lucratividade. Pela análise da dominância estocástica, foi possível separar o plantio direto e a rotação de culturas com dois invernos sem trigo como os tratamentos mais lucrativos e de menor risco.Crop rotation and succession systems lesser the risk level due to diversification of cultivities. Soil tillage and crop rotation and succession systems were assessed in Passo Fundo, RS, Brazil, from 1994/95 to 1997/98. Four soil tillage systems - 1) no-tillage, 2) minimum tillage, 3) conventional tillage using a disk plow, and 4) conventional tillage using a moldboard plow - and three crop rotation and succession systems [system I (wheat/soybean), system II (wheat/soybean and common vetch/sorghum or corn), and system III (wheat/soybean, common vetch/sorghum or corn, and white oats/soybean)] were compared. An experimental design of randomized blocks with split-plots and three replications was used. The main plot was formed by the soil tillage systems, while the split-plots consisted of the crop rotation and succession systems. Two types of analysis were applied to the net return of soil tillage and crop rotation and succession systems: mean-variance and risk analysis. By the mean-variance analysis, no-tillage and minimum tillage, which presented higher net return, were the best alternatives to be offered to the farmer. By the stochastic dominance analysis, no-tillage and crop rotation with two winters without wheat showed the highest profit and the lowest risk.

Henrique Pereira dos Santos; Ivo Ambrosi; Julio Cesar Barreneche Lhamby; Cristiano do Carmo

2004-01-01

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Tropical rotation crops influence nematode densities and vegetable yields.  

UK PubMed Central (United Kingdom)

The effects of eight summer rotation crops on nematode densities and yields of subsequent spring vegetable crops were determined in field studies conducted in north Florida from 1991 to 1993. The crop sequence was as follows: (i) rotation crops during summer 1991; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) 'Lemondrop L' squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) 'Classic' eggplant (Solanum melongena) during spring 1993. The eight summer crop rotation treatments were as follows: 'Hale' castor (Ricinus communis), velvetbean (Mucuna deeringiana), sesame (Sesamum indicum), American jointvetch (Aeschynomene americana), weed fallow, 'SX- 17' sorghum-sudangrass (Sorghum bicolor x S. sudanense), 'Kirby' soybean (Glycine max), and 'Clemson Spineless' okra (Hibiscus esculentus) as a control. Rotations with castor, velvetbean, American jointvetch, and sorghum-sudangrass were most effective in maintaining the lowest population densities of Meloidogyne spp. (a mixture of M. incognita race 1 and M. arenaria race 1), but Paratrichodorus minor built up in the sorghum-sudangrass rotation. Yield of squash was lower (P rotation crops evaluated here may be useful for managing nematodes in the field and for improving yields of subsequent vegetable crops.

McSorley R; Dickson DW; de Brito JA; Hochmuth RC

1994-09-01

24

Tropical rotation crops influence nematode densities and vegetable yields.  

Science.gov (United States)

The effects of eight summer rotation crops on nematode densities and yields of subsequent spring vegetable crops were determined in field studies conducted in north Florida from 1991 to 1993. The crop sequence was as follows: (i) rotation crops during summer 1991; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) 'Lemondrop L' squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) 'Classic' eggplant (Solanum melongena) during spring 1993. The eight summer crop rotation treatments were as follows: 'Hale' castor (Ricinus communis), velvetbean (Mucuna deeringiana), sesame (Sesamum indicum), American jointvetch (Aeschynomene americana), weed fallow, 'SX- 17' sorghum-sudangrass (Sorghum bicolor x S. sudanense), 'Kirby' soybean (Glycine max), and 'Clemson Spineless' okra (Hibiscus esculentus) as a control. Rotations with castor, velvetbean, American jointvetch, and sorghum-sudangrass were most effective in maintaining the lowest population densities of Meloidogyne spp. (a mixture of M. incognita race 1 and M. arenaria race 1), but Paratrichodorus minor built up in the sorghum-sudangrass rotation. Yield of squash was lower (P rotation crops evaluated here may be useful for managing nematodes in the field and for improving yields of subsequent vegetable crops. PMID:19279897

McSorley, R; Dickson, D W; de Brito, J A; Hochmuth, R C

1994-09-01

25

Management of Verticillium wilt with disease-suppressive crop rotations  

Science.gov (United States)

The ability of potential disease-suppressive rotation crops to reduce potato disease problems and increase crop productivity in a field severely infested with Verticillium wilt was evaluated over three field seasons in Maine. Disease-suppressive rotation treatments consisted of 1) a high glucosinola...

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Weed management in short rotation poplar and herbaceous perennial crops grown for biofuel production  

Energy Technology Data Exchange (ETDEWEB)

Weed management is a key element of any crop production system. Weeds are a particular problem in the production of short rotation woody and perennial herbaceous biomass crops due to the shortage of registered herbicides and integrated weed management systems. Herbicides will be an important component of weed management of biomass crops. However, producers should take a broader view of weeds and incorporate all available weed management tactics in these production systems. In both short rotation poplar and herbaceous perennial crops, weed control during the establishment period is most critical. New plantings of these species grow very slowly and do not compete well with weeds until a canopy develops. Effective weed control can double the growth of short rotation poplar crops and affect the variability of the resulting stand. In crops like switchgrass, uncontrolled weeds during establishment can result in stand failure. Cultural practices such as site preparation, using weed-free seed, fallowing, selecting the proper planting dates, companion crops and controlling weeds in previous crops must be combined with herbicides to develop integrated management systems. Weeds may also cause problems in established stands through competition with the biomass crop and by contaminating the product. Effective and economical weed management systems will be essential for the development of short rotation woody and herbaceous perennial biomass crop production systems. (Author)

Buhler, D.D. [USDA-Agricultural Research Service National Soil Tilth Lab., Ames, IA (United States); Netzer, D.A.; Riemenschneider, D.E. [USDA-Forest Service, Forestry Sciences Lab., Rhinelander, WI (United States); Hartzler, R.G. [Iowa State Univ., Ames, IA (United States). Dept. of Agrimony

1998-12-31

27

Rotação de culturas para cevada, após dez anos: efeitos na fertilidade do solo Crop rotation systems for barley, after ten years: effects on soil fertiliy  

Directory of Open Access Journals (Sweden)

Full Text Available A fertilidade do solo foi avaliada, após dez anos (1984 a 1994), num latossolo bruno álico, em Guarapuava, PR, Brasil, em quatro sistemas de rotação de culturas para cevada: sistema I (cevada/ soja); sistema II (cevada/soja e ervilhaca/milho, de 1984 a 1989, e cevada/soja e aveia branca/soja, de 1990 a 1993); sistema III (cevada/soja, linho/soja e ervilhaca/milho, de 1984 a 1989, e cevada/soja, ervilhaca/milho e aveia branca/soja, de 1990 a 1993); e sistema IV (cevada/soja, linho/soja, aveia branca/soja e ervilhaca/milho). Através de contrastes, foram comparados os sistemas e as profundidades de amostragem de solo. Os sistemas de rotação de culturas para cevada, sob plantio direto, elevaram os valores de matéria orgânica, de P e de K, principalmente na camada 0 a 5cm. Os valores de pH, de Ca+Mg, de matéria orgânica, de P e de K foram mais elevados na camada 0 a 5cm, em comparação aos verificados na camada 15 a 20cm. Tendência inversa foi observada para os teores de Al trocável.Soil fertility parameters were evaluated after ten years (1984 to 1994) of no-tiliage cropping in a latossolo bruno álico, in Guarapuava, state of Paraná, Brazil, under four barley crop rotation systems as follows: system I (barley/soybean); system II (barley/soybean and common vetch/corn, from 1984 to 1989, and barley/soybean and white oats/soybean, from 1990 to 1993); system III (barley/soybean, flax/soybean, and common vetch/corn, from 1984 to 1989, and barley/soybean, common vetch/corn, and white oats/soybean, from 1990 to 1993); and system IV (barley/soybean, flax/soybean, white oats/ soybean and common vetch/corn). Crop systems and soil samples at dijferent depths were compared using the contrast procedure. Barley crop rotation systems, under no-till, raised organic matter. P, and K contents, chiefly in the 0 to 5cm layer. Higher pH and Ca+Mg values were observed in the soil layer 0 to 5cm, as compared to the 15 to 20cm layer. The opposite was observed for exchangeable Al contents.

Henrique Pereira dos Santos; Gilberto Ormar Tomm

1998-01-01

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Atributos físicos do solo em sistemas de manejo de solo e de rotação de culturas Soil tillage and crop rotation systems on the soil physical attributes  

Directory of Open Access Journals (Sweden)

Full Text Available A compreensão e a quantificação do impacto do uso e manejo do solo na qualidade física são fundamentais no desenvolvimento de sistemas agrícolas sustentáveis. Com o objetivo de avaliar o efeito de sistemas de manejo de solo e de rotação de culturas sobre alguns atributos físicos de solo em um experimento instalado em 1985, em Latossolo Vermelho Distrófico típico argiloso, em Passo Fundo (RS), estudou-se a variação desses atributos entre 2001 e 2005. Os tratamentos consistiram de quatro modos de manejo de solo: 1) plantio direto (PD); 2) cultivo mínimo (CM); 3) preparo convencional de solo com arado e grade de discos (PCD) e 4) preparo convencional de solo com arado de aivecas e grade de discos (PCA), e três sistemas de rotação de culturas: I (trigo/soja), II (trigo/soja e ervilhaca/milho ou sorgo) e III (trigo/soja, aveia branca/soja e ervilhaca/milho ou sorgo). O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. A parcela foi constituída pelos sistemas de manejo de solo, e as subparcelas, pelos sistemas de rotação de culturas. Amostras de solo também foram coletadas em um fragmento de floresta subtropical adjacente ao experimento, como testemunha da condição original do solo. Os sistemas de manejo e de rotação de culturas influenciaram os atributos físicos do solo quando comparados entre si e com a condição sob floresta subtropical. Em quatro anos (2001 a 2005) ocorreram alterações significativas nos atributos físicos dos solos entre os distintos tipos de manejo. No sistema PD houve maior densidade de solo e microporosidade em comparação aos demais, principalmente na camada subsuperficial, e os sistemas de rotação de plantas não afetaram positivamente os atributos físicos de solo independentemente do tipo de manejo.Evaluation and quantification of soil use impact on its physical quality are important to achieve sustainable cropping systems. Soil physical attributes were assessed after twenty years of implementation (1985 to 2005) on a typical Dystrophic Red Latosol (Rodic Hapludox) located in Passo Fundo, Rio Grande do Sul State, Brazil. Four soil tillage systems were evaluated: 1) no-tillage; 2) minimum tillage; 3) conventional tillage using a disk plow plus disk harrow, and 4) conventional tillage using a moldboard plow plus disk harrow. Three crop rotation systems were evaluated: I (wheat/soybean), II (wheat/soybean and common vetch/corn or sorghum), and III (wheat/soybean, common vetch/corn or sorghum and white oats/soybean). A randomized complete block design, with split-plots and three replicates, was used. The main plots were formed by the soil tillage systems, while split-plots were composed by crop rotation systems. As control, soil samples were collected in a subtropical forest fragment adjacent to the experiment. Soil tillage systems and crop rotation systems influenced soil physical parameters when compared to the samples collected in a fragment of subtropical forest. During four years (2001 to 2005) the physical attributes were altered among different soil tillage management. The no-tillage system (PD) presented higher soil bulk density and microporosity in comparison to the other systems, mainly in 0.10 to 0.15 m layer, characterizing high soil compaction levels. Crop systems did not promote favorable changes in physical attributes independent of the type of soil management.

Silvio Tulio Spera; Henrique Pereira dos Santos; Gilberto Omar Tomm; Rainoldo Alberto Kochhann; Alexandre Ávila

2009-01-01

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The role of short-rotation woody crops in sustainable development  

International Nuclear Information System (INIS)

[en] One answer to increase wood production is by increasing management intensity on existing timberland, especially in plantation forests. Another is to convert land currently in agriculture to timberland. Short-rotation woody crops can be used in both cases. But, what are the environmental consequences? Short-rotation woody crops can provide a net improvement in environmental quality at both local and global scales. Conversion of agricultural land to short-rotation woody crops can provide the most environmental quality enhancement by reducing erosion, improving soil quality, decreasing runoff, improving groundwater quality, and providing better wildlife habitat. Forest products companies can use increased production from intensively managed short-rotation woody crop systems to offset decreased yield from the portion of their timberland that is managed less intensively, e.g. streamside management zones and other ecologically sensitive or unique areas. At the global scale, use of short-rotation woody crops for bioenergy is part of the solution to reduce greenhouse gases produced by burning fossil fuels. Incorporating short-rotation woody crops into the agricultural landscape also increases storage of carbon in the soil, thus reducing atmospheric concentrations. In addition, use of wood instead of alternatives such as steel, concrete, and plastics generally consumes less energy and produces less greenhouse gases. Cooperative research can be used to achieve energy, fiber, and environmental goals. This paper will highlight several examples of ongoing cooperative research projects that seek to enhance the environmental aspects of short-rotation woody crop systems. Government, industry, and academia are conducting research to study soil quality, use of mill residuals, nutrients in runoff and groundwater, and wildlife use of short-rotation woody crop systems in order to assure the role of short-rotation crops as a sustainable way of meeting society's needs

1996-01-01

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Effects of crop rotation and tillage on blackleg disease of canola.  

UK PubMed Central (United Kingdom)

The effects of a 4-year crop rotation and two tillage systems on blackleg (Leptosphaeria maculans) disease of canola were determined in a field experiment carried out from 1999 through 2002 at Carman, Manitoba. Crops in rotation were canola (Brassica napus) (C), wheat (Triticum aestivum) (W), and flax (Linum usitatissimum) (F). Rotations were done under conventional tillage (T) or zero-till (Z) systems. Diseased stem incidence and severity were assessed. Diseased stem incidence and severity in 2001 and 2002 were significantly lower when canola was rotated with wheat, and rotated with wheat and flax under both tillage systems. The CCCCT rotation had a higher disease incidence than CWCCT, CWFCT, and CCWCT rotations, which were not significantly different from each other. Zero-till plots had significantly greater diseased stem incidence and severity than tilled plots, with or without rotation. Tillage reduced the disease when it was performed with a simple-crop rotation; however, the effect was reduced with a two-crop rotation. The results suggest that an appropriate rotation and tillage strategy could be effective in reducing the severity of blackleg of canola in farmers' fields.

Guo XW; Fernando WGD; Entz M

2005-01-01

31

The Effect of Tillage System and Crop Rotation on Soil Microbial Diversity and Composition in a Subtropical Acrisol  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Agricultural management alters physical and chemical soil properties, which directly affects microbial life strategies and community composition. The microbial community drives important nutrient cycling processes that can influence soil quality, cropping productivity and environmental sustainabilit...

Patricia Dorr de Quadros; Kateryna Zhalnina; Austin Davis-Richardson; Jennie R. Fagen; Jennifer Drew; Cimelio Bayer

32

Evaluation of Maize Yield in an On-Farm Maize-Soybean and Maize-Lablab Crop Rotation Systems in the Northern Guinea Savanna of Nigeria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An attempt was made to solving the problem of shortfall of fertilizer to maize production in the Northern Guinea Savanna (NGS) of Nigeria by harnessing the potentials of legume/cereal crop rotation in on-farm trials. The yield of maize that succeeded two soybean varieties and Lablab in a two-...

J.A. Okogun; N. Sanginga; R.C. Abaidoo

33

Crop rotation biomass and arbuscular mycorrhizal fungi effects on sugarcane yield  

Energy Technology Data Exchange (ETDEWEB)

Sugarcane (Saccharum spp.) is an important crop for sugar production and agro-energy purposes in Brazil. In the sugarcane production system after a 4- to 8-year cycle crop rotation may be used before replanting sugarcane to improve soil conditions and give an extra income. This study had the objective of characterizing the biomass and the natural colonization of arbuscular mycorrhizal fungi (AMF) of leguminous green manure and sunflower (Helianthus annuus L.) in rotation with sugarcane. Their effect on stalk and sugar yield of sugarcane cv. IAC 87-3396 grown subsequently was also studied. Cane yield was harvested in three subsequent cuttings. Peanut cv. IAC-Caiapo, sunflower cv. IAC-Uruguai and velvet bean (Mucuna aterrimum Piper and Tracy) were the rotational crops that resulted in the greater percentage of AMF. Sunflower was the specie that most extracted nutrients from the soil, followed by peanut cv. IAC-Tatu and mung bean (Vigna radiata L. Wilczek). The colonization with AMF had a positive correlation with sugarcane plant height, at the first cut (p = 0.01 and R = 0.52) but not with the stalk or cane yields. Sunflower was the rotational crop that brought about the greatest yield increase of the subsequent sugarcane crop: 46% increase in stalk yield and 50% in sugar yield compared with the control. Except for both peanut varieties, all rotational crops caused an increase in net income of the cropping system in the average of three sugarcane harvests. (author)

Ambrosano, Edmilson Jose; Rossi, Fabricio; Guirado, Nivaldo; Teramoto, Juliana Rolim Salome [Agencia Paulista de Tecnologia dos Agronegocios (APTA), Piracicaba, SP (Brazil). Polo Regional Centro Sul; Azcon, Rozario [Consejo Superior de Investigaciones Cientificas (CSIC), Granada (Spain). Estacao Experimental de Zaidin; Cantarela, Heitor [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IAC), Campinas, SP (Brazil). Inst. Agronomico. Centro de Solos e Recursos Ambientais; Ambrosano, Glaucia Maria Bovi [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Fac. de Odontologia. Dept. de Odontologia Social], Email: ambrosano@apta.sp.gov.br; Schammass, Eliana Aparecida [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IZ), Nova Odessa, SP (Brazil). Inst. de Zootecnia; Muraoka, Takashi; Trivelin, Paulo Cesar Ocheuze [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Ungaro, Maria Regina Goncalves [Agencia Paulista de Tecnologia dos Agronegocios (APTA/IAC), Campinas, SP (Brazil). Inst. Agronomico. Centro de Plantas Graniferas

2010-07-01

34

Cereal-forage crop rotations and irrigation treatment effect on water use efficiency and crops sustainability in Mediterranean environment  

Directory of Open Access Journals (Sweden)

Full Text Available Agricultural systems based on crop rotations favour sustainability of cultivation and productivity of the crops. Wheat-forage crops rotations (annual winter binary mixture and perennial alfalfa meadow) combined with irrigation are the agronomical techniques able to better exploit the weather resources in Mediterranean environments. The experiment aimed to study the effect of 18 years of combined effect of irrigation and continuous durum wheat and wheat-forage rotations on productivities of crops and organic matter of topsoil. The experiments were established through 1991-2008 under rainfed and irrigated treatments and emphasized on the effect of irrigation and continuous wheat and wheat-forage crop rotations on water use efficiency and sustainability of organic matter. The effect of irrigation increased 49.1% and 66.9% the dry matter of mixture and meadow, respectively. Continuous wheat rotation reduced seed yield, stability of production, crude protein characteristics of kernel and soil organic matter. The yearly gain in wheat after forage crops was 0.04 t (ha·yr)-1 under rainfed and 0.07 t (ha·yr)-1 under irrigation treatments. The crude protein and soil organic matter of wheat rotations, compared to those of continuous wheat under rainfed and irrigated was increase in term of point percentage by 0.8 and 0.5 in crude protein and 5.1 and 4.4 in organic matter, respectively. The rotations of mixture and meadow under both irrigated treatments increased the point of percentage of organic matter over continuous wheat (9.3.and 8.5 in mixture and 12.5 and 9.5 meadow under rainfed and irrigation, respectively). Irrigation reduce the impact of weather on crop growing reducing water use efficiency (mean over rotations) for dry mater production (15.5 in meadow and 17.5 in mixture [L water (kg·dry·matter)-1 ]) and wheat seed yield. The effect of agronomic advantages achieved by forage crops in topsoil expire its effect after three years of continuous wheat rotation.

Pasquale Martiniello

2012-01-01

35

Environmental enhancement using short-rotation woody crops and perennial grasses as alternative agricultural crops  

Energy Technology Data Exchange (ETDEWEB)

Short-rotation woody crops and perennial grasses are grown as biomass feedstocks for energy and fiber. When replacing traditional row crops on similar lands, these alternative crops can provide multiple environmental benefits in addition to enhancing rural economies and providing valuable feedstock resources. The Department of Energy is supporting research to address how these crops can provide environmental benefits to soil, water and native wildlife species in addition to providing bioenergy feedstocks. Research is underway to address the potential for biomass crops to provide soil conservation and water quality improvements in crop settings. Replacement of traditional erosive row crops with biomass crops on marginal lands and establishment of biomass plantations as filter strips adjacent to streams and wetlands are being studied. The habitat value of different biomass crops for selected wildlife species is also under study. To date, these studies have shown that in comparison with row crops biomass plantings of both grass and tree crops increased biodiversity of birds; however, the habitat value of tree plantations is not equivalent to natural forests. The effects on native wildlife of establishing multiple plantations across a landscape are being studied. Combining findings on wildlife use of individual plantations with information on the cumulative effects of multiple plantations on wildlife populations can provide guidance for establishing and managing biomass crops to enhance biodiversity while providing biomass feedstocks. Data from site-specific environmental studies can provide input for evaluation of the probable effects of large-scale plantings at both landscape and regional levels of resolution.

Tolbert, V.R. [Oak Ridge National Lab., TN (United States); Schiller, A. [Oak Ridge Inst. for Science and Education, TN (United States)

1995-12-31

36

Short-Rotation Woody-Crops Program. Annual progress report for 1981  

Energy Technology Data Exchange (ETDEWEB)

This report is a summary of work sponsored by the US Department of Energy in the Short Rotation Woody Crops Program. The program is concerned with new wood production techniques that attain high productivity levels. Sometimes known as short rotation intensive culture, experimentation concentrated on hardwood tree species that stump sprout and can be re-harvested every 3 to 10 years. Research focused on the screening of fastgrowing species and techniques of short-rotation wood crop management, although plant propagation, new wood recovery systems, and economic evaluations are within the scope of the program. The program's objective is to attain high productivity rates at competitive prices.

Ranney, J.W.; Cushman, J.H.

1982-07-01

37

CROPPING SYSTEMS FOR MANAGING WEEDS  

UK PubMed Central (United Kingdom)

The invention provides cropping systems for managing weeds in crop environments. The cropping systems comprise, in one embodiment, transgenic plants that display tolerance to an auxin-like herbicide such as dicamba. Method for minimizing the development of herbicide resistant weeds are also provided.

ARNEVIK CINDY L; BRINKER RONALD J; ELMORE GREG; GRAHAM JAMES C; SAMMONS ROBERT D; STARKE MICHELLE; VOTH RICHARD D

38

Sustainable soil fertility management in Westsik's crop rotation experiment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

High input agriculture is relatively new in Hungary. Crop rotation was introduced in the XIX. century, extensive use of chemical fertilisers and pesticides became important only in the second half of the last century. Agricultural production has become efficient per unit of human labour and per unit...

Rusu, Mihai Cornel; Lazányi János (1951-) (mez?gazdász)

39

Evaluation of Maize Yield in an On-Farm Maize-Soybean and Maize-Lablab Crop Rotation Systems in the Northern Guinea Savanna of Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available An attempt was made to solving the problem of shortfall of fertilizer to maize production in the Northern Guinea Savanna (NGS) of Nigeria by harnessing the potentials of legume/cereal crop rotation in on-farm trials. The yield of maize that succeeded two soybean varieties and Lablab in a two-cycle of soybean/maize and Lablab/maize crop rotation in NGS Nigeria was assessed in researcher-managed and farmer-managed plots. Though maize that followed the soybean received between 5 kg N ha-1 from improved soybean variety (TGx 1448-2E) and 17 kg N ha-1 from farmer soybean variety (Samsoy-2) as N balance, this did not significantly (p = 0.05) affect the maize yields. The soybean shed 90-100% of its leaves at physiological maturity which resulted in about 110 kg N ha-1 N uptake. This source of N might be one of the factors responsible for the increase in maize yield that followed soybean (20 to 24%) compared with continuous maize yield plot. Maize yield in previous Lablab plot was significantly (p = 0.05) higher than in all other treatments. Maize yield in farmer-managed plot ranged between 0.13 and 4.53 t ha-1, maize yield in researcher-managed plot was over 200% higher than maize yield in farmer-managed plot because of poor crop management on the part of the farmer.

J.A. Okogun; N. Sanginga; R.C. Abaidoo

2007-01-01

40

Effect of Crop Rotation on the Soil Pathogen Population Dynamics and Canola Seedling Establishment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Impact of long-term crop rotations on populations of soilborne pathogens in the genera Fusarium, Pythium and Rhizoctonia and on canola seedling establishment and development was evaluated under controlled conditions. Soil samples were collected from two crop rotation experiments...

S.F. Hwang; H.U. Ahmed; B.D. Gossen; H.R. Kutcher; S.A. Brandt; S.E. Strelkov; K.F. Chang; G.D. Turnbull

 
 
 
 
41

Environmental enhancement using short-rotation woody crops and perennial grasses as alternative agricultural crops  

Energy Technology Data Exchange (ETDEWEB)

Short-rotation woody crops and perennial grasses are grown as biomass feedstocks for energy and fiber. When replacing traditional row crops on similar lands, these alternative crops can provide multiple environmental benefits in addition to enhancing rural economies and providing valuable resources. The DOE is supporting research to address how these crops can provide environmental benefits to soil, water, and native wildlife species in addition to providing bioenergy feedstocks. Research is underway to address the potential for biomass crops to provide soils conservation and water quality improvements in crop settings. Replacement of traditional erosive row drops with biomass crops on marginal lands and establishment of biomass plantations as filter strips adjacent to streams and wetlands are being studied. The habitat value of different crops for wildlife species is also considered. Combining findings on wildlife use of individual plantations with information on the cumulative effects of multiple plantations on wildlife populations can provide guidance for establishing and managing biomass crops to enhance biodiversity while providing feedstocks. Data from site-specific environmental studies can provide input for evaluation of the effects of large-scale plantings at both landscape and regional levels of resolution.

Tolbert, V.R. [Oak Ridge National Lab., TN (United States); Schiller, A. [Oak Ridge Inst. for Science and Education, TN (United States)

1996-10-01

42

Evolution of crop yields in different tillage and cropping systems over two decades in southern Brazil  

UK PubMed Central (United Kingdom)

In the last three decades, the no-tillage system (NT) has provided environmental and economic advantages for farming in southern Brazil, especially when associated with crop rotation. The objective of this study was to evaluate the effects of different tillage and cropping systems on the grain yields of soybean, maize and wheat, in a 23-year experiment established on an Oxisol in the southern region of Brazil. The experiment was carried out in randomized block experimental design with four replications. The treatments consisted of three tillage systems [NT, NT with chiseling every three years (NTC), and conventional tillage (CT)] and two cropping systems [an annual crop sequence with wheat in the winter and soybean in the summer, designated as crop succession (CS), and a 4-year crop rotation with the following species in winter–summer, respectively: white lupine–maize; black oat–soybean; wheat–soybean; and wheat–soybean (CR)]. Soybean yields were correlated to the water requirement satisfaction index (WRSI) estimated for the soybean reproductive period. With few exceptions, the NT showed higher soybean yields in relation to CT from the 7th year of the experiment onwards, especially under crop rotation and in growing seasons with lower water availability expressed by lower WRSI values. The percentage of NT soybean yield advantage over CT increased consistently over the time, and this increase was greater in CR than in CS, reaching on average 23%. The yields of wheat and maize were not influenced by the tillage systems, but the wheat yields were increased by crop rotation. In the most of the growing seasons, the soil chiseling, at every three years, did not increase significantly the yields of soybean, maize and wheat. Crop rotation and NT, allowed high and stable crop yields, especially under water-stress conditions. Results indicate the need of minimizing soil disturbance and diversifying cropping system for sustainable grain production in southern Brazil.

Franchini JC; Debiasi H; Balbinot Junior AA; Tonon BC; Farias JRB; Oliveira MCNd; Torres E

2012-10-01

43

Irrigation treatments, water use efficiency and crop sustainability in cereal-forage rotations in Mediterranean environment  

Directory of Open Access Journals (Sweden)

Full Text Available Agricultural systems based on crop rotation are beneficial to crop sustainability and productivity. Wheat-forage rotations combined with irrigation are the agronomic techniques best able to exploit Mediterranean environmental conditions. This paper describes a long-term field trial to ascertain the effect of combined irrigation and durum wheat-forage rotations on crop yield and soil chemical properties. The two forage crops: annual grass-clover winter binary mixture and perennial lucerne were carried out through 1991-2008 under rainfed and irrigated treatments. The experiments were used to highlight the effect of irrigation and wheat-forage crop rotations on water use efficiency (WUE) and sustainability of organic matter (OM) in topsoil. Irrigation increased the dry matter (DM) of annual binary mixture and lucerne by 49.1% and 66.9%, respectively. Continuous wheat rotation reduced seed yield (SY), stability of production, and crude protein (CP) characteristics of kernel and OM in topsoil. The yearly gain in wheat after forage crops was 0.04 t (ha yr)-1 under rainfed and 0.07 t (ha yr)-1 under irrigation treatments. The CP and soil OM of wheat forage crops rotations, compared with those of continuous wheat under rainfed and irrigated was a 0.8 and 0.5 % increase in CP and 5.1 and 4.4 in OM, respectively. The rotations of annual grass-clover winter binary mixture and lucerne meadow under both irrigated treatments increased the OM over continuous wheat (9.3 % and 8.5 in annual grass-clover winter binary mixture and 12.5 and 9.5 lucerne meadow under rainfed and irrigation, respectively). Irrigation reduced the impact of weather on crop growing, reducing water use efficiency (mean over rotations) for DM production (15.5 in meadow and 17.5 in annual grass-clover winter binary mixture [L water (kg DM)-1]) and wheat SY. However, the agronomic benefits achieved by forage crops in topsoil are exhausted after three years of continuous wheat rotation.

Pasquale Martiniello; Giovanni Annichiarico; Salvatore Claps

2012-01-01

44

Effect of crop rotation on populations of Epitrix tuberis (Coleoptera: Chrysomelidae) in potato.  

UK PubMed Central (United Kingdom)

The effect of crop rotation on populations of tuber flea beetle, Epitrix tuberis Gentner, in potatoes was investigated using data supplied by an integrated pest management (IPM) company and Geographic Information System software and conventional statistical methods. Using combined 1995 and 1996 data, beetles of the overwintered and F1 generations in both the interior and edges of potato fields showed a significant linear increase with an increase in the preceding consecutive years (0, 1, and 2 years) that the current years' crop was planted to potatoes. Populations were significantly higher in nonrotated fields compared with rotated fields. Both the percentage of the cropping region requiring insecticidal control of tuber flea beetles and the cost of insecticides per hectare of potatoes grown increased linearly with an increase in the number of previous years planted to potatoes. Not practicing crop rotation resulted in a 4.2-7.3% increase in the cropping region requiring insecticidal control of tuber flea beetles. The cost of controlling beetles in potato fields planted to potatoes for 3 consecutive years was up to $20/ha greater than potatoes rotated from the preceding year. Beetle counts from the interior of rotated potato fields never exceeded threshold levels when field edges also were below threshold. It is concluded that sampling of overwintered beetles in interior sites of rotated fields could be abandoned, and only 1 monitoring scout rather than 2 would be necessary to monitor a field during this time. From these results, we concluded that rotating potato crops would reduce spray costs to the farmer and monitoring costs to IPM companies.

Kabaluk JT; Vernon RS

2000-04-01

45

Effect of crop rotation on populations of Epitrix tuberis (Coleoptera: Chrysomelidae) in potato.  

Science.gov (United States)

The effect of crop rotation on populations of tuber flea beetle, Epitrix tuberis Gentner, in potatoes was investigated using data supplied by an integrated pest management (IPM) company and Geographic Information System software and conventional statistical methods. Using combined 1995 and 1996 data, beetles of the overwintered and F1 generations in both the interior and edges of potato fields showed a significant linear increase with an increase in the preceding consecutive years (0, 1, and 2 years) that the current years' crop was planted to potatoes. Populations were significantly higher in nonrotated fields compared with rotated fields. Both the percentage of the cropping region requiring insecticidal control of tuber flea beetles and the cost of insecticides per hectare of potatoes grown increased linearly with an increase in the number of previous years planted to potatoes. Not practicing crop rotation resulted in a 4.2-7.3% increase in the cropping region requiring insecticidal control of tuber flea beetles. The cost of controlling beetles in potato fields planted to potatoes for 3 consecutive years was up to $20/ha greater than potatoes rotated from the preceding year. Beetle counts from the interior of rotated potato fields never exceeded threshold levels when field edges also were below threshold. It is concluded that sampling of overwintered beetles in interior sites of rotated fields could be abandoned, and only 1 monitoring scout rather than 2 would be necessary to monitor a field during this time. From these results, we concluded that rotating potato crops would reduce spray costs to the farmer and monitoring costs to IPM companies. PMID:10826179

Kabaluk, J T; Vernon, R S

2000-04-01

46

Short rotation woody crops: Using agroforestry technology for energy in the United States  

International Nuclear Information System (INIS)

[en] Agroforestry in the United States is being primarily defined as the process of using trees in agricultural systems for conservation purposes and multiple products. The type of agroforestry most commonly practiced in many parts of the world, that is the planting of tree crops in combination with food crops or pasture, is the type least commonly practiced in the United States. One type of agroforestry technique, which is beginning now and anticipated to expand to several million acres in the United States, is the planting of short-rotation woody crops (SRWCs) primarily to provide fiber and fuel. Research on SRWC's and environmental concerns are described

1991-10-04

47

Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-RotateN simulation model  

International Nuclear Information System (INIS)

[en] Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-RotateN simulation model. EU-RotateN was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter. - The EU-RotateN model can satisfactorily simulate crop N uptake and Nmin dynamics in a typical greenhouse cucumber production system of North China

2010-01-01

48

Predicting and mitigating the net greenhouse gas emissions of crop rotations in Western Europe  

UK PubMed Central (United Kingdom)

Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases (GHGs) contributing to net greenhouse gas balance of agro-ecosystems. Evaluating the impact of agriculture on climate thus requires capacity to predict the net exchanges of these gases in a systemic approach, as related to environmental conditions and crop management. Here, we used experimental data sets from intensively monitored cropping systems in France and Germany to calibrate and evaluate the ability of the biophysical crop model CERES-EGC to simulate GHG exchanges at the plot-scale. The experiments involved major crop types (maize–wheat–barley–rapeseed) on loam and rendzina soils. The model was subsequently extrapolated to predict CO2 and N2O fluxes over entire crop rotations. Indirect emissions (IE) arising from the production of agricultural inputs and from use of farm machinery were also added to the final greenhouse gas balance. One experimental site (involving a maize–wheat–barley–mustard rotation on a loamy soil) was a net source of GHG with a net GHG balance of 670kgCO2-Ceqha?1yr?1, of which half were due to IE and half to direct N2O emissions. The other site (involving a rapeseed–wheat–barley rotation on a rendzina) was a net sink of GHG for ?650kgCO2-Ceqha?1yr?1, mainly due to high C returns to soil from crop residues. A selection of mitigation options were tested at one experimental site, of which straw return to soils emerged as the most efficient to reduce the net GHG balance of the crop rotation, with a 35% abatement. Halving the rate of N inputs only allowed a 27% reduction in net GHG balance. Removing the organic fertilizer application led to a substantial loss of C for the entire crop rotation that was not compensated by a significant decrease of N2O emissions due to a lower N supply in the system. Agro-ecosystem modeling and scenario analysis may therefore contribute to design productive cropping systems with low GHG emissions.

Lehuger S; Gabrielle B; Laville P; Lamboni M; Loubet B; Cellier P

2011-12-01

49

Management of short rotation coppice crops of Eucalyptus grandis hill ex maiden  

Energy Technology Data Exchange (ETDEWEB)

Three experiments were carried out in the summer rainfall region of South Africa, to compare in short rotations the survival, growth, form and final timber yields of the initial seedling crop of E. grandis with successive coppice crops managed under different systems of coppice thinning. Mean height was not generally affected by the treatments. Three coppice thinning regimes reduced d.b.h. significantly, one increased d.b.h. Early coppice thinning gave significantly greater d.b.h., the largest diameter being obtained when thinning started before the shoots were 4.3 m and only one shoot was retained in the final crop. Retention of 2 shoots per stool in the final crop considerably increased total volume production per ha. (Refs. 12).

Stubbings, J.A.; Schoenau, A.P.G.

1980-01-01

50

The Effects of Weed-Crop Competition on Nutrient Uptake as Affected by Crop Rotation and Fertilizers  

Directory of Open Access Journals (Sweden)

Full Text Available A field study at the Agricultural University of Timiriazev, Moscow, was conducted to determine the effect of crop rotation and Long-term fertilizer application on differences in the competitive ability of spring barley and weeds to nutrient uptake in 2004 and 2005. Spring barley was cultivated in continuous and in crop rotation with winter rye, potato, clover, flax and fallow, with and without NPK application since 1912. Spring barley, especially in no fertilizer plots grown in crop rotation has greater dry mass than spring barley grown in continuous. While dry weed mass markedly decreased in crop rotation. Decrease dry weeds mass was greater when NPK had applied. The statistical analyses show that when spring barley grew in competition with weeds in the no fertilizer plots, crop rotation significantly increased nutrient content in spring barley, but when fertilizer applied the content of N, P2O5 and K2O in barley did not change. Lowest weeds nutrient content observed where soil fertility was increased by crop rotation and NPK application. Crop rotation significantly increased total nutrient uptake of soils by spring barley, but decreased total nutrient uptake by weeds.

Hamid Reza Mohammaddoust-e-Chamanabad Mohammaddoust-e-Chamanabad; Ali Asghari; Aleksander Mikhailovic Tulikov

2007-01-01

51

INFLUÊNCIA DE CULTURAS DE INVERNO SOBRE O RENDIMENTO DE GRÃOS DE SOJA CULTIVADA EM SISTEMAS DE ROTAÇÃO DE CULTURAS INFLUENCE OF WINTER CROPS ON SOYBEAN YIELD IN CROP ROTATION SYSTEMS  

Directory of Open Access Journals (Sweden)

Full Text Available Durante nove anos, avaliou-se o efeito de diferentes culturas antecessoras sobre o rendimento de grãos e sobre a estatura de plantas de soja, na EMBRAPA-Centro Nacional de Pesquisa de Trigo (CNPT), em Passo Fundo, RS. Os tratamentos consistiram em sete sistemas de rotação de culturas, e a soja foi semeada em sucessão à aveia branca, à aveia preta, ao linho e ao trigo. Em 1990, foram adicionadas duas parcelas, uma para completar o sistema II e outra para pousio de inverno antecedendo a soja (sistema VII). As culturas de inverno foram estabelecidas com preparo convencional de solo, e as de verão, em plantio direto. O delineamento experimental foi blocos ao acaso, com três repetições, e parcelas com área útil de 30m². A soja cultivada após linho, na média do período de 1987 a 1989, nos sistemas IV e VI, apresentou menor estatura de plantas e menor rendimento de grãos. Nos períodos de 1990 a 1992 e de 1993 a 1995, não houve diferenças significativas entre tipo de cultura antecessora e rendimento de grãos. A soja cultivada após aveia branca, após aveia preta ou após trigo pode ser incluída, sem prejuízo, nos diferentes sistemas estudados.Different preceding crops on the yield and height of soybean plants was assessed during nine years at EMBRAPA-Centro Nacional de Pesquisa de Trigo (CNPT), in Passo Fundo, RS, Brazil. The treatments consisted of seven crop systems, and soybean was sown in succession to white oat, black oat, flax, and wheat. Two plots were added in 1990; one to complement system II and the other as winter fallow preceding soybean (system VII). Winter crops were set up using conventional soil preparation, and summer crops were sown under no-tillage. An experimental design of blocks at random, with three replications and plots totalling 30m², was used. The grown soybean after flax, in the mean of the period 1987 to 1989, in systems IV and VI showed lower plant on height and lower yield. No significant differences were found on the evoluated preceding crops on the yield over the periods 1990 to 1992 and 1993 to 1995. The grown soybean after white oat, black oat or wheat may be included in the different systems studied without any adverse effect.

Henrique Pereira dos Santos; Julio Cesar Barreneche Lhamby

2001-01-01

52

Carbon storage and recycling in short-rotation energy crops  

International Nuclear Information System (INIS)

[en] Short-rotation energy crops can play a significant role in storing carbon compared to the agricultural land uses they would displace. However, the benefits from these plantations in avoiding further use of fossil fuel and in taking pressure off of native forests for energy uses provides longer term carbon benetfits than the plantation carbon sequestration itself. The fast growth and harvest frequency of plantations tends to limit the amount of above and below-ground carbon storage in them. The primary components of plantation carbon sequestering compared to sustained agricultural practices involve above-ground wood, possible increased soil carbon, litter layer formation, and increased root biomass. On the average, short-rotation plantations in total may increase carbon inventories by about 30 to 40 tonnes per hectare over about a 20- to 56-year period when displacing cropland. This is about doubling in storage over cropland and about one-half the storage in human-impacted forests. The sequestration benefit of wood energy crops over cropland would be negated in about 75 to 100 years by the use of fossil fuels to tend the plantations and handle biomass. Plantation interactions with other land uses and total landscape carbon inventory is important in assessing the relative role plantations play in terrestrial and atmospheric carbon dynamics. It is speculated that plantations, when viewed in this context. could trencrate a global leveling of net carbon emissions for approximately 10 to 20 years

1991-01-01

53

Rotação de culturas para trigo, após quatro anos: efeitos na fertilidade do solo em plantio direto Crop rotation systems for wheat, after four years: effects on soil fertility under no-tillage  

Directory of Open Access Journals (Sweden)

Full Text Available A fertilidade do solo foi avaliada, após quatro anos (1990 a 1994), num latossolo bruno álico, em Guarapuava, PR, Brasil, em quatro sistemas de rotação de culturas para trigo: sistema I (trigo/soja); sistema II (trigo/soja e aveia branca/soja); sistema III (trigo/soja, ervilhaca/ milho e aveia branca/soja); e sistema IV (trigo/soja, aveia branca/soja, cevada/soja e ervilhaca/ milho). As culturas, tanto de inverno como de verão, foram estabelecidas sob plantio direto. O delineamento experimental foi de blocos ao acaso com quatro repetições. Através de contrastes, foram comparados os sistemas e as profundidades de amostragem de solo. Em todos os sistemas de rotação de culturas, na camada de solo 0 a 5cm, observaram-se valores maiores de pH e de Ca+Mg e menores de Al (com exceção do sistema III), em relação à camada 15 a 20cm. Houve elevação dos teores de Ca+Mg, de K e de P na camada de solo com a maior concentração de raízes (0 a 10cm). Os valores de matéria orgânica do solo decresceram progressivamente da camada 0 a 5cm para a camada 15 a 20cm.Soil fertility parameters were evaluated after four years (1990 to 1994) on a alic dusky latosol located in Guarapuava, Paraná, Brazil, under four wheat crop rotation systems as follows: system I (wheat/soybean); system II (wheat/soybean and white oats/soybean); system III (wheat/soybean, common vetch/corn, and white oats/soybean); and system IV (wheat/soybean, white oats/soybean, barley/soybean and common vetch/cor). Both winter and summer crops were seeded under no tillage. A randomized complete block design, with four replications, was used. Crop systems and soil samples at different depths were compared using the contrast procedure. All crop rotation systems, in the 0 to 5cm soil layer, higher values were observed for pH in water and Ca+Mg and lower contents for Al (except system III), as compared to the 15 to 20cm layer. Raising in Ca+Mg, K, and P levels occurred in the soil layer with the greatest root concentration (0 to 10cm). The soil organic matter contents decreased with depth from 0-5cm to 15-20cm.

Henrique Pereira dos Santos; Gilberto Omar Tomm

1999-01-01

54

The Effect of Tobacco Monoculture and Crop Rotations on Tobacco Leaf Composition  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the long-term results relating to the influence of different crop rotations and tobacco monoculture upon the chemical composition of flue-cured tobacco leaf. As a key crop, tobacco is included in all crop rotations. Considering the obtained results in the particular year’s tobacco growing in monoculture or in crop rotation mainly had significant effect on nicotine content in tobacco leaf including a 10-year average. A similar trend was also determined for the content of proteins. The content of total nitrogen and reducing sugars was mainly affected significantly by crop rotation as regards the particular years. Calcium and potassium ratio was also unfavorable, although both of them were significantly influenced by crop rotation. The same is true for magnesium in the particular years.

An?elko Butorac; Ivan Turši?; Milan Mesi?; Jasminka Butorac; Ferdo Baši?; Nikola Vuleti?; Ivica Kisi?; Marijan Berdin

2004-01-01

55

Rotating Aperture System  

Energy Technology Data Exchange (ETDEWEB)

A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.

Rusnak, Brian (Livermore, CA); Hall, James M. (Livermore, CA); Shen, Stewart (Danville, CA); Wood, Richard L. (Santa Fe, NM)

2005-01-18

56

Carbon stock and its compartments in a subtropical oxisol under long-term tillage and crop rotation systems Estoque e compartimentos de carbono em um latossolo vermelho subtropical sob diferentes sistemas de longo prazo de preparo e rotação de culturas  

Directory of Open Access Journals (Sweden)

Full Text Available Soil organic matter (SOM) plays a crucial role in soil quality and can act as an atmospheric C-CO2 sink under conservationist management systems. This study aimed to evaluate the long-term effects (19 years) of tillage (CT-conventional tillage and NT-no tillage) and crop rotations (R0-monoculture system, R1-winter crop rotation, and R2- intensive crop rotation) on total, particulate and mineral-associated organic carbon (C) stocks of an originally degraded Red Oxisol in Cruz Alta, RS, Southern Brazil. The climate is humid subtropical Cfa 2a (Köppen classification), the mean annual precipitation 1,774 mm and mean annual temperature 19.2 ºC. The plots were divided into four segments, of which each was sampled in the layers 0-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30 m. Sampling was performed manually by opening small trenches. The SOM pools were determined by physical fractionation. Soil C stocks had a linear relationship with annual crop C inputs, regardless of the tillage systems. Thus, soil disturbance had a minor effect on SOM turnover. In the 0-0.30 m layer, soil C sequestration ranged from 0 to 0.51 Mg ha-1 yr-1, using the CT R0 treatment as base-line; crop rotation systems had more influence on soil stock C than tillage systems. The mean C sequestration rate of the cropping systems was 0.13 Mg ha-1 yr-1 higher in NT than CT. This result was associated to the higher C input by crops due to the improvement in soil quality under long-term no-tillage. The particulate C fraction was a sensitive indicator of soil management quality, while mineral-associated organic C was the main pool of atmospheric C fixed in this clayey Oxisol. The C retention in this stable SOM fraction accounts for 81 and 89 % of total C sequestration in the treatments NT R1 and NT R2, respectively, in relation to the same cropping systems under CT. The highest C management index was observed in NT R2, confirming the capacity of this soil management practice to improve the soil C stock qualitatively in relation to CT R0. The results highlighted the diversification of crop rotation with cover crops as a crucial strategy for atmospheric C-CO2 sequestration and SOM quality improvement in highly weathered subtropical Oxisols.A matéria orgânica do solo (MOS) desempenha papel relevante na qualidade do solo e pode atuar como dreno de C-CO2 atmosférico em solos sob sistemas de manejo conservacionista. Este estudo foi realizado com o objetivo de investigar o efeito de longo prazo (19 anos) de sistemas de preparo do solo (PC-preparo convencional e PD-plantio direto) e de rotação de culturas (R0- sucessão de monoculturas, R1- rotação de culturas de inverno e R2- rotação intensiva de culturas) no estoque de carbono (C) orgânico total, particulado e associado a minerais de um Latossolo Vermelho, originalmente degradado, do Sul do Brasil. O clima é subtropical úmido Cfa 2, segundo a classificação de Köppen, com média anual de precipitação pluvial de 1.774 mm e média anual de temperatura de 19,2 ºC. As parcelas experimentais foram divididas em três segmentos, e em cada um destes foram coletadas amostras nas profundidades de 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,30 m. As amostras foram coletadas por meio da abertura manual de pequenas trincheiras. O estoque de C no solo apresentou relação linear com o aporte anual de C, independentemente do sistema de preparo investigado. Assim, o preparo do solo teve pequeno efeito no incremento da taxa de decomposição da MOS. Na camada de 0-0,30 m, a taxa de sequestro de C variou de zero a 0,51 Mg ha-1 ano-1 considerando o tratamento CT R0 como referência, sendo a rotação de culturas uma estratégia mais eficiente em determinar o acúmulo de C do que os sistemas de preparo. Na média dos sistemas de cultura, uma taxa de sequestro de C de 0,13 Mg ha-1ano-1 foi observada sob PD em relação ao PC. Isso é claro? Esse resultado foi determinado pelo maior aporte de C proporcionado pela melhoria da qualidade do solo em PD adotado por longo prazo. A fração particulada de C foi um indic

Ben-Hur Costa de Campos; Telmo Jorge Carneiro Amado; Cimélio Bayer; Rodrigo da Silveira Nicoloso; Jackson Ernani Fiorin

2011-01-01

57

Influence of Rotation Crops on the Strawberry Pathogens Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Field microplot, small plot, and greenhouse experiments were conducted to determine the effects of rotation crops on Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae populations. Extraction of P. penetrans from roots and soil in microplots and field plots planted to rotation crop...

LaMondia, J. A.

58

PRE-PLANT CROP ROTATION AND COMPOST AMENDMENTS FOR IMPROVING RASPBERRY ESTABLISHMENT  

Science.gov (United States)

Two preplant treatments, a sorghum x sudangrass hybrid (Sudex) - rapeseed crop rotation, and a preplant compost amendment treatment, were compared to a control corn-barley rotation for alleviating replant problems on a field with a long history of perennial fruit crops. A raspberry selection trial ...

59

Cereal yield and quality as affected by N availability in organic and conventional crop rotations in Denmark  

DEFF Research Database (Denmark)

The effects of nitrogen (N) availability related to fertilizer type, catch crop management, and rotation composition on cereal yield and grain N were investigated in four organic and one conventional cropping systems in Denmark using the FASSET model. The four-year rotation studied was: spring barley–(faba bean or grass-clover)–potato–winter wheat. Experiments were done at three locations representative of the different soil types and climatic conditions in Denmark. The three organic systems that included faba bean as the N fixing crop comprised a system with manure (stored pig slurry) and undersowing catch crops (OF + C + M), a system with manure but without undersowing catch crops (OF ? C + M), and a system without manure and with catch crops (OF + C ? M). A grass-clover green manure was used as N fixing crop in the other organic system with catch crops (OG + C + M). Cuttings of grass-clover were removed from the plots and an equivalent amount of total-N in pig slurry was applied to the cropping system. Theconventional rotation included mineral fertilizer and catch crops (CF + C + F), although only non-legume catch crops were used. Measurements of cereal dry matter (DM) at harvest and of grain N contents were done in all plots. On average the FASSET model was able to predict the yield and grain N of cereals with a reasonable accuracy for the range of cropping systems and soil types studied, having a particularly good performance on winter wheat. Cereal yields were better on the more loamy soil. DM yield and grain N content were mainly influenced by the type and amount of fertilizer-N at all three locations. Although a catch crop benefit in terms of yield and grain N was observed in most of the cases, a limited N availability affected the cereal production in the four organic systems. Scenario analyses conducted with the FASSET model indicated the possibility of increasing N fertilization without significantly affecting N leaching if there is an adequate catch crop management. This would also improve yields of cereal production of organic farming in Denmark

Doltra, Jordi; Lægdsmand, Mette

2011-01-01

60

Atributos bioquímicos e químicos do solo rizosférico e não rizosférico de culturas em rotação no sistema de semeadura direta/ Biochemical and chemical attributes of rhizospheric and non-rhizospheric soil in no till crop rotation system  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Sistemas autossustentáveis favorecem as populações microbianas devido à conservação e ao aumento da matéria orgânica no solo. Além disso, as plantas que fazem parte desses sistemas promovem o efeito rizosférico, por meio da zona de influência das raízes, que resulta no aumento da atividade e na modificação da população microbiana. O objetivo deste trabalho foi avaliar o efeito da rotação de culturas de inverno sobre sequências de verão, em sistema de s (more) emeadura direta, nos atributos bioquímicos (amilase, urease, celulase e protease) e químicos (carbono orgânico total - COT, carboidratos totais e proteínas totais) em solo rizosférico (SR) e não rizosférico (SNR). Este estudo foi constituído de três culturas de inverno: milho (Zea mays L.), girassol (Helianthus anuus L.) e guandu (Cajanus cajan (L.) Millsp), que estavam em rotação sobre três sequências de verão: soja/soja (Glycine max L.), milho/milho e soja/milho, e duas posições no solo: solo aderido às raízes das plantas (SR) e solo da entrelinha de plantio (SNR). As atividades da amilase, celulase, protease e urease no SR foram 16, 85, 62 e 100 % maiores do que no SNR; para COT e proteínas totais a diferença foi de 21 %. Das culturas de inverno, o milho foi a que mais estimulou as atividades das enzimas amilase, celulase, urease e protease no SR, bem como a atividade das enzimas amilase, urease e protease no SNR. De modo geral, os teores de proteínas totais não foram influenciados pelas culturas de inverno e pelas sequências de verão; os carboidratos totais foram influenciados pelas culturas de inverno milho e girassol. Para o COT houve influência apenas da sequência de verão milho/milho. Os atributos bioquímicos e químicos avaliados neste estudo podem ser utilizados como indicadores das alterações no solo promovidas pelas culturas de inverno e pelas sequências de verão. Abstract in english Self-sustaining systems encourage microbial populations due to the conservation and improvement of organic matter in the soil. In addition, the plants constituents of these systems produce the rhizospheric effect through the influence zone of the roots, increasing activity and modifying the microbial population. The objective of this study was to evaluate the effect of winter crop rotation and summer crop sequences in a no tillage system, based on biochemical (amylase, ur (more) ease, cellulase, and protease) and chemical (organic carbon, total carbohydrates, and total protein) characteristics in rhizospheric (SR) and non-rhizospheric soil (SNR). Three winter crops were studied: corn (Zea mays L.), sunflower (Helianthus anuus L.), and pigeon pea (Cajanus cajan (L.) Millsp), in rotation with three summer sequences: soybean/soybean (Glycine max L.), corn/corn, and soybean/corn. Samples were taken from soil adhering to the plant roots (SR) and from in-between the rows (SNR). The activities of amylase, cellulase, protease, and urease in SR were 16, 85, 62, and 100 % higher, respectively, than in SNR. For total organic carbon and total protein, the difference was 21 %. Of the winter crops, corn stimulated higher amylase, cellulase, protease, and urease activity in SR, as well as amylase, protease, and urease activity in SNR. The winter crops and the summer sequences did not affect total protein levels. The total carbohydrates were influenced by winter corn and sunflower crops. Only the summer corn/corn sequence influenced total organic carbon. The biochemical and chemical properties analyzed in this study can be used as indicators of changes in soil caused by winter crops and summer sequences.

Cordeiro, Meire Aparecida Silvestrini; Corá, José Eduardo; Nahas, Ely

2012-12-01

 
 
 
 
61

Influence of cropping systems on Macrophomina phaseolina populations in soil.  

UK PubMed Central (United Kingdom)

Cumulative effects of 15 crop combinations and rotations on populations of sclerotia of Macrophomina phaseolina in soil were studied during the fifth year of a Vertisol cropping system experiment at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) Center in Patancheru, India. Higher counts of sclerotia were recorded in the intercropping systems of sorghum (Sorghum bicolor) or cowpea (Vigna sinensis) with pigeon pea (Cajanus cajan) than in single-cropping systems. The highest counts of sclerotia were recorded in plots where sorghum was intercropped continuously with pigeon pea in both the rainy and postrainy seasons. An increase in the populations of sclerotia was also recorded when rainy season sorghum was followed by either safflower (Carthamus tinctorius) or chickpea (Cicer arietinum). Cropping systems with fallow in the rainy season, followed by sorghum or chickpea in the postrainy season, stabilized the inoculum density of M. phaseolina.

Singh SK; Nene YL; Reddy MV

1990-10-01

62

Modeling the potential benefits of catch-crop introduction in fodder crop rotations in a Western Europe landscape.  

UK PubMed Central (United Kingdom)

Among possible mitigation options to reduce agricultural-borne nitrate fluxes to water bodies, introduction of catch crop before spring crops is acknowledged as a cost-efficient solution at the plot scale, but it was rarely assessed at the catchment level. This study aims to evaluate a set of catch crop implantation scenarios and their consequences in a coastal catchment prone to eutrophication. The objectives are (i) to discuss the potential benefits of catch crop introduction taking into account the limitations due to the physiographic and agricultural context of the area (ii) to propose a multicriteria classification of these scenarios as a basis for discussion with stakeholders. We used the distributed agro-hydrological model TNT2 to simulate 25 scenarios of catch crop management, differing in length of catch crop growing period, place in the crop rotation and residue management. The scenarios were classified considering the variations in main crop yields and either nitrogen fluxes in stream or the global nitrogen mass balance at the catchment level. The simulations showed that in the catchment studied, little improvement can be expected from increasing the catch crop surface. Catch crop cultivation was always beneficial to reduce nitrogen losses, but led to adverse effects on main crop yields in some cases. Among the scenarios involving additional catch crop surface, introducing catch crop between two winter cereals appeared as the most promising. The classification of scenarios depended on the chosen criteria: when considering only the reduction of nitrogen fluxes in streams, exporting catch crop residues was the most efficient while when considering the global nitrogen mass balance, soil incorporation of catch crop residues was the most beneficial. This work highlights the interest, while using integrated models, of assessing simulated scenarios with multicriteria approach to provide stakeholder with a picture as complete as possible of the consequences of prospective policies.

Moreau P; Ruiz L; Raimbault T; Vertès F; Cordier MO; Gascuel-Odoux C; Masson V; Salmon-Monviola J; Durand P

2012-10-01

63

Soil microarthropods (Acari and Collembola) in two crop rotations on a heavy marine clay soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In 1983 and 1984 an inventory was made of the edaphic mites and springtails in a six-year rotation, a three-year rotation and a three-year rotation in which the soil was disinfectedwith metamsodium after the potato crop was harvested. The aim was to find possible direct or indirect biological factor...

Jagers Op Akkerhuis, Gerard; De Ley, F.; Zwetsloot, Henk; Ponge, Jean-François; Brussaard, Lijbert

64

Short Rotation Woody Crops Program: Annual progress report for 1988  

Energy Technology Data Exchange (ETDEWEB)

This report synthesizes the technical progress of research projects in the Short Rotation Woody Crops Program (SRWCP) for the year ending September 30, 1988. The program is sponsored by the US Department of Energy's Biofuels and Municipal Waste Technology Division and has the goal of developing a viable technology for producing renewable feedstocks for conversion to biofuels. The most significant accomplishment has been the attainment of outstanding productivity rates by a Populus hybrid in the Pacific Northwest (43.5 Mg{center dot}ha{sup {minus}1}{center dot}year{sup {minus}1}), highlighting the potential gains achievable with breeding. Genetic improvement studies are broadening species performance within geographic regions and under less-than-optimum site conditions. Advances in physiological research are identifying key characteristics of species productivity and response to nutrient applications. Recent developments utilizing biotechnology have achieved success in cell and tissue culture, somaclonal variation, and gene-insertion studies. Productivity gains have been realized with advanced cultural studies of spacing, coppice, and mixed-species trials. The implications of global warming and climate-change effects on SRWC technology and applications are discussed. The early success of several monoculture viability trials is also presented. 43 refs., 12 figs., 10 tabs.

Wright, L.L.; Doyle, T.W.; Layton, P.A.; Ranney, J.W.

1989-10-01

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Effectiveness of the GAEC standard of cross compliance Crop rotations in maintaining organic matter levels in soils  

Directory of Open Access Journals (Sweden)

Full Text Available Our study was conducted in the framework of EFFICOND project, with the aim of evaluating the environmental effectiveness of GAEC (Good Agricultural and Environmental Conditions) standards with particular focus to the maintenance of soil organic matter (SOM) levels through the appropriate crop rotation. The study analyzed the effect of crop rotation on the build-up of soil organic matter in three different areas of Italy, located in the North (Lodi), Centre (Fagna, Firenze) and South (Foggia) of Italy, characterized by different climate, soil, and cropping systems. In the two experiments conducted in the South of Italy, in a dry Mediterranean climate, the stock of C was kept steady in most of the rotations compared with the monoculture of durum wheat. In such environment, with very dry and hot summers, introducing a year of fallow seems to improve SOM content, but these data need further investigation. In the Centre of Italy (Fagna), with less extreme climate than in Foggia, the effect of rotation compared to the monoculture of maize is negligible, but investigation on the soil organic matter composition, showed that in the rotation the SOM appeared to be more stable and, in the long term, probably more resistant to degradation. Eventually, experiments conducted in the North of Italy, showed that the monoculture, despite the application of FYM (Farm Yard Manure) or semi-liquid manure, led to a decrease of SOM. To an increase of the rotation complexity, corresponded an increase in the stock of C in soil. Summarizing, results showed that crop rotation could guarantee the maintenance of SOM level, given that the input of C to the soil is maintained at a good level or, in other word, that productivity of the system is high. Other practices such as conservation tillage, appropriate management of residues, and manure application could enhance the positive effect of rotations. Moreover, preliminary investigation of soil microbial diversity, suggests the positive effect of rotations on soil biological fertility.

Lamberto Borrelli; Salvatore Colecchia; Antonio Troccoli; Sarah Caradonna; Rossella Papini; Domenico Ventrella; Maria Teresa Dell'Abate; Carlo Galeffi; Cesare Tomasoni; Roberta Farina

2011-01-01

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EFFECTIVENESS OF TURKEY MANURE IN CROP ROTATION IN THE CONDITIONS OF THE ORDINARY BLACK SOIL ????????????? ?????????? ?????? ? ????? ???????? ??????????? ?? ????????? ????????????  

Directory of Open Access Journals (Sweden)

Full Text Available Five-year data of the influence of direct affect and the post action of decomposed turkey droppings on the sunflower husk on crop productivity in three-level field crop rotation of spring barley - sunflower -spring barley and in a comparison of its action with the effect of fertilizers on crop yields were presented in the article. The affect of the droppings exceeded affect of mineral fertilizers on the productivity of field crop ro-tation link in a dose of N90P90K90 on 0,79 t/ ga or on 16%

Agafonov E. V.; Kamenev R. A.; Skuratov N. S.

2012-01-01

67

The Effect of Crop Rotation, Mineral Fertilizer Application and Herbicide on Weed Control in Winter Rye  

Directory of Open Access Journals (Sweden)

Full Text Available The recent years' problems of herbicide use have led a growing number of researchers to seek alternative methods that are less reliant on herbicides. This research was conducted to determine the effect of long-term crop rotation, mineral fertilizer and herbicide on the weed infestation and grain yield of winter rye during 2004 and 2005 at the long-term experimental site of the University of Timiriazev, Moscow. Treatments were control (no weed control), herbicide, combined fertilizer (NPK) and NPK plus herbicide in field winter rye cultivated in continuous and crop rotation with other crops since 1912. Crop rotation significantly decreased weed density and dry mass. Long-term NPK application significantly decreased weed density, but had not any effect on weed dry mass. Crop rotation, NPK application and herbicide increased ground crop cover and decreased ground weed cover. In continuous crop, weed ground cover was 10 % in control plot and 3.33 % in plots where NPK was applied. Data showed that long-term crop rotation and NPK application can reduce weed infestation and increase grain yield of winter rye.

H Mohamad Dost CHamanabad; A Asghari

2009-01-01

68

Soil properties, crop production and greenhouse gas emissions in organic and conventional cropping systems  

DEFF Research Database (Denmark)

Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr-old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots on 19 September 2007, 14 April 2008 and 22 September 2008, i.e. before, during, and after the growth season. The soils were analyzed for multiple attributes: total soil organic carbon (SOC), total N, microbial biomass N (MBN), potentially mineralizable N (PMN), and levels of potential ammonium oxidation (PAO) and denitrifying enzyme activity (DEA). In situ measurements of soil heterotrophic carbon dioxide (CO2) respiration and nitrous oxide emissions were conducted in plots with winter wheat. In April 2008, prior to field operations, intact soil cores were collected at two depths (0–5 and 5–10 cm) in plots under winter wheat. Water retention characteristics of each core were determined and used to calculate relative gas diffusivity (DP/Do). Finally, crop growth was monitored and grain yields measured at harvest maturity. The different management strategies between 1997 and 2007 led to soil carbon inputs that were on average 18–68% and 32–91% higher in the organic than inorganic fertilizer-based rotations for the sampled winter wheat and spring barley crops, respectively. Nevertheless, SOC levels in 2008 were similar across systems. The cumulative soil respiration for the period February to August 2008 ranged between 2 and 3 t CO2–C ha?1 and was correlated (r = 0.95) with average C inputs. In the organic cropping systems, pig slurry application and inclusion of catch crops generally increased soil respiration, PMN and PAO. At field capacity, relative gas diffusivity at 0–5 cm depth was >50% higher in the organic than the inorganic fertilizer-based system (P < 0.05). Crop yields in 2008 were generally lower in the low-input organic rotations than in the high-input inorganic fertilizer-based system; only spring barley in rotations with pig slurry application and incorporation of a catch crop prior to sowing obtained grain yields similar to levels achieved in the system where inorganic fertilizer was applied. These results suggest that within organic cropping systems, both microbial activity and crop yields could be enhanced through inclusion of catch crops. However, the timing of catch crop incorporation is critical.

Chirinda, Ngonidzashe; Olesen, JØrgen E

2010-01-01

69

Controlling annual weeds in cereals by deploying crop rotation at the landscape scale: Avena sterilis as an example.  

UK PubMed Central (United Kingdom)

Weed control through crop rotation has mainly been studied in a nonspatial context. However, weed seeds are often spread beyond the crop field by a variety of vectors. For weed control to be successful, weed management should thus be evaluated at the landscape level. In this paper we assess how seed dispersal affects the interactions between crop rotation and landscape heterogeneity schemes with regard to weed control. A spatially explicit landscape model was developed to study both short- and long-term weed population dynamics under different management scenarios. We allowed for both two- and three-crop species rotations and three levels of between-field weed seed dispersal. All rotation scenarios and seed dispersal fractions were analyzed for both completely homogeneous landscapes and heterogeneous landscapes in which more than one crop was present. The potential of implementing new weed control methods was also analyzed. The model results suggest that, like crop rotation at the field level, crop rotation implemented at the landscape level has great potential to control weeds, whereby both the number of crop species and the cropping sequence within the crop rotation have significant effects on both the short- and long-term weed population densities. In the absence of seed dispersal, weed populations became extinct when the fraction of each crop in the landscape was randomized. In general, weed seed densities increased in landscapes with increasing similarity in crop proportions, but in these landscapes the level of seed dispersal affected which three-crop species rotation sequence was most efficient at controlling the weed densities. We show that ignoring seed dispersal between fields might lead to the selection of suboptimal tactics and that homogeneous crop field patches that follow a specific crop rotation sequence might be the most sustainable method of weed control. Effective weed control through crop rotation thus requires coordination between farmers with regard to cropping sequences, crop allocation across the landscape, and/ or the fraction of each crop across the landscape.

González-Díaz L; van den Berg F; van den Bosch F; González-Andújar JL

2012-04-01

70

CROP SUPPLYING APPARATUS FOR BALE SILAGE AND BALING SYSTEM  

UK PubMed Central (United Kingdom)

PURPOSE: A crude feed crop supplying apparatus for a bale silage, and a bale system using thereof are provided to enable users to uniformly supply crude feed crops. CONSTITUTION: A crude feed crop supplying apparatus for a bale silage comprises the following: a conveyor unit(110) with one end detachably connected to an inlet of a chamber formed on a baler for transferring crude feed crops toward the inlet a storage box unit(120) exposing the conveyor unit on the bottom a base plate(111) with one side connected to the inlet of the chamber gear shafts(112) located on the front and rear sides of the base plate a chain(114) winded to a gear of the gear shafts for surrounding the lower and upper sides of the base plate a scraper(115) attached to the chain for transferring the crude feed crops toward the inlet of the chamber and side walls(121) rotatably installed toward the conveyor unit.

LEE IN HYUN; CHO NAM HONG

71

SOIL PHYSICAL QUALITY INDICES UNDER TECHNICAL CROP ROTATION  

Directory of Open Access Journals (Sweden)

Full Text Available The multiple processes which assists in the physical indices evolution of soil quality, within technical rotation are correlated, this being materialized in their hierarchization to the different integration levels and structural functional organization of the soil system. More pronounced, the technical anthropic modifications affect the levels aggregate – horizon – profile (pedon) being concretized in the agrogen layer compaction and profile stratification. Integrated index of the agrogen modifications are characteristic for the pore space, specially the volume, size, pore space stability and continuity.

Gheorghe Jigau; Ecaterina Chislari; Maria Motelica; Ina Chircu

2011-01-01

72

Seasonal and crop rotational effects of manure management on nitrate-nitrogen leaching in Nova Scotia  

UK PubMed Central (United Kingdom)

High nitrate-nitrogen (NO?-N) concentrations and loads in tile drainage waters in response to crop fertility and other land management practices are a major cause of concern to the health of humans, animals and the environment. The study, conducted at Kentville, Nova Scotia (NS), examined the effect of renovating fallowed land with the introduction of either manure amended permanent forage (PF) or manure amended corn (Zea mays L.) - soybean (Glycine max L.) - wheat (Triticum aestivum L.) Corn-soybean-wheat (CSW) rotations on growing season (GS) and non-growing season (NGS) nitrate (NO?-N) concentrations and loads of tile drainage water. Treatments included (i) PF rotation established with conventional tillage (CT) practices; (ii) CSW-CT rotation; (iii) minimum tillage in a CSW rotation (CSW-MT) and (iv) zero tillage in a CSW rotation (CSW-ZT). NGS drainage was significantly higher and flow-weighted NO?-N concentrations significantly lower in all years when compared with GS. There were no consistent differences observed in GS or NGS NO?-N concentrations and loads between the three levels of tillage in the CSW rotation with loads ranging between 7.1 and 28.2kgNL?¹ and 18.7 and 77.0kgNL?¹ for GS and NGS, respectively. PF rotation was significantly more efficient in N utilization when compared with a CSW rotation, resulting in significantly lower loads. Decreasing nitrate loads over time appeared to be related to increasing evapo-transpiration and N uptake as the forage matured. Although differences in the amount of N removed by corn, soybean and spring wheat in the CSW rotation were observed, these were not significant in determining the magnitude of NO?-N loads. The correlation between LDM application and NO?-N losses in tile water under this rotation in a particular season proved difficult to define. The study showed that the biological response time of the manured, soil system for NO?-N loading is longer than one seasonal cycle and demonstrates the need to evaluate the long-term impacts of these rotations.

Fuller KD; Gordon R; Grimmett M; Fillmore S; Madani A; VanRoestel J; Stratton GW; MacLeod J; Embree C; George ESt

2010-05-01

73

Nitrous oxide emissions from crop rotations including wheat, oilseed rape and dry peas  

Directory of Open Access Journals (Sweden)

Full Text Available Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas (GHG), originate from soils at a global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes can reduce N fertilizer use, and possibly N2O emissions. Nevertheless, the decomposition of crop organic matter during the crop cycle and residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity) and from the subsequent crops in comparison with N2O emissions from wheat and oilseed rape crops, fertilized or not, in various rotations. A field experiment was conducted over 4 consecutive years to compare the emissions during the pea crop, in comparison with those during the wheat (fertilized or not) or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly due to the site's soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after the pea crop. These results should be confirmed over a wider range of soil types. Nevertheless, they demonstrate the absence of N2O emissions linked to the symbiotic N fixation process, and allow us to estimate the decrease in N2O emissions by 20–25% through including one pea crop in a three-year rotation. On a larger scale, this reduction of GHG emissions at field level has to be added to the decrease due to the reduced production and transport of the N fertilizer not applied to the pea crop.

M. H. Jeuffroy; E. Baranger; B. Carrouée; E. de Chezelles; M. Gosme; C. Hénault; A. Schneider; P. Cellier

2013-01-01

74

Nitrous oxide emissions from crop rotations including wheat, oilseed rape and dry peas  

Science.gov (United States)

Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas (GHG), originate from soils at a global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes can reduce N fertilizer use, and possibly N2O emissions. Nevertheless, the decomposition of crop organic matter during the crop cycle and residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity) and from the subsequent crops in comparison with N2O emissions from wheat and oilseed rape crops, fertilized or not, in various rotations. A field experiment was conducted over 4 consecutive years to compare the emissions during the pea crop, in comparison with those during the wheat (fertilized or not) or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly due to the site's soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after the pea crop. These results should be confirmed over a wider range of soil types. Nevertheless, they demonstrate the absence of N2O emissions linked to the symbiotic N fixation process, and allow us to estimate the decrease in N2O emissions by 20-25% through including one pea crop in a three-year rotation. On a larger scale, this reduction of GHG emissions at field level has to be added to the decrease due to the reduced production and transport of the N fertilizer not applied to the pea crop.

Jeuffroy, M. H.; Baranger, E.; Carrouée, B.; de Chezelles, E.; Gosme, M.; Hénault, C.; Schneider, A.; Cellier, P.

2013-03-01

75

Management of lesion nematodes and potato early dying with rotation crops.  

UK PubMed Central (United Kingdom)

Soil-incorporated rotation/green manure crops were evaluated for management of potato early dying caused by Verticillium dahliae and Pratylenchus penetrans. After two years of rotation/green manure and a subsequent potato crop, P. penetrans numbers were less after 'Saia' oat/'Polynema' marigold, 'Triple S' sorghum-sudangrass, or 'Garry' oat than 'Superior' potato or 'Humus' rapeseed. The area under the disease progress curve (AUDPC) for early dying was lowest after Saia oat/marigold, and tuber yields were greater than continuous potato after all crops except sorghum-sudangrass. Saia oat/marigold crops resulted in the greatest tuber yields. After one year of rotation/green manure, a marigold crop increased tuber yields and reduced AUDPC and P. penetrans. In the second potato crop after a single year of rotation, plots previously planted to marigolds had reduced P. penetrans densities and AUDPC and increased tuber yield. Rapeseed supported more P. penetrans than potato, but had greater yields. After two years of rotation/green manure crops and a subsequent potato crop, continuous potato had the highest AUDPC and lowest tuber weight. Rotation with Saia oats (2 yr) and Rudbeckia hirta (1 yr) reduced P. penetrans and increased tuber yields. AUDPC was lowest after R. hirta. Two years of sorghum-sudangrass did not affect P. penetrans, tuber yield or AUDPC. These results demonstrate that P. penetrans may be reduced by one or two years of rotation to non-host or antagonistic plants such as Saia oat, Polynema marigold, or R. hirta and that nematode control may reduce the severity of potato early dying.

Lamondia JA

2006-12-01

76

Management of lesion nematodes and potato early dying with rotation crops.  

Science.gov (United States)

Soil-incorporated rotation/green manure crops were evaluated for management of potato early dying caused by Verticillium dahliae and Pratylenchus penetrans. After two years of rotation/green manure and a subsequent potato crop, P. penetrans numbers were less after 'Saia' oat/'Polynema' marigold, 'Triple S' sorghum-sudangrass, or 'Garry' oat than 'Superior' potato or 'Humus' rapeseed. The area under the disease progress curve (AUDPC) for early dying was lowest after Saia oat/marigold, and tuber yields were greater than continuous potato after all crops except sorghum-sudangrass. Saia oat/marigold crops resulted in the greatest tuber yields. After one year of rotation/green manure, a marigold crop increased tuber yields and reduced AUDPC and P. penetrans. In the second potato crop after a single year of rotation, plots previously planted to marigolds had reduced P. penetrans densities and AUDPC and increased tuber yield. Rapeseed supported more P. penetrans than potato, but had greater yields. After two years of rotation/green manure crops and a subsequent potato crop, continuous potato had the highest AUDPC and lowest tuber weight. Rotation with Saia oats (2 yr) and Rudbeckia hirta (1 yr) reduced P. penetrans and increased tuber yields. AUDPC was lowest after R. hirta. Two years of sorghum-sudangrass did not affect P. penetrans, tuber yield or AUDPC. These results demonstrate that P. penetrans may be reduced by one or two years of rotation to non-host or antagonistic plants such as Saia oat, Polynema marigold, or R. hirta and that nematode control may reduce the severity of potato early dying. PMID:19259461

Lamondia, J A

2006-12-01

77

Análise econômica de sistemas de rotação de culturas para trigo, num período de dez anos, sob plantio direto Economic analysis of crop rotation systems for wheat, over a ten year period, under no-tillage  

Directory of Open Access Journals (Sweden)

Full Text Available Durante os anos de 1984 a 1993, foi conduzido, em Guarapuava, PR, experimento composto de sistemas de rotação de culturas para trigo: sistema I (trigo/soja); sistema II (trigo/soja e ervilhaca/milho, de 1984 a 1989, e trigo/soja e aveia-branca/soja, de 1990 a 1993); sistema III (trigo/soja, linho/soja e ervilhaca/milho, de 1984 a 1989, e trigo/soja, ervilhaca/milho e aveia-branca/soja, de 1990 a 1993); e sistema IV (trigo/soja, leguminosas/milho, cevada/soja e aveia-branca/soja). A análise econômica do período é apresentada neste trabalho. De 1984 a 1989, os sistemas I, II, III e IV não mostraram diferenças entre as médias quanto à receita líquida. Da mesma forma, de 1990 a 1993, os sistemas II, III e IV não diferiram significativamente no tocante a receita líquida, em relação ao sistema I; no entanto, considerando-se as comparações anuais, o sistema II apresentou maior lucratividade do que o sistema I, em seis anos, e não diferiu em quatro anos, sendo, portanto, aquele, uma boa alternativa em relação a este, principalmente no primeiro período.From 1984 to 1993, in Guarapuava, Paraná, Brazil, the effect of crop rotation systems on wheat were assessed. Four rotation systems for wheat were studied: system I (wheat/soybean); system II (wheat/soybean and common vetch/corn, from 1984 to 1989, and wheat/soybean and white oats/soybean, from 1990 to 1993); system III (wheat/soybean, flax/soybean, and common vetch/corn, from 1984 to 1989, and wheat/soybean, common vetch/corn, and white oats/soybean, from 1990 to 1993); and system IV (wheat/soybean, legume/corn, barley/soybean, and white oats/soybean). The economic analysis on that period is presented in this paper. From 1984 to 1989, systems I, II, III, and IV showed no differences in their net return means. Similarly, from 1990 to 1993, systems II, III, and IV mean net returns did not differ significantly in relation to the system I; however, considering the annual comparison, the system II showed higher profit than the system I in six years and did not differ in four years, making it a good alternative, mainly in the first period.

Henrique Pereira dos Santos; Ivo Ambrosi; João Carlos Ignaczak; Celso Wobeto

1999-01-01

78

Análise de risco em quatro sistemas de rotação de culturas para trigo, num período de dez anos, em Passo Fundo, RS Risk analysis of four crop rotation systems for wheat, over a ten-year period, in Passo Fundo, RS  

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Full Text Available Num período de dez anos (1980 a 1989), foi conduzido, na Embrapa-Centro Nacional de Pesquisa de Trigo (CNPT), em Passo Fundo, RS, experimento reunindo quatro sistemas de rotação de culturas para trigo (Triticum aestivum L.): sistema I (trigo/soja); sistema II (trigo/soja, colza/soja, cevada/soja e tremoço ou serradela/milho); sistema III (trigo/soja, trevo vesiculoso/trevo vesiculoso, trevo vesiculoso/milho, de 1980 a 1983, e trigo/soja, aveia branca/soja e ervilhaca/milho, de 1984 a 1989); e sistema IV (trigo/soja, colza/soja, linho/soja e tremoço ou serradela/milho). Utilizou-se o delineamento de blocos ao acaso, com quatro repetições e parcelas com área útil de 120 m². No presente trabalho, mostra-se a análise de risco naquele período. Foram aplicados dois tipos de análise na receita líquida dos sistemas: análise da média variância e análise de risco (distribuição de probabilidade acumulada e dominância estocástica). Pela análise da média variância da receita líquida, os sistemas II e IV foram superiores aos sistemas I e III. Pelo método da dominância estocástica, o sistema II apresentou- se como a melhor alternativa de produção a ser oferecida aos agricultores, do ponto de vista de lucratividade e menor risco.During ten years (1980 to 1989), at the Embrapa-Centro Nacional de Pesquisa de Trigo (CNPT), in Passo Fundo, RS, Brazil, the effects of crop rotation systems on wheat (Triticum aestivum L.) were assessed. Four rotation systems for wheat were studied: system I (wheat/soybean); system II (wheat/soybean, rapeseed/soybean, barley/soybean, lupine or serradella/corn); system III (wheat/soybean, arrowleaf clover/arrowleaf clover, and arrowleaf clover/corn, from 1980 to 1983, and wheat/soybean, white oats/soybean, and common vetch/corn, from 1984 to 1989); and system IV (wheat/soybean, rapeseed/soybean, flax/soybean, and lupine or serradella/corn). A randomized complete block design, with four replications and plots with 120 m², was used. Risk analysis over that period is presented in this paper. Two types of analysis were applied to the net return of the systems: mean-variance analysis and risk analysis (safety-first and stochastic dominance). By the mean-variance analysis, systems II and IV showed higher net returns as compared to systems I and III. The system II showed the highest profit and the lowest risk to be offered to the farmer, as compared to the remaining systems studied.

Henrique Pereira dos Santos; Ivo Ambrosi; Julio Cesar Barreneche Lhamby

1999-01-01

79

Análise de risco em quatro sistemas de rotação de culturas para trigo, num período de dez anos, em Passo Fundo, RS/ Risk analysis of four crop rotation systems for wheat, over a ten-year period, in Passo Fundo, RS  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Num período de dez anos (1980 a 1989), foi conduzido, na Embrapa-Centro Nacional de Pesquisa de Trigo (CNPT), em Passo Fundo, RS, experimento reunindo quatro sistemas de rotação de culturas para trigo (Triticum aestivum L.): sistema I (trigo/soja); sistema II (trigo/soja, colza/soja, cevada/soja e tremoço ou serradela/milho); sistema III (trigo/soja, trevo vesiculoso/trevo vesiculoso, trevo vesiculoso/milho, de 1980 a 1983, e trigo/soja, aveia branca/soja e ervilhaca/ (more) milho, de 1984 a 1989); e sistema IV (trigo/soja, colza/soja, linho/soja e tremoço ou serradela/milho). Utilizou-se o delineamento de blocos ao acaso, com quatro repetições e parcelas com área útil de 120 m². No presente trabalho, mostra-se a análise de risco naquele período. Foram aplicados dois tipos de análise na receita líquida dos sistemas: análise da média variância e análise de risco (distribuição de probabilidade acumulada e dominância estocástica). Pela análise da média variância da receita líquida, os sistemas II e IV foram superiores aos sistemas I e III. Pelo método da dominância estocástica, o sistema II apresentou- se como a melhor alternativa de produção a ser oferecida aos agricultores, do ponto de vista de lucratividade e menor risco. Abstract in english During ten years (1980 to 1989), at the Embrapa-Centro Nacional de Pesquisa de Trigo (CNPT), in Passo Fundo, RS, Brazil, the effects of crop rotation systems on wheat (Triticum aestivum L.) were assessed. Four rotation systems for wheat were studied: system I (wheat/soybean); system II (wheat/soybean, rapeseed/soybean, barley/soybean, lupine or serradella/corn); system III (wheat/soybean, arrowleaf clover/arrowleaf clover, and arrowleaf clover/corn, from 1980 to 1983, and (more) wheat/soybean, white oats/soybean, and common vetch/corn, from 1984 to 1989); and system IV (wheat/soybean, rapeseed/soybean, flax/soybean, and lupine or serradella/corn). A randomized complete block design, with four replications and plots with 120 m², was used. Risk analysis over that period is presented in this paper. Two types of analysis were applied to the net return of the systems: mean-variance analysis and risk analysis (safety-first and stochastic dominance). By the mean-variance analysis, systems II and IV showed higher net returns as compared to systems I and III. The system II showed the highest profit and the lowest risk to be offered to the farmer, as compared to the remaining systems studied.

Santos, Henrique Pereira dos; Ambrosi, Ivo; Lhamby, Julio Cesar Barreneche

1999-04-01

80

Effects of broad-leaf crop frequency in various rotations on soil organic C and N, and inorganic N in a Dark Brown soil  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this study was to determine the impact of frequency of broad-leaf crops canola and pea in various crop rotations on pH, total organic C (TOC), total organic N (TON), light fraction organic C (LFOC) and light fraction organic N (LFON) in the 0 - 7.5 and 7.5 - 15 cm soil depths in autumn 2009 after 12 years (1998-2009) on a Dark Brown Chernozem (Typic Boroll) loam at Scott, Saskatchewan, Canada. The field ex-periment contained monoculture canola (herbicide tolerant and blackleg resistant hybrid) and monoculture pea compared with rotations that contained these crops every 2-, 3-, and 4-yr with wheat. There was no effect of crop rotation duration and crop phase on soil pH. Mass of TOC and TON in the 0 - 15 cm soil was greater in canola phase than pea phase in the 1-yr (monoculture) and 2-yr crop rotations, while the opposite was true in the 3-yr and 4-yr crop rotations. Mass of TOC and TON (averaged across crop phases,) in soil generally increased with increasing crop rotation duration, with the maximum in the 4-yr rotation while no difference in the 1-yr and 2-yr rotations. Mass of LFOC and LFON in soil was greater in canola phase than pea phase in the 1-yr, 2-yr and 3-yr rotations, but the opposite was true in the 4-yr rotation. There was no consistent effect of crop rotation duration on mass of LFOC and LFON. The N balance sheet over the 1998 to 2009 period indicated large amounts of unaccounted N for monoculture pea, suggesting a great potential for N loss from the soil-plant system in this treatment through nitrate leaching and/or denitrification. In conclusion, the findings suggest that the quantity of organic C and N can be maximized by increasing duration of crop rotation and by including hybrid canola in the rotation.

Sukhdev S. Malhi; R. L. Lemke; S. A. Brandt

2012-01-01

 
 
 
 
81

Soil microbial biomass and nitrogen supply in an irrigated lowland rice soil as affected by crop rotation and residue management.  

UK PubMed Central (United Kingdom)

Processes that govern the soil nitrogen (N) supply in irrigated lowland rice systems are poorly understood. The objectives of this paper were to investigate the effects of crop rotation and management on soil N dynamics, microbial biomass C (C(BIO)) and microbial biomass N (N(BIO) in relation to rice N uptake and yield. A maize-rice (M-R) rotation was compared with a rice-rice (R-R) double-cropping system over a 2-year period with four cropping seasons. In the M-R system. maize (Zea mays L.) was grown in aerated soil during the dry season (DS) followed by rice (Oryza sativa L.) grown in flooded soil during the wet season (WS). In the R-R system, rice was grown in flooded soil in both the DS and WS. Three fertilizer N rates (0.50 or 100 kg urea-N ha-1 in WS) were assigned to subplots within the cropping system main plots. Early versus late crop residue incorporation following DS maize or rice were established as additional treatments in sub-sub-plots in the second year. In the R-R system, the time of residue incorporation had a large effect on NO3(-)-N accumulation during the fallow period and also on extractable NH4(+)-N, rice N uptake and yield in the subsequent cropping period. In contrast, time of residue incorporation had little influence on extractable N in both the fallow and rice-cropping periods of the M-R system, and no detectable effects on rice N uptake or yield. In both cropping systems, C(BIO) and N(BIO) were not sensitive to residue incorporation despite differences of 2- to 3-fold increase in the amount of incorporated residue C and N, and were relatively insensitive to N fertilizer application. Extractable organic N was consistently greater after mid-tillering in M-R compared to the R-R system across N rate and residue incorporation treatments, and much of this organic N was alpha-amino N. We conclude that N mineralization-immobilization dynamics in lowland rice systems are sensitive to soil aeration as influenced by residue management in the fallow period and crop rotation, and that these factors have agronomically significant effects on rice N uptake and yield. Microbial biomass measurements, however were a poor indicator of these dynamics.

Witt C; Cassman KG; Ottow JCG; Biker U

1998-01-01

82

Soil enzyme activities under long-term tillage and crop rotation systems in subtropical agro-ecosystems Atividade enzimática em solo sob plantio direto e rotações de culturas em agro-ecossistema subtropical  

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Full Text Available Agricultural practices that reduce soil degradation and improve agricultural sustainability are needed particularly for tropical/subtropical soils. No-tillage planting causes minimal soil disturbance and combined with crop rotation may hold potential to meet these goals. Soil enzyme activities can provide information on how soil management is affecting the potential to perform the processes in soils such as decomposition and nutrient cycling. Soil enzyme activities were investigated in a split-plot experiment (3 replications) where tillage (no till and conventional) was the main plot and crop rotation (soybean/wheat, S/W; maize/wheat, M/W or cotton/wheat, C/W) was the subplot. The experiment was established in 1976 in southern Brazil. Soil samples were taken at 0-5, 5-10 and 10-20 cm depths in 1997 and 1998. The 0-5 cm layer under NT system showed increases up 68% for amylase, 90% for cellulase, 219% for arylsulfatase, 46% for acid phosphatase, and 61% for alkaline phosphatase. There were significant correlations of soil enzyme activities with total organic C, and C and N microbial biomass. These results showed that NT increased microbial activity and that soil enzyme activity is a sensitive indicator of alteration soil quality by management.Práticas agrícolas que reduzam a degradação do solo e promovam sustentabilidade são importantes para os agrossistemas tropicais/subtropicais. O plantio direto (PD) diminui as perdas de solo e, se combinado com rotação de culturas pode proteger o solo da degradação físico-química provocada pela agricultura intensiva. A atividade enzimática do solo pode fornecer importantes informações de como o manejo do solo está afetando a decomposição da material orgânica e a ciclagem dos nutrientes. Assim, avaliou-se a atividade das enzimas amilase, celulose, arilsulfatase, fosfatase ácida e fosfatase alcalina em um experimento a campo, instalado em 1976 em Londrina, PR, que tem como tratamentos o preparo do solo (plantio direto ou convencional) nas parcelas e a rotação de culturas (soja/trigo, milho/trigo e algodão/trigo) nas subparcelas. Amostras de solos foram coletadas a 0-5, 5-10 e 10-20 cm de profundidade em 1997 e 1998. Na profundidade de 0-5 cm sob PD, observaram-se aumentos de 68% na atividade da amilase, 90% na celulase, 219% na arilsulfatase, 46% na fosfatase ácida e 61% na fosfatase alcalina. Observaram-se correlações significativas entre a atividade enzimática e o C-orgânico total do solo e o C e N da biomassa microbiana. Esses resultados evidenciam que a atividade enzimática do solo é um indicador sensível de alterações na qualidade do solo, promovidas pelo manejo.

Elcio Liborio Balota; Miriam Kanashiro; Arnaldo Colozzi Filho; Diva Souza Andrade; Richard Peter Dick

2004-01-01

83

Energy balance of five fodder cropping systems in the irrigated lowlands of Northern Italy  

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Full Text Available Extensification has recently become an important option in Western European agriculture, driven both by economic considerations (product surpluses together with the fact that developed countries cropping systems have been heavily relying on fossil energy) and growing public concern on the possible adverse effects of intensive farming on the environment and human health. The adoption of rational fodder crop rotations, with the rediscovery of the beneficial effect of the meadow, is viewed as a possible mean to reduce the impact of farming systems in the lowlands of Northern Italy, characterised by highly intensive cropping and animal husbandry. For this reason our study examines the effects of crop rotation on the energy balance during 1985-2007 period in a long-term crop rotation trial in Northern Italy comparing five fodder crop systems, different in the degree of crop intensification and for the presence or absence of the meadow: a 1-year continuous cereal double cropping (R1); a 3-year rotation (R3); a 6-year rotation (R6); a permanent meadow (PM); and a continuous grain maize cropping (CM). Each rotation was subjected to two input treatments, defined as high (mostly used in lowlands of northern Italy) and low (input reduction of ca. 30%) respectively, in terms of nutrient levels, herbicide doses, and soil tillage methods. The crop rotations exerted a marked influence on the energy balance. The most efficient rotations in terms of net energy production energy efficiency have been characterized by reduced length and presence of maize and catch-crops.

Cesare Tomasoni; Lamberto Borrelli; Massimo Brambilla

2011-01-01

84

Long-term C-CO2 emissions and carbon crop residue mineralization in an oxisol under different tillage and crop rotation systems Emissões deC-CO2 de longo prazo e a mineralização do carbono dos resíduos culturais em um latossolo sob diferentes sistemas de preparo e rotação de culturas  

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Full Text Available Soil C-CO2 emissions are sensitive indicators of management system impacts on soil organic matter (SOM). The main soil C-CO2 sources at the soil-plant interface are the decomposition of crop residues, SOM turnover, and respiration of roots and soil biota. The objectives of this study were to evaluate the impacts of tillage and cropping systems on long-term soil C-CO2 emissions and their relationship with carbon (C) mineralization of crop residues. A long-term experiment was conducted in a Red Oxisol in Cruz Alta, RS, Brazil, with subtropical climate Cfa (Köppen classification), mean annual precipitation of 1,774 mm and mean annual temperature of 19.2 ºC. Treatments consisted of two tillage systems: (a) conventional tillage (CT) and (b) no tillage (NT) in combination with three cropping systems: (a) R0- monoculture system (soybean/wheat), (b) R1- winter crop rotation (soybean/wheat/soybean/black oat), and (c) R2- intensive crop rotation (soybean/ black oat/soybean/black oat + common vetch/maize/oilseed radish/wheat). The soil C-CO2 efflux was measured every 14 days for two years (48 measurements), by trapping the CO2 in an alkaline solution. The soil gravimetric moisture in the 0-0.05 m layer was determined concomitantly with the C-CO2 efflux measurements. The crop residue C mineralization was evaluated with the mesh-bag method, with sampling 14, 28, 56, 84, 112, and 140 days after the beginning of the evaluation period for C measurements. Four C conservation indexes were used to assess the relation between C-CO2 efflux and soil C stock and its compartments. The crop residue C mineralization fit an exponential model in time. For black oat, wheat and maize residues, C mineralization was higher in CT than NT, while for soybean it was similar. Soil moisture was higher in NT than CT, mainly in the second year of evaluation. There was no difference in tillage systems for annual average C-CO2 emissions, but in some individual evaluations, differences between tillage systems were noticed for C-CO2 evolution. Soil C-CO2 effluxes followed a bi-modal pattern, with peaks in October/November and February/March. The highest emission was recorded in the summer and the lowest in the winter. The C-CO2 effluxes were weakly correlated to air temperature and not correlated to soil moisture. Based on the soil C conservation indexes investigated, NT associated to intensive crop rotation was more C conserving than CT with monoculture.A emissão de C-CO2 do solo é considerada um indicador sensível dos impactos de sistemas de manejo sobre a matéria orgânica do solo (MOS). Nos sistemas agrícolas, as principais fontes de C-CO2 são as decomposições dos resíduos culturais e da MOS, além da respiração das raízes das culturas e da biota do solo. O principal objetivo deste estudo foi avaliar o impacto de sistemas de preparo do solo e culturas nas emissões de longo prazo de C-CO2 do solo e sua relação com a mineralização do carbono (C) de resíduos culturais. Este estudo foi desenvolvido em experimento de longa duração, em Latossolo Vermelho distrófico típico, de ocorrência na região de Cruz Alta, RS, Brasil. O clima é o subtropical Cfa, segundo a classificação de Köppen, com precipitação pluvial anual média de 1.744 mm e temperatura média anual de 19,2 ºC. Os tratamentos investigados foram dois sistemas de preparo - convencional (PC) e plantio direto (PD) - e três sistemas de culturas: R0- sucessão de monoculturas (trigo/soja); R1- rotação de culturas de inverno (aveia-preta/soja/trigo/soja); e R2- rotação intensiva de culturas (aveia-preta/soja/aveia-preta+ervilhaca/milho /nabo forrageiro/trigo/soja). O efluxo de C-CO2 do solo foi avaliado em intervalos fixos de 14 dias, durante dois anos (48 avaliações), por meio da captura do dióxido de carbono em solução alcalina. A umidade gravimétrica do solo, na camada de 0-0,05 m, foi determinada concomitantemente com as medições de C-CO2. Ainda, foi avaliada a taxa de liberação do C dos resíduos culturais utilizando o método dos sacos de

Ben-Hur Costa de Campos; Telmo Jorge Carneiro Amado; Carlos Gustavo Tornquist; Rodrigo da Silveira Nicoloso; Jackson Ernani Fiorin

2011-01-01

85

Propriedades físicas do solo em sistemas de rotação de culturas conforme o uso de corretivos da acidez Soil physical properties in crop rotation systems as affected by liming materials  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi avaliar o efeito de sistemas de rotação de culturas e de corretivos da acidez nas propriedades físicas do solo. O experimento foi realizado entre outubro de 2006 e julho de 2008, em Botucatu, SP, em blocos ao acaso, com parcelas subdivididas e oito repetições. As parcelas foram constituídas por quatro sistemas de rotação: soja/pousio/milho/pousio, soja/aveia-branca/milho/feijão, soja/milheto/milho/guandu e soja/braquiária/milho/braquiária. As subparcelas consistiram do tratamento testemunha, sem correção, e da aplicação de 3,8 Mg ha-1 de calcário dolomítico (PRNT = 90%) ou de 4,1 Mg ha-1 de silicato de cálcio e magnésio (PRNT = 80%), na superfície de um Latossolo Vermelho argiloso. Foram determinadas: estabilidade de agregados, densidade do solo, porosidade total, macro e microporosidade, resistência do solo à penetração e umidade do solo. A aplicação dos corretivos de acidez em superfície não reduz a agregação do solo e aumenta a macroporosidade até 0,20 m de profundidade, após aplicação de silicato, e até 0,10 m, após aplicação de calcário. A manutenção do solo em pousio, na entressafra, prejudica a estruturação do solo, reduz a estabilidade de agregados e aumenta a resistência à penetração nas camadas superficiais. A semeadura de braquiária, entre as safras de verão, aumenta a estabilidade de agregados até 0,10 m de profundidade.The objective of this work was to evaluate the effects of crop rotation systems and liming materials on soil physical properties. The experiment was carried out from October 2006 to July 2008, in Botucatu, SP, Brazil, in a completely randomized block design in a split-plot arrangement with eight replicates. Main plots consisted of four crop rotation systems: soybean/fallow/maize/fallow, soybean/white-oat/maize/bean, soybean/millet/maize/pigeon pea and soybean/signal grass/maize/signal grass. Subplots consisted of the control treatment, without soil correction, and of the application of 3.8 Mg ha-1 of dolomitic lime (ECC = 90%) or 4.1 Mg ha-1 of calcium-magnesium silicate (ECC = 80%), on the surface of a clayed Rhodic Ferralsol. Aggregate stability, soil bulk density, total porosity, macro and microporosity, soil penetration resistance and moisture content were evaluated. Superficial application of the lime materials does not reduce soil aggregation and increases macroporosity down to 0.20 m, with calcium-magnesium silicate application, and to 0.10 m, when lime is applied. Soil under fallow in off-season decreases aggregate stability and increases soil penetration resistance in upper layers. The cultivation of Congo signal grass, between summer crops, increases aggregate stability down to 0.10-m depth.

Gustavo Spadotti Amaral Castro; Juliano Carlos Calonego; Carlos Alexandre Costa Crusciol

2011-01-01

86

Propriedades físicas do solo em sistemas de rotação de culturas conforme o uso de corretivos da acidez/ Soil physical properties in crop rotation systems as affected by liming materials  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo deste trabalho foi avaliar o efeito de sistemas de rotação de culturas e de corretivos da acidez nas propriedades físicas do solo. O experimento foi realizado entre outubro de 2006 e julho de 2008, em Botucatu, SP, em blocos ao acaso, com parcelas subdivididas e oito repetições. As parcelas foram constituídas por quatro sistemas de rotação: soja/pousio/milho/pousio, soja/aveia-branca/milho/feijão, soja/milheto/milho/guandu e soja/braquiária/milho/braq (more) uiária. As subparcelas consistiram do tratamento testemunha, sem correção, e da aplicação de 3,8 Mg ha-1 de calcário dolomítico (PRNT = 90%) ou de 4,1 Mg ha-1 de silicato de cálcio e magnésio (PRNT = 80%), na superfície de um Latossolo Vermelho argiloso. Foram determinadas: estabilidade de agregados, densidade do solo, porosidade total, macro e microporosidade, resistência do solo à penetração e umidade do solo. A aplicação dos corretivos de acidez em superfície não reduz a agregação do solo e aumenta a macroporosidade até 0,20 m de profundidade, após aplicação de silicato, e até 0,10 m, após aplicação de calcário. A manutenção do solo em pousio, na entressafra, prejudica a estruturação do solo, reduz a estabilidade de agregados e aumenta a resistência à penetração nas camadas superficiais. A semeadura de braquiária, entre as safras de verão, aumenta a estabilidade de agregados até 0,10 m de profundidade. Abstract in english The objective of this work was to evaluate the effects of crop rotation systems and liming materials on soil physical properties. The experiment was carried out from October 2006 to July 2008, in Botucatu, SP, Brazil, in a completely randomized block design in a split-plot arrangement with eight replicates. Main plots consisted of four crop rotation systems: soybean/fallow/maize/fallow, soybean/white-oat/maize/bean, soybean/millet/maize/pigeon pea and soybean/signal grass (more) /maize/signal grass. Subplots consisted of the control treatment, without soil correction, and of the application of 3.8 Mg ha-1 of dolomitic lime (ECC = 90%) or 4.1 Mg ha-1 of calcium-magnesium silicate (ECC = 80%), on the surface of a clayed Rhodic Ferralsol. Aggregate stability, soil bulk density, total porosity, macro and microporosity, soil penetration resistance and moisture content were evaluated. Superficial application of the lime materials does not reduce soil aggregation and increases macroporosity down to 0.20 m, with calcium-magnesium silicate application, and to 0.10 m, when lime is applied. Soil under fallow in off-season decreases aggregate stability and increases soil penetration resistance in upper layers. The cultivation of Congo signal grass, between summer crops, increases aggregate stability down to 0.10-m depth.

Castro, Gustavo Spadotti Amaral; Calonego, Juliano Carlos; Crusciol, Carlos Alexandre Costa

2011-12-01

87

Volatile organic compound emissions from Miscanthus and short rotation coppice willow bioenergy crops  

Science.gov (United States)

Miscanthus × giganteus and short rotation coppice (SRC) willow (Salix spp.) are increasingly important bioenergy crops. Above-canopy fluxes and mixing ratios of volatile organic compounds (VOCs) were measured in summer for the two crops at a site near Lincoln, UK, by proton transfer reaction mass spectrometry (PTR-MS) and virtual disjunct eddy covariance. The isoprene emission rate above willow peaked around midday at ˜1 mg m-2 h-1, equivalent to 20 ?g gdw-1 h-1 normalised to 30 °C and 1000 ?mol m-2 s-1 PAR, much greater than for conventional arable crops. Average midday peak isoprene mixing ratio was ˜1.4 ppbv. Acetone and acetic acid also showed small positive daytime fluxes. No measurable fluxes of VOCs were detected above the Miscanthus canopy. Differing isoprene emission rates between different bioenergy crops, and the crops or vegetation cover they may replace, means the impact on regional air quality should be taken into consideration in bioenergy crop selection.

Copeland, Nichola; Cape, J. Neil; Heal, Mathew R.

2012-12-01

88

Soybean benefit to a subsequent wheat crop in a cropping system under zero tillage  

International Nuclear Information System (INIS)

This experiment was conducted to compare biological nitrogen fixation (BNF) contributions to soybean crops and the effect of the presence of its residues to the production of wheat under two tillage systems. The plots were established in the experimental area of the Embrapa Soybean Centre in the State of Parana, southern Brazil. A soybean/wheat rotation was planted under conventional and zero tillage (CT and ZT, respectively). The contribution of BNF to soybean was assessed using the ?15N technique and the relative abundance of ureides. An N balance was performed based on the dry matter and N content of, and the BNF contribution to, the whole crop. Plant-residue decomposition was evaluated by field sampling. Wheat responses to the previous soybean crop and tillage treatments were evaluated from the wheat yields and the 'A'-value technique. Comparing ZT and CT, there were no marked differences in grain yield or N accumulation by the crops, but BNF was higher in the soybean under ZT. Although for both tillage systems the BNF contribution to soybean was over 170 kg N/ha, the benefit to the subsequent crop was due to the release of N from extremely labile soybean residues of low C:N ratio and not because of a net gain of N from BNF. (author)

2002-01-01

89

AFLP analysis of genetic diversity in charcoal rot fungal populations impacted by crop rotations.  

Science.gov (United States)

The application of molecular markers enables scientists to clarify the genetic relationships among fungi who are difficult to classify or partition into sub-species using traditional morphological or physiological criteria. One such fungus is Macrophomina phaseolina, a plant pathogenic soil-borne fungus that is the causative agent of Charcoal Rot on soybeans and 500 other plant species world-wide. This plant pathogenic fungus is a very heterogeneous species and disease population dynamics and pathogen genetic diversity are poorly understood. Using a multi-variant Amplified Fragment Length Polymorphism (AFLP) approach for the analysis of genomic data, valuable insight into cultural and environmental pressures that shape the fungal genome was possible. Fungal isolates from 12-year rotated field plots ranging from 1-3 years of crop rotations of the same plant type(s), rotation duration and plant maturity groups provided a unique opportunity to survey M. phaseolina isolates taken from the different crop rotation conditions. Using different data interval partitioning of amplified restriction fragments it was possible to see trends associated with the specific cropping history of the fungal isolates. AFLP neutral primers of intermediate and large amplified products using 20-bp intervals were the most efficient and reliable for demonstrating intra-population dynamics. Results indicate that the highest amount of M. phaseolina genetic diversity was conclusively found in fungal isolates taken from three-year rotation plots. Lesser amounts of genetic diversity were found in two-year rotated and non-rotated fungal isolates. Insight gained from this study may now be incorporated into a larger understanding of how crop rotation and the availability of hosts shape and influence the genetic variability within Macrophomina isolates and populations. This information can then be used to make better-informed decisions regarding crop protection strategies against this diverse and economically important fungal pathogen. PMID:19226737

Brooker, N; Lord, J R; Long, J; Jayawardhana, A

2008-01-01

90

Controle de doenças de plantas pela rotação de culturas/ Control of plant disease by crop rotation  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Esta revisão aborda a importância da escolha e da adoção de práticas culturais e seus reflexos na intensidade de doenças de plantas. São apresentados conceitos básicos referente ao tema e os de rotação e monocultura. Discutem-se os princípios ou fundamentos e potencialidade do uso da rotação e do manejo integrado de doenças, as consequências da nutrição de fitopatógenos, dos eventos biológicos ocorrentes nos restos culturais, as características dos fitopatógenos potencialmente controláveis e dos não controláveis pela rotação. Abstract in english This review deals with the importance of the selection and use of cultural practices and their reflex in plant disease intensity. Basic concepts related to the subject and crop rotation and monoculture are presented. Principles fundaments are discussed in addition to, the potential use of crop rotation integrated disease management. The consequences of plant pathogens nutrition, biological events in crop residues, characteristics of phytopathogens potentially controlled and not controlled by rotation are also dealt.

Reis, Erlei Melo; Casa, Ricardo Trezzi; Bianchin, Vânia

2011-09-01

91

Controle de doenças de plantas pela rotação de culturas Control of plant disease by crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available Esta revisão aborda a importância da escolha e da adoção de práticas culturais e seus reflexos na intensidade de doenças de plantas. São apresentados conceitos básicos referente ao tema e os de rotação e monocultura. Discutem-se os princípios ou fundamentos e potencialidade do uso da rotação e do manejo integrado de doenças, as consequências da nutrição de fitopatógenos, dos eventos biológicos ocorrentes nos restos culturais, as características dos fitopatógenos potencialmente controláveis e dos não controláveis pela rotação.This review deals with the importance of the selection and use of cultural practices and their reflex in plant disease intensity. Basic concepts related to the subject and crop rotation and monoculture are presented. Principles fundaments are discussed in addition to, the potential use of crop rotation integrated disease management. The consequences of plant pathogens nutrition, biological events in crop residues, characteristics of phytopathogens potentially controlled and not controlled by rotation are also dealt.

Erlei Melo Reis; Ricardo Trezzi Casa; Vânia Bianchin

2011-01-01

92

Effect of Tropical Rotation Crops on Meloidogyne incognita and Other Plant-Parasitic Nematodes.  

UK PubMed Central (United Kingdom)

In a field experiment conducted on sandy soil in Florida during the 1993 season, rotation crops of castor (Ricinus communis), velvetbean (Mucuna deeringina), 'Mississippi Silver' cowpea (Vigna unguiculata), American jointvetch (Aeschynomene americana), 'Dehapine 51' cotton (Gossypium hirsutum), and 'SX-17' sorghum-sudangrass (Sorghum bicolor x S. sudanense) were effective in maintaining low population densities (<12/100 cm(3) soil) of Meloidogyne incognita race 1, whereas high population densities (>450/100 cm(3) soil) resulted after 'Clemson Spineless' okra (Hibiscus esculentus) and 'Kirby' soybean (Glycine max). Following a winter cover crop of rye (Secale cereale), densities of M. incognita following the six most effective rotation crops (1993 season) remained relatively low (crop planted in 1994, but increased by the end of the eggplant crop. The rotation crops planted during 1993 had little effect on yield of eggplant in 1994. Eggplant yield was inversely correlated with preplant densities (Pi) of Belonolaimus longicaudatus (r = -0.282; P crop cultivars were lower (P rotation crops intended for suppression of individual Meloidogyne spp. be evaluated for their response to other nematode pests as well.

McSorley R; Dickson DW

1995-12-01

93

Effect of Tropical Rotation Crops on Meloidogyne incognita and Other Plant-Parasitic Nematodes.  

Science.gov (United States)

In a field experiment conducted on sandy soil in Florida during the 1993 season, rotation crops of castor (Ricinus communis), velvetbean (Mucuna deeringina), 'Mississippi Silver' cowpea (Vigna unguiculata), American jointvetch (Aeschynomene americana), 'Dehapine 51' cotton (Gossypium hirsutum), and 'SX-17' sorghum-sudangrass (Sorghum bicolor x S. sudanense) were effective in maintaining low population densities (450/100 cm(3) soil) resulted after 'Clemson Spineless' okra (Hibiscus esculentus) and 'Kirby' soybean (Glycine max). Following a winter cover crop of rye (Secale cereale), densities of M. incognita following the six most effective rotation crops (1993 season) remained relatively low (crop planted in 1994, but increased by the end of the eggplant crop. The rotation crops planted during 1993 had little effect on yield of eggplant in 1994. Eggplant yield was inversely correlated with preplant densities (Pi) of Belonolaimus longicaudatus (r = -0.282; P crop cultivars were lower (P rotation crops intended for suppression of individual Meloidogyne spp. be evaluated for their response to other nematode pests as well. PMID:19277319

McSorley, R; Dickson, D W

1995-12-01

94

Influence of Rotation Crops on the Strawberry Pathogens Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae.  

Science.gov (United States)

Field microplot, small plot, and greenhouse experiments were conducted to determine the effects of rotation crops on Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae populations. Extraction of P. penetrans from roots and soil in microplots and field plots planted to rotation crops was highest for Garry oat, lowest for Triple S sorgho-sudangrass and Saia oat, and intermediate for strawberry, buckwheat, and canola. Isolation of R. fragariae from bait roots was highest for strawberry and canola after 2 years of rotation and lowest for Saia oat. Nematode extraction from roots of rotation crops in field soils was generally higher than from roots in microplots. Grasses were nonhosts of M. hapla. Strawberry, canola, and buckwheat supported root-knot populations over time, but there were no differences in nematode numbers regardless of crop after one season of strawberry growth. Garry oat, canola, and, to a lesser extent, buckwheat supported large populations of P. penetrans without visible root symptoms. Strawberry plants supported fewer nematodes due to root damage. Nematode numbers from soil were less than from roots for all crops. While there were similar trends for pathogen recovery after more than 1 year of strawberry growth following rotation, differences in pathogen density and fruit yield were not significant. In the greenhouse, P. penetrans populations in roots and soil in pots were much higher for Garry oat than for Saia oat. Total P. penetrans adult and juvenile numbers per pot ranged from 40 to 880 (mean = 365.6) for Garry oat and 0 to 40 (mean = 8.7) for Saia oat. Production of Saia oat as a rotation crop may be a means of managing strawberry nematodes and black root rot in Connecticut. PMID:19270931

Lamondia, J A

1999-12-01

95

Influence of Rotation Crops on the Strawberry Pathogens Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae.  

UK PubMed Central (United Kingdom)

Field microplot, small plot, and greenhouse experiments were conducted to determine the effects of rotation crops on Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae populations. Extraction of P. penetrans from roots and soil in microplots and field plots planted to rotation crops was highest for Garry oat, lowest for Triple S sorgho-sudangrass and Saia oat, and intermediate for strawberry, buckwheat, and canola. Isolation of R. fragariae from bait roots was highest for strawberry and canola after 2 years of rotation and lowest for Saia oat. Nematode extraction from roots of rotation crops in field soils was generally higher than from roots in microplots. Grasses were nonhosts of M. hapla. Strawberry, canola, and buckwheat supported root-knot populations over time, but there were no differences in nematode numbers regardless of crop after one season of strawberry growth. Garry oat, canola, and, to a lesser extent, buckwheat supported large populations of P. penetrans without visible root symptoms. Strawberry plants supported fewer nematodes due to root damage. Nematode numbers from soil were less than from roots for all crops. While there were similar trends for pathogen recovery after more than 1 year of strawberry growth following rotation, differences in pathogen density and fruit yield were not significant. In the greenhouse, P. penetrans populations in roots and soil in pots were much higher for Garry oat than for Saia oat. Total P. penetrans adult and juvenile numbers per pot ranged from 40 to 880 (mean = 365.6) for Garry oat and 0 to 40 (mean = 8.7) for Saia oat. Production of Saia oat as a rotation crop may be a means of managing strawberry nematodes and black root rot in Connecticut.

Lamondia JA

1999-12-01

96

Nitrous oxide emissions from crop rotations including wheat, rapeseed and dry pea  

Directory of Open Access Journals (Sweden)

Full Text Available Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas, originate from soils at global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes allow to reduce N fertilizer use, and possibly N2O emission. Nevertheless, the decomposition of crop organic matter during the crop cycle and during the residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity) and from the subsequent crops in comparison with N2O emissions from wheat and oilseed-rape crops, fertilized or not, in various rotations. A field experiment was conducted during 4 consecutive years, aiming at comparing the emissions during the pea crop, in comparison with those during the wheat (fertilized or not) or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly linked with the site soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after pea. These results, combined with the emission reduction allowed by the production and transport of the N fertiliser not applied on the pea crop, should be confirmed in a larger range of soil types. Nevertheless, they demonstrate the absence of N2O emission linked to the symbiotic N fixation process, and allow us to estimate the decrease of N2O emissions to 20–25% by including one pea crop in a three-year rotation. At a larger scale, this reduction of GHG emissions at field level has to be cumulated with the reduction of GHG emissions linked with the lower level of production and transport of the N fertiliser not applied on the pea crop.

M. H. Jeuffroy; E. Baranger; B. Carrouée; E. de Chezelles; M. Gosme; C. Hénault; A. Schneider; P. Cellier

2012-01-01

97

Nitrous oxide emissions from crop rotations including wheat, rapeseed and dry pea  

Science.gov (United States)

Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas, originate from soils at global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes allow to reduce N fertilizer use, and possibly N2O emission. Nevertheless, the decomposition of crop organic matter during the crop cycle and during the residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity) and from the subsequent crops in comparison with N2O emissions from wheat and oilseed-rape crops, fertilized or not, in various rotations. A field experiment was conducted during 4 consecutive years, aiming at comparing the emissions during the pea crop, in comparison with those during the wheat (fertilized or not) or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly linked with the site soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after pea. These results, combined with the emission reduction allowed by the production and transport of the N fertiliser not applied on the pea crop, should be confirmed in a larger range of soil types. Nevertheless, they demonstrate the absence of N2O emission linked to the symbiotic N fixation process, and allow us to estimate the decrease of N2O emissions to 20-25% by including one pea crop in a three-year rotation. At a larger scale, this reduction of GHG emissions at field level has to be cumulated with the reduction of GHG emissions linked with the lower level of production and transport of the N fertiliser not applied on the pea crop.

Jeuffroy, M. H.; Baranger, E.; Carrouée, B.; de Chezelles, E.; Gosme, M.; Hénault, C.; Schneider, A.; Cellier, P.

2012-07-01

98

Yield trends in the long-term crop rotation with organic and inorganic fertilisers on Alisols in Mata (Rwanda)  

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Full Text Available A crop rotation system with various species was established on «Alisols» at Mata grassland site, oriental side of Zaire-Nile Watershed Divide (CZN), Rwanda. Inorganic and organic fertilisers were applied in various plots led in randomised complete blocs with three replicates. Crop yield data were each season recorded over a 9-year period. Results showed that there was very low or no harvest in plots without fertilisers. Where fertilisers were applied, the yield generally increased but remained relatively low: only few crops and varieties adapted to the Mata ecology such as potatoes and fi nger millet responded well to fertilisers. Liming was absolutely necessary to get any acceptable crop yield improvement with NPK. High rate of rich farmyard manure was effi cient alone and its effect was seen up to 4 seasons after its four regular seasonal applications. Mata compost (C/N>25, 0,3 g P.kg-1) had little benefi cial effect. One, four and half, and eight tons of lime per ha applied 3 times in 8 years increased soil pH (in water) but not up to 6,5. It is then concluded that to succeed improving food production at the CZN area, selection of crops and varieties to fi t ecological conditions and amending soils to fi t crops be combined, but not opposed.

Rutunga V.; Neel H.

2006-01-01

99

Soil enzyme activities under long-term tillage and crop rotation systems in subtropical agro-ecosystems/ Atividade enzimática em solo sob plantio direto e rotações de culturas em agro-ecossistema subtropical  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Práticas agrícolas que reduzam a degradação do solo e promovam sustentabilidade são importantes para os agrossistemas tropicais/subtropicais. O plantio direto (PD) diminui as perdas de solo e, se combinado com rotação de culturas pode proteger o solo da degradação físico-química provocada pela agricultura intensiva. A atividade enzimática do solo pode fornecer importantes informações de como o manejo do solo está afetando a decomposição da material orgân (more) ica e a ciclagem dos nutrientes. Assim, avaliou-se a atividade das enzimas amilase, celulose, arilsulfatase, fosfatase ácida e fosfatase alcalina em um experimento a campo, instalado em 1976 em Londrina, PR, que tem como tratamentos o preparo do solo (plantio direto ou convencional) nas parcelas e a rotação de culturas (soja/trigo, milho/trigo e algodão/trigo) nas subparcelas. Amostras de solos foram coletadas a 0-5, 5-10 e 10-20 cm de profundidade em 1997 e 1998. Na profundidade de 0-5 cm sob PD, observaram-se aumentos de 68% na atividade da amilase, 90% na celulase, 219% na arilsulfatase, 46% na fosfatase ácida e 61% na fosfatase alcalina. Observaram-se correlações significativas entre a atividade enzimática e o C-orgânico total do solo e o C e N da biomassa microbiana. Esses resultados evidenciam que a atividade enzimática do solo é um indicador sensível de alterações na qualidade do solo, promovidas pelo manejo. Abstract in english Agricultural practices that reduce soil degradation and improve agricultural sustainability are needed particularly for tropical/subtropical soils. No-tillage planting causes minimal soil disturbance and combined with crop rotation may hold potential to meet these goals. Soil enzyme activities can provide information on how soil management is affecting the potential to perform the processes in soils such as decomposition and nutrient cycling. Soil enzyme activities were i (more) nvestigated in a split-plot experiment (3 replications) where tillage (no till and conventional) was the main plot and crop rotation (soybean/wheat, S/W; maize/wheat, M/W or cotton/wheat, C/W) was the subplot. The experiment was established in 1976 in southern Brazil. Soil samples were taken at 0-5, 5-10 and 10-20 cm depths in 1997 and 1998. The 0-5 cm layer under NT system showed increases up 68% for amylase, 90% for cellulase, 219% for arylsulfatase, 46% for acid phosphatase, and 61% for alkaline phosphatase. There were significant correlations of soil enzyme activities with total organic C, and C and N microbial biomass. These results showed that NT increased microbial activity and that soil enzyme activity is a sensitive indicator of alteration soil quality by management.

Balota, Elcio Liborio; Kanashiro, Miriam; Colozzi Filho, Arnaldo; Andrade, Diva Souza; Dick, Richard Peter

2004-12-01

100

EFFECT OF CROP ROTATION AND LONG TERM FERTILIZATION ON THE CARBON AND GLOMALIN CONTENT IN THE SOIL  

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Full Text Available The research was performed on the basis of soil samples taken from a multi-year long fertilization experiment carried out in Skierniewice. The source of samples was soil under potato and rye cultivated in monoculture and in the 5-fields rotation system. The following combinations of fertilization were concerned: Ca, NPK and CaNPK (doses since 1976: 1.6 t·ha-1 CaO every 4 years in monoculture and 2 t·ha-1 CaO every 5 years in crop rotation, 90 kg·ha-1 N, 26 kg·ha-1 P, 91 kg·ha-1 K). Laboratory analyzes involved determination of total organic carbon (TOC) and glomalin operationally described as a total glomalin related soil protein (TGRSP). It was found that regardless of cultivated plants and the method of fertilization, only cultivation system such as rotation and monoculture significantly influenced the content of TGRSP. TOC was significantly influenced by interaction between species of cultivated plant and the system of cultivation. The analyzed factors within the method of cultivation (monoculture and crop rotation) did not influence significantly the TGRSP content while cultivated plant species, in monoculture, significantly influenced on TOC content. There was also noted positive correlation (r = 0.72) between TGRSP and TOC.

Piotr WOJEWÓDZKI; Bogumi?a CIESCINSKA

2012-01-01

 
 
 
 
101

Future Market Scenarios for Pulpwood Supply from Agricultural Short-Rotation Woody Crops  

Energy Technology Data Exchange (ETDEWEB)

NAPAP model and USDS POLYSYS models were linked to project future market scenarios of pulpwood supply from agricultural short-rotation woody crops in the US. Results suggest that pulpwood supply from fast-growing hybrid poplars and cottonwoods will become marginally economical but fairly limited in the next several decades.

Alexander N. Moiseyev; Daniel G. de la Torre Ugarte; Peter J. Ince

2000-10-13

102

Effects of grass-clover management and cover crops on nitrogen cycling and nitrous oxide emissions in a stockless organic crop rotation  

DEFF Research Database (Denmark)

Nitrogen (N) supply in stockless organic farming may be improved through use of grass-clover for anaerobic digestion, producing biogas and digested manure for use as fertilizer in the crop rotation. We studied the effects of grass-clover management on N cycling, nitrous oxide (N2O) emissions and cash-crop yields in an organic arable crop rotation on a sandy loam soil in a cool temperate climate. The four-course crop rotation included spring barley (with undersown grass-clover), grass-clover, potato and winter wheat (with undersown cover crop). Two fertilization treatments were compared: “?M” where plant material from grass-clover cuts was left in the field to decompose and no fertilizer or manure was applied to any crop in the rotation; and “+M” where plant material from grass-clover cuts was harvested and equivalent amounts of N in digested manure used for fertilization of cash crops in the rotation (spring barley, potato and winter wheat); actual digestion of grass-clover cuttings was not possible, instead digested pig manure was used as substitute for digested grass-clover. Nitrous oxide fluxes were monitored between April 2008 and May 2009. In general, application of digested manure had little or no effect on N2O emissions. Periods of high N2O emissions coincided with cover crop and grass-clover residue turnover, with little added effect of digested manure application. Annual N2O emissions did not vary between fertilization treatments, but the +M treatment had cash crop dry matter yields that were 14% higher than in the ?M treatment, and cash crop N yields were increased by 40%. The results show that reallocation of nutrients from grass-clover to cash crops following anaerobic digestion can help solve problems with low N availability. However, issues remain regarding N2O from cover crops and grass-clover in spring.

Brozyna, M A; Petersen, SØren O

2013-01-01

103

Effect of Crop Rotation on the Soil Pathogen Population Dynamics and Canola Seedling Establishment  

Directory of Open Access Journals (Sweden)

Full Text Available Impact of long-term crop rotations on populations of soilborne pathogens in the genera Fusarium, Pythium and Rhizoctonia and on canola seedling establishment and development was evaluated under controlled conditions. Soil samples were collected from two crop rotation experiments conducted at two sites in Saskatchewan, Canada. A part of the 2006-soil sample of each rotation was sterilized to compare canola seedling growth with and without soilborne pathogens. With 2007-soil, the sterilization treatment was replaced with a fungicide seed treatment (Apron Maxx) to assess the potential to reduce seedling diseases. Populations of Fusarium, Pythium and Rhizoctonia sp. were estimated in the soil of each rotation using dilution plating onto selective media for each fungus. Higher seedling emergence and increased growth of canola were obtained in the sterilized soil or due to seed treatment. Fusarium was the predominant genus followed by Pythium and Rhizoctonia sp. in the soil of both sites. This study suggests that diverse crop in the rotation may reduce the populations of Fusarium, Pythium and Rhizoctonia in the soil and may contribute to improve the overall growth of canola.

S.F. Hwang; H.U. Ahmed; B.D. Gossen; H.R. Kutcher; S.A. Brandt; S.E. Strelkov; K.F. Chang; G.D. Turnbull

2009-01-01

104

Mycocentrospora acerina in carrots; effects of crop rotation on disease incidence.  

UK PubMed Central (United Kingdom)

Four experimental sites located in different climatic regions in Norway were inoculated with Mycocentrospora acerina in 1985. In 1986, crop rotation experiments including carrot, barley, grass, red clover, onion and potato, were established at these sites. Incidence of M. acerina on the foliage and the roots of carrots after storage were recorded in 1989/90 and 1994/95. The 3 yr rotation only slightly reduced the inoculum of M. acerina in the soil. Red clover and grass were the most effective crops in reducing the inoculum, potato and barley were less effective, and onion had no effect on the inoculum. Differences in M. acerina infection on carrots between 3, 6 and 8 yr of rotation with barley and grass were not statistically significant. 22 October 1997 17 December 1996

Hermansen A; Amundsen T; Taksdal G; Dragland S; Synnevag G; Flones M; Sundheim L

1997-12-01

105

Long-term C-CO2 emissions and carbon crop residue mineralization in an oxisol under different tillage and crop rotation systems/ Emissões deC-CO2 de longo prazo e a mineralização do carbono dos resíduos culturais em um latossolo sob diferentes sistemas de preparo e rotação de culturas  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A emissão de C-CO2 do solo é considerada um indicador sensível dos impactos de sistemas de manejo sobre a matéria orgânica do solo (MOS). Nos sistemas agrícolas, as principais fontes de C-CO2 são as decomposições dos resíduos culturais e da MOS, além da respiração das raízes das culturas e da biota do solo. O principal objetivo deste estudo foi avaliar o impacto de sistemas de preparo do solo e culturas nas emissões de longo prazo de C-CO2 do solo e sua rel (more) ação com a mineralização do carbono (C) de resíduos culturais. Este estudo foi desenvolvido em experimento de longa duração, em Latossolo Vermelho distrófico típico, de ocorrência na região de Cruz Alta, RS, Brasil. O clima é o subtropical Cfa, segundo a classificação de Köppen, com precipitação pluvial anual média de 1.744 mm e temperatura média anual de 19,2 ºC. Os tratamentos investigados foram dois sistemas de preparo - convencional (PC) e plantio direto (PD) - e três sistemas de culturas: R0- sucessão de monoculturas (trigo/soja); R1- rotação de culturas de inverno (aveia-preta/soja/trigo/soja); e R2- rotação intensiva de culturas (aveia-preta/soja/aveia-preta+ervilhaca/milho /nabo forrageiro/trigo/soja). O efluxo de C-CO2 do solo foi avaliado em intervalos fixos de 14 dias, durante dois anos (48 avaliações), por meio da captura do dióxido de carbono em solução alcalina. A umidade gravimétrica do solo, na camada de 0-0,05 m, foi determinada concomitantemente com as medições de C-CO2. Ainda, foi avaliada a taxa de liberação do C dos resíduos culturais utilizando o método dos sacos de decomposição, com amostragens aos 14, 28, 56, 84, 112 e 140 dias após o início das avaliações de mineralização do C. Foram utilizados quatro índices de conservação do C para avaliar a relação entre as emissões de C-CO2 e estoques de C e seus compartimentos no solo. A mineralização do C dos resíduos culturais no tempo seguiu o modelo exponencial. Para os resíduos de aveia-preta, trigo e milho, a mineralização do C foi maior no CT do que no PD, enquanto para a soja foi semelhante entre os sistemas de preparo do solo. A umidade do solo foi maior sob PD do que no PC, especialmente no segundo ano de avaliação. Não houve diferença na emissão média anual de C-CO2 entre sistemas de preparo; diferenças foram observadas apenas em algumas avaliações individuais. As emissões de C-CO2 seguiram padrão bimodal, com picos nos meses de outubro-novembro e fevereiro-março. As maiores emissões de C-CO2 foram registradas no verão, e as menores, no inverno. As emissões de C-CO2 apresentaram baixa correlação com a temperatura do ar e não foram influenciadas pela umidade do solo. Com base nos índices de conservação de C investigados, o PD associado à rotação intensiva de culturas foi mais conservador de C do que o PC com sucessão de culturas. Abstract in english Soil C-CO2 emissions are sensitive indicators of management system impacts on soil organic matter (SOM). The main soil C-CO2 sources at the soil-plant interface are the decomposition of crop residues, SOM turnover, and respiration of roots and soil biota. The objectives of this study were to evaluate the impacts of tillage and cropping systems on long-term soil C-CO2 emissions and their relationship with carbon (C) mineralization of crop residues. A long-term experiment w (more) as conducted in a Red Oxisol in Cruz Alta, RS, Brazil, with subtropical climate Cfa (Köppen classification), mean annual precipitation of 1,774 mm and mean annual temperature of 19.2 ºC. Treatments consisted of two tillage systems: (a) conventional tillage (CT) and (b) no tillage (NT) in combination with three cropping systems: (a) R0- monoculture system (soybean/wheat), (b) R1- winter crop rotation (soybean/wheat/soybean/black oat), and (c) R2- intensive crop rotation (soybean/ black oat/soybean/black oat + common vetch/maize/oilseed radish/wheat). The soil C-CO2 efflux was measured every 14 days for two years (48 measurements)

Campos, Ben-Hur Costa de; Amado, Telmo Jorge Carneiro; Tornquist, Carlos Gustavo; Nicoloso, Rodrigo da Silveira; Fiorin, Jackson Ernani

2011-06-01

106

European Perspectives on the Adoption of Nonchemical Weed Management in Reduced -Tillage Systems for Arable Crops  

DEFF Research Database (Denmark)

Noninversion tillage with tine- or disc-based cultivations prior to crop establishment is the most common way of reducing tillage for arable cropping systems with small grain cereals, oilseed rape, and maize in Europe. However, new regulations on pesticide use might hinder further expansion of reduced-tillage systems. European agriculture is asked to become less dependent on pesticides and promote crop protection programs based on integrated pest management (IPM) principles. Conventional noninversion tillage systems rely entirely on the availability of glyphosate products, and herbicide consumption is mostly higher compared to plow-based cropping systems. Annual grass weeds and catchweed bedstraw often constitute the principal weed problems in noninversion tillage systems, and crop rotations concurrently have very high proportions of winter cereals. There is a need to redesign cropping systems to allow for more diversification of the crop rotations to combat these weed problems with less herbicide input. Cover crops, stubble management strategies, and tactics that strengthen crop growth relative to weed growth are also seen as important components in future IPM systems, but their impact in noninversion tillage systems needs validation. Direct mechanical weed control methods based on rotating weeding devices such as rotary hoes could become useful in reduced-tillage systems where more crop residues and less workable soils are more prevalent, but further development is needed for effective application. Owing to the frequent use of glyphosate in reduced-tillage systems, perennial weeds are not particularly problematic. However, results from organic cropping systems clearly reveal that desisting from glyphosate use inevitably leads to more problems with perennials, which need to be addressed in future research.

Melander, Bo; Munier-Jolain, Nicolas

2013-01-01

107

Crop isolation, not extended rotation length, reduces blackleg (Leptosphaeria maculans) severity of canola (Brassica napus) in south-eastern Australia.  

UK PubMed Central (United Kingdom)

Due to the large increase of canola production in Australia, current blackleg cultural control recommendations (extended rotation length and isolation distance from canola stubble) are not adhered to by farmers in many canola-producing regions. Canola crops are increasingly being sown in short rotation and, in many instances, adjacent to paddocks containing canola stubble. In this study, the level of disease in commercial canola crops was determined for different rotations and distances from canola stubble. There was a strong relationship between the presence of canola stubble from the previous year (6-month-old stubble) and distance to current canola crops, but no relationship between the presence of older (18–42 month old) stubble and distance to current canola crops. Blackleg severity was highest where canola crops had been sown adjacent to 6-month-old canola stubble, with the level of blackleg severity decreasing markedly in the first 100 m. Disease severity then generally declined up to 500 m. Plants 500–1000 m from 6-month-old stubble had similar levels of blackleg infection. Blackleg severity was similar between canola crops sown into 18-month-old canola stubble (short rotation) and crops sown into paddocks that had no history of canola for at least the previous 3 years (long rotation). Based on these findings, we recommend that canola crops should be sown at distances greater than 100 m and preferably 500 m from last season's canola stubble, rather than extending rotation length between crops.

Marcroft SJ; Sprague SJ; Pymer SJ; Salisbury PA; Howlett BJ

2004-01-01

108

Biogas from ley crops  

International Nuclear Information System (INIS)

This report describes the cost of producing biogas from energy crops. Five process systems, sized 0.25-8 MW are studied. The cultivation of biogas-crops is made in three regions in Sweden. Also valued are the positive cultivation effects obtained when cereal dominated crop rotation is broken by biogas crops. 8 refs, 40 figs, 10 tabs.

1993-01-01

109

Evaluation of Cuphea as a rotation crop for control of western corn rootworm (Coleoptera: Chrysomelidae).  

Science.gov (United States)

The ability to prevent significant root feeding damage to corn, Zea mays L., by the western corn rootworm, Diabrotica virgifera virgifera LeConte, by crop rotation with soybean, Glycine max (L.) Merr., has been lost in portions of the Corn Belt because this pest has adapted to laying eggs in soybean fields. Cuphea spp. has been proposed as a new broadleaf crop that may provide an undesirable habitat for rootworm adults because of its sticky surface and therefore may reduce or prevent oviposition in these fields. A 4-yr study (1 yr to establish seven rotation programs followed by 3 yr of evaluation) was conducted to determine whether crop rotation with Cuphea would provide cultural control of corn rootworm. In support of Cuphea as a rotation crop, fewer beetles were captured by sticky traps in plots of Cuphea over the 4 yr of this study compared with traps in corn and soybean, suggesting that fewer eggs may be laid in plots planted to Cuphea. Also, corn grown after Cuphea was significantly taller during vegetative growth, had significantly lower root damage ratings for 2 of 3 yr, and had significantly higher yields for 2 of 3 yr compared with continuous corn plots. In contrast to these benefits, growing Cuphea did not prevent economic damage to subsequent corn crops as indicated by root damage ratings > 3.0 recorded for corn plants in plots rotated from Cuphea, and sticky trap catches that exceeded the threshold of five beetles trap(-1) day(-1). Beetle emergence from corn plots rotated from Cuphea was significantly lower, not different and significantly higher compared with beetle emergence from continuous corn plots for 2002, 2003 and 2004 growing seasons, respectively. A high number of beetles were captured by emergence cages in plots planted to Cuphea, indicating that rootworm larvae may be capable of completing larval development by feeding on roots of Cuphea, although peak emergence lagged approximately 4 wk behind peak emergence from corn. Based on these data, it is unlikely that crop rotation with Cuphea will provide consistent, economical, cultural control of corn rootworm. PMID:16539123

Behle, Robert W; Isbell, Terry A

2005-12-01

110

Evaluation of Cuphea as a rotation crop for control of western corn rootworm (Coleoptera: Chrysomelidae).  

UK PubMed Central (United Kingdom)

The ability to prevent significant root feeding damage to corn, Zea mays L., by the western corn rootworm, Diabrotica virgifera virgifera LeConte, by crop rotation with soybean, Glycine max (L.) Merr., has been lost in portions of the Corn Belt because this pest has adapted to laying eggs in soybean fields. Cuphea spp. has been proposed as a new broadleaf crop that may provide an undesirable habitat for rootworm adults because of its sticky surface and therefore may reduce or prevent oviposition in these fields. A 4-yr study (1 yr to establish seven rotation programs followed by 3 yr of evaluation) was conducted to determine whether crop rotation with Cuphea would provide cultural control of corn rootworm. In support of Cuphea as a rotation crop, fewer beetles were captured by sticky traps in plots of Cuphea over the 4 yr of this study compared with traps in corn and soybean, suggesting that fewer eggs may be laid in plots planted to Cuphea. Also, corn grown after Cuphea was significantly taller during vegetative growth, had significantly lower root damage ratings for 2 of 3 yr, and had significantly higher yields for 2 of 3 yr compared with continuous corn plots. In contrast to these benefits, growing Cuphea did not prevent economic damage to subsequent corn crops as indicated by root damage ratings > 3.0 recorded for corn plants in plots rotated from Cuphea, and sticky trap catches that exceeded the threshold of five beetles trap(-1) day(-1). Beetle emergence from corn plots rotated from Cuphea was significantly lower, not different and significantly higher compared with beetle emergence from continuous corn plots for 2002, 2003 and 2004 growing seasons, respectively. A high number of beetles were captured by emergence cages in plots planted to Cuphea, indicating that rootworm larvae may be capable of completing larval development by feeding on roots of Cuphea, although peak emergence lagged approximately 4 wk behind peak emergence from corn. Based on these data, it is unlikely that crop rotation with Cuphea will provide consistent, economical, cultural control of corn rootworm.

Behle RW; Isbell TA

2005-12-01

111

Effect of Rotation Crops on Heterodera glycines Population Density in a Greenhouse Screening Study.  

Science.gov (United States)

Crop rotation is a common means of reducing pathogen populations in soil. Several rotation crops have been shown to reduce soybean cyst nematode (Heterodera glycines) populations, but a comprehensive study of the optimal crops is needed. A greenhouse study was conducted to determine the effect of growth and decomposition of 46 crops on population density of H. glycines. Crops were sown in soil infested with H. glycines. Plants were maintained until 75 days after planting, when the soil was mixed, a sample of the soil removed to determine egg density, and shoots and roots chopped and mixed into the soil. After 56 days, soil samples were again taken for egg counts, and a susceptible soybean ('Sturdy') was planted in the soil as a bioassay to determine egg viability. Sunn hemp (Crotalaria juncea), forage pea (Pisum sativum), lab-lab bean (Lablab purpureus), Illinois bundleflower (Desman-thus illinoensis), and alfalfa (Medicago sativa) generally resulted in smaller egg population density in soil or number of cysts formed on soybean in the bioassay than the fallow control. Sunn hemp most consistently showed the lowest numbers of eggs and cysts. As a group, legumes resulted in lower egg population densities than monocots, Brassica species, and other dicots. PMID:19259545

Warnke, S A; Chen, S Y; Wyse, D L; Johnson, G A; Porter, P M

2006-09-01

112

Faraday rotation system. Topical report  

Energy Technology Data Exchange (ETDEWEB)

The Faraday Rotation System (FRS) is one of the advanced laser-based diagnostics developed at DIAL to provide support for the demonstration of prototype-scale coal-fired combustion magnetohydrodynamic (MHD) electrical power generation. Intended for application in the MHD channel, the system directly measures electron density through a measurement of the induced rotation in the polarization of a far infrared laser beam after passing through the MHD flow along the magnetic field lines. A measurement of the induced polarization ellipticity provides a measure of the electron collision frequency which together with the electron density gives the electron conductivity, a crucial parameter for MHD channel performance. The theory of the measurements, a description of the system, its capabilities, laboratory demonstration measurements on seeded flames with comparison to emission absorption measurements, and the current status of the system are presented in this final report.

Bauman, L.E.; Wang, W.

1994-07-01

113

[Influence of double rice cropping system innovation on paddy soil profile form and soil characteristics].  

UK PubMed Central (United Kingdom)

Field experiments were conducted on the double rice cropping paddy field in red soil area to evaluate the influence of cropping system innovation on soil profile form and related soil characteristics. Four cropping systems of rice-rice-Chinese Milkvetch (Astragalus sinicus Linn.), forage, paddy-upland rotation, and upland were substituted for the double rice cropping system. The results indicated that compared with those under double rice cropping system, the thickness of cultivated horizon under upland cropping system increased by 4 cm, that of plow pan declined by 2 cm, > 2 mm aggregates in wet-sieved particle-size fractions increased by 6.94%, wet-sieved mean-mass diameter increased by 0.37 mm, contents of humic acid carbon and fulvic acid carbon increased by 0.15 and 0.49 g kg(-1), respectively, and quotient of aggregates water stability was 0.78 times higher. Under paddy-upland rotation, the quotient of aggregates water stability was higher (95.86), while soil nutrient contents changed a little. Under rice-rice-Chinese Milkvetch system, soil organic matter content increased by 1.3 g kg(-1), quotient of aggregates water stability declined by 8.82, but other parameters had less changes. Under forage system, the thickness of cultivated and transitional horizons increased by 2 cm and 9 cm, respectively, quotient of aggregates water stability increased by 1.39, while the contents of soil organic matter and total potassium decreased by 5.6 and 2.8 g kg(-1), respectively. Among all test cropping systems, forage system had the greatest changes in soil characteristics. It was completely feasible to substitute the local double rice cropping system for paddy-upland rotation or upland cropping, particularly in the areas where full irrigation was not available. However, attention should be paid to the decrease of soil potassium content when the cropping system innovation was practiced.

Zeng XB; Sun N; Gao JS; Li LF; Wang BR; Bai LY

2008-05-01

114

[Influence of double rice cropping system innovation on paddy soil profile form and soil characteristics].  

Science.gov (United States)

Field experiments were conducted on the double rice cropping paddy field in red soil area to evaluate the influence of cropping system innovation on soil profile form and related soil characteristics. Four cropping systems of rice-rice-Chinese Milkvetch (Astragalus sinicus Linn.), forage, paddy-upland rotation, and upland were substituted for the double rice cropping system. The results indicated that compared with those under double rice cropping system, the thickness of cultivated horizon under upland cropping system increased by 4 cm, that of plow pan declined by 2 cm, > 2 mm aggregates in wet-sieved particle-size fractions increased by 6.94%, wet-sieved mean-mass diameter increased by 0.37 mm, contents of humic acid carbon and fulvic acid carbon increased by 0.15 and 0.49 g kg(-1), respectively, and quotient of aggregates water stability was 0.78 times higher. Under paddy-upland rotation, the quotient of aggregates water stability was higher (95.86), while soil nutrient contents changed a little. Under rice-rice-Chinese Milkvetch system, soil organic matter content increased by 1.3 g kg(-1), quotient of aggregates water stability declined by 8.82, but other parameters had less changes. Under forage system, the thickness of cultivated and transitional horizons increased by 2 cm and 9 cm, respectively, quotient of aggregates water stability increased by 1.39, while the contents of soil organic matter and total potassium decreased by 5.6 and 2.8 g kg(-1), respectively. Among all test cropping systems, forage system had the greatest changes in soil characteristics. It was completely feasible to substitute the local double rice cropping system for paddy-upland rotation or upland cropping, particularly in the areas where full irrigation was not available. However, attention should be paid to the decrease of soil potassium content when the cropping system innovation was practiced. PMID:18655589

Zeng, Xi-Bai; Sun, Nan; Gao, Ju-Sheng; Li, Lian-Fang; Wang, Bo-Ren; Bai, Ling-Yu

2008-05-01

115

Crop rotation and soil biochemical and microbiological characteristics and corn crop yield Rotação de culturas e relações com atributos químicos e microbiológicos do solo e produtividade do milho  

Directory of Open Access Journals (Sweden)

Full Text Available Soil management practices exert important influence on biological and biochemical properties of soil. This work aimed to valuate the impact of crop rotation on soil biochemical and microbiological attributes, as well and influence on corn crop yield. The experiment was carried out during 2005/06 crop season, in Dourados – MS, Brazil. Experimental design was randomized blocks with treatments established in sub-divided plots with tree replications, which seasons were plots and management systems were sub-plots. Studied seasons were winter and summer and no tillage systems were represented by five crop rotation schemes, which involved the cultures of hairy vetch, bean, oat, forage turnip, soybean, crotalaria, corn, sorghum, pearl millet, sunflower and, in conventional tillage, with corn in winter and with soybean in summer. Native vegetation constituted one treatment and, with conventional tillage, it was used as ecosystem of reference as control for comparison between possible alterations in chemical and microbiological attributes with the establishment of a system more conservationist for soil management. There was a positive correlation among Norg, Corg, Porg and C-BMS contents with chemical attributes of soil fertility, which shows interdependence between chemical and biology of soil. The elimination of native vegetation and the substitution for cultivation system after that reduce the C-BMS. In Cerrado conditions, studied cultivation systems increased phosphorus content in soil. Crop rotation influenced corn yield after the cultivation of determined species as crotalaria and vetch in crop rotation.As práticas de manejo do solo exercem importantes influências nas propriedades biológicas e bioquímicas do solo. Neste sentido, objetivou-se com este trabalho avaliar o impacto do manejo do solo nos atributos químicos e microbiológicos, bem como, a influência na produtividade da cultura do milho. O estudo foi realizado no ano agrícola de 2005/06, no Município de Dourados, MS, Brasil. O delineamento experimental foi de blocos casualizados com os tratamentos dispostos em parcelas subdivididas com três repetições, sendo as estações do ano alocados nas parcelas e os sistemas de manejo nas subparcelas. As estações estudadas foram inverno e verão e, os sistemas de manejo no plantio direto foram representados por cinco esquemas de rotação envolvendo as culturas ervilhaca peluda, feijão, aveia, nabo forrageiro, soja, crotalária, milho, sorgo, milheto, girassol e, no plantio convencional, com milho no inverno e soja no verão. A vegetação nativa constituiu um tratamento e, juntamente com o plantio convencional, foi utilizada como ecossistema de referência. Houve correlação positiva entre os teores de Norg, Corg, Porg e C-BMS com os atributos químicos de fertilidade do solo demonstrando a interdependência entre a química e a biologia do solo. A eliminação da vegetação nativa e posterior substituição por sistemas de cultivo reduze o C-BMS. Nas condições de Cerrado, os sistemas de cultivos estudados incrementam o teor de fósforo no solo. A rotação de culturas influencia a produtividade do milho quando cultivado após determinadas espécies de cobertura como crotalária e ervilhaca no sistema de rotação.

Elaine Reis Pinheiro Lourente; Fabio Martins Mercante; Marlene Estevão Marchetti; Luiz Carlos Ferreira de Souza; Cristiano Márcio Alves de Souza; Manoel Carlos Gonçalves; Maria Anita Gonçalves Silva

2010-01-01

116

Factors affecting soil organic matter conservation in Mediterranean hillside winter cereals-legumes cropping systems  

Directory of Open Access Journals (Sweden)

Full Text Available Soil conservation is an important issue for farming and environmental protection in Mediterranean areas. Hillside farming systems, based on winter cereals and legumes, are common in these areas and are the target of several environmental policies. Soil organic matter (SOM) is widely used to assess the environmental performance of these cropping systems. Nevertheless, few studies have considered soil conservation practices in hillside systems in terms of implementing more effective agro-environmental policies for these areas. This paper compares the SOM conservation of different winter cereal based cropping systems within Mediterranean hillside crops/livestock farms. Seventeen cropping systems were characterised by on-farm surveys in the inland hilly area of Grosseto (Tuscany, Italy). For each cropping system, we performed a SOM balance, based on Hénin-Dupuis’ equation, using either local environmental databases or data from on-farm surveys. Differences between cropping systems were analysed by the Kruskal-Wallis test. On average, the cropping systems identified did not guarantee SOM conservation and varied considerably from farm to farm, however, some practices seemed to have a positive performance, e.g. cropping systems of cattle farms. According to the literature, annual SOM balance differs significantly depending on crop rotation length and longer crop rotations performed better than shorter ones. However, we found a local effect indicating that this better performance was influenced by local farmers' cooperatives, which to some extent counteracted the negative effect of crop rotation length. There were significant differences in the performance of dairy sheep and cattle farms (-1031 kg ha-1 yr-1 vs. +103 kg ha-1 yr-1, respectively). This suggests that the presence of livestock did not have the same favourable effect on soil conservation in Mediterranean systems and that this factor should be more investigated. Surprisingly, in our sample, for the same crop rotation length, livestock density did not affect the annual SOM balance. Due to the high variability in local cropping systems and soil characteristics, further surveys on a larger sample are needed to confirm these trends. However, our results shed light on the soil conservation effects of Mediterranean hillside cropping systems of winter cereals and legumes, and could support the local implementation of agro-environmental measures.

Elisa Marraccini; Marta Debolini; Claudia Di Bene; Hélène Rapey; Enrico Bonari

2012-01-01

117

Climate change impact on crop rotations of winter durum wheat and tomato in southern Italy: yield analysis and soil fertility  

Directory of Open Access Journals (Sweden)

Full Text Available Cropping systems are affected by climate change because of the strong relationship between crop development, growth, yield, CO2 atmospheric concentration and climate conditions. The increasing temperatures and the reduction of available water resources may result in negative impacts on the agricultural activity in Mediterranean environments than other areas. In this study the CERES-Wheat and CROPGRO-Tomato models were used to assess the effects of climate change on winter wheat (Triticum durum L.) and processing tomato (Lycopersicon aesculentum Mill.) in one of most productive areas of Italy, located in the northern part of the Puglia region. In particular we have compared three different General Circulation Models (HadCM3, CCSM3, ECHAM5) subjected to a statistical downscaling under two future IPCC scenarios (B1 and A2). The analysis was carried out at regional scale repeating the simulations for seven homogeneous area characterizing the spatial variability of the region. In the second part of the study, considering only HadCM3 data set, climate change impact on long-term sequences of the two crops combined in three crop rotations were evaluated in terms of yield performances and soil fertility as indicated by the soil organic content of carbon and nitrogen. The comparison between GCMs showed no significant differences for winter durum wheat yield, while noticeable differences were found for yield and irrigation requirements of tomato. Under future scenarios, the production levels were reduced for tomato, whereas positive yield effects were observed for winter durum wheat. For winter durum wheat the simulation indicated that two- and three-year rotations, including one year of tomato cultivation, improved the cereal yield and this positive effect maintained its validity also in future scenarios. For both crops higher requirements of water and nitrogen were predicted under future scenarios. This result coupled with the decrease of yield caused negative reduction of water use efficiency and nitrogen use efficiency for tomato cultivation.

Domenico Ventrella; Luisa Giglio; Monia Charfeddine; Raffaele Lopez; Mirko Castellini; Donato Sollitto; Annamaria Castrignanò; Francesco Fornaro

2012-01-01

118

Effect of Crop Rotation on Meloidogyne spp. and Pratylenchus spp. Populations in Strawberry Fields in Taiwan.  

Science.gov (United States)

Changes in population levels of Meloidogyne hapla, M. incognita, Pratylenchus coffeae, and P. penetrans were studied in 12 strawberry fields in the Dahu region of Taiwan. Ten potential rotation crops and two cultural practices were evaluated for their effect on nematode populations and influence on strawberry yield. Rotation with rice or taro and the cultural practice of flooding and bare fallowing for four months were found to reduce nematode soil populations to two or fewer nematodes per 100 ml soil. Average strawberry yields increased between 2.4% to 6.3% following taro compared to the bare fallow treatment. Corn suppressed M. incognita and M. hapla populations and resulted in an increased in strawberry yield compared to bare fallow. Other phytopathogens also present in these fields limited taro as the rotation choice for nematode management. Results of this research and economic analysis of the input requirements for various rotation crops, corn and bare fallow were recommended as the most appropriate rotation strategies for nematode management in strawberry in this region. PMID:19259538

Chen, P; Tsay, T T

2006-09-01

119

Soil properties, crop production and greenhouse gas emissions from organic and inorganic fertilizer-based arable cropping systems  

UK PubMed Central (United Kingdom)

Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr-old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots on 19 September 2007, 14 April 2008 and 22 September 2008, i.e. before, during, and after the growth season. The soils were analyzed for multiple attributes: total soil organic carbon (SOC), total N, microbial biomass N (MBN), potentially mineralizable N (PMN), and levels of potential ammonium oxidation (PAO) and denitrifying enzyme activity (DEA). In situ measurements of soil heterotrophic carbon dioxide (CO?) respiration and nitrous oxide emissions were conducted in plots with winter wheat. In April 2008, prior to field operations, intact soil cores were collected at two depths (0-5 and 5-10cm) in plots under winter wheat. Water retention characteristics of each core were determined and used to calculate relative gas diffusivity (D P/D o). Finally, crop growth was monitored and grain yields measured at harvest maturity. The different management strategies between 1997 and 2007 led to soil carbon inputs that were on average 18-68% and 32-91% higher in the organic than inorganic fertilizer-based rotations for the sampled winter wheat and spring barley crops, respectively. Nevertheless, SOC levels in 2008 were similar across systems. The cumulative soil respiration for the period February to August 2008 ranged between 2 and 3t CO?-C ha?¹ and was correlated (r =0.95) with average C inputs. In the organic cropping systems, pig slurry application and inclusion of catch crops generally increased soil respiration, PMN and PAO. At field capacity, relative gas diffusivity at 0-5cm depth was >50% higher in the organic than the inorganic fertilizer-based system (P <0.05). Crop yields in 2008 were generally lower in the low-input organic rotations than in the high-input inorganic fertilizer-based system; only spring barley in rotations with pig slurry application and incorporation of a catch crop prior to sowing obtained grain yields similar to levels achieved in the system where inorganic fertilizer was applied. These results suggest that within organic cropping systems, both microbial activity and crop yields could be enhanced through inclusion of catch crops. However, the timing of catch crop incorporation is critical.

Chirinda N; Olesen JE; Porter JR; Schjønning P

2010-12-01

120

Soil properties, crop production and greenhouse gas emissions from organic and inorganic fertilizer-based arable cropping systems  

DEFF Research Database (Denmark)

Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr-old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots on 19 September 2007, 14 April 2008 and 22 September 2008, i.e. before, during, and after the growth season. The soils were analyzed for multiple attributes: total soil organic carbon (SOC), total N, microbial biomass N (MBN), potentially mineralizable N (PMN), and levels of potential ammonium oxidation (PAO) and denitrifying enzyme activity (DEA). In situ measurements of soil heterotrophic carbon dioxide (CO2) respiration and nitrous oxide emissions were conducted in plots with winter wheat. In April 2008, prior to field operations, intact soil cores were collected at two depths (0–5 and 5–10 cm) in plots under winter wheat. Water retention characteristics of each core were determined and used to calculate relative gas diffusivity (DP/Do). Finally, crop growth was monitored and grain yields measured at harvest maturity. The different management strategies between 1997 and 2007 led to soil carbon inputs that were on average 18–68% and 32–91% higher in the organic than inorganic fertilizer-based rotations for the sampled winter wheat and spring barley crops, respectively. Nevertheless, SOC levels in 2008 were similar across systems. The cumulative soil respiration for the period February to August 2008 ranged between 2 and 3 t CO2–C ha-1 and was correlated (r = 0.95) with average C inputs. In the organic cropping systems, pig slurry application and inclusion of catch crops generally increased soil respiration, PMN and PAO. At field capacity, relative gas diffusivity at 0–5 cm depth was >50% higher in the organic than the inorganic fertilizer-based system (P < 0.05). Crop yields in 2008 were generally lower in the low-input organic rotations than in the high-input inorganic fertilizer-based system; only spring barley in rotations with pig slurry application and incorporation of a catch crop prior to sowing obtained grain yields similar to levels achieved in the system where inorganic fertilizer was applied. These results suggest that within organic cropping systems, both microbial activity and crop yields could be enhanced through inclusion of catch crops. However, the timing of catch crop incorporation is critical.

Chirinda, Ngonidzashe; Olesen, JØrgen Eivind

2010-01-01

 
 
 
 
121

CROP PRODUCTIVITY AND ECONOMICS DURING THE TRANSITION TO ALTERNATIVE CROPPING SYSTEMS IN THE NORTHERN CORN BELT  

Science.gov (United States)

Long-term cropping systems plots were established in west central Minnesota in 2002 to investigate the agronomic, economic and environmental performance of alternative cropping systems. Our hypothesis is that systems which increase crop diversity, reduce tillage and reduce use of purchased inputs ho...

122

Cropping systems and control of soil erosion in a Mediterranean environment  

Science.gov (United States)

The research has been carried out over the years 1996-2010 in an area of the internal hill of Sicily region (Enna, c.da Geracello, 550 m a. s. l. 37° 23' N. Lat, 14° 21' E. Long) in the center of Mediterranean Sea, mainly devoted to durum wheat cultivation, using the experimental plots, established in 1996 on a slope of 26-28%, equipped to determine surface runoff and soil losses. The establishment consists of twelve plots, having 40 m length and 8 m width. In order to study the effect of different field crop systems in controlling soil erosion in slopes subjected to water erosion, the following systems were studied: permanent crops, tilled annual crops, no-tilled annual crops, set-aside. The used crops were: durum wheat, faba bean, rapeseed, subterranean clover, Italian ryegrass, alfalfa, sweetvetch, moon trefoil, barley, sweet sorghum, sunflower. The results pointed out that the cropping systems with perennial crops allowed to keep low the soil loss, while annual crop rotation determined a high amount of soil loss. Sod seeding showed promising results also for annual crop rotations.

Cosentino, Salvatore; Copani, Venera; Testa, Giorgio; Scalici, Giovanni

2013-04-01

123

Short-rotation woody crops for bioenergy and biofuels applications.  

UK PubMed Central (United Kingdom)

Purpose-grown trees will be part of the bioenergy solution in the United States, especially in the Southeast where plantation forestry is prevalent and economically important. Trees provide a "living biomass inventory" with existing end-use markets and associated infrastructure, unlike other biomass species such as perennial grasses. The economic feasibility of utilizing tree biomass is improved by increasing productivity through alternative silvicultural systems, improved breeding and biotechnology. Traditional breeding and selection, as well as the introduction of genes for improved growth and stress tolerance, have enabled high growth rates and improved site adaptability in trees grown for industrial applications. An example is the biotechnology-aided improvement of a highly productive tropical Eucalyptus hybrid, Eucalyptus grandis x Eucalyptus urophylla. This tree has acquired freeze tolerance by the introduction of a plant transcription factor that up-regulates the cold-response pathways and makes possible commercial plantings in the Southeastern United States. Transgenic trees with reduced lignin, modified lignin, or increased cellulose and hemicellulose will improve the efficiency of feedstock conversion into biofuels. Reduced lignin trees have been shown to improve efficiency in the pre-treatment step utilized in fermentation systems for biofuels production from lignocellulosics. For systems in which thermochemical or gasification approaches are utilized, increased density will be an important trait, while increased lignin might be a desired trait for direct firing or co-firing of wood for energy. Trees developed through biotechnology, like all transgenic plants, need to go through the regulatory process, which involves biosafety and risk assessment analyses prior to commercialization.

Hinchee M; Rottmann W; Mullinax L; Zhang C; Chang S; Cunningham M; Pearson L; Nehra N

2009-12-01

124

Short-rotation woody crops for bioenergy and biofuels applications.  

Science.gov (United States)

Purpose-grown trees will be part of the bioenergy solution in the United States, especially in the Southeast where plantation forestry is prevalent and economically important. Trees provide a "living biomass inventory" with existing end-use markets and associated infrastructure, unlike other biomass species such as perennial grasses. The economic feasibility of utilizing tree biomass is improved by increasing productivity through alternative silvicultural systems, improved breeding and biotechnology. Traditional breeding and selection, as well as the introduction of genes for improved growth and stress tolerance, have enabled high growth rates and improved site adaptability in trees grown for industrial applications. An example is the biotechnology-aided improvement of a highly productive tropical Eucalyptus hybrid, Eucalyptus grandis x Eucalyptus urophylla. This tree has acquired freeze tolerance by the introduction of a plant transcription factor that up-regulates the cold-response pathways and makes possible commercial plantings in the Southeastern United States. Transgenic trees with reduced lignin, modified lignin, or increased cellulose and hemicellulose will improve the efficiency of feedstock conversion into biofuels. Reduced lignin trees have been shown to improve efficiency in the pre-treatment step utilized in fermentation systems for biofuels production from lignocellulosics. For systems in which thermochemical or gasification approaches are utilized, increased density will be an important trait, while increased lignin might be a desired trait for direct firing or co-firing of wood for energy. Trees developed through biotechnology, like all transgenic plants, need to go through the regulatory process, which involves biosafety and risk assessment analyses prior to commercialization. PMID:19936031

Hinchee, Maud; Rottmann, William; Mullinax, Lauren; Zhang, Chunsheng; Chang, Shujun; Cunningham, Michael; Pearson, Leslie; Nehra, Narender

2009-08-26

125

The consequent influence of crop rotation and six-year-long spring barley monoculture on yields and weed infestation of white mustard and oats  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was conducted in the years 2007- 2008, after 6-year-long experiments in the cultivation of spring barley in a crop rotation system and in monoculture. The other experimental factor was the spring barley protection method. Intensive protection involved comprehensive treatment of barley (in-crop harrowing, seed dressing, application of herbicides, fungicides, a retardant and an insecticide). Extensive protection consisted only in in-crop harrowing, without the application of crop protection agents, except for seed dressing. The above mentioned factors formed the background for the study on the cultivation of white mustard and oats, as phytosanitary species, in successive years. In the test plants, no mineral fertilization and crop protection were applied. Such agricultural method enabled an objective assessment of the consequent effect of monoculture, crop rotation and crop treatments. A hypothesis was made that the cultivation of the phytosanitary plants in the stand after 6-year-long barley monoculture would allow obtaining the level of yields and weed infestation similar to those of the crop rotation treatments. It was also assumed that the cultivation of white mustard and oats would eliminate differences in plant productivity caused by the negative influence of extensive protection. It was proved that the cultivation of the phytosanitary plants eliminated the negative influence of monoculture on the level of their yields and weed infestation. However, the test plants did not compensate negative consequences of extensive protection. In spite of this, white mustard and oats effectively competed with weeds, and the number and weight of weeds in a crop canopy did not cause a dramatic decline in yields. In the test plant canopy, the following short-lived weeds were predominant: Chenopodium album, Galinsoga parviflora, Echinochloa crus-galli. The absence of herbicide application resulted in the compensation of perennial species: Elymus repens and Cirsium arvense.

Cezary Kwiatkowski

2009-01-01

126

Role of genetic improvement in the Short Rotation Woody Crops Program  

Energy Technology Data Exchange (ETDEWEB)

A major effort in the Short Rotation Woody Crops Program (SRWCP) is species screening and genetic improvement of selected species. Of the 125 species initially evaluated for SRIC, 20 are being seriously considered with most of emphasis on 16 hardwood species. Range-wide seed collections of 12 species were provenance tested; these include Platanus occidentalis (sycamore), Alnus glutinosa (European black alder), and Robinia pseudoacacia (black locust). Based on the results of these tests, highly productive, site-specific seed sources are being chosen for several geographic regions. Three of these species re currently being bred for increased productivity in SRIC systems. Genetic improvement is viewed as a tool for increasing productivity, having anticipated gains of 40 to 50%. The techniques of somaclonal screening and genetic engineering are being evaluated for their usefulness in the SRIC improvement program. Currently, salt-tolerant Atriplex canescens (four-wing saltbush) and herbicide-resistant Populus spp. are being sought via somaclonal screening. 35 refs., 4 figs., 3 tabs.

Layton, P.A.; Wright, L.L.

1986-01-01

127

Sustainable Production of Japanese Eggplants in a Piedmont Soil in Rotation with Winter Cover Crops  

Directory of Open Access Journals (Sweden)

Full Text Available Eggplant is a popular vegetable consumed all over the world. Cover cropping is an efficient way of recycling nutrients and reducing inorganic fertilizer requirements to maintain the sustainability of the soil without affecting productivity and profitability. Eggplants (Solanum melongena) (Japanese varieties Hansel and Kamo) were grown in a Piedmont soil with two main treatments, cover crop (CC) and no cover crop (NC), and four sub-fertilizer treatments (T1: 0-0-0, T2: 56-28-112, T3: 84-56-168, and T4: 168-112-224 N-P-K kg/ha), using four replications. The Hansel variety eggplant yield was significantly higher than the Kamo variety. Eggplant yields from CC treatments for both varieties were significantly higher (p < 0.001) than the yields from NC treatments. No significant difference was observed in the yields between T1 and T2 treatments, but the yields from T3 were significantly higher than T1 and T2 and yields from T4 were significantly higher than T3 yields. N released through mineralization of cover crop mixture ranged from 13.33 g/kg at the beginning of the growing season and increased to 18.32 g/kg at the end of the growing season. These results suggest that Japanese eggplants can be successfully grown in the Piedmont area of North Carolina in rotation with cover crops for higher yields.

Ramesh Ravella; Muchha Reddy; Kurt Taylor; Ahmed Elobeid

2013-01-01

128

Rotating fluidized bed gasifier system  

Energy Technology Data Exchange (ETDEWEB)

A rotating fluidized bed gasifier system especially useful in compound engines comprises an annular fluidization chamber containing a bed of carbon containing pulverulent solid materials. The chamber, which is defined by inner and outer spaced apart coaxial, cylindrical, perforated walls, rotates about the longitudinal axis of the cylinders. Steam enters the bed, which is maintained at about 1800/sup 0/ F., through the outer perforated wall and fluidizes the particles. The steam reacts endothermically with the carbon to produce reaction product gas which exits the bed, together with unreacted steam, through the inner perforated wall. In a preferred form of the invention the bed is maintained at approximately 1800/sup 0/ F. By combining a rotating fluidized bed combustor with the gasifier. In this embodiment compressed air and powdered coal enter the bed with the steam through the outer perforated wall. The air reacts exothermically with the fuel within the bed to generate heat for the endothermic steam-carbon reaction and to produce hot combustion gas which exit the bed, together with the reaction product gas, unreacted steam and compressed air, through the inner perforated wall.

Belke, W.H.; Goloff, A.; Grim, G.B.

1981-08-04

129

Role of nematodes, nematicides, and crop rotation on the productivity and quality of potato, sweet potato, peanut, and grain sorghum.  

UK PubMed Central (United Kingdom)

The objective of this experiment was to determine the effects of fenamiphos 15G and short-cycle potato (PO)-sweet potato (SP) grown continuously and in rotation with peanut (PE)-grain sorghum (GS) on yield, crop quality, and mixed nematode population densities of Meloidogyne arenaria, M. hapla, M. incognita, and Mesocriconema ornatum. Greater root-gall indices and damage by M. hapla and M. incognita occurred on potato than other crops. Most crop yields were higher and root-gall indices lower from fenamiphos-treated plots than untreated plots. The total yield of potato in the PO-SP and PO-SP-PE-GS sequences increased from 1983 to 1985 in plots infested with M. hapla or M. arenaria and M. incognita in combination and decreased in 1986 to 1987 when root-knot nematode populations shifted to M. incognita. The total yields of sweet potato in the PO-SP-PE-GS sequence were similar in 1983 and 1985, and declined each year in the PO-SP sequence as a consequence of M. incognita population density increase in the soil. Yield of peanut from soil infested with M. hapla increased 82% in fenamiphos-treated plots compared to untreated plots. Fenamiphos treatment increased yield of grain sorghum from 5% to 45% over untreated controls. The declining yields of potato and sweet potato observed with both the PO-SP and PO-SP-PE-GS sequences indicate that these crop systems should not be used longer than 3 years in soil infested with M. incognita, M. arenaria, or M. hapla. Under these conditions, these two cropping systems promote a population shift in favor of M. incognita, which is more damaging to potato and sweet potato than M. arenaria and M. hapla.

Johnson AW; Dowler CC; Glaze NC; Handoo ZA

1996-09-01

130

DYNAMIC CROPPING SYSTEMS INFLUENCE ON SOIL BIOCHEMISTRY  

Science.gov (United States)

In the Northern Great Plains, more intensive, diverse cropping systems have been developed as a means to improve soil and water conservation in the region. A no-till field research project was conducted near Mandan, ND on a Wilton-Temvik silt loam (fine-silty, mixed, superactive, frigid Pachic and T...

131

Nitrous oxide and carbon dioxide emissions from monoculture and rotational cropping of corn, soybean and winter wheat  

International Nuclear Information System (INIS)

[en] Nitrous oxide (N2O) and carbon dioxide (CO2) emissions from agricultural soils are influenced by different types of crops, the amounts and types of nitrogen fertilizers used, and the soil and climatic conditions under which the crops are grown. Crop rotation also has an impact on N2O emissions, as the crop residues used to supply soluble carbon to soil biota often differ from the crops being grown. This study compared the influence of crops and residues from preceding crops on N2O and CO2 emissions from monoculture crops of soybeans, corn, and winter wheat at a site in Ontario. The phases of different rotations were compared with 2- and 3-year crop rotations. Results of the study showed that N2O emissions were approximately 3.1 to 5.1 times higher in monoculture corn than levels observed in winter wheat or soybean crops. When corn followed corn, average N2O emissions twice as high as when corn followed soybeans, and 65 per cent higher than when corn followed winter wheat. The higher levels of both N2O and CO2 were attributed to higher inorganic nitrogen (N) application rates in corn crops. In the corn phase, CO2 levels were higher when the preceding crop was winter wheat. It was concluded that N2O and CO2 emissions from agricultural fields are influenced by both current and preceding crops, a fact which should be considered and accounted for in estimates and forecasts of agricultural greenhouse gas (GHG) emissions. 21 refs., 3 tabs., 10 figs

2008-01-01

132

Effects of Long Term Cropping Systems on Soil Chemical Properties  

Directory of Open Access Journals (Sweden)

Full Text Available In this study we examined the impact on soil C, total soil N and available P of six rotations namely: long season tobacco cultivar ‘KM10’ grown continuously (ContKM10), medium season tobacco cultivar ‘RK8’ grown continuously (ContRK8), grass-grass-grass-KM10 (G-G-G-KM10), grass-grass-grass-RK8 (G-G-G-RK8), KM10-Crotalaria juncea (KM10-Cr) and RK8-Crotalaria juncea (RK8-Cr). The experiment was established in 1990 under irrigation on a sandy loam soil at Kutsaga Research Station, Zimbabwe. Soil samples were taken from 0- to 15-cm deep, after each season. After 9 years, tobacco-grass rotations showed higher soil C than monocropping, regardless of variety. The monocropping systems, ContKM10 and ContRK8, did not differ from KM10-Cr and RK8-Cr respectively showing that when crop intensity is maintained soil C will be reduced regardless of a winter C. juncea green manure in a sandy loam soil. After 9 years, soil N was greatest in the G-G-G-KM10 rotation. Available P was lower in the grass (G-G-G-KM10, G-G-G-RK8) relative to the other rotations regardless of variety. Available P accumulated in monocropping systems (ContRK8, ContKM10) and was consistently lower in the grass-tobacco rotations. This indicated an accumulation of P in the case of monocropping systems because of continuous inorganic fertiliser input. The results reaffirmed the deleterious effect of monocropping and suggested the need for diverse rotations.

U. Mazarura; C. Chisango

2012-01-01

133

Comportamento de Sternechus subsignatus (Boheman) em dez espécies vegetais de verão para rotação de culturas ou cultura armadilha no plantio direto/ Sternechus subsignatus (Boheman) behaviour in ten summer rotation specles and trapping crops for no-tillage system  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O desenvolvimento de Sternechus subsignatus (Boheman) (Coleoptera: Curculionidae) foi avaliado em dez espécies vegetais sob condições naturais num solo manejado há três anos no sistema de plantio direto corn soja cultivada no verão. Foram observados o número de plantas atacadas, a oviposição, o núrnero e peso de larvas, o número de larvas hibernantes no solo e o número de adultos emergidos. O inseto se reproduziu e desenvolveu ern feijão (Phaseolus vulgaris L (more) ) guandu anão (Cajanus cajan L), lab-lab (Dolichos lablab L.) e soja (Glycine max L.) e ao contrário, em crotalária júncea (Crotalaria júncea L). girassol (Helianthus annuus L.), milheto (Pennisetum americanum Leek), milho (Zea mays L), mucuna preta (Stizolobium aterrimum Piper et Tracy) e sorgo (Sorghum bicolor L.) não completou o ciclo de vida. Os resultados indicaram que a cultura do feijão, guandu anão, lab-lab e soja aumentaram a população do inseto. Entretanto, ocorreu redução na população do inseto corn as culturas da crotalária júncea, girassol, milheto, milho, mucuna preta e sorgo. As quatro primeiras espécies são hospedeiras preferenciais, podendo ser usadas como culturas armadilhas e as demais, não são hospedeiras, pois propiciam a diminuição da população do inseto, sendo ideais para uso em sistemas derotação de culturas no verão, em áreas infestadas, para substituir o monocultivo da soja em plantio direto. Abstract in english The development of Sternechus subsignatus (Boheman) (Coleoptera. Curculionidae) was evaluated on ten crop species under natural conditions under no-tillage system for three years and infested with the insect Soybean was the Summer crop continously cultivated in the area. Number of attacked plants, oviposition, number and weight of larvae and number of adults emerged were the parameters evaluated. The insect reproduced and developed in bean (Phaseolus vulgaris L), grandull (more) (Cajanus cajan L.), dolichos (Dolichos lablab L.) and soybean (Glycine max L.) and not in bengal hemp (Crotalaria júncea L ), sunflower (Helianthus annuus L.), millet (Pennisetum americanum Leek), corn (Zea mays L.), black velvet bean (Stizolobium aterrimum Piper et Tracy) and sorghum (Sorghum bicolor L.) did not complete lhe life cycle Results indicated that P. vulgaris, C. cajan, D. lablab and G. max increased insect populatron but, a reduction was observed on C. juncea, H. annuus, P. americanum, Z. mays, S. aterrimum and S. bicolor. The first four related species are the preferred hosts and may be used as trap crops. The other six species did not host the insect, decreasing its populations and thus being ideal to be included in Summer crop rotafion systems to subslitute soybean monocropping under no-tillage.

Silva, Mauro Tadeu Braga da

1997-12-01

134

Crop rotation in the Valle Calido del Alto Magdalena a sustainable focus of high yield  

International Nuclear Information System (INIS)

[en] Experiments were carried out during five years at the Nataima Research Center, located at 431 m.a.s.l, with average temperature of 28 Celsius degrades and annual rainfall of 1274 Boyaca mm, on a soil classified as Arenic Haplustalf, to evaluate different crops rotation based on rice and sorghum; the combinations used were as follows; rice-rice (R-R), rice-- soybean (R-SY), rice-crotalaria-sorghum (R-C-S), sorghum-sorghum (S-S), sorghum-soybean (S-SY) and cotton-sorghum (Al-S). Simultaneously it was evaluated the response to four nitrogen levels, which allowed to find out yield functions and optimum economical. The rotations S-SY, R-SY and AI-S have been the best qualified from an environmental perspective. Sorghum-soybean rotation presents increases in yield compared with expected values, which allows thinking that it is a truly sustainable rotation. This rotation also had an excellent profitability and for that reason is considered the best option within the goals of this work

1996-01-01

135

Weed infestation of a cereal-legume mixture depending on its concentration and position in a crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available A field study was carried out in the period 2000-2006 at the Experimental Station in Tomaszkowo belonging to the University of Warmia and Mazury in Olsztyn. Its aim was to compare weed infestation of a mixture of spring barley and field pea grown in a four crop rotation with different crop selection and sequence. Each year during tillering of spring barley and before the harvest of the mixture, weed species composition and density were evaluated, while additionally weed biomass was also estimated before the harvest. These results were used to determine species constancy, Simpson’s dominance index, the Shannon-Wiener diversity and evenness indices as well as the community similarity index based on floristic richness, numbers and biomass of particular weed species. The cropping frequency and the position of the mixture in the crop rotation did not differentiate the species composition and total biomass of weed communities in the cereal-legume mixture crops. The crop rotation in which the mixture constituted 50% and was grown after itself had a reducing effect on weed numbers. Growing field pea in the 4-year crop rotation promoted weed infestation of the mixture and the dominance of weed communities. Capsella bursa-pastoris, Chenopodium album, Echinochloa crus-galli, Elymus repens, Polygonum convolvulus, and Sonchus arvensis were constant components of the agrophytocenoses. The weed communities were more similar in terms of their floristic composition than in terms of weed density and air-dry weight of weeds.

Marta K. Kostrzewska; Maria Wanic; Magdalena Jastrz?bska

2012-01-01

136

Industry/government collaborations on short-rotation woody crops for energy, fiber and wood products  

Energy Technology Data Exchange (ETDEWEB)

More than twenty-five organizations can be identified in the US and Canada that have research plantings of 20 ha in size or greater of short-rotation woody crops and most of those are well-established forest products companies. In 1990, only 9 forest products companies had commercial or substantial research plantings of short-rotation woody crops. The recent harvest and use of hybrid poplars for pulp and paper production in the Pacific Northwest has clearly stimulated interest in the use of genetically superior hybrid poplar clones across North America. Industry and government supported research cooperatives have been formed to develop sophisticated techniques for producing genetically superior hybrid poplars and willows suited for a variety of locations in the US. While the primary use of commercially planted short-rotation woody crops is for pulp and paper, energy is a co-product in most situations. A document defining a year 2020 technology vision for America`s forest, wood and paper industry affirms that {open_quotes}biomass will be used not only for building materials and paper and paperboard products, but also increasingly for steam, power, and liquid fuel production.{close_quotes} To accomplish the goals of {open_quotes}Agenda 2020{close_quotes} a new collaborative research effort on sustainable forestry has been initiated by the Department of Energy (DOE) and the American Forest and Paper Association (AF&PA). Both the new and old collaborative efforts are focusing on achieving substantial and sustainable gains in U.S. wood production for both energy and traditional wood products. AF&PA and DOE hope that industry and government partnerships addressing the competitiveness and energy efficiency of U.S. industries, can serve as a model for future research efforts.

Wright, L.L. [Oak Ridge National Lab., TN (United States); Berg, S. [American Forest and Paper Association, Washington, DC (United States)

1996-12-31

137

Net greenhouse gas emissions and the economics of annual crop management systems  

Energy Technology Data Exchange (ETDEWEB)

The relative economic profitability and greenhouse gas (GHG) abatement potential of alternative tillage and cropping systems were examined. The aim of the study was to provide information about climate change mitigation strategies targeted at annual crop production in the agricultural sector. A model was used to estimate the relative potential of each of the management practices to sequester carbon and to emit GHGs. The model also provided estimates of the profitability of the management practices over a period of 30 years. The model used biophysical and economic data representing different crop rotations under traditional, minimum and zero tillage cropping systems in the Black soil zone of Saskatchewan. Results of the simulation were then used to develop trade-off functions reflecting net income and net GHG abatement for each cropping system. An income risk measure was used to facilitate the analysis of the economic viability of the simulated cropping systems, and a sensitivity analysis was performed on nitrous oxide emission coefficients and weather patterns to account for uncertainties in future climate change impacts. The baseline simulation indicated that all the management systems were net GHG sinks. However, the minimum and zero tillage cropping systems provided a greater net sink than the conventional system, while the reduced tillage cropping system provided lower profitability over the 30 year time frame. It was suggested that economic factors such as risk and economies of size may have a significant influence on future results. 23 refs., 8 tabs., 2 figs.

Samarawickrema, A.K.; Belcher, K.W. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Agricultural Economics

2005-12-15

138

Produção de trigo e triticale em rotações de sequeiro Wheat and triticale in crop rotations  

Directory of Open Access Journals (Sweden)

Full Text Available Apresentam-se os resultados de um ensaio de rotações que decorreu durante dez anos em Vila Real (Trás-os-Montes). O ensaio incluiu a rotação tradicional das condições de sequeiro de Trás-os-Montes, cereal-alqueive (TA), e rotações alternativas susceptíveis de serem adoptadas nestas condições, cereal-leguminosa (TL), cereal-consociação forrageira (TC) e cereal-prado de sequeiro (TP). Os cereais das rotações foram o trigo e, posteriormente, o triticale. Determinaram-se e analisaram-se as produções de grão e palha, os teores de nutrientes do grão e da palha e acompanharam-se os parâmetros do solo, pH, matéria orgânica e os teores de P2 O 5, K2 O e bases de troca. Destacam-se alguns resultados importantes, tais como: as produções de grão de cereal das rotações não mostrarem diferenças significativas entre si; a produção de palha da rotação TL ser superior às das restantes; o trigo cultivado após prado de sequeiro não dispensar a adubação azotada; as rotações conduzirem a modificações dos teores de matéria orgânica, cálcio de troca ou do valor do pH do solo, factores a que se deve atender, caso a rotação se prolongue por muitos anos.The results of a field trial of crop rotations conducted over a period of ten years in Vila Real (Northeast Portugal) are presented. The rotations tested were cereal-cultivated fallow (TA), traditional in rain-fed conditions of the region, and alternative rotations that could be adopted in these conditions: cereal-grain legume crop (TL), cereal-forage mixture (TC) and cereal-rain-fed pasture (TP). The cereals were wheat and, later, triticale. Grain, straw and aerial biomass yields were evaluated together with concentrations of nutrients. The soil parameters studied were pH, organic matter and P 2 O 5, K2O and exchange cations. Wheat straw yield of TL rotation was higher than that of the others. Wheat from TP rotation still requires nitrogen fertilization. The soils of the different rotations registered changes of organic matter, Ca, Mg and pH values, which should be taken into account if these rotations are practised over several years.

Carlos Castro; João Coutinho; Nuno Moreira; António Crespi

2008-01-01

139

Produção de trigo e triticale em rotações de sequeiro/ Wheat and triticale in crop rotations  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Apresentam-se os resultados de um ensaio de rotações que decorreu durante dez anos em Vila Real (Trás-os-Montes). O ensaio incluiu a rotação tradicional das condições de sequeiro de Trás-os-Montes, cereal-alqueive (TA), e rotações alternativas susceptíveis de serem adoptadas nestas condições, cereal-leguminosa (TL), cereal-consociação forrageira (TC) e cereal-prado de sequeiro (TP). Os cereais das rotações foram o trigo e, posteriormente, o triticale. Det (more) erminaram-se e analisaram-se as produções de grão e palha, os teores de nutrientes do grão e da palha e acompanharam-se os parâmetros do solo, pH, matéria orgânica e os teores de P2 O 5, K2 O e bases de troca. Destacam-se alguns resultados importantes, tais como: as produções de grão de cereal das rotações não mostrarem diferenças significativas entre si; a produção de palha da rotação TL ser superior às das restantes; o trigo cultivado após prado de sequeiro não dispensar a adubação azotada; as rotações conduzirem a modificações dos teores de matéria orgânica, cálcio de troca ou do valor do pH do solo, factores a que se deve atender, caso a rotação se prolongue por muitos anos. Abstract in english The results of a field trial of crop rotations conducted over a period of ten years in Vila Real (Northeast Portugal) are presented. The rotations tested were cereal-cultivated fallow (TA), traditional in rain-fed conditions of the region, and alternative rotations that could be adopted in these conditions: cereal-grain legume crop (TL), cereal-forage mixture (TC) and cereal-rain-fed pasture (TP). The cereals were wheat and, later, triticale. Grain, straw and aerial bioma (more) ss yields were evaluated together with concentrations of nutrients. The soil parameters studied were pH, organic matter and P 2 O 5, K2O and exchange cations. Wheat straw yield of TL rotation was higher than that of the others. Wheat from TP rotation still requires nitrogen fertilization. The soils of the different rotations registered changes of organic matter, Ca, Mg and pH values, which should be taken into account if these rotations are practised over several years.

Castro, Carlos; Coutinho, João; Moreira, Nuno; Crespi, António

2008-01-01

140

Avaliação do potencial de coberturas verdes e de sitemas de rotações de cultura na supressão do nematoide anelado (Mesocriconema xenoplax) em pré-plantio ao pessegueiro Evaluation of green covering potential and crop rotation systems in the suppression of the ring nematode (Mesocriconema xenoplax) in peach pre-planting  

Directory of Open Access Journals (Sweden)

Full Text Available Em uma área naturalmente infestada com o nematoide anelado (Mesocriconema xenoplax), coberturas verdes foram testadas quanto a sua hospedabilidade, em cultivos de inverno e verão, comparativamente às parcelas mantidas sob pousio. Três sistemas de rotação de culturas, com as mesmas espécies vegetais (aveia-preta/feijão-de-porco/milheto/nabo-forrageiro; nabo-forrageiro/milheto/aveia-branca/milho, e aveia-branca/mucuna-anã/trigo/sorgo), foram avaliados quanto ao potencial supressor do nematóide de M. xenoplax por dois anos, utilizando-se, como testemunhas, de parcelas mantidas sob pousio e alqueive. Os experimentos foram conduzidos a campo, em blocos ao acaso, com seis repetições. Antes e após o estabelecimento de cada cultivo, as populações do nematoide foram avaliadas quanto ao número de M. xenoplax/100cm³ de solo e fator de reprodução (FR= população final/população inicial) do nematoide anelado, onde FR1,00, favorecimento da reprodução. A maioria das culturas testadas foi hospedeira desfavorável (FRIn a field naturally infested with ring nematode (Mesocriconema xenoplax), green covering were tested for their hostel in winter and summer crops comparing to plots kept in fallow lands. Tree crop rotation system with the same plant species (black oat/pig bean/ millet/forage radish; forage radish/ millet/white oat/corn; and white oat/mucuna deeringiana/wheat/sorghum) were evaluated for suppression potential to nematode M. xenoplax for two years, using as witness plots that were kept in fallow lands. The experiments were conducted in the field in a randomized block design with six repetitions. Before and after the establishment of each plot, the nematode populations were evaluated on the number of M. xenoplax/100cm³ of soil and the reproduction factor (RF= final population/initial population) of the ring nematode, where RF 1,00, favoring of the reproduction. Most of the crops analyzed were unfavorable host (RF<1,00) of M. xenoplax, except the mucuna deeringiana that behaved as favorable to the nematode reproduction. Although all treatments have removed M. xenoplax the crop rotations forage radish/ millet/white oat/corn and white oat/mucuna deeringiana/wheat/sorghum realized the largest reduction of the nematode in the soil (93-95%).It was noted a sharp decline in the M. xenoplax population in the first two crops, with later stabilization of its level, regardless of the studied system.

Cesar Bauer Gomes; Flávio Luiz Carpena Carvalho; João Guilherme Casagrande Júnior; Elizete Beatriz Radmann

2010-01-01

 
 
 
 
141

Harvest of Short-Rotation Woody Crops in Plantations with a Biobaler  

Directory of Open Access Journals (Sweden)

Full Text Available The biobaler is an alternative to the modified self-propelled forage harvester to cut and collect short rotation woody crops (SRWC). It is less capital intensive and more versatile, being able to harvest woody crops on plantations, on abandoned farmland, on brush land or within forest understory. The biobaler was evaluated specifically on five different plantations over 19 experimental units (546 bales harvested with an average mass of 427 kg and 49% moisture content). Average bale density was 266 kg wet mass (WM)/m3 or 139 kg dry mass (DM)/m3. Average harvest capacity was 35 bales/h (7.7 t dry matter/h), and ranged from 23 to 48 bales/h. Harvest in plantations with a 149 kW tractor cost on average CAN $175/h, $5/bale and $22.84/t DM. Non recovered biomass (field loss) averaged 11% at random locations in the field and 8% at the point of bale ejection as a result of chip abrasion. While the biobaler remains a versatile harvester for SRWC, its preferred utilization will be in environments of diverse woody crops with final application as a rough mulch or for combustion in furnaces requiring minimal processing or size reduction.

Philippe Savoie; Pierre-Luc Hébert; François-Simon Robert; Derek Sidders

2013-01-01

142

Coastal bermudagrass rotation and fallow for management of nematodes and soilborne fungi on vegetable crops.  

Science.gov (United States)

The efficacy of clean fallow, bermudagrass (Cynodon dactylon) as a rotational crop, and fenamiphos for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus), snapbean (Phaseolus vulgaris), and pepper (Capsicum annuum) production was evaluated in field tests from 1993 to 1995. Numbers of M. incognita in the soil and root-gall indices were greater on okra than on snapbean or pepper. Application of fenamiphos at 6.7 kg a.i./ha did not suppress numbers of nematodes on any sampling date when compared with untreated plots. The lack of efficacy could be the result of microbial degradation of the nematicide. Application of fenamiphos suppressed root-gall development on okra following fallow and 1-year sod in 1993, but not thereafter. A few galls were observed on roots of snapbean following 2- and 3-year fallow but none following 1-, 2-, and 3-year bermudagrass sod. Population densities of Pythium aphanidermatum, P. myriotylum, and Rhizoctonia solani in soil after planting vegetables were suppressed by 2- or 3-year sod compared with fallow but were not affected by fenamiphos. Yields of snapbean, pepper, and okra did not differ between fallow and 1-year sod. In the final year of the study, yields of all crops were greater following 3-year sod than following fallow. Application of fenamiphos prior to planting each crop following fallow or sod did not affect yields. PMID:19274273

Johnson, A W; Burton, G W; Sumner, D R; Handoo, Z

1997-12-01

143

Coastal bermudagrass rotation and fallow for management of nematodes and soilborne fungi on vegetable crops.  

UK PubMed Central (United Kingdom)

The efficacy of clean fallow, bermudagrass (Cynodon dactylon) as a rotational crop, and fenamiphos for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus), snapbean (Phaseolus vulgaris), and pepper (Capsicum annuum) production was evaluated in field tests from 1993 to 1995. Numbers of M. incognita in the soil and root-gall indices were greater on okra than on snapbean or pepper. Application of fenamiphos at 6.7 kg a.i./ha did not suppress numbers of nematodes on any sampling date when compared with untreated plots. The lack of efficacy could be the result of microbial degradation of the nematicide. Application of fenamiphos suppressed root-gall development on okra following fallow and 1-year sod in 1993, but not thereafter. A few galls were observed on roots of snapbean following 2- and 3-year fallow but none following 1-, 2-, and 3-year bermudagrass sod. Population densities of Pythium aphanidermatum, P. myriotylum, and Rhizoctonia solani in soil after planting vegetables were suppressed by 2- or 3-year sod compared with fallow but were not affected by fenamiphos. Yields of snapbean, pepper, and okra did not differ between fallow and 1-year sod. In the final year of the study, yields of all crops were greater following 3-year sod than following fallow. Application of fenamiphos prior to planting each crop following fallow or sod did not affect yields.

Johnson AW; Burton GW; Sumner DR; Handoo Z

1997-12-01

144

Impact of reduced tillage and cover cropping on the greenhouse gas budget of a maize/soybean rotation ecosystem  

UK PubMed Central (United Kingdom)

Agricultural ecosystems have been viewed with the potential to sequester atmospheric carbon dioxide (CO?) by increasing soil organic carbon (SOC) through reduced tillage and cover cropping practices. There remains considerable uncertainty, however, regarding the carbon (C) sink/source potential of these systems and few studies have examined C dynamics in conjunction with other important greenhouse gases. The objective of this study was to evaluate the impact of an alternative management scenario (reduced tillage and cover cropping) on ecosystem respiration (R E) and nitrous oxide (N?O) and methane (CH?) fluxes in a maize (Zea mays L.)/soybean (Glycine max L.) rotation ecosystem in east-central Minnesota, United States. The control treatment was managed using fall tillage with a chisel plow in combination with a tandem disk, and the experimental treatment was managed using strip tillage and a winter rye (Secal cereale) cover crop. Over the two-year study period (2004-2005), cumulative R E was 222.7gCm?² higher in the alternatively managed treatment as a result of increased decomposition of the cover crop residue. N?O fluxes were similar in both treatments during the 2004 growing season and were 100.1mgNm?² higher in the conventional treatment during the 2005 growing season after nitrogen (N) fertilization. N fertilization and fertilizer type were the dominant factors controlling N?O fluxes in both treatments. CH? fluxes were negligible in both treatments and often below the detection limit. Cumulative growing season N?O losses in the control and experimental treatments, which totalled 38.9±3.1 and 26.1±1.7gCm?² when converted to CO? equivalents, were comparable to the annual estimates of net ecosystem CO? exchange in both treatments. This study further supports that N?O losses are an important component of the total greenhouse gas budget of agroecosystems. It also suggests that spring cover cropping, without residue removal, has limited C sequestration potential. The results from this study, however, may not necessarily represent equilibrium conditions in the experimental treatment. Rather, they are a measure of the transient response of the system after tillage conversion and cover crop addition. It is expected that the soil microbes will continue to adjust to the reduction in tillage and increased C inputs. Therefore, continued, long-term monitoring is needed to confirm whether the results are representative of equilibrium conditions.

Bavin TK; Griffis TJ; Baker JM; Venterea RT

2009-12-01

145

Breathing Relativistic Rotators and Fundamental Dynamical Systems  

CERN Multimedia

Breathing rotators are relativistic dynamical systems consisting of a single null vector associated with position and described by a relativistically invariant action. They extend a class of rotators recently considered by Staruszkiewicz in the context of rigid bodies of Hanson and Regge. Of great interest are fundamental dynamical systems, that is such, whose Casimir invariants of the Poincar\\'{e} group have fixed numerical values, independently of the state of motion. This is because they provide a classical counterpart of quantum particles. However, it has turned out recently that Staruszkiewicz fundamental rotator is defective as a dynamical system. Therefore, more general classes of objects should be considered in order to find fundamental objects with well posed Cauchy problem. In this respect breathing rotators are considered. Surprisingly, it has been shown that, similarly as Staruszkiewicz fundamental rotator, fundamental breathing rotators are also defective as dynamical systems due to vanishing of ...

Bratek, ?ukasz

2009-01-01

146

Influence of ammonium sulfate and rotation crops on strawberry black root rot.  

UK PubMed Central (United Kingdom)

The combined effects of rotation crops and nitrogen fertilizers were examined on the strawberry black root rot disease complex. In July 1995, microplots were filled with soil that had a history of strawberry black root rot and seeded with two types of oats (Avena strigosa 'Saia oats' or A. sativa 'Garry oats') or with sorgho-sudangrass (Sorghum bicolor x S. sudanense 'Triple S'). Microplots planted with 1-year-old 'Honeoye' strawberry crowns served as the controls. In May 1996, the crops were chopped and incorporated into the soil. The soil was re-planted with 1-year-old strawberry 'Honeoye' crowns and then fertilized with (NH4)2SO4 or Ca(NO3)2 at equivalent rates of N. Two months later, (NH4)2SO4-treated plants had 36% more leaf area and 41% more runners than strawberries treated with Ca(NO3)2. Strawberries that had been precropped with 'Saia' oats had 135% more runners and 38% more early fruit yield than strawberries grown in control microplots. Total fruit yield was not affected by the treatments. Compared to Ca(NO3)2, the (NH4)2SO4 treatment reduced the percentage of blackened roots. The influence of the cover crops on growth and disease was stronger with (NH4)2SO4 fertilization than with Ca(NO3)2 fertilization. Combining 'Saia' oats or sorghum-sudangrass rotation with (NH4)2SO4 fertilization reduced lesion nematode (Pratylenchus penetrans) numbers in subsequent strawberry roots when compared to controls. Also, the combination of 'Saia' or 'Garry' oats as a precrop with applications of (NH4)2SO4 reduced black root rot severity when compared to controls. Only the 'Garry' oat rotation reduced strawberry root colonization by Rhizoctonia fragariae when compared to controls. Other effects were associated with using (NH4)2SO4. The (NH4)2SO4 treatment lowered the rhizosphere soil pH by 0.2 units, reduced the numbers of fluorescent pseudomonads in the rhizosphere by 10- to 15-fold, and produced leaves that had more N, K, S, Mn, and Zn content than plants treated with Ca(NO3)2. Rotation with 'Saia' oats combined with (NH4)2SO4 fertilization may suppress strawberry black root rot and increase yields through multiple effects on the host, pathogens, and associated microflora.

Elmer WH; LaMondia JA

1999-02-01

147

Crop yield, root growth, and nutrient dynamics in a conventional and three organic cropping systems with different levels of external inputs and N re-cycling through fertility building crops  

DEFF Research Database (Denmark)

One of the core ideas behind organic production is that cropping systems should be less dependent on import of resources, and minimize negative effects on the surrounding environment compared to conventional production. However, even when clearly complying with regulations for organic production, it is not always obvious that these goals are reached. As an example, strong dependence on import of manure is often seen in current organic production, especially in systems producing high value crops such as vegetable crops. The aim of the present study was to test novel approaches to organic rotations, designed to reduce the reliance on import of external resources significantly. We compared a conventional system (C) and an organic system relying on manure import for soil fertility (O1) to two novel systems (O2 and O3) all based on the same crop rotation. The O2 and O3 systems represented new versions of the organic rotation, both relying on green manures and catch crops grown during the autumn after the maincrop as their main source of soil fertility, and the O3 system further leaving rows of the green manures to grow as intercrops between vegetable rows to improve the conditions for biodiversity and natural pest regulation in the crops. Reliance on resource import to the systems differed, with average annual import of nitrogen fertilizers of 149, 85, 25 and 25 kg N ha-1 in the C, O1, O2 and O3 systems, respectively. As expected, the crop yields were lower in the organic system. It differed strongly among crop species, but on average the organic crops yielded c. 82% of conventional yields in all three organic systems, when calculated based on the area actually grown with the main crops. In the O3 system some of the area of the vegetable fields was allocated to intercrops, so vegetable yields calculated based on total land area was only 63% of conventional yields. Differences in quality parameters of the harvested crops, i.e. nutrient content, dry matter content or damages by pests or diseases were fewand not systematic, whereas clear effects on nutrient balances and nitrogen leaching indicators were found. Root growth of all crops was studied in the C and O2 system, but only few effects of cropping system on root growth was observed. However, the addition of green manures to the systems almost doubled the average soil exploration by active root systems during the rotation from only 21% in C to 38% in O2 when measured to 2.4 m depth. This relates well to the observed differences in subsoil inorganic N content (Ninorg, 1–2 m depth) across the whole rotation (74 and 61 kg N ha-1 in C and O1 vs. only 22 and 21 kg N ha-1 in O2 and O3), indicating a strongly reduced N leaching loss in the two systems based on fertility building crops (green manures and catch crops). In short, the main distinctions were not observed between organic and conventional systems (i.e. C vs. O1, O2 and O3), but between systems based mainly on nutrient import vs. systems based mainly on fertility building crops (C and O1 vs. O2 and O3).

Thorup-Kristensen, Kristian; DresbØll, Dorte Bodin

2012-01-01

148

Nitrogen management in a maize-groundnut crop rotation of humid tropics: effect on N2O emission.  

UK PubMed Central (United Kingdom)

Development of appropriate land management techniques to attain sustainability and increase the N use efficiency of crops in the tropics has been gaining momentum. The nitrous oxides (N2Os) affect global climate change and its contribution from N and C management systems is of great significance. Thus, N transformations and N2O emission during maize-groundnut crop rotation managed with various N sources were studied. Accumulation of nitrate (NO3- ) and its disappearance happened immediately after addition of various N sources, showing liming effect. The mineral N retained for 2-4 weeks depending on the type and amount of N application. The chicken manure showed rapid nitrification in the first week after application during the fallow period, leading to a maximum N2O flux of 9889 g N2O-N m(-2) day(-1). The same plots showed a residual effect by emitting the highest N2O (4053 microg N2O-N m(-2) day(-1)) during maize cultivation supplied with a half-rate of N fertilizer. Application of N fertilizer only or in combination with crop residues exhibited either lowered fluxes or caused a sink during the groundnut and fallow periods due to small availability of substrates and/or low water-filled pore space (<40%). The annual N2O emission ranged from 1.41 to 3.94 kg N2O-N ha(-1); the highest was estimated from the chicken manure plus crop residues and half-rate of inorganic N-amended plots. Results indicates a greater influence of chicken manure on the N transformations and thereby N2O emission.

Khalil MI; Rosenani AB; Van Cleemput O; Fauziah CI; Shamshuddin J

2001-12-01

149

Model evaluation of cover crops, application to eleven species for banana cropping systems  

UK PubMed Central (United Kingdom)

Cover crops are increasingly used for weed management. But selecting the most suitable species of cover crop to be associated with a main crop requires long-term trials. We present a model-based method that uses a reduced number of parameters to help select cover crops in the context of banana cover-cropping systems. We developed the SIMBA-CC model to focus on radiation interception. The model was calibrated for 11 cover crop species by measuring their growth in 4m² plots with three levels of shade (0, 50, and 75%). The SIMBA-CC model served to predict the long term growth potential of the 11 cover crop species in function of the radiation under the banana crop canopy. The model was validated using three species in association with banana plants. We defined three indicators based on outputs of the model to assess the ability of each of the 11 species (i) to compete with weeds and (ii) to be maintained in the long-term under the canopy of the main crop, and (iii) to evaluate competition with the main crop for nitrogen resource. This ex ante evaluation revealed the most promising species to be intercropped with banana. Finally, the SIMBA-CC model was used to define the light interception traits of a virtual cover crop that satisfy the three indicators in the case of intercropping with banana. We showed that to satisfy the three criteria, cover crops with low values of optimal photosynthetically active radiation (PARopti) should have moderate maximal biomass productivity, while crops with higher PARopti values should have a higher maximal productivity. The use of functional traits and modeling appears effective to disentangle the relations between intrinsic traits of cover crops and effect traits that affect the performances of the intercropping system.

Tixier P; Lavigne C; Alvarez S; Gauquier A; Blanchard M; Ripoche A; Achard R

2011-02-01

150

Breathing relativistic rotators and fundamental dynamical systems  

Energy Technology Data Exchange (ETDEWEB)

According to the Staruszkiewicz definition, a relativistic dynamical system is said to be fundamental if its Casimir invariants are parameters, not constants of motion. This property is the classical counterpart of quantum irreducibility idea, which makes fundamental dynamical systems particularly interesting. An example of a fundamental dynamical system is provided by the fundamental relativistic rotator known also as the (m, s) particle. Recently, however, it turns out that the rotator is defective as a dynamical system. Therefore, as a first step toward finding a well behaving fundamental dynamical system, a class of breathing rotators, being a natural extension of the smallest class containing the fundamental relativistic rotator, is considered. A breathing rotator is a relativistic dynamical system consisting of its worldline and a single null vector. Surprisingly, fundamental dynamical systems from this extended class also turn out to be defecti0008.

Bratek, Lukasz [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskego 152, PL-31342 Krakow (Poland)], E-mail: lukasz.bratek@ifj.edu.pl

2010-01-08

151

Enhancing native arbuscular mycorrhizal association to improve phosphorus nutrition of rainfed upland rice (Oryza sativa L.) through cropping systems  

Directory of Open Access Journals (Sweden)

Full Text Available Efficiency of three upland rice based cropping systems in enhancing mycorrhizal population were tested in field and were compared with rice mono-cropping and the established rice + pigeon pea (Cajanus cajan L.; both annual and perennial) intercropping systems during 1998, 1999 and 2000, 2001 wet seasons. The two years’ crop rotations were (i) maize (Zea mays L.) relay cropped by horse gram (Dolichos biflorus) in the first year followed by rice sole in the second year, (ii) maize relay cropped by niger (Guizotia abyssinica L. f. Cass.) in the first year followed by rice sole in the second year and (iii) black gram (vigna mungo) sole in the first year followed by rice sole in the second year. The crop rotation involving maize relay cropped by horse gram was superior to the other systems as this system encouraged 26% more native arbuscular mycorrhizal (AM) colonization and 27% more phosphorus uptake as compared to monocropped rice in alternate years. Rice yield in two year rotation was higher by 23-29% over rice monocropping (1.1 t/ha). The total productivity of two years’ rotation (5.6 t/ha; rice equivalent), however, was comparable with rice + pigeon pea intercropping system.

D. MAITI*, M.K. BARNWAL, SULOCHANA K. RANA, M. VARIAR and R.K. SINGH

2012-01-01

152

Increases of soil phosphatase and urease activities in potato fields by cropping rotation practices  

Science.gov (United States)

Potato yield in Maine has remained relatively constant for over 50 years. To identify and quantify constraints to potato productivity, we established Status Quo (SQ), Soil Conserving (SC), Soil Improving (SI), Disease Suppressive (DS), and Continuous Potato (PP) cropping systems under both rainfed ...

153

Cooling system for rotating machine  

Energy Technology Data Exchange (ETDEWEB)

An electrical machine comprising a rotor is presented. The electrical machine includes the rotor disposed on a rotatable shaft and defining a plurality of radial protrusions extending from the shaft up to a periphery of the rotor. The radial protrusions having cavities define a fluid path. A stationary shaft is disposed concentrically within the rotatable shaft wherein an annular space is formed between the stationary and rotatable shaft. A plurality of magnetic segments is disposed on the radial protrusions and the fluid path from within the stationary shaft into the annular space and extending through the cavities within the radial protrusions.

Gerstler, William Dwight (Niskayuna, NY); El-Refaie, Ayman Mohamed Fawzi (Niskayuna, NY); Lokhandwalla, Murtuza (Clifton Park, NY); Alexander, James Pellegrino (Ballston Lake, NY); Quirion, Owen Scott (Clifton Park, NY); Palafox, Pepe (Schenectady, NY); Shen, Xiaochun (Schenectady, NY); Salasoo, Lembit (Schenectady, NY)

2011-08-09

154

Cropping systems control winter annual grass weeds in winter wheat.  

UK PubMed Central (United Kingdom)

Downy brome (Bromus tectorum L.), jointed goatgrass (Aegilops cylindrica Host), and volunteer cereal rye (Secale cereale L.) are winter annual grass weeds that are increasingly troublesome in the winter wheat (Triticum aestivum L. emend. Thell.)-fallow rotation areas of the western USA. Six dryland cropping systems--continuous no-till winter wheat, winter wheat-fallow with fall tillage, winter wheat-fallow with fall applied herbicide, winter wheat-fallow-fallow, winter wheat-sunflower-fallow, and winter wheat-proso millet-fallow--were compared for their effect on winter annual grass densities in winter wheat. Winter annual grass densities averaged 145, 4.4, and 0.4 plants/sq yard for the 1-, 2-, and 3-yr systems, respectively. Eradication of the winter annual grasses was not achieved with any of the systems. Dockage and foreign material levels in wheat grain were lower in 3-yr than in 2-yr cropping systems. Jointed goatgrass was the most persistent annual grass investigated.

Lyon DJ; Baltensperger DD

1995-12-01

155

Crop sequences, nitrogen fertilizer and grazing intensity in relation to wheat yields in rainfed systems  

UK PubMed Central (United Kingdom)

The Mediterranean region is experiencing unrelenting land-use pressure, largely driven by population growth. Long-term cropping system trials can guide crop and soil management options that are biophysically and economically sustainable. Thus, an extensive cereal-based rotation trial (1983–98) was established in northern Syria, to assess various two-course rotations with durum wheat (Triticum turgidum Desf.). The alternative rotations were: continuous wheat, fallow, chickpea (Cicer arietinum), lentil (Lens culinaris), medic (Medicago spp.), vetch (Vicia sativa) and watermelon (Citrullus vulgaris) as a summer crop. Ancillary treatments were: nitrogen (N) fertilizer application to the cereal phase (0, 30, 60 and 90 kg N/ha) and variable stubble grazing management (zero or stubble retention, moderate and heavy grazing). Both phases of the rotation trial occurred each year. The soil is a fine clay, thermic Calcixerollic Xerochrept. Seasonal rainfall was the dominant factor in influencing overall yields. Rotations significantly influenced yields, being highest for fallow (2·43 t/ha), followed by watermelon (similar to fallow), vetch, lentil, medic and chickpea, and least for continuous wheat (1·08 t/ha). Overall, yields increased consistently with added N, but responses varied with the rotation. The various stubble grazing regimes had little or no effect on either grain or straw yields. While the trial confirmed the value of fallow and the drawbacks of continuous cereal cropping, it also showed that replacing either practice with chickpea or lentil, or vetch for animal feed, was potentially a viable option. Given favourable economics, legume-based rotations for food and forage could contribute to sustainable cropping throughout the Mediterranean region.

Ryan J; Singh M; Pala M; Makhboul R; Masri S; Harris HC; Sommer R

2010-04-01

156

Improving Resilience of Northern Field Crop Systems Using Inter-Seeded Red Clover: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available In light of the environmental challenges ahead, resilience of the most abundant field crop production systems must be improved to guarantee yield stability with more efficient use of nitrogen inputs, soil and water resources. Along with genetic and agronomic innovations, diversification of northern agro-ecosystems using inter-seeded legumes provides further opportunities to improve land management practices that sustain crop yields and their resilience to biotic and abiotic stresses. Benefits of legume cover crops have been known for decades and red clover (Trifolium pratense) is one of the most common and beneficial when frost-seeded under winter wheat in advance of maize in a rotation. However, its use has been declining mostly due to the use of synthetic fertilizers and herbicides, concerns over competition with the main crop and the inability to fully capture red clover benefits due to difficulties in the persistence of uniform stands. In this manuscript, we first review the environmental, agronomic, rotational and economical benefits associated with inter-seeded red clover. Red clover adaptation to a wide array of common wheat-based rotations, its potential to mitigate the effects of land degradation in a changing climate and its integration into sustainable food production systems are discussed. We then identify areas of research with significant potential to impact cropping system profitability and sustainability.

Amélie C. M. Gaudin; Sabrina Westra; Cora E. S. Loucks; Ken Janovicek; Ralph C. Martin; William Deen

2013-01-01

157

Fungi Associated With Rice-Wheat Cropping System in Relation to Zero and Conventional Tillage Technologies  

Directory of Open Access Journals (Sweden)

Full Text Available Soil mycoflora play an important role in agricultural economy of a country. Soil borne pathogen produces serious losses to the yield of a crop. In rice Bwheat cropping system due to continuous cropping and reduced rotation, soil borne pathogens have become increasingly important with the yield decline. The current study was made to have the knowledge about soil borne fungi associated with rice and wheat crop in rice- wheat cropping system under zero and conventional tillage technologies. One hundred and seven fungal species belonging to 54 genera were isolated from foliar parts, roots and soil on general and specific media. Forty three genera including 59 species were isolated for the first time from rice, wheat plants and soil of rice-wheat cropping system. The fungi were categorized into four groups (pathogenic, saprophytic, toxin producing and beneficial). Aspergillus flavus was identified as only toxin producing fungus and isolated from both rice and wheat crops. Trichoderma spp were isolated from both crops and Paecilomyces spp were isolated only from wheat fields and are known as beneficial fungi. Among the pathogenic fungi Bipolaris sorokiniana, Fusarium oxysporum and Rhizoctonia solani were isolated as pathogenic fungi both from rice and wheat soils. Alternaria trtiticina, Fusarium equiseti, F. grameniarum, F. poae, F. solani and Pythium sp. were isolated only from wheat fields whereas Nigrospora oryzae, Rhizopus oryzae and Sclerotium oryzae were isolated only form rice fields. Total fungal colony counts isolated from soil on five specific media show some effect of zero tillage on soil mycoflora.

Shamim Iftikhar; Amir Sultan; Anjum Munir; Shazia Iram; Iftikhar Ahmad

2003-01-01

158

Rainfed wheat-based rotations under Mediterranean conditions: Crop sequences, nitrogen fertilization, and stubble grazing in relation to grain and straw quality  

UK PubMed Central (United Kingdom)

Crop rotations have evolved as a strategy to obtain harvestable yields in stressed environments due to improved water-use efficiency, nitrogen (N) fixation, and breaking diseases cycles. While fallowing or growing legume crops in the alternate year have shown to consistently increase yields in semi-arid environments such as in the Mediterranean area, little emphasis has been given to cereal quality in rotation trials, especially with respect to N, and thus improved animal and human nutrition. This paper reports the effect of those treatments on cereal quality parameters, especially N, and thus protein, in wheat grain and straw in a long-term (14 years) rainfed cropping systems trial in the medium rainfall zone (300-400 mm year-1) in northern Syria that examined seven alternative-year options with durum wheat (Triticum turgidum var durum), i.e., vetch (Vicia sativa), medic (Medicago spp.), chickpea (Cicer arietinum), lentil (Lens culinaris), fallow, watermelon (Citrullus vulgaris) as a summer crop in the fallow year, and continuous wheat. Two ancillary treatments involved N fertilization (0, 30, 60, 90 kg N ha-1) in the cereal phase, and stubble grazing management (moderate and heavy grazing, and no grazing or stubble retention). Both the rotation and N treatments had a significant influence on all parameters (test weight, grain and straw N percentage, and total N uptake). By comparison, grazing management had little influence on quality parameters except test weight; however, the residue x N interaction was significant. Rotations such as those with medic and vetch enriched the N in grain and straw. These rotations thus improved the nutritional value in terms of protein of the grain, an important consideration as per capita consumption of bread is high in the Middle East and other sources of protein are limited. Similarly, as grazed or fed straw is dominant in the diet of sheep, the enhanced nutrition is of significance. While fallow produced the highest yields, and is a hedge against the effects of drought, it produces grain and straw of low nutritional value with respect to protein, as a result of dilution of available soil N in the increased biomass. Though less obvious than yield, crop quality parameters should be considered in any cropping system involving rotations, especially those involving legumes.

Ryan J; Pala M; Masri S; Singh M; Harris H

2008-02-01

159

Work and energy in rotating systems  

CERN Multimedia

Literature analyzes the way in which Newton's second law can be used when non-inertial rotating systems are used. However, the treatment of the work and energy theorem in rotating systems is not considered in textbooks. In this paper, we show that the work and energy theorem can still be applied to a closed system of particles in a rotating system, as long as the work of fictitious forces is properly included in the formalism. The coriolis force does not contribute to the work coming from fictitious forces. It worths remarking that real forces that do not do work in an inertial reference frame can do work in the rotating reference frame and viceversa. The combined effects of acceleration of the origin and rotation of the non-inertial system are also studied.

Manjarres, Diego A; Diaz, Rodolfo A

2012-01-01

160

Tillage, Crop Rotation, and Cultural Practice Effects on Dryland Soil Carbon Fractions  

Directory of Open Access Journals (Sweden)

Full Text Available Information is needed on novel management practices to increase dryland C sequestration and soil quality in the northern Great Plains, USA. We evaluated the effects of tillage, crop rotation, and cultural practice on dryland crop biomass (stems and leaves) yield, surface residue, and soil C fractions at the 0-20 cm depth from 2004 to 2008 in a Williams loam in eastern Montana, USA. Treatments were two tillage (no-tillage [NT] and conventional tillage [CT]), two crop rotations (continuous spring wheat [Triticum aestivum L.] [CW] and spring wheat-barley [Hordeum vulgaris L.] hay-corn [Zea mays L.]-pea [Pisum sativum L.] [W-B-C-P]), and two cultural practices (regular [conventional seed rates and plant spacing, conventional planting date, broadcast N fertilization, and reduced stubble height] and ecological [variable seed rates and plant spacing, delayed planting, banded N fertilization, and increased stubble height]). Carbon fractions were soil organic C (SOC), particulate organic C (POC), microbial biomass C (MBC), and potential C mineralization (PCM). Crop biomass was 24% to 39% greater in W-B-C-P than in CW in 2004 and 2005. Surface residue C was 36% greater in NT than in CT in the regular practice. At 5 - 20 cm, SOC was 14% greater in NT with W-B-C-P and the regular practice than in CT with CW and the ecological practice. In 2007, POC and PCM at 0 - 20 cm were 23 to 54% greater in NT with CW or the regular practice than in CT with CW or the ecological practice. Similarly, MBC at 10 - 20 cm was 70% greater with the regular than with the ecological practice in NT with CW. Surface residue, PCM, and MBC declined from autumn 2007 to spring 2008. No-tillage with the regular cultural practice increased surface residue and soil C storage and microbial biomass and activity compared to conventional tillage with the ecological practice. Mineralization reduced surface residue and soil labile C fractions from autumn to spring.

Upendra M. Sainju; Andrew W. Lenssen; Thecan Caesar-TonThat; Jalal D. Jabro; Robert T. Lartey; Robert G. Evans; Brett L. Allen

2012-01-01

 
 
 
 
161

The impact of nitrogen source and crop rotation on nitrogen mass balances in the Mississippi River Basin.  

UK PubMed Central (United Kingdom)

Nitrogen (N) leaching to surface waters from grain farms in the Mississippi River Basin (MRB), USA, is the primary cause of hypoxia in the Gulf of Mexico. Regional-scale N mass balances indicate that a small, intensively cropped area of the upper MRB contributes disproportionately to nitrate loading. These aggregate balances miss small-scale variability, especially that caused by differences in farm management. We constructed N mass balances for a gradient of farm types, from corn-soybean monocultures to diversified grain farms that rely on biological N fixation (BNF) as a primary N source, to compare the relative efficiency of diverse farming systems in the MRB. Five-year N balances were calculated for a most and least productive field on each farm using data collected from interviews with 95 grain farmers in Iowa, Ohio, Minnesota, and Wisconsin; from legume biomass and corn grain samples collected from a subset of farms; and published values from the literature. Nitrogen balances ranged from high average annual surpluses (149 kg N x ha(-1) x yr(-1)) to large deficits (80 kg N x ha(-1) x yr(-1)), and differed based on N source and crop rotation. Fields with > 50% of total N additions from legume N sources and fields with complex crop rotations that included both annual and perennial species were approximately in balance (3.7 kg N x ha(-1) x yr(-1) and 5.7 kg N x ha(-1) x yr(-1), respectively) compared to fertilizer-based practices in corn-soybean rotations with average annual surpluses near 35 kg N x ha(-1) x yr(-1). Surplus N was also inversely related to the proportion of total N inputs from BNF for medium (80-160 kg N x ha(-1) x yr(-1)) to high (> 160 kg N x ha(-1) x yr(-1)) N rates. Diversified farmers were more likely to adjust their management practices in response to environmental variability compared to fertilizer-based farmers. Taken together, results from this study suggest that significantly reducing surplus N in agroecosystems will require reducing N inputs and increasing C availability to support the internal biological mechanisms for storing N in farm fields.

Blesh J; Drinkwater LE

2013-07-01

162

The impact of nitrogen source and crop rotation on nitrogen mass balances in the Mississippi River Basin.  

Science.gov (United States)

Nitrogen (N) leaching to surface waters from grain farms in the Mississippi River Basin (MRB), USA, is the primary cause of hypoxia in the Gulf of Mexico. Regional-scale N mass balances indicate that a small, intensively cropped area of the upper MRB contributes disproportionately to nitrate loading. These aggregate balances miss small-scale variability, especially that caused by differences in farm management. We constructed N mass balances for a gradient of farm types, from corn-soybean monocultures to diversified grain farms that rely on biological N fixation (BNF) as a primary N source, to compare the relative efficiency of diverse farming systems in the MRB. Five-year N balances were calculated for a most and least productive field on each farm using data collected from interviews with 95 grain farmers in Iowa, Ohio, Minnesota, and Wisconsin; from legume biomass and corn grain samples collected from a subset of farms; and published values from the literature. Nitrogen balances ranged from high average annual surpluses (149 kg N x ha(-1) x yr(-1)) to large deficits (80 kg N x ha(-1) x yr(-1)), and differed based on N source and crop rotation. Fields with > 50% of total N additions from legume N sources and fields with complex crop rotations that included both annual and perennial species were approximately in balance (3.7 kg N x ha(-1) x yr(-1) and 5.7 kg N x ha(-1) x yr(-1), respectively) compared to fertilizer-based practices in corn-soybean rotations with average annual surpluses near 35 kg N x ha(-1) x yr(-1). Surplus N was also inversely related to the proportion of total N inputs from BNF for medium (80-160 kg N x ha(-1) x yr(-1)) to high (> 160 kg N x ha(-1) x yr(-1)) N rates. Diversified farmers were more likely to adjust their management practices in response to environmental variability compared to fertilizer-based farmers. Taken together, results from this study suggest that significantly reducing surplus N in agroecosystems will require reducing N inputs and increasing C availability to support the internal biological mechanisms for storing N in farm fields. PMID:23967572

Blesh, J; Drinkwater, L E

2013-07-01

163

N-fixation of selected green manure plants in an organic crop rotation.  

UK PubMed Central (United Kingdom)

The aim of this study was to investigate the N-fixation potential of different leguminous green manure plants grown in the autumn after harvest of a barley main crop. Fixed above ground N derived from the atmosphere (Ndfa) was estimated both by the 15N isotope dilution method and by the total-N difference method. Winter rape (Brassica napus), winter rye (Secale cereale) and Italian ryegrass (Lolium multiflorum) were grown as non-fixing control plants for the estimation of N-fixation of leguminous green manure plants. It was concluded that Italian ryegrass was the most suitable control plant, and that the choice of control plant can be important for the results. When using Italian ryegrass as control plant, no significant difference was observed between the total N difference method and the 15N isotope dilution method. N-fixation varied strongly among the plant species and differed between the two years. Hairy vetch (Vicia villosa), crimson clover (Trifolium incarnatum) and Persian clover (Trifolium resupinatum) fixed more than 100 kg N ha(-1) at least in one of the two investigated years. The highest estimated Ndfa was 149 kg N ha(-1) in the above ground plant material of hairy vetch in 1997. Ndfa of common vetch (Vicia sativa) and Egyptian clover (Trifolium alexandrinum) was below 60 or 100 kg N ha(-1) in 1996 and 1997, respectively. Weather conditions and soil moisture, which are crucial during germination and early plant development, may be an explanation for lower N-fixation in 1996 than in 1997. With respect to N, the results indicate that extended use of green manure could strongly reduce the need for full year green manure crops in stockless organic crop rotations.

Mueller T; Thorup-Kristensen K

2001-01-01

164

Short rotation forestry production systems  

Energy Technology Data Exchange (ETDEWEB)

The level of concern about non-technical barriers to short rotation forestry production systems differed greatly among the participant countries. In Canada and U.S.A. the greatest concern was the differential costs between fossil fuels and biomass fuels and the lack of energy policy equalizing the playing field. In Sweden, Denmark and U.K. the concerns related to technology transfer, incentives for getting long-term commitments from biomass fuel suppliers, financing mechanisms, and environmental issues. The reason for these differing concerns can be seen partly in a comparison of energy prices for gasoline and electricity for industry and households. The conclusion is that government intervention is required to facilitate the commercialization of biomass energy and that new policy tools may be needed. The Handbook on How to Grow Short Rotation Forests was in hard copy and electronic format, which can be downloaded from the World Wide Web and is available on CD-ROM. Full-scale plants for post-treatment of sewage water with the aim of improved nitrogen reduction have been built at several sites in southern Sweden. The ability of willow, when used as vegetation filters, to capture nutrients from the wastewater is being studied at some of these sites. This ability varies considerably with the development stage of the plantation and also with site conditions. The use of ash as a fertilizer is under investigation. Ash additions gave equal Salix stem mass as commercial fertilizers did. A lower uptake of P in ash treatments receiving P fertilizer indicated that the short term availability of P in ash could be 80% of that in P fertilizer. The liming effect of ash was similar to that of slaked lime. Due to increased pH in the lime and ash treatments, Mn and Cd mass in stems decreased. In the coppice research one study showed that the high-N plants had lower amounts of starch in the tissue than the low-N plants. The major storage locations for starch were in roots, stems and stool in this order. In these organs most of the starch was found in cortex cells in the bark followed by phloem cells and also to some extent in the xylem. The seasonal variation showed at what time the reserves were built up and when reserve products were utilised for the regrowth and resprouting. Also the effect of different harvesting techniques was studied. It was shown that significant damage to stools at harvesting remained throughout the three-year period of investigation. Even stools with extremely severe damage still showed a high ability to sprout, although at a lower level than less damaged stools. Studies have also indicated significant variation in sprouting ability between clones of S. viminalis, probably mainly due to genotypic differences

Ledin, S. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Soil Sciences; Sennerby-Forsse, L. [Swedish Forestry Research Inst., Uppsala (Sweden); Wright, Lynn [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

1998-12-31

165

Turbulent shear flows subject to system rotation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Turbulent flows in rotating frame-of-reference are of considerable interest in a variety of industrial, geophysical and astrophysical applications. In these flows, the system rotation induces additional body forces, i.e. centrifugal and Coriolis forces, acting on the turbulent flow, so that th...

Barri, Mustafa

166

Energy utilization in crop and dairy production in organic and conventional livestock production systems  

Energy Technology Data Exchange (ETDEWEB)

Due to interactions between crop and livestock enterprises and between levels of different input factors and their effects on yields, it is proposed to analyze agricultural energy utilization through system modelling of data from farm studies. Energy use in small grains, grass-clover and fodder beets registered in organic and conventional mixed dairy farms was analyzed and used together with crop yields in order to model energy prices on three Danish soil types. On the same farms, the energy use in dairy production registered in organic and conventional mixed dairy farms was analyzed and used together with milk and meat yields in order to model energy prices for three different feeding strategies and two soil types. In general, the crop energy price models can be used together with the dairy production to model the effects of different feeding and crop rotation strategies on the overall utilization in mixed dairy production systems. (author)

Refsgaard, K. [Agricultural University of Norway, Aas (Norway). Dept. of Economics and Social Sciences; Halberg, N.; Kristensen, E.S. [Danish Institute of Agricultural Science, Tjele (Denmark)

1998-12-31

167

Integration of crop rotation and arbuscular mycorrhiza (AM) inoculum application for enhancing AM activity to improve phosphorus nutrition and yield of upland rice (Oryza sativa L.).  

UK PubMed Central (United Kingdom)

Upland rice (Oryza sativa L.) is a major crop of Eastern India grown during the wet season (June/July to September/October). Aerobic soils of the upland rice system, which are acidic and inherently phosphorus (P) limiting, support native arbuscular mycorrhizal (AM) activity. Attempts were made to improve P nutrition of upland rice by exploiting this natural situation through different crop rotations and application of AM fungal (AMF) inoculum. The effect of a 2-year crop rotation of maize (Zea mays L.) followed by horse gram (Dolichos biflorus L.) in the first year and upland rice in the second year on native AM activity was compared to three existing systems, with and without application of a soil-root-based inoculum. Integration of AM fungal inoculation with the maize-horse gram rotation had synergistic/additive effects in terms of AMF colonization (+22.7 to +42.7%), plant P acquisition (+11.2 to +23.7%), and grain yield of rice variety Vandana (+25.7 to +34.3%).

Maiti D; Toppo NN; Variar M

2011-11-01

168

Integration of crop rotation and arbuscular mycorrhiza (AM) inoculum application for enhancing AM activity to improve phosphorus nutrition and yield of upland rice (Oryza sativa L.).  

Science.gov (United States)

Upland rice (Oryza sativa L.) is a major crop of Eastern India grown during the wet season (June/July to September/October). Aerobic soils of the upland rice system, which are acidic and inherently phosphorus (P) limiting, support native arbuscular mycorrhizal (AM) activity. Attempts were made to improve P nutrition of upland rice by exploiting this natural situation through different crop rotations and application of AM fungal (AMF) inoculum. The effect of a 2-year crop rotation of maize (Zea mays L.) followed by horse gram (Dolichos biflorus L.) in the first year and upland rice in the second year on native AM activity was compared to three existing systems, with and without application of a soil-root-based inoculum. Integration of AM fungal inoculation with the maize-horse gram rotation had synergistic/additive effects in terms of AMF colonization (+22.7 to +42.7%), plant P acquisition (+11.2 to +23.7%), and grain yield of rice variety Vandana (+25.7 to +34.3%). PMID:21448812

Maiti, Dipankar; Toppo, Neha Nancy; Variar, Mukund

2011-03-30

169

Wheat cropping systems and technologies in China  

UK PubMed Central (United Kingdom)

Chinese wheat (Triticum aestivum) production has developed rapidly during the last 57 years, largely due to improved crop management technologies and new varieties. The history of wheat planting technologies in China was reviewed, and the physiological mechanisms that allow wheat to attain high yield under these planting systems were analyzed. The use of leaf number and stage of development to indicate the optimum timing for applications of fertilizers and irrigation water, and uniform seeding at reduced seeding rates to control lodging contributed significantly to the substantial progress in wheat productivity. However, flood irrigation and tillage-based practices also resulted in serious problems, including a decline in soil fertility and quality, environmental pollution, and inefficient use of water resources. The major future challenges facing wheat production are to improve water and nutrient use efficiency. Conservation agriculture-based resource conservation technologies such as zero or reduced tillage, flat or raised bed-planting systems, and rational management of crop residues to eliminate burning in the field are among the strategies we strongly recommend for improving agricultural environments and stabilizing/increasing wheat production in China.

Wang Fahong; He Zhonghu; Sayre Ken; Li Shengdong; Si Jisheng; Feng Bo; Kong Lingan

2009-04-01

170

Faba beans and other legumes add nitrogen to irrigated cotton cropping systems.  

UK PubMed Central (United Kingdom)

Summary. Legumes have become common rotation crops in cotton cropping systems in northern New South Wales. Levels of nitrogen fixation and yield achieved on-farm were measured in commercial faba beans and other winter and summer legume crops sown after cotton over 3 years to assess the relative inputs of fixed nitrogen (N) into this system. Faba bean crops fixed up to 350 kg N/ha, removed up to 160 kg N/ha in harvested grain and contributed up to 270 kg fixed N/ha to soil N after harvest. Grain yields, N2 fixation and dry matter production were reduced in late-sown crops and those water-stressed during pod-filling, but most faba bean crops fixed almost 3 times as much N as was removed in grain. Below-ground legume N, determined with 15N shoot feeding techniques, accounted for 40% of the total crop N at peak biomass, or about 100 kg N/ha for the average faba bean crops. Residual fixed N after harvest was predicted from crop dry matter and grain yield, and this could be used to assess the contribution to soil N from faba beans. Amounts of nitrogen fixed by other legume crops ranged from 20 kg N/ha for adzuki bean and droughted lablab to more than 450 kg N/ha by irrigated soybean. Soybean, peanut and Dolichos lablab contributed more fixed N to the soil than adzuki bean, mung bean or pigeon pea under irrigated conditions. Winter crops including field peas, lentils and lupins and green-manured pasture species fixed up to 240 kg N/ha.

Rochester IJ; Peoples MB; Constable GA; Gault RR

1998-01-01

171

Effect of rotational fallows on abundance of soil insects and weeds in maize crops in eastern Zambia  

UK PubMed Central (United Kingdom)

Improved fallows or the rotation of fast growing nitrogen-fixing legume species with cereals have been shown to accumulate nitrogen and organic matter, recycle nutrients in the soil and improve soil physical and chemical properties, and increase crop yield compared to traditional fallows. However, the effect of soil nutrients added by fallow species on the incidence of pests, weeds and pathogens in the subsequent crop has not been assessed in southern Africa. In this study, we assessed the relationships between nutrients in the soil after fallows of crotalaria (Crotalaria grahamiana), pigeon pea (Cajanus cajan), sesbania (Sesbania sesban), tephrosia (Tephrosia vogelii), and their mixtures, and the incidence of soil insects, namely, snout beetles (Diaecoderus sp.) and termites, and weeds in eastern Zambia. Rotational fallows of sesbania+crotalaria, sesbania+tephrosia, sesbania+pigeon pea and tephrosia+pigeon pea increased infestation of maize by snout beetles as compared to the natural fallow or unfertilised maize grown continuously in monoculture. The beetles showed aggregated spatial distribution, influenced mainly by the nitrate and total inorganic nitrogen content of the soil. Termite incidence was higher in maize after a natural fallow and pure crotalaria, which had 11 and 7 times as much damage as maize planted after pigeon pea+tephrosia mixture. Total weed biomass in maize grown after a natural fallow was six times higher than in maize planted after pure sesbania fallows. The weed biomass was correlated positively with the potassium content of the top 20 cm soil and negatively with plant litter on the soil surface. It is concluded that organic inputs from pure sesbania, sesbania+pigeon pea, sesbania+tephrosia and tephrosia+pigeon pea reduce infestation by termites and weeds, and give maize grain yield comparable with the recommended rates of inorganic fertilisers. However, these fallows have the potential to increase infestation by snout beetles. This is the first study on the snout beetle in Africa, and we recommend more systematic investigation on its ecology in agroforestry systems.

Sileshi G; Mafongoya PL

2003-07-01

172

Farm-scale costs and returns for second generation bioenergy cropping systems in the US Corn Belt  

Science.gov (United States)

While grain crops are meeting much of the initial need for biofuels in the US, cellulosic or second generation (2G) materials are mandated to provide a growing portion of biofuel feedstocks. We sought to inform development of a 2G crop portfolio by assessing the profitability of novel cropping systems that potentially mitigate the negative effects of grain-based biofuel crops on food supply and environmental quality. We analyzed farm-gate costs and returns of five systems from an ongoing experiment in central Iowa, USA. The continuous corn cropping system was most profitable under current market conditions, followed by a corn–soybean rotation that incorporated triticale as a 2G cover crop every third year, and a corn–switchgrass system. A novel triticale–hybrid aspen intercropping system had the highest yields over the long term, but could only surpass the profitability of the continuous corn system when biomass prices exceeded foreseeable market values. A triticale/sorghum double cropping system was deemed unviable. We perceive three ways 2G crops could become more cost competitive with grain crops: by (1) boosting yields through substantially greater investment in research and development, (2) increasing demand through substantially greater and sustained investment in new markets, and (3) developing new schemes to compensate farmers for environmental benefits associated with 2G crops.

Manatt, Robert K.; Hallam, Arne; Schulte, Lisa A.; Heaton, Emily A.; Gunther, Theo; Hall, Richard B.; Moore, Ken J.

2013-09-01

173

Long-term effects of cropping systems on N2O emission potential  

DEFF Research Database (Denmark)

The potential for N2O emissions outside the main growing season may be influenced by long-term effects of cropping system. This was investigated by collecting intact soil cores (100 cm3, 0–4 cm depth) under winter wheat in three organic cropping systems and a conventional reference within a long-term crop rotation experiment. Average annual inputs of C in crop residues and manure ranged from 1.7 to 3.3 Mg ha?1. A simulated freeze–thaw cycle resulted in a flush of CO2 during the first 48 h, which could be mainly from microbial sources. Other samples were adjusted to approximately ?10, ?30 or ?100 hPa and amended with excess 15NO3? prior to freezing and thawing. Denitrification was the main source of N2O during a 72-h incubation at 22 °C, as judged from N2O and total 15N evolution. Although the input of C in the conventionally managed cropping system was significantly less than in the organic cropping systems, it showed higher N2O evolution at all three matric potentials. Estimates of relative gas diffusivity (DP/D0) in soil from the four cropping systems indicated that C input affected soil aeration. Soil from the two cropping systems with highest C input showed N2O evolution at DP/D0 in excess of 0.02, which is normally considered a threshold for development of anaerobic sites in the soil, presumably because the oxygen demand was also high. The study shows that cropping system affects both soil gas diffusivity and C availability, and that both characteristics significantly influence the N2O emission potential.

Petersen, SØren O; Ambus, Per

2013-01-01

174

Soil Management Practices to Improve Nutrient-use Efficiencies and Reduce Risk in Millet-based Cropping Systems in the Sahel  

Directory of Open Access Journals (Sweden)

Full Text Available Low soil fertility and moisture deficit are among the main constraints to sustainable crop yields in the Sahel. A study therefore, was conducted at the ICRISAT Sahelian Center, Sadore in Niger to test the hypothesis that integrated soil husbandry practices consisting of manure, fertilizer and crop residues in rotational cropping systems use organic and mineral fertilizes efficiently, thereby resulting in higher yields and reduced risk. Results from an analysis of variance showed that choice of cropping systems explained more than 50% of overall variability in millet and cowpea grain yields. Among the cropping systems, rotation gave higher yields than sole crop and intercropping systems and increased millet yield by 46% without fertilizer. Rainfall-use efficiency and partial factor productivity of fertilizer were similarly higher in rotations than in millet monoculture system. Returns from cowpea grown in cowpea-millet rotation without fertilizer and the medium rates of fertilizers (4 kg P.ha-1 + 15 kg N.ha-1) were found to be most profitable in terms of high returns and low risk, principally because of a higher price of cowpea than millet. The study recommends crop diversification, either in the form of rotations or relay intercropping systems for the Sahel as an insurance against total crop failure.

Yamoah, CF.; Bationo, A.; Shapiro, B.; Koala, S.

2003-01-01

175

COMPARISON OF CROP ROTATION FOR VERTICILLIUM WILT MANAGEMENT IN CONVENTIONAL AND ORGANIC STRAWBERRY PRODUCTION  

Science.gov (United States)

Wilt caused by Verticillium dahliae is a major disease in non-fumigated and organic strawberry production systems in California. A comparative study of the effects of broccoli and lettuce rotations on strawberry growth, Verticillium wilt, and yield were evaluated in conventional and organic producti...

176

Crop Yields and Nematode Population Densities in Triticale-Cotton and Triticale-Soybean Rotations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Triticale cv. Beagle 82, cotton cv. McNair 235, and soybean cv. Twiggs were arranged in three cropping sequences to determine the effects of fenamiphos and cropping sequence on nematode population densities and crop yields under conservation tillage for 4 years. The cropping sequences were triticale...

Johnson, A. W.; Dowler, C. C.; Baker, S. H.; Handoo, Z. A.

177

Conversão e balanço energético de sistemas de rotação de culturas para triticale, sob plantio direto/ Energy and balance conversion of crop rotation systems for triticale , under no-tillage  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Na agricultura moderna, interessam sistemas de produção eficientes no uso da energia. Objetivou-se avaliar a conversão e o balanço energético de cinco sistemas de rotação de culturas envolvendo o triticale. Os sistemas avaliados, no período de 1987 a 1991, foram: I (triticale/soja), II (triticale/soja e aveia preta/soja), III (triticale/soja e ervilhaca/milho), IV (triticale/ soja, ervilhaca/milho e aveia preta/soja) e V (triticale/soja, triticale/soja, ervilhaca/ (more) milho e aveia preta/soja). Em 1990, nos sistemas II, IV e V, a aveia preta foi substituída por aveia branca. O experimento foi estabelecido em plantio direto, em delineamento de blocos ao acaso, com três repetições e parcelas com área útil de 24 m². Na média do período de 1987 a 1989, o sistema III apresentou conversão (9,30) e balanço energético (23.860 Mcal/ha) maiores do que os demais sistemas estudados (I: 5,38, II: 5,02, IV: 8,12 e V: 7,37; I: 18.067 Mcal/ha, II: 13.790 Mcal/ha, IV: 19.875 Mcal/ha e V: 19.264 Mcal/ha, respectivamente). Nesse período, as condições climáticas transcorreram normalmente. Na média do período de 1990 a 1991, não houve diferenças significativas entre as médias para conversão e para balanço energético. Nesse período, as condições climáticas foram adversas às culturas em estudo. Abstract in english Efficient energy conversion production systems are important for modern agriculture. The objetive was to evaluate the energy conversion and balance of five rotation systems that included triticale. The evaluated systems, from 1987 to 1991, were: I (triticale/soybean), II (triticale/soybean and black oats/soybean), III (triticale/soybean and common vetch/corn), IV (triticale/soybean, common vetch/corn, and black oats/soybean), and V (triticale/soybean, triticale/soybean, c (more) ommon vetch/corn, and black oats/ soybean). In 1990, black oats was replaced by white oats in systems II, IV, and V. The experiment was set up under no-tillage, using a randomized block design with three replications and plots totalizing 24 m² . On average, for the period 1987 to 1989, system III showed higher energy conversou (9.30) and balance (23.860 Mcal/ha), as compared to the othen studied systems (I: 5.38, II: 5.02, IV: 8.12 e V: 7.37; I: 18.067 Mcal/ha, II: 13.790 Mcal/ha, IV: 19.875 Mcal/ha e V: 19.264 Mcal/ha, respectivily). In this period, the climatic conditions were normal. On average, the period 1990 to 1991, there were no significant differences between energy conversion and balance means. In this period, climatic conditions were adverse.

Santos, Henrique Pereira dos; Ignaczak, João Carlos; Lhamby, Julio Cesar Barreneche; Baier, Augusto Carlos

2000-03-01

178

Feature Recognition System for Rotational Features  

Directory of Open Access Journals (Sweden)

Full Text Available This study presents the development of a knowledge-based features recognition system for mechanical parts. The main aim of the research was to concentrate on recognition of rotational features, namely, blind hole, through hole and slanting hole to be used in automatic process planning system. The rule-based technique was applied to recognize rotational features. The recognition criteria were based upon geometrical data from Standard for Exchange of Product data file (STEP) of Computer-aided Design (CAD) system. The system consists of several modules, namely, pre-processing module, inference engine module and user interface module. The developed system succeeds the design activities in manufacturing industries.

C.F. Tan; N. Ismail; S.S.S. Ranjit; V.K. Kher

2013-01-01

179

Emissions of nitrous oxide from arable organic and conventional cropping systems on two soil types  

DEFF Research Database (Denmark)

Conventional cropping systems rely on targeted short-term fertility management, whereas organic systems depend, in part, on long-term increase in soil fertility as determined by crop rotation and management. Such differences influence soil nitrogen (N) cycling and availability through the year. The main objective of this study was to compare nitrous oxide (N2O) emissions from soil under winter wheat (Triticum aestivum L.) within three organic and one conventional cropping system that differed in type of fertilizer, presence of catch crops and proportion of N2-fixing crops. The study was replicated in two identical long-term crop rotation experiments on sandy loam soils under different climatic conditions in Denmark (Flakkebjerg—eastern Denmark and Foulum—western Denmark). The conventional rotation received 165–170 kg N ha?1 in the form of NH4NO3, while the organic rotations received 100–110 kg N ha?1 as pig slurry. For at least 11 months, as from September 2007, static chambers were used to measure N2O emissions at least twice every calendar month. Mean daily N2O emissions across the year ranged from 172 to 438 ?g N m?2 d?1 at Flakkebjerg, and from 173 to 250 ?g N m?2 d?1 at Foulum. A multiple linear regression analysis showed inter-seasonal variations in emissions (P < 0.001), but annual N2O emissions from organic and conventional systems were not significantly different despite the lower N input in organic rotations. The annual emissions ranged from 54 to 137 mg N m?2, which corresponded to 0.5–0.8% of the N applied in manure or mineral fertilizer. Selected soil attributes were monitored to support the interpretation of N2O emission patterns. A second multiple linear regression analysis with potential drivers of N2O emissions showed a negative response to soil temperature (P = 0.008) and percent water-filled pore space (WFPS) (P = 0.052) at Foulum. However, there were positive interactions of both factors with NO3-N, i.e., high N2O emissions occurred during periods when high soil nitrate levels coincided with high soil temperature (P = 0.016) or high soil water content (P = 0.056). A positive effect (P = 0.03) of soil temperature was identified at Flakkebjerg, but the number of soil samplings was limited. Effects of cropping system on N2O emissions were not observed.

Chirinda, Ngoni; Carter, Mette Sustmann

2010-01-01

180

Emissions of nitrous oxide from arable organic and conventional cropping systems on two soil types  

DEFF Research Database (Denmark)

Conventional cropping systems rely on targeted short-term fertility management, whereas organic systems depend, in part, on long-term increase in soil fertility as determined by crop rotation and management. Such differences influence soil nitrogen (N) cycling and availability through the year. The main objective of this study was to compare nitrous oxide (N2O) emissions from soil under winter wheat (Triticum aestivum L.) within three organic and one conventional cropping system that differed in type of fertilizer, presence of catch crops and proportion of N2-fixing crops. The study was replicated in two identical long-term crop rotation experiments on sandy loam soils under different climatic conditions in Denmark (Flakkebjerg-eastern Denmark and Foulum-western Denmark). The conventional rotation received 165-170 kg N ha-1 in the form of NH4NO3, while the organic rotations received 100-110 kg N ha-1 as pig slurry. For at least 11 months, as from September 2007, static chambers were used to measure N2O emissions at least twice every calendar month. Mean daily N2O emissions across the year ranged from 172 to 438 µg N m-2 d-1 at Flakkebjerg, and from 173 to 250 µg N m-2 d-1 at Foulum. A multiple linear regression analysis showed inter-seasonal variations in emissions (P < 0.001), but annual N2O emissions from organic and conventional systems were not significantly different despite the lower N input in organic rotations. The annual emissions ranged from 54 to 137 mg N m-2, which corresponded to 0.5-0.8% of the N applied in manure or mineral fertilizer. Selected soil attributes were monitored to support the interpretation of N2O emission patterns. A second multiple linear regression analysis with potential drivers of N2O emissions showed a negative response to soil temperature (P = 0.008) and percent water-filled pore space (WFPS) (P = 0.052) at Foulum. However, there were positive interactions of both factors with NO3-N, i.e., high N2O emissions occurred during periods when high soil nitrate levels coincided with high soil temperature (P = 0.016) or high soil water content (P = 0.056). A positive effect (P = 0.03) of soil temperature was identified at Flakkebjerg, but the number of soil samplings was limited. Effects of cropping system on N2O emissions were not observed.

Chirinda, Ngonidzashe; Carter, Mette Sustmann

2010-01-01

 
 
 
 
181

Silviculture and biology of short-rotation woody crops in temperate regions: Then and now  

Energy Technology Data Exchange (ETDEWEB)

Although its roots are in antiquity, the current concept of short-rotation woody crops (SRWC) for fiber and energy evolved scientifically from pioneering tree breeding work begun in the early 20th century. A natural outgrowth of this work was the culture of fast-growing trees on rotations of 1-15 years. Close-spaced tree culture received further impetus with the introduction of the 'silage sycamore' concept in the southeastern US in the mid-1960s and the OPEC oil embargo in 1973, leading to statistically designed trials at numerous locations in North America, Europe, and Scandinavia. Early silvicultural research focused on spacing and species trials, propagation methods, site preparation, weed management, nutrition, growth, and yield. Because these trials were based on small plots, and the importance of pest depredations or site variation were not fully recognized, early biomass yield predictions tended to be overly optimistic. Soon physiologists and ecologists began to unravel the biological characteristics of SRWC plantations and their responses to environment. Knowledge of the influence and diversity of pests-insects, diseases, and animals-provided a necessary reality check. Many hardwood tree species and a few conifers have been evaluated over the years for SRWC in temperate regions of the world. Clones of Populus and Salix, however, became the dominant plantation material because of their inherently rapid growth and ease of propagation by hardwood cuttings. Among conifers, loblolly pine (Pinus taeda) also shows promise. Because genetic variation is readily exploitable in the dominant SRWC taxa, strongly focused breeding programs began to provide highly productive genotypes and seed sources in the last decades of the 20th century. A new plateau, with significant practical potential, was reached in the late 20th century when biotechnological methods were applied to tree taxa. Recently, the DNA in the Populus genome was sequenced. Thus, the few current commercial applications of SRWC rest on a substantial base of silvicultural and biological knowledge. (author)

Dickmann, Donald I. [Department of Forestry, Michigan State University, East Lansing, MI 48824-1222 (United States)

2006-08-15

182

Seedbank and Emerged Weed Communities Following Adoption of Glyphosate-Resistant Crops in a Long-Term Tillage and Rotation Study  

UK PubMed Central (United Kingdom)

The compositions of the germinable weed seedbank and aboveground weed communities in a long-term tillage and rotation study were characterized 4, 5, and 6 yr (2002 to 2004) after the adoption of glyphosate-tolerant corn and soybean. Averaged across rotation, mean germinable weed seed density and diversity were greatest in the no-tillage treatment as compared to the minimum- and conventional-tillage treatments. Averaged over tillage, density and diversity were greater in the corn-oat-hay (ryegrass+alfalfa) system as compared to the continuous corn and corn-soybean rotations. Similar trends in density and diversity were observed for the aboveground weed communities. Differences in community composition among treatments were quantified with the use of a multiresponse permutation procedure. Results indicated that the weed seedbank community in a corn-oat-hay rotational system differed from the communities associated with the continuous corn and corn-soybean rotational systems. Weed seedbank communities developing under a no-tillage operation differed from those in minimum- and conventional-tillage scenarios. Compositional differences among the aboveground weed communities were less pronounced in response to tillage and rotation. Indicator species analyses indicated that the number of significant indicator weed species was generally higher for no tillage than minimum or conventional tillage for both the seedbank and the aboveground weed communities. The number of significant indicator species for the seedbank and weed communities was generally greater in the three-crop rotation as compared to the continuous corn and corn-soybean rotations. The trends observed in density, diversity, and community composition after the adoption of glyphosate-tolerant corn and soybeans, and a glyphosate-dominated weed management program, were also observed when soil-applied herbicides were included in the study. We suggest that the switch to a POST-glyphosate protocol did not significantly alter weed communities in the short term in this study.

Sosnoskie LynnM; Herms CatherineP; Cardina John; Webster TheodoreM

2009-05-01

183

Excitation system for rotating synchronous machines  

Energy Technology Data Exchange (ETDEWEB)

A system for providing DC current to a rotating superconducting winding is provided. The system receives current feedback from the superconducting winding and determines an error signal based on the current feedback and a reference signal. The system determines a control signal corresponding to the error signal and provides a positive and negative superconducting winding excitation voltage based on the control signal.

Umans, Stephen D. (Belmont, MA); Driscoll, David J. (South Euclid, OH)

2002-01-01

184

Entropy bounds for charged and rotating systems  

CERN Multimedia

It was shown in a previous work that, for systems in which the entropy is an extensive function of the energy and volume, the Bekenstein and the holographic entropy bounds predict new results. In this paper, we go further and derive improved upper bounds to the entropy of {\\it extensive} charged and rotating systems. Furthermore, it is shown that for charged and rotating systems (including non-extensive ones), the total energy that appear in both the Bekenstein entropy bound (BEB) and the causal entropy bound (CEB) can be replaced by the {\\it internal} energy of the system. In addition, we propose possible corrections to the BEB and the CEB.

Gour, G

2003-01-01

185

Entropy bounds for charged and rotating systems  

International Nuclear Information System (INIS)

[en] It was shown in a previous work that, for systems in which the entropy is an extensive function of the energy and volume, the Bekenstein and the holographic entropy bounds predict new results. In this paper, we go further and derive improved upper bounds to the entropy of extensive charged and rotating systems. Furthermore, it is shown that for charged and rotating systems (including non-extensive ones), the total energy that appears in both the Bekenstein entropy bound (BEB) and the causal entropy bound (CEB) can be replaced by the internal energy of the system. In addition, we propose possible corrections to the BEB and the CEB

2003-08-07

186

Entropy bounds for charged and rotating systems  

Energy Technology Data Exchange (ETDEWEB)

It was shown in a previous work that, for systems in which the entropy is an extensive function of the energy and volume, the Bekenstein and the holographic entropy bounds predict new results. In this paper, we go further and derive improved upper bounds to the entropy of extensive charged and rotating systems. Furthermore, it is shown that for charged and rotating systems (including non-extensive ones), the total energy that appears in both the Bekenstein entropy bound (BEB) and the causal entropy bound (CEB) can be replaced by the internal energy of the system. In addition, we propose possible corrections to the BEB and the CEB.

Gour, Gilad [Theoretical Physics Institute, Department of Physics, University of Alberta, Edmonton, T6G 2J1 (Canada)

2003-08-07

187

An estimation of annual nitrous oxide emissions and soil quality following the amendment of high temperature walnut shell biochar and compost to a small scale vegetable crop rotation.  

Science.gov (United States)

Agricultural soils are responsible for emitting large quantities of nitrous oxide (N2O). The controlled incomplete thermal decomposition of agricultural wastes to produce biochar, once amended to soils, have been hypothesized to increase crop yield, improve soil quality and reduce N2O emissions. To estimate crop yields, soil quality parameters and N2O emissions following the incorporation of a high temperature (900°C) walnut shell (HTWS) biochar into soil, a one year field campaign with four treatments (control (CONT), biochar (B), compost (COM), and biochar+compost (B+C)) was conducted in a small scale vegetable rotation system in Northern California. Crop yields from five crops (lettuce, winter cover crop, lettuce, bell pepper and Swiss chard) were determined; there were no significant differences in yield between treatments. Biochar amended soils had significant increases in % total carbon (C) and the retention of potassium (K) and calcium (Ca). Annual cumulative N2O fluxes were not significantly different between the four treatments with emissions ranging from 0.91 to 1.12kg N2O-Nha(-1)yr(-1). Distinct peaks of N2O occurred upon the application of N fertilizers and the greatest mean emissions, ranging from 67.04 to 151.41g N2O-Nha(-1)day(-1), were observed following the incorporation of the winter cover crop. In conclusion, HTWS biochar application to soils had a pronounced effect on the retention of exchangeable cations such as K and Ca compared to un-amended soils and composted soils, which in turn could reduce leaching of these plant available cations and could thus improve soils with poor nutrient retention. However, HTWS biochar additions to soil had neither a positive or negative effect on crop yield nor cumulative annual emissions of N2O. PMID:23490323

Suddick, Emma C; Six, Johan

2013-03-11

188

Environmental effects of growing short-rotation woody crops on former agricultural lands  

Energy Technology Data Exchange (ETDEWEB)

Field-scale studies in the Southeast have been addressing the environmental effects of converting agricultural lands to biomass crop production since 1994. Erosion, surface water quality and quantity and subsurface movement of water and nutrients from woody crops, switchgrass and agricultural crops are being compared. Nutrient cycling, soil physical changes and crop productivity are also being monitored at the three sites. Maximum sediment losses occurred in the spring and fall. Losses were greater from sweetgum planted without a cover crop than with a cover crop. Nutrient losses of N and P in runoff and subsurface water occurred primarily after spring fertilizer application.

Tolbert, V.R. [Oak Ridge National Lab., TN (United States); Thornton, F.C.; Joslin, J.D. [Tennessee Valley Authority, Muscle Shoals, AL (United States). Atmospheric Sciences Div.] [and others

1997-10-01

189

Assessment of Carbon Sequestration in German Alley Cropping Systems  

Science.gov (United States)

Alley cropping systems (ACS) are agroforestry practices in which perennial trees or shrubs are grown in wide rows and arable crops are cultivated in the alleys between the tree rows. Recently, ACS which integrate stripes of short rotation coppices into conventional agricultural sites have gained interest in Germany. These systems can be used for simultaneous production of crops and woody biomass which enables farmers to diversify the provision of market goods. Adding trees into the agricultural landscape creates additional benefits for the farmer and society also known as ecosystem services. An ecosystem service provided by land use systems is carbon sequestration. The literature indicates that ACS are able to store more carbon compared to agriculture and their implementation may lead to greater benefits for the environment and society. Moreover, carbon sequestration in ACS could be included in carbon trading schemes and farmers rewarded additionally for the provision of this ecosystem service. However, methods are required which are easy to use and provide reliable information regarding change in carbon sequestration with change of the land use practice. In this context, our aim was to develop a methodology to assess carbon sequestration benefit provided by ACS in Germany. Therefore, the change of carbon in both soil and biomass had to be considered. To predict the change in soil carbon our methodology combined the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the soil organic carbon balance recommended by the Association of German Agricultural Investigation and Research Centers (VDLUFA). To reflect the change in biomass carbon average annual yields were adopted. The results showed that ACS established on agricultural sites can increase the carbon stored because in the new soil-plant system carbon content is higher compared to agriculture. ACS have been recommended as suitable land use systems for marginal sites, such as post-mining areas. In such areas soil carbon usually increases at a faster initial rate compared to agricultural land which means that these areas could provide high level of carbon sequestration service in the short term. The approach will be broadened to include assessment of other ecosystem services provided by ACS in Germany which would increase the possibility to adequately compensate farmers for the supply of environmental benefits. Keywords: agroforestry, biomass production, carbon sequestration, ecosystem services, marginal sites

Tsonkova, P. B.; Quinkenstein, A.; Böhm, C.; Freese, D.

2012-04-01

190

Eucalyptus and Populus short rotation woody crops for phosphate mined lands in Florida USA  

Energy Technology Data Exchange (ETDEWEB)

Our short-rotation woody crops (SRWC) research in central and southern Florida is (1) developing superior Eucalyptus grandis (EG), E. amplifolia (EA), and cottonwood (Populus deltoides, PD) genotypes, (2) determining appropriate management practices for and associated productivities of these genotypes, and (3) assessing their economics and markets. Reclaimed clay settling areas (CSA) and overburden sites in phosphate mined areas in central Florida are a potential land base of over 80,000ha for SRWC production. On CSAs, PD grows well in the absence of cogongrass (Imperata cylindrica) but is not as productive as the non-invasive EG and EA. SRWC establishment on CSAs requires strict implementation of the following cultural practices: thorough site preparation through herbiciding/disking and bedding, superior trees, watering/packing seedlings, fertilization with ammonium nitrate at planting and annually thereafter as feasible, high planting density possibly including double row planting, and winter harvesting so that coppice regeneration suppresses weeds. PD cultural requirements, that may require post-planting weed control to suppress herbaceous competition, exceed those of the eucalypts. EG SRWCs on CSAs are at risk of blowdown 3-4 years after planting or coppicing; younger PD, EG, and EA SRWCs appear much less susceptible to wind damage. Genetic improvement must continue if EG, EA, and PD are to increase in commercial feasibility. SRWC cost competitiveness will depend on establishment success, yield improvements, harvesting costs, and identifying/using incentives. Strong collaboration among public and private partners is necessary for commercializing SRWCs in Florida. (author)

Rockwood, D.L.; Carter, D.R.; Langholtz, M.H. [The School of Forest Resources and Conservation, University of Florida, Box 110410, Gainesville, FL 32611 0410 (United States); Stricker, J.A. [Polk County Extension Service, University of Florida, Gainesville, FL 32611 (United States)

2006-08-15

191

Stem Weight Ratios of Siberian Elm (Ulmus Pumila L.) Grown as a Short Rotation Crop  

Energy Technology Data Exchange (ETDEWEB)

Siberian elm (Ulmus pumila L.) is a fast growing tree which has not been studied extensively for short rotation crop (SRC) purposes. Seedlings were planted in Madrid (Spain) in the year 2000 at a density of 1 plant/m{sup 2}. Trials were carried out in order to evaluate the biomass production in high-density plantations. The plantation was cut after the fourth growing season and evaluated for height, diameter, and dry weight. The same measurements were repeated for the sprouts of the 1st and 2nd year that followed. The mean biomass yield after 4 years was 101.6 g dw/m{sup 2} year-1; 269 g dw /m{sup 2} for 1-year-old sprouts and 480.4 g dw /m{sup 2} for 2-year-old sprouts. Correlations between height and basal diameter with dry weight were calculated for each year. There was a close correlation between the 4th year original plant weight and the 1-year-old sprouts but less than with the 2nd year. Water efficiency for biomass production was higher during the 2nd sprouting cycle.

Iriarte, Leyre; Fernandez, Jesus [Univ. Politecnica de Madrid (Spain). Dept. de Produccion Vegetal

2006-07-15

192

Grassland carbon sequestration and emissions following cultivation in a mixed crop rotation  

DEFF Research Database (Denmark)

Grasslands are potential carbon sinks to reduce unprecedented increase in atmospheric CO2. Effect of age (1–4-year-old) and management (slurry, grazing multispecies mixture) of a grass phase mixed crop rotation on carbon sequestration and emissions upon cultivation was compared with 17-year-old grassland and a pea field as reference. Aboveground and root biomass were determined and soils were incubated to study CO2 emissions after soil disturbance. Aboveground biomass was highest in 1-year-old grassland with slurry application and lowest in 4-year-old grassland without slurry application. Root biomass was highest in 4-year-old grassland, but all 1–4-year-old grasslands were in between the pea field (0.81 ± 0.094 g kg?1 soil) and the 17-year-old grassland (3.17 ± 0.22 g kg?1 soil). Grazed grasslands had significantly higher root biomass than cut grasslands. There was no significant difference in the CO2 emissions within 1–4-year-old grasslands. Only the 17-year-old grassland showed markedly higher CO2 emissions (4.9 ± 1.1 g CO2 kg?1 soil). Differences in aboveground and root biomass did not affect CO2 emissions, and slurry application did not either. The substantial increase in root biomass with age but indifference in CO2 emissions across the age and management in temporary grasslands, thus, indicates potential for long-term sequestration of soil C.

Acharya, Bharat Sharma; Rasmussen, Jim

2012-01-01

193

Efeito na produtividade da rotação de culturas de verão e crotalária no inverno/ The efect of crotalaria cropped in the winter and of crop rotation on the yield of summer crops  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Em ensaio de rotação de culturas, conduzido em Pindorama, SP, num solo podzólico vermelho amarelo, fase arenosa, durante os anos agrícolas de 1991/92, 1992/93 e 1993/94, avaliou-se o efeito da rotação entre milho, soja e arroz, com e sem crotalária júncea de inverno, na produção das culturas, no final do terceiro ano da experimentação. Não houve diferença entre tratamentos na produção da soja. A rotação aumentou a produção de arroz e milho, comparativa (more) mente ao monocultivo dessas culturas. A boa produtividade alcançada das culturas no terceiro ano pode ser atribuída, além da rotação, à ocorrência regular de chuvas e ao uso de cultivares tolerantes à acidez Abstract in english The effect of crop rotation among corn, soybean and rice as summer crops, and of crotalaria as a winter crop, was evaluated by the crop yield at the end of the third year.The experiment was established at Pindorama, SP, Brazil, on an acid soil(Red -Yellow Podzolic, sandy phase). After three years , there was no yield difference among treatments for soybeam production. Crop rotation was beneficial for rice and corn prodution when compared to monocultures. The good productivity in the third year could also be atributed to regular rainfall and acidity tolerant cultivars.

MASCARENHAS, H.A.A.; NOGUEIRA, S.S.S.; TANAKA, R.T.; MARTINS, A.L.M.; CARMELLO, Q.A.C.

1998-01-01

194

Efeito na produtividade da rotação de culturas de verão e crotalária no inverno The efect of crotalaria cropped in the winter and of crop rotation on the yield of summer crops  

Directory of Open Access Journals (Sweden)

Full Text Available Em ensaio de rotação de culturas, conduzido em Pindorama, SP, num solo podzólico vermelho amarelo, fase arenosa, durante os anos agrícolas de 1991/92, 1992/93 e 1993/94, avaliou-se o efeito da rotação entre milho, soja e arroz, com e sem crotalária júncea de inverno, na produção das culturas, no final do terceiro ano da experimentação. Não houve diferença entre tratamentos na produção da soja. A rotação aumentou a produção de arroz e milho, comparativamente ao monocultivo dessas culturas. A boa produtividade alcançada das culturas no terceiro ano pode ser atribuída, além da rotação, à ocorrência regular de chuvas e ao uso de cultivares tolerantes à acidezThe effect of crop rotation among corn, soybean and rice as summer crops, and of crotalaria as a winter crop, was evaluated by the crop yield at the end of the third year.The experiment was established at Pindorama, SP, Brazil, on an acid soil(Red -Yellow Podzolic, sandy phase). After three years , there was no yield difference among treatments for soybeam production. Crop rotation was beneficial for rice and corn prodution when compared to monocultures. The good productivity in the third year could also be atributed to regular rainfall and acidity tolerant cultivars.

H.A.A. MASCARENHAS; S.S.S. NOGUEIRA; R.T. TANAKA; A.L.M. MARTINS; Q.A.C. CARMELLO

1998-01-01

195

A comparative analysis of conservation agriculture systems: Benefits and challenges of rotations and intercropping in Zimbabwe  

UK PubMed Central (United Kingdom)

Increasing soil degradation in southern Africa and the potentially negative effects of climate change demand “greener” solutions to reverse this trend. Conservation agriculture (CA) has been proposed as one of those solutions and field level data show marked benefits of this new cropping system. Nevertheless, the use of rotations and/or associations in CA systems is challenging at both the farm and community level. Intercropped maize (Zea mays L.) with grain legumes, cowpea and pigeonpea (Cajanus cajan L. (Millsp.)), as well as maize rotated with cowpea (Vigna unguiculata L. (Walp)) and sunnhemp (Crotalaria ochroleuca L.) was studied for up to eight seasons under CA and conventional agriculture in Zimbabwe. The objective of this study, carried out on-farm and on-station, was to highlight the effects of CA systems on some soil quality indicators and crop productivity. Where possible the specific effects of rotation and intercropping was separated and compared with monocropping. The on-station and on-farm results show: an increase of up to 331% in water infiltration, a 31% greater soil carbon in the top 60cm than on adjacent conventionally ploughed fields, a 6% lower bulk density in the top 10cm and 32.5–36tha?¹ less cumulative soil erosion in CA fields after seven cropping seasons compared with the conventional control treatment. The comparative productivity analysis between continuous maize, maize intercropped with cowpea or pigeonpea and maize in rotation with cowpea or sunnhemp, shows marked benefits of rotation especially in CA systems. The benefits of CA especially when rotated with leguminous crops, increase over time, suggesting that there are improvements in soil structure and fertility. However, field level benefits will not increase the overall adoption of rotations and intercropping in CA systems, unless the socio-economic constraints at the farm and community level are addressed.

Thierfelder C; Cheesman S; Rusinamhodzi L

2012-10-01

196

Integrating crops and livestock in subtropical agricultural systems.  

UK PubMed Central (United Kingdom)

As the demand for livestock products increases, and is expected to continue to increase over the next few decades, especially in developing countries, smallholder mixed systems are becoming more intensive. However, with limited land and water resources and concern about the environmental impact of agricultural practices and climate change, the challenge is to find ways of increasing productivity that do not compromise household food security, but rather increase incomes equitably and sustain or enhance the natural resource base. In developed countries there has been increased specialisation of crop and livestock production. In contrast, the majority of livestock in developing countries is kept in mixed crop/livestock systems. Crops (cereal grains and pulses) and crop residues provide the basis of the diet for animals, e.g. cereal straw fed to dairy cattle or sweet potato vines fed to pigs. Animal manure can provide significant nutrient inputs to crops. Water productivity is higher in mixed crop/livestock systems compared with growing crops alone. Mixed systems allow for a more flexible and profitable use of family labour where employment opportunities are limited. They also spread risks across several enterprises, a consideration in smallholder systems that may become even more important under certain climate change scenarios. Integrated crop/livestock systems can play a significant role in improving global food security but will require appropriate technological developments, institutional arrangements and supportive policy environments if they are to fulfil that potential in the coming decades.

Wright IA; Tarawali S; Blümmel M; Gerard B; Teufel N; Herrero M

2012-03-01

197

Integrating crops and livestock in subtropical agricultural systems.  

Science.gov (United States)

As the demand for livestock products increases, and is expected to continue to increase over the next few decades, especially in developing countries, smallholder mixed systems are becoming more intensive. However, with limited land and water resources and concern about the environmental impact of agricultural practices and climate change, the challenge is to find ways of increasing productivity that do not compromise household food security, but rather increase incomes equitably and sustain or enhance the natural resource base. In developed countries there has been increased specialisation of crop and livestock production. In contrast, the majority of livestock in developing countries is kept in mixed crop/livestock systems. Crops (cereal grains and pulses) and crop residues provide the basis of the diet for animals, e.g. cereal straw fed to dairy cattle or sweet potato vines fed to pigs. Animal manure can provide significant nutrient inputs to crops. Water productivity is higher in mixed crop/livestock systems compared with growing crops alone. Mixed systems allow for a more flexible and profitable use of family labour where employment opportunities are limited. They also spread risks across several enterprises, a consideration in smallholder systems that may become even more important under certain climate change scenarios. Integrated crop/livestock systems can play a significant role in improving global food security but will require appropriate technological developments, institutional arrangements and supportive policy environments if they are to fulfil that potential in the coming decades. PMID:21769884

Wright, Iain A; Tarawali, Shirley; Blümmel, Michael; Gerard, Bruno; Teufel, Nils; Herrero, Mario

2011-07-18

198

Organic and conventional tomato cropping systems  

Directory of Open Access Journals (Sweden)

Full Text Available Among several alternative agricultural systems have been developed, organic agriculture has deserved increasing interest from. The objective of this paper was comparing both organic (OS) and conventional (CS) tomato cropping systems for varieties Débora and Santa Clara, through an interdisciplinary study. The experiment was set up in a randomized blocks design with six replicates, in a dystrophic Ultisol plots measuring 25 ´ 17 m. Cropping procedures followed by either local conventional or organic growers practices recommendations. Fertilization in the OS was done with organic compost, single superphosphate, dolomitic limes (5L, 60 g, and 60 g per pit), and sprayed twice a week with biofertilizer. Fertilization in the CS was done with 200 g 4-14-8 (NPK) per pit and, after planting, 30 g N, 33 g K and 10.5 g P per pit; from 52 days after planting forth, plants were sprayed once a week with foliar fertilizer. In the CS, a blend of insecticides, fungicides and miticides was sprayed twice a week, after planting. In the OS, extracts of black pepper, garlic, and Eucalyptus; Bordeaux mixture, and biofertilizer, were applied twice a week to control diseases and pests. Tomato spotted wilt was the most important disease in the OS, resulting in smaller plant development, number of flower clusters and yield. In the CS, the disease was kept under control, and the population of thrips, the virus vector, occurred at lower levels than in the OS. Variety Santa Clara presented greater incidence of the viral disease, and for this reason had a poorer performance than 'Débora', especially in the OS. Occurrence of Liriomyza spp. was significantly smaller in the OS, possibly because of the greater frequency of Chrysoperla. The CS had smaller incidence of leaf spots caused by Septoria lycopersici and Xanthomonas vesicatoria. However, early blight and fruit rot caused by Alternaria solani occurred in larger numbers. No differences were observed with regard to the communities of fungi and bacteria in the phylloplane, and to the occurrence of weeds.

Bettiol Wagner; Ghini Raquel; Galvão José Abrahão Haddad; Siloto Romildo Cássio

2004-01-01

199

Effect of crop rotation on specialization and genetic diversity of Macrophomina phaseolina/ Efeito da rotação de culturas na especialização e diversidade genética de Macrophomina phaseolina  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Podridão de carvão, causada por Macrophomina phaseolina é uma das mais importantes doenças da soja. Variabilidade genética tem sido observada entre isolados. Entretanto, o efeito de especialização deste fungo, de acordo com a planta hospedeira, não foi ainda relatado. Isolados de soja, milho e girassol foram avaliados, em inoculações cruzadas, quanto à capacidade de formação de microesclerócios em raiz. A maior e menor produção significativa de microescler (more) ócios (P Abstract in english Charcoal rot, caused by Macrophomina phaseolina, is one of the most important diseases of soybean. Genetic variability among soybean isolates has been observed but the effect of host specialization on genetic variability has not been reported. In this work, isolates from soybean, corn and sunflower were evaluated based on cross inoculations and number of microsclerotia/g of roots. The highest and lowest significant (P(more) ybean (863 microsclerotia/g of roots) and sunflower (578 microsclerotia/g of roots), respectively, regardless of the origin of the isolate. Additionally, the effect of a 20-year crop rotation on genetic variability based on RAPD was studied. Eighty-nine isolates from five populations were obtained from soil samples under four crop rotation systems and an uncropped soil. Seven clusters were obtained considering a similarity level of 85%. Analysis indicated that M. phaseolina is a highly diverse species and also revealed a strong effect of the rotation system on genetic diversity. AMOVA was conducted for the RAPD data. From the total genetic variability, 21% (P

Almeida, Álvaro M.R.; Sosa-Gomez, Daniel R.; Binneck, Eliseu; Marin, Silvana R.R.; Zucchi, Maria I.; Abdelnoor, Ricardo V.; Souto, Eliezer R.

2008-08-01

200

Crop pest management with an aerial imaging system  

Science.gov (United States)

Remote sensing along with Global Positioning Systems, Geographic Information Systems, and variable rate technology has been developed, which scientists can implement to help farmers maximize the economic and environmental benefits of crop pest management through precision agriculture. Airborne remo...

 
 
 
 
201

Atributos físicos de um Latossolo Vermelho e produtividade de culturas cultivadas em sucessão e rotação/ Physical properties of an Oxisol and crops yield under succession and rotation  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este estudo objetivou avaliar os efeitos da sucessão e rotação de culturas nos atributos físicos e na produtividade dos cultivos agrícolas de um Latossolo Vermelho sob plantio direto, localizado no Estado do Rio Grande do Sul. Os tratamentos contaram de quatro seqüências de culturas cultivadas de 1998 a 2001: 1) sucessão trigo / soja; 2) rotação milho / aveia / milho+guandu anão / trigo / soja / trigo; 3) rotação guandu anão / trigo / soja / trigo / soja / a (more) veia; e 4) rotação Crotalária / trigo / soja / aveia / milho / trigo. Em outubro de 2000 e de 2001, foram coletadas amostras de solo para determinar os atributos físicos do solo. Em todas as safras foi medida a produtividade das culturas. O Latossolo Vermelho cultivado com plantio direto apresenta um grau de compactação elevado, com densidade do solo acima e volume de macroporos abaixo do limite crítico para a classe textural muito argiloso. As maiores limitações ocorrem abaixo da camada de 0 a 0,03m, pois na camada mais superficial, apesar das pressões exercidas, a mobilização do solo nas operações de semeadura e adubação em linha aumenta a porosidade e reduz a densidade do solo. Nessa camada, houve maior volume de poros entre a saturação e a capacidade de campo, responsáveis pela aeração do solo, e entre a capacidade de campo e o ponto de murcha permanente, responsáveis pelo armazenamento da água disponível para as plantas. A introdução de plantas de cobertura a cada três anos não foi eficiente para reduzir a compactação. A produtividade das culturas foi influenciada positivamente na rotação com Crotalária, enquanto os demais sistemas não diferiram da sucessão de culturas. Abstract in english This study had as objective to evaluate the effects of crops succession and rotation on physical properties and crops yield on an Oxisol (clayey Haplortox) under no tillage system, in Rio Grande do Sul State, Brazil. The treatments included four cropping sequences, used from 1998 to 2001: 1) succession wheat / soybean, 2) rotation corn / oat / corn+ Cajanus cajan L. Millsp / wheat / soybean / wheat, 3) rotation Cajanus cajan L. Millsp / wheat / soybean / wheat / soybean / (more) oat, and 4) rotation Crotalaria juncea L. / wheat / soybean / oat / corn / wheat. In October of 2000 and 2001, soil samples were collected to determine physical properties. In all years, the crops yield was measured. The Oxisol cultivated under no-tillage had a high compaction degree, with soil bulk density greater and macroporosity smaller than the critical limit for clay texture. The largest limitations were observed below the layer of 0 to 0,03m, because in the uppermost layer soil mobilization by successive operations of fertilization and sowing increases soil porosity and reduces soil density. Thus, greater volume of pores is observed between soil saturation and field capacity, responsible for soil aeration, and between field capacity and wilting point, responsible for storage of plant available water. The use of cover crops once every three years was not efficient to reduce soil compaction. The yield of the subsequent crops was influenced positively in the rotation with Crotalaria juncea, while the other cropping systems did not differ from crop succession.

Genro Junior, Silvio Aymone; Reinert, Dalvan José; Reichert, José Miguel; Albuquerque, Jackson Adriano

2009-02-01

202

Increases in wheat yield on limed soil after reduction of take-all by fungicide application and crop rotation.  

UK PubMed Central (United Kingdom)

The severity of take-all, caused by Gaeumannomyces graminis var. tritici, was measured with lime, rotation and flutriafol treatments in a long-term field experiment. The incidence of eyespot lesions caused by Pseudocercosporella herpotrichoides was also measured. Flutriafol reduced the number of plants with deadheads or no heads and resulted in 12-60% more grain yield. However flutriafol had no effect on the number of plants with eyespot lesions. The number of plants with deadheads or no heads was highest (50-53%) on the wheat which was a third consecutive crop and on soil which had been amended with 2.5 and 5.0 t/ha lime. Sowing wheat after a subterranean clover based pasture considerably reduced the number of deadheads. Control of annual grasses in the pasture by spray-topping further reduced deadheads and with this treatment and at nil and low lime there were 2-7% deadheads. The percentage of plants with eyespot lesions was higher with the continuous cropped wheat. Lime increased grain yield only where the disease incidence was low but had no effect on the percentage of eyespot lesions. This work demonstrates the importance of crop rotation for disease control, particularly where soils are limed to amend severe soil acidity; the value of controlling annual grasses in pasture in the year preceding wheat cropping; and the potential of fungicide treatment as a practical means for controlling take-all in field grown wheat.

Conventry DR; Brooke HD; Killmorgen JF; Ballinger DJ

1989-01-01

203

Effectiveness of Sulphuric Acid and Gypsum for the Reclamation of a Calcareous Saline-Sodic Soil Under Four Crop Rotations  

UK PubMed Central (United Kingdom)

As a low-cost strategy, the cultivation of certain salt-tolerant crop species on calcareous saline-sodic soils, i.e. phytoreclamation, has enjoyed great attention in recent years. A lysimeter study was carried out to evaluate whether a phytoreclamation approach alone, or in combination with some booster dose of either gypsum or sulphuric acid, is sufficient to reclaim a calcareous, moderately saline-sodic soil. Four crop rotations, rice (Oryza sativa L.)-wheat (Triticum aestivum L.)-sesbania (Sesbania aculeata L.); rice-berseem (Trifolium alexandrinum L.); Kallar grass (Leptochloa fusca L.)-alfalfa (Medicago sativa L.) and sesbania-berseem were tested against three treatments: (T?) control, (T?) sulphuric acid application 25 % of soil gypsum requirement (SGR), and (T?) application of gypsum 25 % SGR. To decrease the sodium adsorption ratio of the saline-sodic soil well below the threshold level, especially from deeper depth, a booster dose of gypsum or sulphuric acid 25 % SGR was quite effective. Rice-berseem and Kallar grass-alfalfa rotations were more promising in combination with inorganic amendments than the rest of the rotations. The study also suggests that better yields of wheat and rice crops can be obtained with the application of inorganic amendments like gypsum or sulphuric acid. However, Kallar grass yield was somewhat suppressed with these amendments.

Zia MH; Saifullah; Sabir M; Ghafoor A; Murtaza G

2007-08-01

204

Current status and future directions for the U.S. Department of Energy`s short-rotation woody crop research  

Energy Technology Data Exchange (ETDEWEB)

The US Department of Energy (DOE) initiated the Biofuels Feedstock Development Program (BFDP) at Oak Ridge National Laboratory (ORNL) in 1978. The program`s goal is to provide leadership in the development, demonstration and implementation of environmentally acceptable and commercially viable biomass supply systems. Three model short-rotation woody crop (SRWC) species, i.e. Populus spp., Acer saccharinum and Salix spp., have been selected for further development based on their productivity, adaptability, and suitability as biomass feedstocks. Of these three, Populus is the primary candidate for SRWC in the United States. For Populus the prescribed management system involves the use of intensive site preparation of agricultural quality lands, improved clonal plant materials at ca. 1,000 trees/ac, mechanical and chemical weed control for the first 2 years, and rotation length of 6--8 years, followed by replanting. Currently, due to the wider spacings and larger tree sizes, traditional, start-stop, one-piece harvesting techniques are being applied to SRWC; this includes the use of feller-bunchers, skidding to a common landing, and on-site chipping. Under the above silvicultural system, harvesting and transportation expenditures account for 50 to 60% of the total production costs. The productivity goals for SRWC are 8--12 t/ac/yr, with the current average across all sites and clones at ca. 4 t/ac/yr. Productivity rates on large-scale plantings have been documented at 11 t/ac/yr. To increase the average productivity rates, silvicultural enrichments [e.g., spacing variances, fertilization once per rotation (ca. 70 lbs/ac N), and irrigation], genetic improvement, and molecular genetics techniques are being applied to all model species. This research is being managed under the concept of regional, integrated Crop Development Centers. There are presently 3 Populus crop development centers.

Tuskan, G.A.; Downing, M.E.; Wright, L.L.

1994-09-01

205

Sucessão de cultura sob pivô central para controle de fitonematoides: variação populacional, patogenicidade e estimativa de perdas/ Crop rotation in center-pivot for phytonematode control: density variation, pathogenicity and crop loss estimation  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Estudo de campo realizado em três anos consecutivos, em propriedade agrícola com sucessão de cultura, irrigada por pivô central e infestada pelos nematoides Pratylenchus brachyurus, P. zeae, Meloidogyne incognita, Paratrichodorus minor, Helicotylenchus dihystera, Mesocriconema ornata e M. onoense, comprovou que o controle dos nematoides polífagos é muito difícil. Dentre as culturas implantadas durante o período (algodão, milho, soja e caupi), o algodão se destac (more) ou pelas perdas causadas por M. incognita e a soja por P. brachyurus. A exclusão do milho, por ser suscetível a ambos os nematóides, porém tolerante a M. incognita, beneficiaria as culturas de algodão, soja e caupi. Resultados obtidos em condições controladas confirmaram a patogenicidade de P. brachyurus a algodoeiro. O uso da resistência genética como componente do manejo mostrou-se válido para o binômio soja/M. incognita, embora prejudicado pela baixa resistência da soja a P. brachyurus. Concluiu-se que a sucessão de cultura precisa ser cuidadosamente planejada em áreas infestadas com nematoides polífagos, principalmente naquelas em que ocorrem mais de duas espécies patogênicas às culturas utilizadas. Abstract in english A field study conducted over three consecutive years, on a farm using crop rotation system under center-pivot and infested with the nematodes Pratylenchus brachyurus, P. zeae, Meloidogyne incognita, Paratrichodorus minor, Helicotylenchus dihystera, Mesocriconema ornata and M. onoense, demonstrated that intensive crop systems provide conditions for the maintenance of high densities of polyphagous phytonematodes. Of the crops established on the farm (cotton, maize, soybean (more) and cowpea), cotton and soybean suffered the most severe crop losses, caused respectively by M. incognita and P. brachyurus. Since maize is a good host for both nematodes, but tolerant of M. incognita, its exclusion from cropping system would be favorable to the performance of cotton, soybean and cowpea. Results from experiments carried out in controlled conditions confirmed the pathogenicity of P. brachyurus on cotton. Additional management with genetic resistance was useful in fields infested with M. incognita, although the soybean performance was affected by low resistance of the cultivars used for P. brachyurus. In conclusion, crop rotation must be carefully planned in areas infested with polyphagous nematodes, specifically in the case of occurrence of two or more major pathogenic nematodes.

Inomoto, Mário M.; Siqueira, Kércya M.S.; Machado, Andressa C.Z.

2011-06-01

206

Cropping systems alter weed seed banks in Pacific Northwest semi-arid wheat region  

UK PubMed Central (United Kingdom)

Arable land weed seed banks are dynamic and reflect cropping history, current management, and environment. Changes in crop rotation and tillage system can alter weed seed density and species composition. In the semi-arid region of the Pacific Northwest, USA, no-till spring cropping is being studied as an alternative to the traditional winter wheat (Triticum aestivum L.)/dust-mulch fallow (WWF) rotation. Weed seed bank density and species composition were assessed during the first 6 years of an ongoing cropping system study comparing WWF with three no-till rotations; spring wheat (Triticum aestivum L.)/chemical fallow (SWF), continuous spring wheat (CSW), and spring wheat/spring barley (Hordeum vulgare L.) (SWSB). Soil cores were collected at depths of 0-8, 8-15, and 15-23 cm in all plots during August each year following crop harvest. Weed seeds were washed from the soil, dried, and germinated in a glasshouse. Weed species most associated with the 0-8 cm depth was Bromus tectorum L., the major winter annual grass weed in WWF. Species most associated with 8-15 cm depth was Chenopodium leptophyllum (Moq.) Nut. ex S. Wats, a native warm season broadleaf weed that may have long seed bank persistence. An initial high density of B. tectorum was reduced with no-till spring crops and in WWF with intensive management strategies. In comparison an initial low weed seed density of B. tectorum remained low with no-till but increased in WWF with less management. Broadleaf weed species did not become management problems in no-till; however, seed bank weed shifts occurred where winter annual broadleaf species remained following reduction of high densities of B. tectorum. Summer annual broadleaf weed seeds such as C. leptophyllum and Salsola tragus L. were present but not at high densities. Summer annual grass weed seeds were not present and are not typical in this region. In this research, no-till spring cereal based systems did not result in an increase in total seed density at the soil surface. Results from this research show that no-till spring crop rotations are effective at controlling winter annual grass weeds as well as broadleaf weeds normally associated with WWF.

Thorne ME; Young FL; Yenish JP

2007-08-01

207

Infiltração de água no solo sob escarificação e rotação de culturas/ Water infiltration in soil as influenced by chiseling and crop rotations  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Nos solos com restrições físicas e, ou, físico-hídricas ao crescimento de raízes, aumentar o potencial de armazenagem de água por meio de melhorias na infiltração pode ser uma estratégia viável para aumento da produtividade das culturas. Nesse sentido, este trabalho teve como objetivo avaliar a infiltração de água em um Nitossolo Vermelho distrófico, com três sistemas de rotação de culturas sob semeadura direta com e sem escarificação inicial. O sistem (more) a de rotação de culturas constou de: (1) milheto/soja/sorgo/milho/sorgo (M/S/So/Mi/So), (2) milheto/soja/Brachiaria ruziziensis/milho/Brachiaria ruziziensis (M/S/B/Mi/B) e (3) milheto/soja/Brachiaria ruziziensis + mamona/milho/Brachiaria ruziziensis + mamona (M/S/B+Ma/Mi/B+Ma). A infiltração de água no solo foi avaliada em campo com anéis concêntricos instalados na superfície, a 0,10 e 0,20 m de profundidade, em 2006 e 2007. Após o primeiro ano, o manejo com escarificação inicial do solo apresentou a maior infiltração de água. A rotação Brachiaria ruziziensis + mamona proporcionou maior infiltração da água no solo. A atividade do sistema radicular das espécies nas parcelas sem escarificação inicial aumentou a velocidade de infiltração da água no solo. Abstract in english In soils with physical and/or physical hydric restrictions for root growth, it may be a viable strategy to increase crop productivity by increasing water storage potential through improvements in water infiltration. Accordingly, the objective of this study was to determine water infiltration in a Hapludult in three crop rotations under no-tillage, with and without initial chiseling. Crop rotations consisted of: millet/soybean/sorghum/maize/sorghum; millet/soybean/Brachiar (more) ia ruziziensis/corn/Brachiaria ruziziensis; and millet/soybean/Brachiaria ruziziensis + castor bean/corn/Brachiaria ruziziensis + castor bean. Water infiltration in soil was evaluated in the field, using concentric discs at the soil surface and at depths of 0.10 and 0.20 m, in 2006 and 2007. After the first year, chiseling led to increased infiltration of water into the soil. Water infiltration was greatest in the crop rotation system with Brachiaria ruziziensis + castor bean. The activity of root systems of crops in the plots without chiseling increased the rate of water infiltration into the soil.

Prando, Maryara Buriola; Olibone, Dácio; Olibone, Ana Paula Encide; Rosolem, Ciro Antonio

2010-06-01

208

Infiltração de água no solo sob escarificação e rotação de culturas Water infiltration in soil as influenced by chiseling and crop rotations  

Directory of Open Access Journals (Sweden)

Full Text Available Nos solos com restrições físicas e, ou, físico-hídricas ao crescimento de raízes, aumentar o potencial de armazenagem de água por meio de melhorias na infiltração pode ser uma estratégia viável para aumento da produtividade das culturas. Nesse sentido, este trabalho teve como objetivo avaliar a infiltração de água em um Nitossolo Vermelho distrófico, com três sistemas de rotação de culturas sob semeadura direta com e sem escarificação inicial. O sistema de rotação de culturas constou de: (1) milheto/soja/sorgo/milho/sorgo (M/S/So/Mi/So), (2) milheto/soja/Brachiaria ruziziensis/milho/Brachiaria ruziziensis (M/S/B/Mi/B) e (3) milheto/soja/Brachiaria ruziziensis + mamona/milho/Brachiaria ruziziensis + mamona (M/S/B+Ma/Mi/B+Ma). A infiltração de água no solo foi avaliada em campo com anéis concêntricos instalados na superfície, a 0,10 e 0,20 m de profundidade, em 2006 e 2007. Após o primeiro ano, o manejo com escarificação inicial do solo apresentou a maior infiltração de água. A rotação Brachiaria ruziziensis + mamona proporcionou maior infiltração da água no solo. A atividade do sistema radicular das espécies nas parcelas sem escarificação inicial aumentou a velocidade de infiltração da água no solo.In soils with physical and/or physical hydric restrictions for root growth, it may be a viable strategy to increase crop productivity by increasing water storage potential through improvements in water infiltration. Accordingly, the objective of this study was to determine water infiltration in a Hapludult in three crop rotations under no-tillage, with and without initial chiseling. Crop rotations consisted of: millet/soybean/sorghum/maize/sorghum; millet/soybean/Brachiaria ruziziensis/corn/Brachiaria ruziziensis; and millet/soybean/Brachiaria ruziziensis + castor bean/corn/Brachiaria ruziziensis + castor bean. Water infiltration in soil was evaluated in the field, using concentric discs at the soil surface and at depths of 0.10 and 0.20 m, in 2006 and 2007. After the first year, chiseling led to increased infiltration of water into the soil. Water infiltration was greatest in the crop rotation system with Brachiaria ruziziensis + castor bean. The activity of root systems of crops in the plots without chiseling increased the rate of water infiltration into the soil.

Maryara Buriola Prando; Dácio Olibone; Ana Paula Encide Olibone; Ciro Antonio Rosolem

2010-01-01

209

Integrating soil solarization into crop production systems  

Science.gov (United States)

Soil solarization remains one of but a handful of nonchemical soil disinfestation methods suitable for high-value crops such as cut-flowers, strawberry and fresh market tomato and pepper. Recognition of soil solarization within the context of an integrated pest management (IPM) approach is paramoun...

210

Dynamical flexibilities of mechanical rotational systems  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: of this work is to present dynamical flexibilities of rotational beams and rods systems. The results ofmathematical calculations were presented in the form of dynamical flexibility of analyzed systems. In final solutionthere were took into consideration the interactions between the major motions and local vibrations of subsystems.Design/methodology/approach: The dynamical flexibilities were derived by the Galerkin’s method. The dynamicalflexibilities for example numerical cases were presented onto charts of attenuation-frequency characteristics. Themathematical models were derived on the basis of known equations of motion derived in previous thesis’s.Findings: After analysis of characteristics we can observe the transportation effect. We can notice additional poleson the characteristic of dynamical flexibility characteristics and after increasing angular velocity created modessymmetrically propagate from the origin mode and instead of the original mode there is created a zero’s amplitude.Research limitations/implications: Analyzed systems are beams and rods in rotational motion. Motion waslimited to plane motion. Future works will be connected with consideration of complex systems.Practical implications: of derived dynamical flexibilities of free-free and fixed beams and rods systems is apossibility of derivation of the stability zones of analyzed systems and derivation of eigenfrequencies and zerosin the function of angular velocity of work motion.Originality/value: Models analyzed in this thesis apply to rotating rod and beam systems with taking intoconsideration the transportation effect. This new approach of analyzing rod and beam systems can be put to usein modelling, analyzing and designing machines and mechanisms with rotational elements.

S. ?ó?kiewski

2008-01-01

211

Productivity and nutrient cycling in bioenergy cropping systems  

Science.gov (United States)

One of the greatest obstacles confronting large-scale biomass production for energy applications is the development of cropping systems that balance the need for increased productive capacity with the maintenance of other critical ecosystem functions including nutrient cycling and retention. To address questions of productivity and nutrient dynamics in bioenergy cropping systems, we conducted two sets of field experiments during 2005-2007, investigating annual and perennial cropping systems designed to generate biomass energy feedstocks. In the first experiment we evaluated productivity and crop and soil nutrient dynamics in three prototypical bioenergy double-crop systems, and in a conventionally managed sole-crop corn system. Double-cropping systems included fall-seeded forage triticale (x Triticosecale Wittmack), succeeded by one of three summer-adapted crops: corn (Zea mays L.), sorghum-sudangrass [Sorghum bicolor (L.) Moench], or sunn hemp (Crotalaria juncea L.). Total dry matter production was greater for triticale/corn and triticale/sorghum-sudangrass compared to sole-crop corn. Functional growth analysis revealed that photosynthetic duration was more important than photosynthetic efficiency in determining biomass productivity of sole-crop corn and double-crop triticale/corn, and that greater yield in the tiritcale/corn system was the outcome of photosynthesis occurring over an extended duration. Increased growth duration in double-crop systems was also associated with reductions in potentially leachable soil nitrogen relative to sole-crop corn. However, nutrient removal in harvested biomass was also greater in the double-crop systems, indicating that over the long-term, double-cropping would mandate increased fertilizer inputs. In a second experiment we assessed the effects of N fertilization on biomass and nutrient partitioning between aboveground and belowground crop components, and on carbon storage by four perennial, warm-season grasses: big bluestem (Andropogon geradii Vitman), switchgrass (Panicum virgatum L.), indiangrass [ Sorghastrum nutans (L.) Nash], and eastern gamagrass (Tripsacum dactyloides L.). Generally, the optimum rate of fertilization for biomass yield by the grasses was 140 kg N ha-1. Nitrogen inputs also had pronounced but grass-specific effects on biomass and nutrient partitioning, and on carbon storage. For big bluestem and switchgrass, 140 kg N ha -1. maximized root biomass, favored allocation of nutrients to roots over shoots, and led to net increases in carbon storage over the study duration. In contrast, for indiangrass and eastern gamagrass, root biomass and root nutrient allocation were generally adversely affected by N fertilization and carbon storage increased only with 0 or 65 kg N ha-1. For all grasses, 220 kg N ha -1 tended to shift allocation of nutrients to shoots over roots and resulted in no net increase in carbon storage. Optimal nitrogen management strategies for perennial, warm-season grass energy crops should take into consideration the effects of N on biomass yield as well as factors such as nutrient and carbon balance that will also impact economic feasibility and environmental sustainability.

Heggenstaller, Andrew Howard

212

Password Based Rotational Multistory Car Parking System  

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Full Text Available Parking is a big issue in thickly populated areas and in larger cities due to heavy traffic. This intended application of rotational multistory parking system effectively minimizes this issue. It results in less space and more secure parking. ATMEL microcontroller is used as main processor while LCD and motors are as complimentary components for display and rotation The model is based on circular mechanism giving low cost, less space and optimum performance. Password locking system is used to verify the object and detects number of free spaces available in the parking lot. The world has become a global market and numbers of vehicles are also increased to an uncontrollable situation. Keeping this problem the intended model is designed. Password locking system embedded in the work has made the parking of vehicles very much secure.

Nayab Suhail Hamirani; Imdad Ali Ismaili; Asad Ali Shaikh; Faheem Ahmed; Azhar Ali Shah

2011-01-01

213

Effect of tillage, rotation and crop residues on wheat crop productivity, fertilizer nitrogen and water use efficiency and soil organic carbon status in dry area (rainfed) of north-west Pakistan  

Directory of Open Access Journals (Sweden)

Full Text Available Crop productivity, soil organic carbon (SOC), fertilizer nitrogen and water use efficiency (WUE) in rainfed dry area is influenced by tillage, rotation and crop residues management. Field experiments were conducted during 2004-09 to study the effect of tillage, rotation and crop residues on wheat yield, nitrogen fertilizer and water use efficiency and SOC under semi-arid condition in north-west Pakistan. The treatments consisted of three rotations: i) Wheat-fallow-wheat (farmers' practice) ii) Wheat- summer legume-wheat and iii) Wheat-summer cereal-wheat with two tillage and crop residues management treatments: i) Tillage (crop residues removed) and Tillage (crop residues retained) and ii) No-tillage (crop residues removed) and No-tillage (crop residues retained). Basal doses of N60: P60 (kg ha-1) to wheat, N90: P60 and N20: P60 (kg ha-1) to summer cereals and legumes rotation crops were applied respectively. Labeled urea having 1% 15N atom excess at 60 kg N ha-1 was applied to wheat as an aqueous solution in micro plot within each treatment plot. Changes in soil water storage were monitored with neutron moisture probe for calculation of WUE. The results revealed that the wheat grain and straw yield was not increased by the tillage treatment. Crop residues retention significantly enhanced the wheat grain and straw yield. Crop residues with no-tillage resulted in 520 kg ha-1 greater wheat grain yield than residues removed treatment. Similarly WUE, N yield and fertilizer N utilization by wheat was increased significantly by crop residues under no-tillage compared to the tillage treatment. Maximum N fertilizer utilization 24.1 %, 62.7 % and 38.0 % in wheat were obtained under no-tillage + residues treatment during 2006, 2007 and 2008 respectively. The SOC in surface soil (0-15 cm) was higher in wheat-fallow-wheat and wheat-legume-wheat rotation under no-tillage + residues treatment. The results showed that no-tillage + crop residues and legume based rotation treatment were beneficial under the rainfed (dry) conditions.

W Mohammad; S. M Shah; S Shehzadi; S. A Shah

2012-01-01

214

Effect of tillage, rotation and crop residues on wheat crop productivity, fertilizer nitrogen and water use efficiency and soil organic carbon status in dry area (rainfed) of north-west Pakistan  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Crop productivity, soil organic carbon (SOC), fertilizer nitrogen and water use efficiency (WUE) in rainfed dry area is influenced by tillage, rotation and crop residues management. Field experiments were conducted during 2004-09 to study the effect of tillage, rotation and crop residues on wheat yield, nitrogen fertilizer and water use efficiency and SOC under semi-arid condition in north-west Pakistan. The treatments consisted of three rotations: i) Wheat-fallow-wheat ( (more) farmers' practice) ii) Wheat- summer legume-wheat and iii) Wheat-summer cereal-wheat with two tillage and crop residues management treatments: i) Tillage (crop residues removed) and Tillage (crop residues retained) and ii) No-tillage (crop residues removed) and No-tillage (crop residues retained). Basal doses of N60: P60 (kg ha-1) to wheat, N90: P60 and N20: P60 (kg ha-1) to summer cereals and legumes rotation crops were applied respectively. Labeled urea having 1% 15N atom excess at 60 kg N ha-1 was applied to wheat as an aqueous solution in micro plot within each treatment plot. Changes in soil water storage were monitored with neutron moisture probe for calculation of WUE. The results revealed that the wheat grain and straw yield was not increased by the tillage treatment. Crop residues retention significantly enhanced the wheat grain and straw yield. Crop residues with no-tillage resulted in 520 kg ha-1 greater wheat grain yield than residues removed treatment. Similarly WUE, N yield and fertilizer N utilization by wheat was increased significantly by crop residues under no-tillage compared to the tillage treatment. Maximum N fertilizer utilization 24.1 %, 62.7 % and 38.0 % in wheat were obtained under no-tillage + residues treatment during 2006, 2007 and 2008 respectively. The SOC in surface soil (0-15 cm) was higher in wheat-fallow-wheat and wheat-legume-wheat rotation under no-tillage + residues treatment. The results showed that no-tillage + crop residues and legume based rotation treatment were beneficial under the rainfed (dry) conditions.

Mohammad, W; Shah, S. M; Shehzadi, S; Shah, S. A

2012-12-01

215

What crop rotation will provide optimal first-generation ethanol production in Ireland, from technical and economic perspectives?  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a technical and economic analysis of the potential ethanol production from wheat, barley and sugar beet in Ireland for three different combinations of the crops. Scenarios are investigated which include for three crop rotations: (1) wheat, barley and sugar beet; (2) wheat, wheat and sugar beet; and (3) wheat only. Ethanol production facilities typically employ either starch or sugar feedstocks which may not be optimised if both starch and sugar feedstocks are used. Thus, the scenarios which include sugar beet require two separate facilities. The study shows that technical optimisation gives a different rotation to an economic optimisation. It was found that the starch feedstocks (wheat and barley) produce more ethanol per tonne of feedstock than the sugar feedstock (sugar beet). However, on a land area basis, sugar beet produces significantly more ethanol, and hence more energy, than either wheat or barley. In order to meet the EU Biofuels Directive, it is crucial to maximise the energy return per unit of land. Thus, optimisation on the basis of minimisation of land take gives a rotation of wheat, wheat and sugar beet, as this scenario produces the greatest quantity of energy per hectare, whereas optimisation on an economic basis suggests wheat alone with the lowest production cost of EUR0.6/l. (author)

Power, N. [Department of Civil, Structural and Environmental Engineering, Cork Institute of Technology, Cork (Ireland); Murphy, J.D.; McKeogh, E. [Department of Civil and Environmental Engineering, University College Cork, Cork (Ireland)

2008-07-15

216

Trigo e Triticale em rotações de sequeiro efeitos na qualidade Wheat and triticale in crop rotations quality effects  

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Full Text Available Este trabalho resume parte dos resultados de um ensaio de rotações que decorreu durante dez anos (1986-1996) em Vila Real (Trásos-Montes). O ensaio incluiu a rotação tradicional das condições de sequeiro da região, cereal-alqueive (TA), e rotações alternativas susceptíveis de serem adoptadas nestas condições, cereal-leguminosa (TL), cereal-consociação forrageira (TC) e cereal-prado de sequeiro (TP). Os cereais das rotações foram o trigo e, posteriormente, o triticale. Determinaram-se e analisaram-se as produções de grão e palha das diversas culturas e respectivos teores em nutrientes, parâmetros do solo, peso de mil grãos, peso do hectolitro e os índices de Zeleny, Queda e Pelshenke do grão de trigo. A rotação do trigo com tremocilha (leguminosa para grão) induz no grão de trigo maiores valores do índice de Pelshenke e de teor em azoto; no triticale esta influência positiva da rotação com leguminosa fez-se sentir no peso de mil grãos e no peso do hectolitro. Como principais conclusões pode-se referir: alguma influência da rotação com tremocilha no conjunto dos parâmetros de qualida de do grão analisados, a influência decisiva do ano agrícola nos resultados e a importância da espécie de cereal para extracção de conclusões significativas.Results of a field trial of crop rotations conducted over a period of ten years (19861996) in Vila Real (Northeast Portugal) are presented. The rotations tested were cereal-cultivated fallow (TA), traditional in rain-fed conditions of the region, and alternative rotations that could be adopted in these conditions: cereal-grain legume crop (TL), cereal-forage mixture (TC) and cereal-rain-fed seeded pasture (TP). The cereals were wheat and, later, triticale. Grain, straw and aerial biomass yields, nutrient levels of crops and soil parameters were evaluated together with one thousand grain weight, hectolitre weight, Zeleny, Falling Number and Pelshenke indices of cereal grain. Wheat grain from TL rotation have the highest Pelshenke indices and nitrogen content. Triticale grain from TL rotation was the heavier and with the highest specific weight. As main conclusions we can refer the influence of the rotation with lupin in the group of the parameters of grain quality , the decisive influence of the agricultural year on the results and the importance of the cereal species to obtain significant conclusions.

Carlos Castro; João Coutinho; Nuno Moreira; António Crespi

2008-01-01

217

Trigo e Triticale em rotações de sequeiro efeitos na qualidade/ Wheat and triticale in crop rotations quality effects  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este trabalho resume parte dos resultados de um ensaio de rotações que decorreu durante dez anos (1986-1996) em Vila Real (Trásos-Montes). O ensaio incluiu a rotação tradicional das condições de sequeiro da região, cereal-alqueive (TA), e rotações alternativas susceptíveis de serem adoptadas nestas condições, cereal-leguminosa (TL), cereal-consociação forrageira (TC) e cereal-prado de sequeiro (TP). Os cereais das rotações foram o trigo e, posteriormente, (more) o triticale. Determinaram-se e analisaram-se as produções de grão e palha das diversas culturas e respectivos teores em nutrientes, parâmetros do solo, peso de mil grãos, peso do hectolitro e os índices de Zeleny, Queda e Pelshenke do grão de trigo. A rotação do trigo com tremocilha (leguminosa para grão) induz no grão de trigo maiores valores do índice de Pelshenke e de teor em azoto; no triticale esta influência positiva da rotação com leguminosa fez-se sentir no peso de mil grãos e no peso do hectolitro. Como principais conclusões pode-se referir: alguma influência da rotação com tremocilha no conjunto dos parâmetros de qualida de do grão analisados, a influência decisiva do ano agrícola nos resultados e a importância da espécie de cereal para extracção de conclusões significativas. Abstract in english Results of a field trial of crop rotations conducted over a period of ten years (19861996) in Vila Real (Northeast Portugal) are presented. The rotations tested were cereal-cultivated fallow (TA), traditional in rain-fed conditions of the region, and alternative rotations that could be adopted in these conditions: cereal-grain legume crop (TL), cereal-forage mixture (TC) and cereal-rain-fed seeded pasture (TP). The cereals were wheat and, later, triticale. Grain, straw an (more) d aerial biomass yields, nutrient levels of crops and soil parameters were evaluated together with one thousand grain weight, hectolitre weight, Zeleny, Falling Number and Pelshenke indices of cereal grain. Wheat grain from TL rotation have the highest Pelshenke indices and nitrogen content. Triticale grain from TL rotation was the heavier and with the highest specific weight. As main conclusions we can refer the influence of the rotation with lupin in the group of the parameters of grain quality , the decisive influence of the agricultural year on the results and the importance of the cereal species to obtain significant conclusions.

Castro, Carlos; Coutinho, João; Moreira, Nuno; Crespi, António

2008-12-01

218

ROMANIA’S IRRIGATION SYSTEMS AND CROPPING TENDENCIES  

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Full Text Available Irrigation facilities play an important role in the development of agriculture inRomania. Over the years, there have been consistent investments in irrigation systems, which occupied 22% of the agricultural area in late 2011. However, the share of irrigated area was located below 10% in most years, after 1989. The main objective of this paper was to analyze the structure and evolution of areas farmed by the main crop groups in five irrigation systems. The main conclusion that emerged was that the crop structure indicates the existence and development of intensive and professional agriculture attributes. This shows an increase in the areas under high value crops, a trend that could be a chance for poor rural communities to reduce their dependence for grain crops, and facilitate the transition from subsistence to market-oriented agriculture.

Marioara Rusu

2013-01-01

219

Radiative dosimetry on rotating gamma system  

International Nuclear Information System (INIS)

The physical test of dosimetry on rotating gamma system has to be made before the clinical use of a radiation medical treatment equipment. It is a systematic test for design, processing and fabrication, fixing and electric controlling of stereotactic radiosurgical set up. The absolute dosimetry is determined using ionization chamber. The relative dose profile is measured by film. The test results are presented and discussed

1998-01-01

220

Control of Common Scab of Potato Caused by Streptomyces spp. by Soil pH Adjustment and Crop Rotation  

Directory of Open Access Journals (Sweden)

Full Text Available In 2006, the effect of soil pH adjustment on control of common scab of potato caused by Streptomyces spp. was evaluated in the field. Soil with an original pH 5.7 was treated with sulfur of 42 kg/10a and calcium hydroxide of 81.6 kg/10a and 184.5 kg/10a to adjust pH 5.0, 6.0 and 6.5, respectively. Additionally, the effect of gypsum(522 kg/10a) on soil pH and disease severity was examined. The soil pH of sulfur treatment plot was continuously declined from 5.13 at tuber initiation time to 5.01 at harvest. The disease severity of sulfur treatment plot was relatively low (22.8%) and the marketable yield of that was high (90.5%). By contrast, the soil pHs treated with calcium hydroxide (81.6 kg/10a and 184.5 kg/10a) were increased (pH 6.06 and 6.49, respectively) at harvest. In addition, calcium hydroxide treatment plots showed higher disease severities (51.0% and 61.1%), and lower marketable yields (55.7% and 37.0%). Meanwhile, the soil pH of gypsum treatment plot was not changed until harvest, and the disease severity and the marketable yield were not significantly different from those of control. The effect of crop rotation was also evaluated with four crops such as welsh onion, soybean, corn and Chinese cabbage. These crops were planted n the infested field from 2005 to 2007, and potatoes were planted in the same field in 2008. The disease severities of potatoes produced after rotations with welsh onion, soybean, corn and Chinese cabbage for 3 years were 13.1%, 16.7%, 28.9% and 30.2%, respectively. However, the disease severity of 73.1% was shown in continuous cropping of potato for 3 years. In addition, similar effects were exhibited in the marketable yield. These results demonstrate that the adjustment of soil pH and crop rotation might be very useful tools to control common scab of potato.

Jeom-Soon Kim; Young-Gyu Lee; Min Kwon; Ju-Il Kim; Gye-Jun Lee; Jeong-Tae Lee; Jong-Soo Ryu

2012-01-01

 
 
 
 
221

Agregados em um Latossolo sob sistema plantio direto e rotação de culturas Aggregates in a Rhodic Ferralsol under no-tillage and crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi avaliar a influência dos cultivos de outono-inverno e primavera, em sistema de plantio direto, nos agregados e matéria orgânica de um Latossolo. O experimento foi conduzido durante as safras 2006/2007, 2007/2008 e 2008/2009. No outono-inverno foram estabelecidas parcelas principais com braquiária (Urochloa ruziziensis), sorgo granífero (Sorghum bicolor) e sorgo consorciado com braquiária. Na primavera, foram cultivados, em subparcelas, milheto (Pennisetum glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense), crotalária (Crotalaria juncea) ou pousio. A soja foi cultivada como safra de verão, o que totalizou 12 tratamentos. A massa de matéria seca e o crescimento radicular das plantas de cobertura da primavera foram determinados em 2006 e 2008. Foram coletadas amostras de solo nas camadas de 0-5 e 5-10 cm, após o manejo das plantas de cobertura de primavera, no primeiro e terceiro anos agrícolas. Foram determinados o diâmetro médio ponderado, o diâmetro médio geométrico, o índice de estabilidade de agregados, os agregados maiores que 2 mm, a matéria orgânica e os teores de carbono orgânico total nas amostras coletadas no terceiro ano. O milheto e 'Cober Crop' produziram maior quantidade de massa de matéria seca e maior crescimento radicular. A estruturação do solo melhorou com a rotação dos cultivos das plantas de cobertura antecedentes à safra de verão. O cultivo de 'Cober Crop' e milheto influenciou a formação de macroagregados nas camadas superficiaisThe objective of this work was to evaluate the influence of fall-winter and spring crops, cultivated under no-tillage system, on the aggregates and organic matter of a Rhodic Ferralsol. The experiment was performed in the 2006/2007, 2007/2008 and 2008/2009 growing seasons. Congo signal grass (Urochloa ruziziensis), grain sorghum (Sorghum bicolor) and sorghum mixed with brachiaria were cropped in the fall-winter to consist the main plots. In the spring, millet (Pennisetum glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense) and Indian hemp (Crotalaria juncea) were cultivated as subplots as well as a fallow treatment. Soybean was cropped in the summer, totaling 12 treatments. Cover crop dry matter and root growth were evaluated in 2006 and 2008. Soil samples were taken from 0-5 and 5-10 cm depths, after spring cover crops managing, in the first and third years. The mean weight diameter, geometric mean diameter, aggregate stability index, aggregates larger than 2 mm, organic matter and total organic carbon levels were evaluated in the samples of the third year. Millet and 'Cober Crop' showed higher dry matter production and root growth. The soil aggregation was improved by cover crop rotations before the summer growing season. The cultivation of 'Cober Crop' and millet influenced the macroaggregate formation in the superficial layers

Rodrigo Arroyo Garcia; Ciro Antonio Rosolem

2010-01-01

222

Agregados em um Latossolo sob sistema plantio direto e rotação de culturas/ Aggregates in a Rhodic Ferralsol under no-tillage and crop rotation  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo deste trabalho foi avaliar a influência dos cultivos de outono-inverno e primavera, em sistema de plantio direto, nos agregados e matéria orgânica de um Latossolo. O experimento foi conduzido durante as safras 2006/2007, 2007/2008 e 2008/2009. No outono-inverno foram estabelecidas parcelas principais com braquiária (Urochloa ruziziensis), sorgo granífero (Sorghum bicolor) e sorgo consorciado com braquiária. Na primavera, foram cultivados, em subparcelas, (more) milheto (Pennisetum glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense), crotalária (Crotalaria juncea) ou pousio. A soja foi cultivada como safra de verão, o que totalizou 12 tratamentos. A massa de matéria seca e o crescimento radicular das plantas de cobertura da primavera foram determinados em 2006 e 2008. Foram coletadas amostras de solo nas camadas de 0-5 e 5-10 cm, após o manejo das plantas de cobertura de primavera, no primeiro e terceiro anos agrícolas. Foram determinados o diâmetro médio ponderado, o diâmetro médio geométrico, o índice de estabilidade de agregados, os agregados maiores que 2 mm, a matéria orgânica e os teores de carbono orgânico total nas amostras coletadas no terceiro ano. O milheto e 'Cober Crop' produziram maior quantidade de massa de matéria seca e maior crescimento radicular. A estruturação do solo melhorou com a rotação dos cultivos das plantas de cobertura antecedentes à safra de verão. O cultivo de 'Cober Crop' e milheto influenciou a formação de macroagregados nas camadas superficiais Abstract in english The objective of this work was to evaluate the influence of fall-winter and spring crops, cultivated under no-tillage system, on the aggregates and organic matter of a Rhodic Ferralsol. The experiment was performed in the 2006/2007, 2007/2008 and 2008/2009 growing seasons. Congo signal grass (Urochloa ruziziensis), grain sorghum (Sorghum bicolor) and sorghum mixed with brachiaria were cropped in the fall-winter to consist the main plots. In the spring, millet (Pennisetum (more) glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense) and Indian hemp (Crotalaria juncea) were cultivated as subplots as well as a fallow treatment. Soybean was cropped in the summer, totaling 12 treatments. Cover crop dry matter and root growth were evaluated in 2006 and 2008. Soil samples were taken from 0-5 and 5-10 cm depths, after spring cover crops managing, in the first and third years. The mean weight diameter, geometric mean diameter, aggregate stability index, aggregates larger than 2 mm, organic matter and total organic carbon levels were evaluated in the samples of the third year. Millet and 'Cober Crop' showed higher dry matter production and root growth. The soil aggregation was improved by cover crop rotations before the summer growing season. The cultivation of 'Cober Crop' and millet influenced the macroaggregate formation in the superficial layers

Garcia, Rodrigo Arroyo; Rosolem, Ciro Antonio

2010-12-01

223

Weed control in short rotation coppice crops: a review of recently published literature and current guidance for farmers  

Energy Technology Data Exchange (ETDEWEB)

This review with 41 references is based on a literature review and consultation with experts, and examines the importance of effective weed control. Herbicides currently approved for use in short rotation coppice plantations are listed. Current practices and recommendations to farmers on pre-planting, post-planting, post cut-back, post-harvest, and directed herbicide applications in the growing crop are outlined, and the results of recent research on chemical and mechanical weed control, mulches, and ground cover plants are addressed. Research need relating to weed competition, herbicide evaluation, vegetation management without chemicals, and quantification of post-harvest herbicide applications are identified.

Britt, C.

2000-07-01

224

Efeito da rotação de culturas, da monocultura e da densidade de plantas na incidência de grãos ardidos em milho/ Effect of crop rotation, monoculture and plant density on the incidence of rot corn grains  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Neste trabalho, avaliou-se o efeito de sistemas de rotação de culturas, de monocultura e de densidade de plantas na incidência de grãos ardidos em milho (Zea mays). A quantificação da incidência de grãos ardidos foi determinada pelo método de separação visual de grãos com sintomas de descoloração, causada pela infecção por fungos na lavoura. A maior incidência de grãos ardidos ocorreu em monocultura, com média de 10,02%, enquanto sob rotação de cultur (more) as esta foi de 4,81%. A incidência de grãos ardidos foi maior à medida que a densidade de plantas aumentou para os dois sistemas. Os principais fungos isolados dos grãos de milho nos sistemas de rotação e monocultura foram Cephalosporium spp., Diplodia spp., Fusarium graminearum, F. moniliforme e F. subglutinans. Abstract in english The effect of crop rotation, monoculture, and plant density on the incidence of injuried corn (Zea mays) grains was evaluated in this work. Visual separation of grains showing symptoms of discoloration caused by fungi in the field was used to quantify the incidence. The highest incidence of injuried grains, an average of 10.02% was found in continuous cropping system, while in the crop rotation system the incidence average was 4.81%.The incidence of injuried grains was hi (more) ghest in both systems as plant density increased. The main fungi isolated from corn grains in crop rotation and monoculture were Cephalosporium spp., Diplodia spp., Fusarium graminearum, F. moniliforme and F. subglutinans.

TRENTO, SIMONE M.; IRGANG, HELBER H.; REIS, ERLEI M.

2002-11-01

225

Crop yields and nematode population densities in triticale-cotton and triticale-soybean rotations.  

UK PubMed Central (United Kingdom)

Triticale cv. Beagle 82, cotton cv. McNair 235, and soybean cv. Twiggs were arranged in three cropping sequences to determine the effects of fenamiphos and cropping sequence on nematode population densities and crop yields under conservation tillage for 4 years. The cropping sequences were triticale (T)-cotton (C)-T-C, T-soybean (S)-T-S, and T-C-T-S. Numbers of Meloidogyne incognita second-stage juveniles declined on trificale but increased on cotton and soybean each year. Root-gall indices of cotton and soybean ranged from 1.00 to 1.08 (1 to 5 scale: 1 = 0%, 2 = 1% to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = 76% to 100% of roots galled) each year and were not affected by fenamiphos treatment or cropping sequence. Numbers of Pratylenchus brachyurus were maintained on trificale and generally increased more on soybean than on cotton. Population densities of Helicotylenchus dihystera were near or below detection levels in all plots during the first year and increased thereafter in untreated plots in the T-C-T-C and T-S-T-S sequences. Generally, yields of triticale in all cropping sequences declined over the years. Yields of cotton and soybean were not affected by fenamiphos at 6.7 kg a.i./ha. Cotton and soybean were grown successfully with little or no suppression in yields caused by nematodes in conservation tillage following triticale harvested for grain.

Johnson AW; Dowler CC; Baker SH; Handoo ZA

1998-09-01

226

Estabilidade de agregados do solo após manejo com rotações de culturas e escarificação Soil aggregate stability after management with crop rotation and chiseling  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo desse trabalho foi avaliar, em solo compactado, a estabilidade dos agregados influenciada pelo cultivo de espécies de cobertura em esquema de rotações de culturas, em sistema de semeadura direta, mediante o efeito da escarificação mecânica. As rotações de culturas repetidas por três anos consecutivos envolveram o cultivo de triticale e girassol, no outono-inverno, associados ao cultivo de milheto, de sorgo forrageiro e de Crotalária júncea como plantas de cobertura, antecedendo o da soja (cultura de verão). No tratamento envolvendo a escarificação mecânica, a área permaneceu em pousio entre os cultivos de outono-inverno e de verão. O experimento foi realizado na Fazenda Experimental Lageado (Botucatu-SP), nos anos agrícolas de 2003/2004, 2004/2005 e 2005/2006. O delineamento experimental foi o de blocos ao acaso, com quatro repetições, em esquema de parcelas subdivididas. As amostras para a análise da estabilidade de agregados foram coletadas nas profundidades de 0 a 0,05 m e de 0,05 a 0,10 m após o manejo das plantas de cobertura em dezembro de 2003 e de 2005. Logo no primeiro ano de instalação do experimento, o cultivo de triticale resultou em maior porcentagem de agregados com mais de 2 mm, maior DMG e maior DMP na camada de 0 a 5 cm, além de maior DMP na camada de 0,05 a 0,10 m. Já a escarificação do solo e a ausência do cultivo de plantas de cobertura proporcionaram menor porcentagem de agregados maiores que 2 mm e menor DMP na camada de 0,05 a 0,10 m. A estabilidade dos agregados foi influenciada pela rotação de culturas, sendo maior na camada de 0 a 0,05 m e de 0,05 a 0,10 m quando o triticale foi introduzido como espécie de outono-inverno.The objective of this study was to compare, in compacted soil condition, the aggregate stability after different crops rotations under no-tillage system and chiseling. The following crop rotations were repeated for three consecutive years under no-tillage: triticale (X Triticosecale Wittmack) and sunflower (Helianthus annus) as autumn-winter crops, together with pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor) and sunn hemp (Crotalaria juncea) in spring, preceeding soybean (summer crop). In the chiseling treatment the area was kept bare between the autumn-winter and the summer crops. The study was carried out in three growing seasons (2003/2004, 2004/2005 and 2005/2006), in Botucatu, state of São Paulo, Brazil. The experiment had a complete randomized block design with split-plot and four replications. The samples for aggregate stability analysis were collected in the layers 0-5 and 5-10 cm after cover crop desiccation, in the first and third year of the experiment. In the first year of the experiment, triticale resulted in a higher percentage of aggregates larger than 2 mm, higher Mean Geometric Diameter and Mean Weight Diameter (MWD) of aggregates at the depth of 0-5 cm, and higher MWD at 5-10 cm. Chiseling and absence of cover crops reduced the percentage of aggregates larger than 2 mm and MWD values at 5-10 cm. Aggregate stability is influenced by crop rotation, and was highest in the layers 0-5 and 5-10 cm when triticale was used as autumn-winter species.

Juliano Carlos Calonego; Ciro Antonio Rosolem

2008-01-01

227

Estabilidade de agregados do solo após manejo com rotações de culturas e escarificação/ Soil aggregate stability after management with crop rotation and chiseling  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo desse trabalho foi avaliar, em solo compactado, a estabilidade dos agregados influenciada pelo cultivo de espécies de cobertura em esquema de rotações de culturas, em sistema de semeadura direta, mediante o efeito da escarificação mecânica. As rotações de culturas repetidas por três anos consecutivos envolveram o cultivo de triticale e girassol, no outono-inverno, associados ao cultivo de milheto, de sorgo forrageiro e de Crotalária júncea como plant (more) as de cobertura, antecedendo o da soja (cultura de verão). No tratamento envolvendo a escarificação mecânica, a área permaneceu em pousio entre os cultivos de outono-inverno e de verão. O experimento foi realizado na Fazenda Experimental Lageado (Botucatu-SP), nos anos agrícolas de 2003/2004, 2004/2005 e 2005/2006. O delineamento experimental foi o de blocos ao acaso, com quatro repetições, em esquema de parcelas subdivididas. As amostras para a análise da estabilidade de agregados foram coletadas nas profundidades de 0 a 0,05 m e de 0,05 a 0,10 m após o manejo das plantas de cobertura em dezembro de 2003 e de 2005. Logo no primeiro ano de instalação do experimento, o cultivo de triticale resultou em maior porcentagem de agregados com mais de 2 mm, maior DMG e maior DMP na camada de 0 a 5 cm, além de maior DMP na camada de 0,05 a 0,10 m. Já a escarificação do solo e a ausência do cultivo de plantas de cobertura proporcionaram menor porcentagem de agregados maiores que 2 mm e menor DMP na camada de 0,05 a 0,10 m. A estabilidade dos agregados foi influenciada pela rotação de culturas, sendo maior na camada de 0 a 0,05 m e de 0,05 a 0,10 m quando o triticale foi introduzido como espécie de outono-inverno. Abstract in english The objective of this study was to compare, in compacted soil condition, the aggregate stability after different crops rotations under no-tillage system and chiseling. The following crop rotations were repeated for three consecutive years under no-tillage: triticale (X Triticosecale Wittmack) and sunflower (Helianthus annus) as autumn-winter crops, together with pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor) and sunn hemp (Crotalaria juncea) in spring (more) , preceeding soybean (summer crop). In the chiseling treatment the area was kept bare between the autumn-winter and the summer crops. The study was carried out in three growing seasons (2003/2004, 2004/2005 and 2005/2006), in Botucatu, state of São Paulo, Brazil. The experiment had a complete randomized block design with split-plot and four replications. The samples for aggregate stability analysis were collected in the layers 0-5 and 5-10 cm after cover crop desiccation, in the first and third year of the experiment. In the first year of the experiment, triticale resulted in a higher percentage of aggregates larger than 2 mm, higher Mean Geometric Diameter and Mean Weight Diameter (MWD) of aggregates at the depth of 0-5 cm, and higher MWD at 5-10 cm. Chiseling and absence of cover crops reduced the percentage of aggregates larger than 2 mm and MWD values at 5-10 cm. Aggregate stability is influenced by crop rotation, and was highest in the layers 0-5 and 5-10 cm when triticale was used as autumn-winter species.

Calonego, Juliano Carlos; Rosolem, Ciro Antonio

2008-08-01

228

Perturbation theory approach to rotational tunneling systems  

Directory of Open Access Journals (Sweden)

Full Text Available Diagrammatic perturbation theory is used to consider the problem of the coupling of a molecular group libration to the lattice vibrations in solids exhibiting rotational tunneling detected by inelastic neutron scattering. The technique is applied to a molecular group of symmetry C3 in presence of the hindering potential of the solid. The spectral density for transitions between rotational tunneling states in the ground librational level is obtained as a function of temperature. Low temperature results are presented for di erent phonon spectrum parameters. They are used to check the assumption that this coupling is the origin of the peculiar behaviour of the line shifting and broadening as a function of temperature in the INS spectra of such systems.

Peixoto Luciano T.

2000-01-01

229

Perturbation theory approach to rotational tunneling systems  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Diagrammatic perturbation theory is used to consider the problem of the coupling of a molecular group libration to the lattice vibrations in solids exhibiting rotational tunneling detected by inelastic neutron scattering. The technique is applied to a molecular group of symmetry C3 in presence of the hindering potential of the solid. The spectral density for transitions between rotational tunneling states in the ground librational level is obtained as a function of temper (more) ature. Low temperature results are presented for di erent phonon spectrum parameters. They are used to check the assumption that this coupling is the origin of the peculiar behaviour of the line shifting and broadening as a function of temperature in the INS spectra of such systems.

Peixoto, Luciano T.

2000-03-01

230

Integrated soil-crop system management for food security.  

UK PubMed Central (United Kingdom)

China and other rapidly developing economies face the dual challenge of substantially increasing yields of cereal grains while at the same time reducing the very substantial environmental impacts of intensive agriculture. We used a model-driven integrated soil-crop system management approach to develop a maize production system that achieved mean maize yields of 13.0 t ha(-1) on 66 on-farm experimental plots--nearly twice the yield of current farmers' practices--with no increase in N fertilizer use. Such integrated soil-crop system management systems represent a priority for agricultural research and implementation, especially in rapidly growing economies.

Chen XP; Cui ZL; Vitousek PM; Cassman KG; Matson PA; Bai JS; Meng QF; Hou P; Yue SC; Römheld V; Zhang FS

2011-04-01

231

Integrated soil-crop system management for food security.  

Science.gov (United States)

China and other rapidly developing economies face the dual challenge of substantially increasing yields of cereal grains while at the same time reducing the very substantial environmental impacts of intensive agriculture. We used a model-driven integrated soil-crop system management approach to develop a maize production system that achieved mean maize yields of 13.0 t ha(-1) on 66 on-farm experimental plots--nearly twice the yield of current farmers' practices--with no increase in N fertilizer use. Such integrated soil-crop system management systems represent a priority for agricultural research and implementation, especially in rapidly growing economies. PMID:21444818

Chen, Xin-Ping; Cui, Zhen-Ling; Vitousek, Peter M; Cassman, Kenneth G; Matson, Pamela A; Bai, Jin-Shun; Meng, Qing-Feng; Hou, Peng; Yue, Shan-Chao; Römheld, Volker; Zhang, Fu-Suo

2011-03-28

232

System design description for the HMT Rotation Motor Heater System  

International Nuclear Information System (INIS)

This document is the design description for the Rotation Motor Heater System on waste tank 241-SY-101. The description includes the certified vendor (CV) file number, operators instructions, and heater sizing calculations

1995-01-01

233

The effects of two organic manures on soil properties and crop yields on a temperate calcareous soil under a wheat-maize cropping system  

UK PubMed Central (United Kingdom)

To improve soil fertility, efforts need to be made to increase soil organic matter content. Straw manure is considered another important management practice to maintain soil organic matter content. This study compared effects of two organic manures (straw and farmyard manure) on soil properties and crop yields in a crop rotation system under semi-arid conditions. Soil physical, chemical and biological characteristics were determined in the experiment. After 25 years cropping and fertilization, two organic manures significantly influenced soil properties and crop yields. Farmyard manure combined with chemical fertilizer management (M+NP) resulted in higher increase in SOC, available-N, available-P, and higher activities of protease, urease, and alkaline-phosphatase compared with those found under straw manure combined with chemical fertilizer management (S+NP). However, soil of straw treatment had higher levels of potential soil respiration, soil water retention, microbial biomass, soil porosity, invertase, catalase and lower bulk density than farmyard manure treatment. M+NP produced the highest crop yields at all treatments. Biochemical properties of both treatments were positively correlated with SOC and nutrient content. These results indicate that straw management positively affected soil physical, chemical and biochemical properties as manure treatment in calcareous soil. Adding straw manure, as a replacement of farmyard manure, could be a promising strategy on some soil physical and biological properties as compared to farmyard manure in calcareous soil.

Zhao Yunchen; Wang Ping; Li Jianlong; Chen Yuru; Ying Xianzhi; Liu Shuying

2009-07-01

234

Suitability of a wheat-sorghum, double-crop rotation to manage Criconemella xenoplax in peach production.  

UK PubMed Central (United Kingdom)

Twenty-one sorghum cultivars were evaluated for host suitability to the ring nematode Criconemella xenoplax in the greenhouse. No C. xenoplax were detected on peach in soil previously planted to GK8172C, Funks G-522DR, Jacques-505, McCurdy M51YG, Northrup King NK2660, or Northrup King NK-Savannah 5. Additionally, the effects of 1-, 2-, and 3-year wheat-sorghum and wheat-fallow preplant double-crop rotations for the management of C. xenoplax were studied from 1990 to 1993 in a field experiment in central Georgia. The field site had a previous history of peach tree short life and was heavily infested with C. xenoplax. All wheat-sorghum and wheat-fallow rotations suppressed population densities of C. xenoplax compared with 3 years of continuous peach (P less than or equal to 0.05). One year of wheat-fallow did not suppress C. xenoplax population densities as low as did 1 year of wheat-sorghum. No differences in suppression of C. xenoplax population density were detected among the 1, 2, and 3 years of wheat-sorghum rotation. A wheat-sorghum rotation has potential as a preplant strategy to manage C. xenoplax in peach orchards in the southeastern United States.

Nyczepir AP; Bertrand PF; Cunfer BM

1996-06-01

235

Evaluation of Carabid Beetle Diversity in Different Bioenergy Cropping Systems  

Directory of Open Access Journals (Sweden)

Full Text Available Normal 0 7.8 ? 0 2 false false false EN-US ZH-CN X-NONE MicrosoftInternetExplorer4 Changes in agricultural land use as a consequence of an increased demand of energy crops have resulted in an increase of maize cropped area in many regions of Germany. The focus on maize as main biogas substrate, has led in some cases to negative ecological and environmental impacts, such as a loss of agro biodiversity reflected in a loss of field flora and fauna biodiversity. The present paper deals with the evaluation of the fauna in different bioenergy cropping systems on two sites in South-West Germany, with a special focus on the species richness of carabid beetle (Coleoptera: Carabidae) assemblages as an indicator for the general status of diversity. A maize field, an agroforestry system with maize and different tree species as well as different alternative biogas crops (amaranth, sunflower) was investigated for their carabid beetle activity, density, and species richness using pitfall traps. Moreover, for an adequate evaluation of the carabid assemblages different common diversity indices (Shannon-Wiener diversity (H’), Simpson diversity (D) and Evenness (J’)) were used. In the case of the maize field on both field edges 8 and 6 carabid beetle species, respectively were trapped, while in the field centre 2 carabid beetle species were trapped. The agroforestry system indicated slightly higher crabid beetle species richness close to the tree strips. The investigation of alternative biogas crops showed no significant differences in carabid beetle diversity. Overall, the results of the different studies showed, that biodiversity of bioenergy cropping systems could be enhanced by the creation of refuge areas for carabid beetles or other animals. Refuges could be either field margins with grass and hedgerows or strips of more extensively used perennial energy crops across the field.

Benjamin Mast; Simone Graeff Hönninger; Wilhelm Claupein

2012-01-01

236

Long-term effects of cropping system on N2O emission potential  

DEFF Research Database (Denmark)

The potential for N2O emissions outside the main growing season may be influenced by long-term effects of cropping system. This was investigated by collecting intact soil cores (100 cm3, 0-4 cm depth) under winter wheat in three organic cropping systems and a conventional reference within a long-term crop rotation experiment. Average annual inputs of C in crop residues and manure ranged from 1.7 to 3.3 Mg ha-1. A simulated freeze-thaw cycle resulted in a flush of CO2 during the first 48 h, which could be mainly from microbial sources. Other samples were adjusted to approximately –10, -30 or –100 hPa and amended with excess 15NO3- prior to freezing and thawing. Denitrification was the main source of N2O during a 72-h incubation at 22 °C, as judged from N2O and total 15N evolution. Although the input of C in the conventionally managed cropping system was significantly less than in the organic cropping systems, it showed higher N2O evolution at all three matric potentials. Estimates of relative gas diffusivity (DP/D0) in soil from the four cropping systems indicated that C input affected soil aeration. Soil from the two cropping systems with highest C input showed N2O evolution at DP/D0 in excess of 0.02, which is normally considered a threshold for development of anaerobic sites in the soil, presumably because the oxygen demand was also high. The study shows that cropping system affects both soil gas diffusivity and C availability, and that both characteristics significantly influence the N2O emission potential.

Petersen, SØren O.; Ambus, Per

2013-01-01

237

Managing nematode population densities on tomato transplants using crop rotation and a nematicide.  

UK PubMed Central (United Kingdom)

Millet, milo, soybean, crotalaria, and Norman pigeon pea were used in conjunction with clean fallow and a nematicide (fensulfothion) for managing nematode populations in the production of tomato transplants (Lycopersicon esculentum Mill.). Glean fallow was the most effective treatment in suppressing nematode numbers. After 2 years in tomato, root-knot nematodes increased in numbers to damaging levels, and fallow was no longer effective for complete control even in conjunction with fensulfothion. After 4 years in tomato, none of the crops used as summer cover crops alone or in conjunction with fensulfothion reduced numbers of root-knot nematodes in harvested tomato transplants sufficiently to meet Georgia certification regulations. Milo supported large numbers of Macroposthonia ornata and Pratylenchus spp. and crotalaria supported large numbers of Pratylenchus spp. Millet, milo, soybean, crotalaria, and pigeon pea are poor choices for summer cover crops in sites used to produce tomato transplants, because they support large populations of root-knot and other potentially destructive nematodes.

Johnson AW; Campbell GM

1980-01-01

238

A rotating inertial navigation system with the rotating axis error compensation consisting of fiber optic gyros  

Science.gov (United States)

An effective and flexible rotation and compensation scheme is designed to improve the accuracy of rotating inertial navigation system (RINS). The accuracy of single-axial RINS is limited by the errors on the rotating axis. A novel inertial measurement unit (IMU) scheme with error compensation for the rotating axis of fiber optic gyros (FOG) RINS is presented. In the scheme, two couples of inertial sensors with similar error characteristics are mounted oppositely on the rotating axes to compensate the sensors error. Without any change for the rotation cycle, this scheme improves the system's precision and reliability, and also offers the redundancy for the system. The results of 36 h navigation simulation prove that the accuracy of the system is improved notably compared with normal strapdown INS, besides the heading accuracy is increased by 3 times compared with single-axial RINS, and the position accuracy is improved by 1 order of magnitude.

Zha, Feng; Hu, Bai-qing; Qin, Fang-jun; Luo, Yin-bo

2012-03-01

239

Soil water retention and s index after crop rotation and chiseling/ Retenção de água no solo e índice s influenciados por rotação de culturas e escarificação  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A compactação do solo pode ser corrigida mecanicamente ou usando espécies vegetais com sistema radicular vigoroso. Um experimento foi conduzido com soja (Glycine max) em rotação com triticale (X Triticosecale) e girassol (Helianthus annuus) cultivados no outono/inverno, associados com milheto (Pennisetum glaucum), sorgo (Sorghum bicolor) ou crotalária (Crotalaria juncea) cultivados na primavera. Rotações sob semeadura direta foram comparadas com um tratamento com (more) escarificação no início do experimento. A qualidade do solo foi estimada usando-se o índice S e as curvas de retenção de água do solo nas profundidades de 0-0,05, 0,075-0,15, 0,15-0,20, 0,275-0,325 e 0,475-0,525 m. As rotações de culturas e a escarificação melhoraram a qualidade do solo, aumentando o índice S acima de 0,035 até 0,20 m no perfil do solo. Entretanto, a melhoria na qualidade do solo, conforme determinada por meio do índice S, não justifica o uso de escarificação mecânica, uma vez que as parcelas sob rotação de culturas em semeadura direta mostraram qualidade física do solo semelhante após três anos. Abstract in english Soil compaction can be minimized either mechanically or biologically, using plant species with vigorous root systems. An experiment was carried out with soybean (Glycine max) in rotation with triticale (X Triticosecale) and sunflower (Helianthus annuus) in fall-winter associated with pearl millet (Pennisetum glaucum), grain sorghum (Sorghum bicolor) or sunn hemp (Crotalaria juncea) in spring. Crop rotation under no-till was compared with mechanical chiseling. The experime (more) nt was carried out in Botucatu, São Paulo State, Brazil. Soil quality was estimated using the S index and soil water retention curves (in the layers of 0-0.05, 0.075-0.125, 0.15-0.20, 0.275-0.325, and 0.475-0.525 m deep). Crop rotation and chiseling improved soil quality, increasing the S index to over 0.035 to a depth of 20 cm in the soil profile. The improved soil quality, as shown by the S index, makes the use of mechanical chiseling unnecessary, since after 3 years the soil physical quality under no-tilled crop rotation and chiseling was similar.

Calonego, Juliano Carlos; Rosolem, Ciro Antonio

2011-12-01

240

Maize Yield Response in a Long-term Rotation and Intercropping Systems in the Guinea Savannah Zone of Northern Ghana  

Directory of Open Access Journals (Sweden)

Full Text Available To sustain crop production, cowpea, groundnut, soybean, sorghum and cassava were compared for their potential in crop rotation or as an intercropping partner to maize over an eleven-year period in Northern Ghana. The trial in each year consisted of 12 treatments arranged in an RCBD with five replicates. There was a gradual decline in maize yield for groundnut-maize, soybean-maize and cassava-maize as compared to a rapid decline in the other rotation combinations over the years. The best combination was maize-groundnut rotation with grain yields above 3.0 t ha-1. Intercropping advantage for most combinations in the first two years was not sustained in later years, except for sorghum-maize and cassava-maize systems. Sorghum-maize combination was the best in terms of crop yield, based on Land Equivalent Ratio (LER). Cassava-maize and soybean-maize systems were the best in terms of energy value and protein yield respectively. Maize yields obtained were comparatively better in rotation than intercrops, underlining the superiority of rotation to intercropping in the long-term, consequently its potential to improve on household food security. The results so far indicate that good cropping system and proper agronomic practices can sustain maize production on the same piece of land for more than 10 years.

W.A. Agyare; V.A. Clottey; H. Mercer-Quarshie; J.M. Kombiok

2006-01-01

 
 
 
 
241

Potassium cycling in a corn-brachiaria cropping system  

UK PubMed Central (United Kingdom)

Growing corn mixed with forage crops can be an alternative for pasture and mulch production during relatively dry winters in tropical areas, making no-till feasible in some regions. However, little is known about nutrient dynamics in this cropping system. The objective of the present work was to evaluate K dynamics in a production system in which corn was either grown as a sole crop or mixed with Brachiaria brizantha. In the second year of the experiment, nitrogen rates ranging from 0 to 200kgha?¹ were applied to the system. Dry matter yields and potassium contents in the soil, as well as residues and plants were determined at corn planting and harvest. Potassium balance in the system was calculated. Corn grain yield in mixed crop responded up to 200kgha?¹ N. The introduction of brachiaria in the system resulted in higher amounts of straw on the soil surface and higher K recycling. Soil exchangeable K balance showed an excess K for both N rates only in the mixed system; however, when non-exchangeable K was also included in calculations, excess K was found in both mixed and sole corn systems. Large amounts of non-exchangeable K were taken up in the system involving brachiaria, which showed a considerable capacity in recycling K, increasing its contents in the surface soil layer.

Garcia RA; Crusciol CAC; Calonego JC; Rosolem CA

2008-05-01

242

Some charged rotating systems in general relativity  

Energy Technology Data Exchange (ETDEWEB)

In this paper we present a study of some charged rotating systems in general relativity. We divide our work into two parts. In the first part, we extend the Wald-Ipser-Bose-Wang theorem to the whole class of charged Tomimatsu-Sato sources. In the second part, a solution of the stationary axially symmetric Einstein-Maxwell field equations for a quadrupole is obtained. The explicit form of the axially symmetric metric corresponding to a charged Kerr-Newman source and a charged quadrupole in equilibrium under their mutual electromagnetic and gravitational forces is also given. The proper asymptotic behavior of the metric is discussed.

Krori, K.D.; Chaudhury, T.

1980-12-15

243

Crop Yield and Plant Density under Different Tillage Systems  

Directory of Open Access Journals (Sweden)

Full Text Available To determine the optimal ploughing depth and to make tillage simpler and less costly, but also taking account of edaphic and climatic conditions as well as biological and agrotechnical requirements of crops grown, long-term investigations (1994-2009) have been carried out on Stagnic Luvisol of sloping terrains in central Croatia near Daruvar. The paper presents the results relating to plant density and yields of maize (Zea mays L.), soybean (Glycine max L.), oilseed rape (Brassica napus L.), winter wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.). Investigation results point to the conclusion that high density crops (winter wheat, spring barley and oilseed rape) are suitable for growing under reduced tillage systems. Yields of low density spring crops (maize and soybean) obtained under the no-tillage system are not satisfactory, especially in climatically extreme years.

Ivica Kisi?; Ferdo Baši?; Marta Birkas; Aleksandra Juriši?; Vlado Bi?ani?

2010-01-01

244

Crop growth responses to free air CO2 enrichment and nitrogen fertilization: Rotating barley, ryegrass, sugar beet and wheat  

UK PubMed Central (United Kingdom)

Model based projections of overall climate change effects on future crop yields strongly depend on the integration of the direct CO2 fertilization effect. For European crops little information from field experimentation with elevated CO2 levels ([eCO2]) exists, which may be used for model validation purposes. Over six years an arable crop rotation with winter barley, ryegrass, sugar beet and winter wheat was exposed to ambient and elevated CO2 levels (550ppm) using a FACE facility under adequate nitrogen (N100) and 50% of adequate N fertilization (N50). Total plant N concentrations of all crops were lower between ?4.9% and ?17% under [eCO2] compared to ambient CO2. Green leaf area index (GLAI) of sugar beet and ryegrass late in the growing season was reduced by [eCO2], while it slightly increased or remained unchanged for the cereals at anthesis. However, the results of total plant N and GLAI were statistically significant only for wheat and ryegrass. Final above-ground biomass and yield of all crop species significantly increased under [eCO2]. Averaged across both growth seasons and N supply levels the stimulation of total above ground biomass by [eCO2] amounted to +14% (barley), +11.9% (wheat), +10.6% (sugar beet) and +9.9% (ryegrass). On average, cereal grain yield and storage root yield were enhanced by +12.5% (barley), +12.7% (wheat) and +12.1% (sugar beet). There were no significant effects of [eCO2] on N yield. Contrary to expectations, [eCO2] effects on the plant growth variables were independent from the N supply level. Overall, growth and yield stimulations of the different crop species by [eCO2] under FACE conditions were smaller than observed in many previous enclosure studies. The losses observed for plant N concentrations point to possible future problems with animal forage quality if atmospheric CO2 levels continue to increase.

Weigel HJ; Manderscheid R

2012-11-01

245

The perspective crops for the bioregenerative human life support systems  

Science.gov (United States)

The perspective crops for the bioregenerative human life support systems V.I. Polonskiy, J.E. Polonskaya aKrasnoyarsk State Agrarian University, 660049, Krasnoyarsk, Russia In the nearest future the space missions will be too long. In this case it is necessary to provide the crew by vitamins, antioxidants, and water-soluble dietary fibers. These compounds will be produced by higher plants. There was not enough attention at present to increasing content of micronutrients in edible parts of crops candidates for CELSS. We suggested to add the new crops to this list. 1. Barley -is the best crop for including to food crops (wheat, rice, soybean). Many of the health effects of barley are connected to dietary fibers beta-glucan of barley grains. Bar-ley is the only seed from cereals including wheat with content of all eight tocopherols (vitamin E, important antioxidant). Barley grains contain much greater amounts of phenolic compounds (potential antioxidant activities) than other cereal grains. Considerable focus is on supplement-ing wheat-based breads with barley to introduce the inherent nutritional advantages of barley flour, currently only 20We have selected and tested during 5 generations two high productive barley lines -1-K-O and 25-K-O. Our investigations (special breeding program for improving grain quality of barley) are in progress. 2. Volatile crops. Young leaves and shoots of these crops are edible and have a piquant taste. A lot of organic volatile compounds, oils, vitamins, antioxidants are in their biomass. These micronutrients are useful for good appetite and health of the crew. We have investigated 11 species: basil (Ocimum basilicum), hyssop (Hyssopus officinalis), marjoram (Origanum majorana), sweet-Mary (Melissa officinalis), common thyme (Thymus vulgaris), creeping thyme (Thymus serpyllum), summer savory (Satureja hortensis), catnip (Nepeta cataria), rue (Ruta graveolens), coriander (Coriandrum Ativum), sulfurwort (Levisticum officinale). These plants were grown under artificial light conditions from 5 to 7 months. All crops were cut periodically in every month. On the base of our investigations it is possible to recommend for using in CELSS the next crops: marjoram, sweet-Mary and common thyme. The micronutrients containing in barley and above mentioned volatile crops will be useful for good appetite and health of the crew.

Polonskiy, Vadim; Polonskaya, Janna

246

Energy crops for biogas plants. Bavaria; Energiepflanzen fuer Biogasanlagen. Bayern  

Energy Technology Data Exchange (ETDEWEB)

For agriculturists in Bavaria (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

Aigner, A.; Biertuempel, A.; Conrad, M. (and others)

2012-08-15

247

Soil organisms in organic and conventional cropping systems  

Directory of Open Access Journals (Sweden)

Full Text Available Despite the recent interest in organic agriculture, little research has been carried out in this area. Thus, the objective of this study was to compare, in a dystrophic Ultisol, the effects of organic and conventional agricultures on soil organism populations, for the tomato (Lycopersicum esculentum) and corn (Zea mays) crops. In general, it was found that fungus, bacterium and actinomycet populations counted by the number of colonies in the media, were similar for the two cropping systems. CO2 evolution during the cropping season was higher, up to the double for the organic agriculture system as compared to the conventional. The number of earthworms was about ten times higher in the organic system. There was no difference in the decomposition rate of organic matter of the two systems. In general, the number of microartropods was always higher in the organic plots in relation to the conventional ones, reflectining on the Shannon index diversity. The higher insect population belonged to the Collembola order, and in the case of mites, to the superfamily Oribatuloidea. Individuals of the groups Aranae, Chilopoda, Dyplopoda, Pauropoda, Protura and Symphyla were occasionally collected in similar number in both cropping systems.

Bettiol Wagner; Ghini Raquel; Galvão José Abrahão Haddad; Ligo Marcos Antônio Vieira; Mineiro Jeferson Luiz de Carvalho

2002-01-01

248

Effect of Tree Prunings on Soil Fertility and Crop Yield in Alley Cropping System  

Directory of Open Access Journals (Sweden)

Full Text Available The study was conducted to find the impact of incorporation of green prunings from Samanea saman and Dalbergia sissoo in alley cropping system on soil fertility and subsequently yields of rice and wheat. Three treatments used were, 100 kg N ha -1 from 15N ammonium sulphate, 80 kg N ha -1 provided through prunings either from D. sissoo or S. saman plus 20 kg N ha -1 from 15N ammonium sulphate. Grain and straw yields of rice were increased by 23.8 and 32.1%. %15N atom excess (a. e.) and percent nitrogen derived from fertilizer were higher in treatment receiving 100% chemical fertilizer compared to those with tree prunings. Nitrogen contribution of tree prunings to rice yield was 51.3% in D. sissoo and 54.1% in S. saman. The positive effect of pruning was observed in P and K uptake by rice grain and straw. Residual effect of added prunings in succeeding wheat crop was also noticed for both in D. sissoo prunings (11.7%) and S. saman prunings (11.3%). In wheat crop , %15N (a. e.) and %Ndff were higher in 100% chemical fertilizer treatment compared to the residues of those with tree prunings. Nitrogen availability from the residues of tree prunings for wheat crop was 17.72 to 22.54%. P and K uptake in wheat were also more in previously tree pruning treated plots, as compared to the untreated ones. Improvement of soil fertility were observed due to application of tree prunings. Total N, available P, K and organic C were increased, resulting in good soil health, due to prunings.

M. A. Haque; M. I. Ali; M. K. Khan

2001-01-01

249

Broiler Litter Fertilization and Cropping System Impacts on Soil Properties  

UK PubMed Central (United Kingdom)

Understanding the effects of management practices on soil properties is necessary because soil properties are directly related to the capacity of soil to function. Soil physical, chemical and biological properties were determined after 3 yr in three cropping sequences [continuous cotton (Gossypium hirsutum L.) (CCC), cotton-corn (Zea mays L.)-cotton (CMC), and corn-cotton-cotton (MCC) each at four broiler litter fertilization rates (0, 4.5, 9, and 13.4 Mg ha–1) to a soil depth of 15 cm on a Catalpa silty clay loam soil in Verona, MS. Inorganic N fertilizer was applied at the rate of 123 kg ha–1 yr–1 to cotton and 180 kg ha–1 yr–1 to corn. Averaged across crop sequences, broiler litter application significantly increased soil nutrient concentrations, microbial biomass C (MBC), total porosity, and aggregate stability (AS). The inclusion of corn into rotation with cotton increased soil MBC, AS, and reduced bulk density (D(b)). Application of broiler litter at rate greater than 9 Mg ha–1 to CCC resulted in increasing NO3–N concentration at the lower 30-cm depth and P accumulation by fourfold at the 0- to 5-cm depth. Rotating cotton with corn in this study improved soil quality parameters and decreased NO3–N and P accumulation at the soil surface by approximately 24 and 20%, respectively. Hence, corn is sown in rotation with cotton in Mississippi, the Mississippian cotton industry could potentially improve soil organic carbon, nutrient cycling, and soil quality if broiler litter is used as the nutrient source.

Adeli A; Tewolde H; Sistani KR; Rowe DE

2009-11-01

250

The Antonov problem for rotating systems  

CERN Multimedia

We study the classical Antonov problem (of retrieving the statistical equilibrium properties of a self-gravitating gas of classical particles obeying Boltzmann statistics in space and confined in a spherical box) for a rotating system. It is shown that a critical angular momentum $\\lambda_c$ (or, in the canonical language, a critical angular velocity $\\omega_c$) exists, such that for $\\lambda\\lambda_c$, instead, the low-energy phase is characterized by the formation of two dense clusters (a ``binary star''). Remarkably, no Antonov limit is found for $\\lambda>\\lambda_c$. The thermodynamics of the system (phase diagram, caloric curves, local stability) is analyzed and compared with the recently-obtained picture emerging from a different type of statistics which forbids particle overlapping.

De Martino, A; Gross, D H E

2003-01-01

251

Online diagnostic system for rotating electrical apparatus  

UK PubMed Central (United Kingdom)

An online system for diagnosing operability of a rotating electrical apparatus includes sensors (38a-38c) producing electrical signals having values corresponding to operating parameters of the apparatus, data converters (42a-42c) for converting the electrical variables to digital values, a comparator (microprocessor 46) for comparing the values to corresponding predetermined baseline values of the apparatus and producing a corresponding comparison value, and a signalling mechanism (47,49) for outputting signals related to a period of predicted operability of the apparatus whenever the comparison value exceeds a corresponding predetermined deadband value. The operating conditions may be non-electrical operating conditions, such as a condition of a lubrication system or a bearing of the apparatus. Alternatively, the sensors may sense electrical insulation non-thermal parameters during operation of the apparatus, in order to produce signals related to the operability of an insulator of the apparatus.

Salnick Richard E.; Emerson Mark H.; Gaberson Paul C.; Bice Charles D.

252

Cultivation of energy crops with low-input factors short rotation forestry  

International Nuclear Information System (INIS)

[en] This paper concentrates on the cultivation of wood solely for energy purposes in the form of Short Rotation Forestry including the possibility of cultivating with the use of less fertiliser, irrigation and pesticides. Short rotation forestry is a type of forest cultivation which depends on the fast juvenile growth of a few broad-leaved tree species and their ability to cut reproduction and formation of stump shoots. Through intensive cultivation, these characteristics are exploited with the aim of producing biomass which is used for production of energy. (author)

1994-01-01

253

Cropping System to Limit Blast Disease in Upland Rice  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cropping system is an essential aspect to take into account to manage blast disease (caused by the fungus Magnaporthe oryzae). In addition to the selection of resistant cultivars, studies report opportunities to limit blast incidence by managing mineral amendment (N, Si, P, etc.), cultivar mixtures ...

Sester, M.; Raveloson, H.; Michellon, R.; Dusserre, J.; Tharreau, D.

254

Life cycle assessment of a willow bioenergy cropping system  

Energy Technology Data Exchange (ETDEWEB)

The environmental performance of willow biomass crop production systems in New York (NY) is analyzed using life cycle assessment (LCA) methodology. The base-case, which represents current practices in NY, produces 55 units of biomass energy per unit of fossil energy consumed over the biomass crop's 23-year lifetime. Inorganic nitrogen fertilizer inputs have a strong influence on overall system performance, accounting for 37% of the non-renewable fossil energy input into the system. Net energy ratio varies from 58 to below 40 as a function of fertilizer application rate, but application rate also has implications on the system nutrient balance. Substituting inorganic N fertilizer with sewage sludge biosolids increases the net energy ratio of the willow biomass crop production system by more than 40%. While CO{sub 2} emitted in combusting dedicated biomass is balanced by CO{sub 2} adsorbed in the growing biomass, production processes contribute to the system's net global warming potential. Taking into account direct and indirect fuel use, N{sub 2}O emissions from applied fertilizer and leaf litter, and carbon sequestration in below ground biomass and soil carbon, the net greenhouse gas emissions total 0.68 gCO{sub 2} eq. MJ{sub biomassproduced}{sup -1}. Site specific parameters such as soil carbon sequestration could easily offset these emissions resulting in a net reduction of greenhouse gases. Assuming reasonable biomass transportation distance and energy conversion efficiencies, this study implies that generating electricity from willow biomass crops could produce 11 units of electricity per unit of fossil energy consumed. Results from the LCA support the assertion that willow biomass crops are sustainable from an energy balance perspective and contribute additional environmental benefits. (author)

Heller, M.C.; Keoleian, G.A. [University of Michigan, Ann Arbor (United States). Center for Sustainable Systems; Volk, T.A. [SUNY College of Environmental Science and Forestry, Syracuse, NY (United States)

2003-08-01

255

Arbuscular mycorrhizal fungal diversity and species dominance in a temperate soil with long-term conventional and low-input cropping systems.  

UK PubMed Central (United Kingdom)

The aim of this work was to study the effect of long-term contrasting cropping systems on the indigenous arbuscular mycorrhizal fungal (AMF) spore populations in the soil of a field experiment located in western Finland. Conventional and low-input cropping systems were compared, each with two nutrient management regimes. The conventional cropping system with a non-leguminous 6-year crop rotation (barley-barley-rye-oat-potato-oat) was fertilized at either full (rotation A) or half (rotation B) the recommended rate. In the low-input cropping system, plant residues were returned to the plots either as such (rotation C) or composted (rotation D). In the rotation of this system, 1 year with barley was replaced by clover, and oat was cultivated mixed with pea. Thus, the 6-year rotation was barley-red clover-rye-oat + pea-potato-oat + pea. Each rotation was replicated three times, starting the 6-year rotation in three different years, these being designated point 1, point 2, and point 3, respectively. In the low-input system, biotite and rock phosphate were used to compensate for K and P in the harvested yield, while animal manure was applied at the start only. After 13 years, rotation points 1 and 3 were studied. Barley was the standing crop in all plots of rotation point 1, while oat and oat + pea were grown in rotations C and D, respectively. AMF spores were studied by direct extraction and by trapping, sampled on 15 June and 15 August. In addition, a special assay was designed for isolation of fast colonizing, dominating AMF. The cropping system did not significantly affect AMF spore densities, although the low-input cropping system with composted plant residues had the highest density with 44 spores on average and the conventional system with full fertilization 24 spores per 100 cm(3) soil in the autumn samples. Species richness was low in the experimental area. Five Glomus spp., one Acaulospora, and one Scutellospora were identified at the species level. In addition to these, three unidentified Glomus spp. were found. Species richness was not affected by cropping system, rotation point, or their interactions. The Shannon-Wiener index of AMF spore distributions was significantly higher in the fully fertilized than in the half-fertilized conventional plots. Glomus claroideum was the most commonly identified single species in the experimental area. It occurred in all the cropping systems and their various rotation points, representing about 30% of the total number of identified spores. In August, G. claroideum accounted for as much as 45-55% of the total numbers of spores identified in the conventional system with halved fertilization. In contrast, Glomus mosseae occurred more commonly in June (26%) than in August (9%). A bioassay using roots as inoculum for isolation and culture of dominating AMF was successfully developed and yielded only G. claroideum. This indicates a high probability of being able to more generally identify, isolate, and culture fast colonizing generalist AMF for use as inoculants in agriculture and horticulture.

Vestberg M; Kahiluoto H; Wallius E

2011-07-01

256

Population Dynamics of Meloidogyne incognita, M. arenaria,and Other Nematodes and Crop Yields in Rotations of Cotton, Peanut, and Wheat Under Minimum Tillage.  

UK PubMed Central (United Kingdom)

Wheat, cotton, and peanut were arranged in three cropping sequences to determine the effects of fenamiphos (6.7 kg a.i./ha) and cropping sequence on nematode population densities and crop yields under conservation tillage and irrigation for 6 years. The cropping sequences included a wheat winter cover crop each year and summer crops of cotton every year, peanut every year, or cotton rotated every other year with peanut. The population densities of Meloidogyne spp. and Helicotylenchus dihystera were determined monthly during the experiment. Numbers of M. incognita increased on cotton and decreased on peanut, whereas M. arenaria increased on peanut, and decreased on cotton; both nematode species remained in moderate to high numbers in plots of wheat. Root damage was more severe on cotton than peanut and was not affected by fenamiphos treatment. The H. dihystera population densities were highest in plots with cotton every summer, intermediate in the cotton-peanut rotation, and lowest in plots with peanut every summer. Over all years and cropping sequences, yield increases in fenamiphos treatment over untreated control were 9% for wheat, 8% for cotton, and 0% for peanut. Peanut yields following cotton were generally higher than yields following peanut. These results show that nematode problems may be manageable in cotton and peanut production under conservation tillage and irrigation in the southeastern United States.

Johnson AW; Dowler CC; Handoo ZA

2000-03-01

257

Black locust (Robinia pseudoacacia L.) Short-Rotation Crops under Marginal Site Conditions  

Directory of Open Access Journals (Sweden)

Full Text Available The improvement of the reliability of renewable resources and the decline in reserves offossile raw material in the coming decades will lead to increasing demands for wood material andconsequently to a greater role of short rotation forestry (SRF). Particular efforts have been made inEurope to substitute fossils with renewables, in this context the proportion of renewable energy shouldbe increased to 20% by 2020. SRF can be provide relatively high dendromass (biomass) incrementrates if the short rotation tree plantations are grown under favourable site conditions and for anoptimum rotation length. However, in many countries only so-called marginal sites are available forsetting up tree plantations for energy purpose. For SRF under marginal site conditions black locust(Robinia pseudoacacia L.) can be considered as one of the most promising tree species thanks to itsfavourable growing characteristics. According to a case study presented in the paper black locust canproduce a Mean Annual Increment (MAI) of 2.9 to 9.7 oven-dry tons ha–1 yr–1 at ages between 3 and7 years using a stocking density of 6667 stems ha–1. On the base of the presented results and accordingto international literature the expected dendromass volume shows great variation, depending upon site,species, their cultivars, initial spacing and length of rotation cycle.

RÉDEI, Károly; CSIHA, Imre; KESER?, Zsolt

2011-01-01

258

Soilless cultivation system for functional food crops  

International Nuclear Information System (INIS)

This soilless cultivation system is based on the fertigation system and cultivation technologies using Functional Plant Cultivation System (FPCS). EBARA Japan has been studying on the cultivation conditions in order to enhance the function of decease risk reduction in plants. Through the research and development activities, EBARA found the possibilities on the enhancement of functions. Quality and quantity of the products in term of bioactive compounds present in the plants may be affected by unforeseen environmental conditions, such as temperature, strong light and UV radiation. The main objective to develop this system is, to support? Functional Food Industry? as newly emerging field in agriculture business. To success the system, needs comprehensive applying agriculture biotechnologies, health biotechnologies and also information technologies, in agriculture. By this system, production of valuable bioactive compounds is an advantage, because the market size of functional food is increasing more and more in the future. (Author)

2007-01-01

259

Performance testing rotating gamma camera SPECT systems  

International Nuclear Information System (INIS)

[en] A reasonably simple protocol for testing the performance of rotating gamma camera SPECT systems has been established, which could be performed in about 10 hours. This protocol has been used to test almost all currently available systems, including GE, Siemens, Technicare, Elscint, Phillips, CGR, etc. In general, several models of a given system were tested in order to give an indication of the range of results that might be obtained. Reconstructions were performed in a standard manner (Uniformity correction, Ramp filter, no attenuation correction) in order to try to eliminate the effect of differences in software. In addition to using the Jaszczak phantom as an overall test pattern, measurements were made of spatial resolution, energy resolution, contrast, variations of sensitivity and uniformity with angle, etc. Results indicated that some systems, with a high resolution collimator and after very careful setting up, could achieve a spatial resolution of the order of 11mm, with good image quality. Not all commercially available systems performed as well. Strong indication was given of the need to improve spatial resolution, even at the expense of sensitivity, confirming the results from simulated tomographic data for various design compromises. Tests were also performed varying the energy window used. It was found that only very few system were capable of producing artefact free images with other than a symmetric photopeak window. However, very significant improvement of image quality of current systems with respect to older systems were noted. This protocol has been used, in addition, to establish a routine quality assurance program for such SPECT systems

1984-01-01

260

Some current research in rotating-disc systems.  

UK PubMed Central (United Kingdom)

Rotating-disc systems are used to model the flow and heat transfer that occurs inside the cooling-air systems of gas-turbine engines. In this paper, recent computational and experimental research in three systems is discussed: rotor-stator systems, rotating cavities with superposed flow and buoyancy-induced flow in a rotating cavity. Discussion of the first two systems concentrates respectively on pre-swirl systems and rotating cavities with a peripheral inflow and outflow of cooling air. Buoyancy-induced flow in a rotating cavity is one of the most difficult problems facing computationalists and experimentalists, and there are similarities between the circulation in the Earth's atmosphere and the flow inside gas-turbine rotors. For this case, results are presented for heat transfer in sealed annuli and in rotating cavities with an axial throughflow of cooling air.

Owen JM; Wilson M

2001-05-01

 
 
 
 
261

Legumes in the Cropping Systems of Southeastern Nigeria.  

UK PubMed Central (United Kingdom)

Soil nutrient and physical status in small holder farms in southeastern Nigeria are subjected to debilitating effects of continuous cropping without adequate efforts towards replenishment and conservation to ensure sustainability of soil resources. Although inorganic fertilizers are quick acting for soil nutrient enhancement, to guarantee soil health they must be used within the context of integrated soil fertility management relative to soil type and other climatic conditions. On the other hand, apart from maintaining required nutrient levels, the use of appropriate crop combinations and arrangements in farmers' fields can improve soil health. Leguminous plants including tree, shrub and annual species have been determined to be useful components in such systems. These species can contribute immensely to soil carbon and other mineral contents in addition to improving soil physical properties. Apart from their high edible protein content, some leguminous seeds also have high phytate content, which should enhance the bioavailability of Zn, making them good nutrient sources in human and animal nutrition. However, indigenous leguminous tree, shrub, and grain legume species are currently underutilized in the common cropping systems on smallholder farms. While tree species are lost through logging, with very limited research toward their improvement, research on grain legumes has been limited in this zone resulting in the loss of indigenous grain species. Low available soil P is another constraint to legume cultivation in this region that has to be addressed through well coordinated agronomic research. Increased and sustainable food production on small holder farms in southeastern Nigeria is possible with improved practices within the prevailing cropping systems. This is achievable with intensive breeding, agronomic and utilization studies on legume species in the cropping systems.

Ogoke IJ; Ibeawuchi II; Ngwuta AA; Tom CT; Onweremadu EU

2009-12-01

262

Changes in bird community composition in response to growth changes in short-rotation woody crop plantings  

Energy Technology Data Exchange (ETDEWEB)

Hybrid poplar established as intensively managed short-rotation woody crops (SRWC) former agricultural lands can provide habitat for wildlife. Studies of bird use of SRWC for nesting and during fall migration have shown that the numbers and kinds of breeding birds using mature plantings of hybrid poplar are similar to natural-forested lands. In Minnesota, the number and species of breeding birds using habitat provided by clonal-trial plantings and young larger-scale plantings (12--64 ha) of hybrid poplar were initially most similar to those using grasslands and row-crops. As the plantings approached canopy closure, successional species became predominant. In the Pacific Northwest, breeding bird composition and density were very similar for mature plantings and forested areas; however, fall migrants were found primarily in forested areas. In the Southeast, preliminary comparisons of breeding bird use of plantings of sweetgum and sycamore with naturally regenerating forests of different ages and sizes and vegetation structure are showing no size effect on use. As with hybrid poplar, species use of the more mature plantings of sweetgum and sycamore was most similar to that of natural forests.

Tolbert, V.R. [Oak Ridge National Lab., TN (United States); Hanowski, J.; Christian, D. [Univ. of Minnesota, Duluth, MN (United States); Hoffman, W. [National Audubon Society, Tavernier, FL (United States); Schiller, A. [Clark Univ., Worcester, MA (United States). Graduate School of Geography; LIndberg, J. [Oak Ridge Inst. for Science and Education, TN (United States)

1997-10-01

263

Rotations with Coastal Bermudagrass and Fallow for Management of Meloidogyne incognita and Soilborne Fungi on Vegetable Crops.  

Science.gov (United States)

The efficacy of fallow and coastal bermudagrass (Cynodon dactylon) as a rotation crop for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus cv. Emerald), squash (Cucurbita pepo cv. Dixie Hybrid), and sweet corn (Zea mays cv. Merit) was evaluated in a 3-year field trial. Numbers of M. incognita in the soil and root-gall indices were greater on okra and squash than sweet corn and declined over the years on vegetable crops following fallow and coastal bermudagrass sod. Fusarium oxysporum and Pythium spp. were isolated most frequently from soil and dying okra plants. Numbers of colony-forming units of soilborne fungi generally declined as the number of years in sod increased, but were not affected by coastal bermudagrass sod. Yields of okra following 2-year and 3-year sod and squash following 2-year sod were greater than those following fallow. Yield of sweet corn was not different following fallow and coastal bermudagrass sod. PMID:19277312

Johnson, A W; Burton, G W; Wilson, J P; Golden, A M

1995-12-01

264

Rotations with Coastal Bermudagrass and Fallow for Management of Meloidogyne incognita and Soilborne Fungi on Vegetable Crops.  

UK PubMed Central (United Kingdom)

The efficacy of fallow and coastal bermudagrass (Cynodon dactylon) as a rotation crop for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus cv. Emerald), squash (Cucurbita pepo cv. Dixie Hybrid), and sweet corn (Zea mays cv. Merit) was evaluated in a 3-year field trial. Numbers of M. incognita in the soil and root-gall indices were greater on okra and squash than sweet corn and declined over the years on vegetable crops following fallow and coastal bermudagrass sod. Fusarium oxysporum and Pythium spp. were isolated most frequently from soil and dying okra plants. Numbers of colony-forming units of soilborne fungi generally declined as the number of years in sod increased, but were not affected by coastal bermudagrass sod. Yields of okra following 2-year and 3-year sod and squash following 2-year sod were greater than those following fallow. Yield of sweet corn was not different following fallow and coastal bermudagrass sod.

Johnson AW; Burton GW; Wilson JP; Golden AM

1995-12-01

265

Changes in bird community composition in response to growth changes in short-rotation woody crop planting  

International Nuclear Information System (INIS)

[en] Hybrid poplar established as intensively managed short-rotation woody crops (SRWC) on former agricultural lands can provide habitat for wildlife. Studies of bird use of SRWC for nesting and during fall migration have shown that the numbers and kinds of breeding birds using mature plantings of hybrid poplar are similar to natural forested lands. In Minnesota, the number of species of breeding birds using habitat provided by clonal-trial plantings and young larger-scale plantings (12-64 ha) of hybrid poplar were initially most similar to those using grasslands and row-crops. As the plantings approached canopy closure, successional species became predominant. In the Pacific Northwest, breeding bird composition and density were very similar for mature plantings and forested areas; however, fall migrants were found primarily in forested areas. In the Southeast, preliminary comparisons of breeding bird use of plantings of sweetgum and sycamore with naturally regenerating forests of different ages and sizes and vegetation structure are showing no size effect on use. As with hybrid poplar, species use of the more mature plantings of sweetgum and sycamore was most similar to that of natural forests. (author)

1997-01-01

266

WEED INFESTATION OF THREE GRAIN SPECIES CULTIVATED UNDER CEREAL CROP ROTATION AND THREE TECHNOLOGIES VARYING IN PRODUCTION INTENSITY  

Directory of Open Access Journals (Sweden)

Full Text Available Assessment of weed infestation in winter wheat, winter triticale and spring barley cultivated since year 1998 in cereal crop rotation under three technologies varying in production intensity was conducted in years 2005, 2006 and 2007 at the Experimental Station Osiny (Institute of Soil Science and Plant Cultivation in Pu?awy). The degree of potential weed infestation (weed total dry matter per 1 m2) collected from areas protected against applied herbicides was evaluated, as well as herbicide efficacy. Generally, herbicide efficacy was very good or good. Potential weed infestation increased significantly as the intensity degree of production technology decreased. In 2006, the degree of potential weed infestation was generally much lower compared to 2005 and 2007 in particular under economical technology. In 2005 spring barley was the most infested by weeds and winter triticale was the least infested. In 2006, herbicide efficacy also was very good but generally all crops were less infested compared to 2005 and 2007. In 2007, winter wheat was the most infested by weeds, while spring barley was the least infested. The analysis of precipitation and monthly average temperature in spring does not give a logic answer why in 2006 weed infestation was so different compared to 2005 and 2007. Due to remarkable differences in potential weed infestation of tested crops grown under different technologies in 3-year period of study, it is impossible to give the final answer whether the changes in weed population and their total dry matter production depend on grain species grown under different cultivation technologies. It looks like the seed bank in soil is many times higher under economical production technology compared to intensive and integrated technologies.

Edward Szeleniak; Jerzy Grabiski; Piotr Nieróbca

2007-01-01

267

Soil/plant nutrition in lowland cropping systems  

International Nuclear Information System (INIS)

Farming system approaches have led to rapid changes in agricultural systems in Asia and the Pacific. They have increased food and other agricultural commodities as well as developing awareness of scarcity of natural resources, environmental degradation and dissemination of new agricultural technology. This paper reviews and summarizes recent research and technology on soil/plant nutrition with emphasis on nitrogen, phosphorus, and sulphur in rice-based lowland cropping systems in Asia and the Pacific region. It mainly focuses on the application of isotopes 15N, 32P and 35S in such studies, but some current research using conventional methods is also covered. A search of the literature shows that technology studies have mostly concentrated on identifying improved varieties for short duration rice, improving tillage practices, pest and weed management. Research in soil/plant nutrition in rice-based cropping systems particularly using isotopes, is limited. (author). 51 refs, 2 tabs

1993-04-00

268

Soil carbon dioxide emission and carbon content as affected by conventional and organic cropping systems in Mediterranean environment  

UK PubMed Central (United Kingdom)

Carbon sequestration in soil is an important means for reducing net emissions of CO? into the atmosphere. We hypothesized that organic cropping systems (ORG) would reduce soil CO? emission and increase C storage compared to conventional cropping systems (CONV). The objectives of this study were to: (i) analyze the ORG and CONV systems in terms of soil CO? emission and soil C balance and (ii) establish if the soil in the ORG and CONV systems represents a source or a sink of C. A 3-year crop rotation (durum wheat -Triticum durum Desf., tomato -Licopersicum esculentum Mill., and pea -Pisum sativum L.) was carried out in both cropping systems, but the crop rotation was implemented with common vetch (Vicia sativa L.) before tomato planting and sorghum (Sorghum bicolor (L.) Moench.) before pea sowing and both green manured only in the ORG system. It was found that the soil CO? emission rate at peak times (in spring or at the end of summer - beginning of autumn) in the ORG system was higher than the CONV system. The peak of CO? was attributed to the fact that at this time the soil temperature and the relative soil water content (RWC) were probably in the optimal range for soil respiration (17.2°C and 36.4% of RWC) and the difference between ORG and CONV was probably due to the green manuring of the cover crops in the ORG system. However, even if the cropping systems had a temporary impact on the rate of soil CO? emissions, the soil C output calculated as the average of cumulative CO? emission over the 3-year period did not show significant differences between the ORG and CONV systems (8.98MgC-CO? ha?¹ vs. 8.06MgC-CO? ha?¹). On the other hand, the C input in the ORG system was higher than in the CONV (9.46MgCha?¹ vs. 5.57MgCha?¹) as well as the C input/output ratio (1.10 vs. 0.72). The 3-year average of TOC content and C stock were higher in the ORG than in the CONV system (1.24% vs. 1.10% and 27.4MgCha?¹ vs. 23.9MgCha?¹, respectively). However, the decrease of TOC and C stock over 3 years period suggested that further studies over a longer period are needed to verify if C limitation for soil microbial growth and nitrogen limitation for crop growth in the organic system could hinder soil C accumulation over a longer period.

Mancinelli R; Campiglia E; Di Tizio A; Marinari S

2010-09-01

269

Influence of Rice Rotation Systems on Soil Nematode Trophic Groups in Arkansas  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of crop rotation sequences and combinations on soil nematode populations were investigated. Tillage versus non-tillage treatments were applied to crop rotation sequences dominated by flooded rice in a split plot design. The rotated crops were rice, soybean, and corn, including a fallow for a total of eight rotation treatments. All nematode feeding groups were recovered i.e bacterial feeding-, fungal feeding-, plant feeding-, carnivorous-, and omnivorous- nematodes. A total of 24 nematode genera in 20 families were identified and categorized into their respective trophic groups and colonizer persister (cp) values. All rotations that included soybean significantly (P, had a nematode reductive effect. No-tillage plots recorded significantly higher populations of the predatory nematodes. The effectiveness of a rotation sequence depends primarily on the crop species and secondarily on soil conditions e.g anaerobic.

Martin Moluwa Matute; Merle Anders

2012-01-01

270

SELF BALANCING SYSTEM FOR ROTATING MECHANISMS  

Directory of Open Access Journals (Sweden)

Full Text Available A self balancing system analysis is presented which utilizes freely moving balancing bodies (balls) rotating in unison with a rotor to be balanced. Using Lagrange´s Equation, we derive the non-linear equations of motion for an autonomous system with respect to the polar coordinate system. From the equations of motion for the autonomous system, the equilibrium positions and the linear variational equations are obtained by the perturbation method. Because of resistance to motion, eccentricity of race over which the balancing bodies are moving and the influence of external vibrations, it is impossible to attain a complete balance. Based on the variational equations, the dynamic stability of the system in the neighborhood of the equilibrium positions is investigated. The results of the stability analysis provide the design requirements for the self balancing system.Se presenta el análisis de un sistema de autobalance el cual utiliza bolas libres de movimiento rotando con el rotor que será balanceado. Se usa la ecuación de Lagrange para derivar un sistema de ecuaciones no lineales para un sistema autónomo con respecto a un sistema de coordenadas polares. De las ecuaciones de movimiento, se obtienen ecuaciones linealizadas variacionalmente y posiciones de equilibrio por el método de perturbación. A causa de la resistencia al movimiento, la excentricidad y el movimiento de los cuerpos libres que son provocados por la influencia de vibraciones externas, hace imposible obtener un balanceo completo. Basado en el método variacional, se investiga el comportamiento dinámico del sistema en la frontera de la posición de equilibrio. Los resultados del análisis de estabilidad proveen los requerimientos de diseño para el sistema de autobalance.

Marco Antonio Meraz; Andrés Yánez; Carlos Jiménez; Raúl Pichardo

2005-01-01

271

Long-term rice-based cropping system effects on near-surface soil compaction  

Directory of Open Access Journals (Sweden)

Full Text Available Irrigated rice (Oryza sativa L.) production is as-sociated with frequent cycling between anaero-bic and aerobic conditions, which can lead to a greater rate of soil organic matter (SOM) de-composition, thus potentially increasing soil bulk density (BD) over time. A study was con-ducted in the Mississippi River Delta region of eastern Arkansas, USA to evaluate the long-term effects of rice-based crop rotations, tillage [conventional tillage (CT) and no-tillage (NT)], soil fertility regime (optimal and sub-optimal), and soil depth (0-10 and 10-20 cm) after 10 years of consistent management on near-surface soil compaction, as measured by BD. Soil BD was greater under NT than CT in the top 10 cm, but was similar between NT and CT in the 10- to 20-cm depth interval. Soil BD differed among common rice-based cropping systems with corn, soybean, and winter wheat, but few consistent trends were evident. It appears that, even after 10 years of continuous CT or NT rice production on a silt-loam soil, substantially increased near-surface soil BD has not occurred to the point where soil compaction would be a likely culprit responsible for a reduced early season stand establishment or crop yield differences among rice-based copping systems.

Jill Motschenbacher; Kristofor R. Brye; Merle M. Anders

2011-01-01

272

Impact of shortened crop rotation of oilseed rape on soil and rhizosphere microbial diversity in relation to yield decline.  

Science.gov (United States)

Oilseed rape (OSR) grown in monoculture shows a decline in yield relative to virgin OSR of up to 25%, but the mechanisms responsible are unknown. A long term field experiment of OSR grown in a range of rotations with wheat was used to determine whether shifts in fungal and bacterial populations of the rhizosphere and bulk soil were associated with the development of OSR yield decline. The communities of fungi and bacteria in the rhizosphere and bulk soil from the field experiment were profiled using terminal restriction fragment length polymorphism (TRFLP) and sequencing of cloned internal transcribed spacer regions and 16S rRNA genes, respectively. OSR cropping frequency had no effect on rhizosphere bacterial communities. However, the rhizosphere fungal communities from continuously grown OSR were significantly different to those from other rotations. This was due primarily to an increase in abundance of two fungi which showed 100% and 95% DNA identity to the plant pathogens Olpidium brassicae and Pyrenochaeta lycopersici, respectively. Real-time PCR confirmed that there was significantly more of these fungi in the continuously grown OSR than the other rotations. These two fungi were isolated from the field and used to inoculate OSR and Brassica oleracea grown under controlled conditions in a glasshouse to determine their effect on yield. At high doses, Olpidium brassicae reduced top growth and root biomass in seedlings and reduced branching and subsequent pod and seed production. Pyrenochaeta sp. formed lesions on the roots of seedlings, and at high doses delayed flowering and had a negative impact on seed quantity and quality. PMID:23573215

Hilton, Sally; Bennett, Amanda J; Keane, Gary; Bending, Gary D; Chandler, David; Stobart, Ron; Mills, Peter

2013-04-01

273

Impact of shortened crop rotation of oilseed rape on soil and rhizosphere microbial diversity in relation to yield decline.  

UK PubMed Central (United Kingdom)

Oilseed rape (OSR) grown in monoculture shows a decline in yield relative to virgin OSR of up to 25%, but the mechanisms responsible are unknown. A long term field experiment of OSR grown in a range of rotations with wheat was used to determine whether shifts in fungal and bacterial populations of the rhizosphere and bulk soil were associated with the development of OSR yield decline. The communities of fungi and bacteria in the rhizosphere and bulk soil from the field experiment were profiled using terminal restriction fragment length polymorphism (TRFLP) and sequencing of cloned internal transcribed spacer regions and 16S rRNA genes, respectively. OSR cropping frequency had no effect on rhizosphere bacterial communities. However, the rhizosphere fungal communities from continuously grown OSR were significantly different to those from other rotations. This was due primarily to an increase in abundance of two fungi which showed 100% and 95% DNA identity to the plant pathogens Olpidium brassicae and Pyrenochaeta lycopersici, respectively. Real-time PCR confirmed that there was significantly more of these fungi in the continuously grown OSR than the other rotations. These two fungi were isolated from the field and used to inoculate OSR and Brassica oleracea grown under controlled conditions in a glasshouse to determine their effect on yield. At high doses, Olpidium brassicae reduced top growth and root biomass in seedlings and reduced branching and subsequent pod and seed production. Pyrenochaeta sp. formed lesions on the roots of seedlings, and at high doses delayed flowering and had a negative impact on seed quantity and quality.

Hilton S; Bennett AJ; Keane G; Bending GD; Chandler D; Stobart R; Mills P

2013-01-01

274

Microbial soil quality indicators under different crop rotations and tillage management Indicadores microbianos da qualidade do solo sob diferentes rotações de culturas e manejo do solo  

Directory of Open Access Journals (Sweden)

Full Text Available An experiment was carried out under field conditions to assess the effects of soil management (no-tillage- NT and conventional tillage- CT) and crop rotation systems on microbial biomass-C (Cmic), basal soil respiration (BSR), metabolic quotient (qCO2), soil organic carbon content (Corg) and microbial carbon to organic carbon ratio (Cmic/Corg). Soil samples were collected on an area cultivated with wheat as winter crop and soybean as summer crop, both in rotation with vetch, maize and oats. Samples were also collected in a secondary forest used as reference. Data of each management system (NT and CT) were compared to forest area by "t" test (pFoi conduzido um experimento sob condições de campo para avaliar o efeito da forma de manejo do solo (Plantio direto - PD e plantio convencional - PC) e dos sistemas de rotação de culturas sobre o carbono da biomassa microbiana (Cmic), respiração basal do solo (RBS), quociente metabólico (qCO2), carbono orgânico total (Corg) e relação carbono da biomassa microbiana: carbono orgânico total (Cmic/Corg). As amostras de solo foram coletadas em uma área cultivada com trigo como cultura de inverno e soja como cultura de verão, ambas em rotação com ervilhaca, milho e aveia preta. Amostras de solo também foram coletadas em uma floresta secundária usada com referência. Os dados de cada sistema de manejo do solo (PD e PC) foram comparados com a floresta secundária pelo teste "t" (p<0.05) e as rotações de culturas foram comparadas pelo teste de Tukey (p<0.05). Todos os dados foram submetidos a uma análise multivariada (Análise de Componentes Principais - ACP). Foram observadas diferenças significativas (teste "t"; p<0.05) para Cmic, RBS, qCO2 e Cmic/Corg entre PD e PC, em que estes valores foram semelhantes àqueles encontrados na floresta. Entre as rotações de culturas foram observadas diferenças significativas (teste de Tukey; p<0.05) apenas para RBS e qCO2. A análise de componentes principais mostrou que o PD aproximou-se mais da floresta do que o PC, especialmente nos tratamentos em que soja e ervilhaca faziam parte da rotação de culturas antes do trigo. A formação do agrupamento entre floresta e PD ocorreu principalmente devido ao Cmic e à relação Cmic/Corg. Os resultados indicam que o PD apresenta maior sustentabilidade que o PC, podendo contribuir para o acúmulo de uma grande quantidade de carbono no solo.

Enderson Petrônio de Brito Ferreira; Henrique Pereira dos Santos; Janaina Ribeiro Costa; Helvécio De-Polli; Norma Gouvêa Rumjanek

2010-01-01

275

DEFOCUSED OPTICAL ROTATION MEASUREMENT APPARATUS, OPTICAL ROTATION MEASUREMENT METHOD AND DEFOCUSED OPTICAL FIBER SYSTEM  

UK PubMed Central (United Kingdom)

Disclosed are an optical rotation measurement apparatus, an optical rotation measurement system, a polarization conversion optical system and an optical rotation measurement method. The optical rotation measurement apparatus and system can take a real-time measurement of the concentration of glucose in a collected blood sample or a living body without using reagent, and the measurement precision thereof is high enough to be actually used in medical practices. In addition, the optical rotation measurement apparatus and system can measure the concentration of glucose in a living body noninvasively with high precision, and are easy to operate. Furthermore, the polarization conversion optical system is new and can be used in the optical rotation measurement apparatus or system. The optical rotation measurement method is performed by using the optical rotation measurement apparatus or system. A nonreciprocal polarization conversion optical system in which a test sample is held is inserted into an optical fiber ring interferometer. As input/output optical fibers for the nonreciprocal polarization conversion optical system, optical fibers, each of which is fabricated by connecting single-mode optical fibers to one another through a mode matching unit, are used. One of the single-mode optical fibers has a small core diameter and high NA and functions as a transmission portion, and the other thereof has a large core diameter and low NA and functions as an input/output portion. An end of each input/output optical fiber is not positioned at the focal point of a lens. Thus, the fiber end is positioned at the defocused location.

KAJIOKA HIROSHI

276

Elevated atmospheric CO? effects on biomass production and soil carbon in conventional and conservation cropping systems  

UK PubMed Central (United Kingdom)

Increasing atmospheric CO2 concentration has led to concerns about potential effects on production agriculture as well as agriculture's role in sequestering C. In the fall of 1997, a study was initiated to compare the response of two crop management systems (conventional and conservation) to elevated CO2. The study used a split-plot design replicated three times with two management systems as main plots and two CO2 levels (ambient=375 ?L L-1 and elevated CO2=683 ?L L-1) as split-plots using open-top chambers on a Decatur silt loam (clayey, kaolinitic, thermic Rhodic Paleudults). The conventional system was a grain sorghum (Sorghum bicolor (L.) Moench.) and soybean (Glycine max (L.) Merr.) rotation with winter fallow and spring tillage practices. In the conservation system, sorghum and soybean were rotated and three cover crops were used (crimson clover (Trifolium incarnatum L.), sunn hemp (Crotalaria juncea L.), and wheat (Triticum aestivum L.)) under no-tillage practices. The effect of management on soil C and biomass responses over two cropping cycles (4 years) were evaluated. In the conservation system, cover crop residue (clover, sunn hemp, and wheat) was increased by elevated CO2, but CO2 effects on weed residue were variable in the conventional system. Elevated CO2 had a greater effect on increasing soybean residue as compared with sorghum, and grain yield increases were greater for soybean followed by wheat and sorghum. Differences in sorghum and soybean residue production within the different management systems were small and variable. Cumulative residue inputs were increased by elevated CO2 and conservation management. Greater inputs resulted in a substantial increase in soil C concentration at the 0-5 cm depth increment in the conservation system under CO2-enriched conditions. Smaller shifts in soil C were noted at greater depths (5-10 and 15-30 cm) because of management or CO2 level. Results suggest that with conservation management in an elevated CO2 environment, greater residue amounts could increase soil C storage as well as increase ground cover.

Prior SA; Runion GB; Rogers HH; Torbert HA; Reeves DW

2005-04-01

277

Prototype Geographic Information Systems Mapping of Crop Products Featured Local  

Directory of Open Access Journals (Sweden)

Full Text Available Local featured program in Indonesia cannot be separated entirely from commodity strategic bases. Until in 2006, agricultural development formulation showed indicative targets for featured crops commodity production. The problem of food security is forming of farmer’s independence to protect local resources in efficiently and optimally, so these resources can be more utilized. It can be achieved by assist of information technologies and communication in forming of Geographic Information System (GIS) to support consistency of food security in Indonesia. This research designs prototype geographic information system in order to conduct the accurate mapping and to know the local featured crops production in Indonesia. This level is conducted for documentation and mapping of agricultural products which is the local featured production. This documentation requires the usage of potential physical, economic, social and cultural environment by the utilization of information technology and communication, which have the ability of relevancy and accessibility of reliable information.

Teddy Oswari; Euphrasia Susy Suhendra; Emy Haryatmi; Fenni Agustina

2013-01-01

278

Agrobiodiversity of Field Crops: A Case Study for Iran.  

UK PubMed Central (United Kingdom)

Agrobiodiversity of field crops in Iran was studied at the cropping system, crop species, and crop variety levels using the data collected from 183 counties in 27 provinces. Two wheat-based and rice-based cropping systems were studied. While the rice-based system is limited to a narrow strip of land adjacent to the Caspian Sea, the wheat-based system is dominant in other parts of the country. The cropping intensity index (CII) of the whole country was 0.74, with higher values in the Caspian Sea basin and lowest values in the central and southern regions. Crop rotation indices (CRI) and crop rotation diversity indices (CRDI) were low in all provinces, indicating that crop rotation was either not practiced or was done using very short-sequenced rotations. The Shannon index for crop species diversity was low, ranging between 0.8 and 1.97, with the highest and the lowest values for forage crops and cereals, respectively. ?-and ?-diversity, estimated from species-area curves, varied considerably between provinces, depending on their climatic homogeneity. The Margalef index for varietal richness varied from 1.7 for rice to 0.3 for rainfed wheat. In general, 25% to 30% of the total varieties accounted for 70% to 85% of the total cultivated area of each crop. Intensive use of a limited number of varieties has led to strong inter-provincial similarity among the main crop species.

Koocheki Alireza; Nassiri Mehdi; Gliessman StephenR; Zarea Ahmad

2008-01-01

279

The effect of cover crop and crop rotation on soil water storage and on sorghum yield Efeito de cultura de cobertura e de rotação de cultura no armazenamento de água do solo e no rendimento de sorgo  

Directory of Open Access Journals (Sweden)

Full Text Available Crop rotation and cover crop can be important means for enhancing crop yield in rainfed areas such as the lower Coastal Bend Region of Texas, USA. A trial was conducted in 1995 as part of a long-term cropping experiment (7 years) to investigate the effect of oat (Avena sativa L.) cover and rotation on soil water storage and yield of sorghum (Sorghum bicolor L.). The trial design was a RCB in a split-plot arrangement with four replicates. Rotation sequences were the main plots and oat cover crop the subplots. Cover crop reduced sorghum grain yield. This effect was attributed to a reduced concentration of available soil N and less soil water storage under this treatment. By delaying cover termination, the residue with a high C/N acted as an N sink through competition and/or immobilization instead of an N source to sorghum plants. Crop rotation had a significantly positive effect on sorghum yield and this effect was attributed to a significantly larger amount of N concentration under these rotation sequences.Rotação de cultura e cultura de cobertura constituem importantes meios para melhoria do rendimento de culturas em áreas de sequeiro como a região "Coastal Bend" do Estado do Texas. Um ensaio foi conduzido em 1995, como parte de um experimento de longa duração (7 anos), com o objetivo de investigar o efeito da aveia (Avena sativa L.) como cultura de cobertura, e da rotação de cultura, no armazenamento da água do solo e no rendimento do sorgo (Sorghum bicolor L.). O delineamento experimental adotado foi o de blocos ao acaso, em parcelas subdivididas, com quatro repetições. As rotações foram alocadas nas parcelas, e a cultura de cobertura, nas subparcelas. A cultura de cobertura reduziu o rendimento do sorgo. Este efeito foi atribuído à reduzida concentração de N disponível do solo. Por atraso no extermínio e incorporação da aveia, seu resíduo, com elevada relação C/N, atuou como dreno, pela imobilização, em lugar de ser fonte de N para o sorgo. As rotações sorgo/algodão e sorgo/soja proporcionaram efeito positivo no rendimento de sorgo. Este efeito foi atribuído à maior concentração de N nestas seqüências.

Demóstenes Marcos Pedrosa de Azevedo; Juan Landivar; Robson Macedo Vieira; Daryl Moseley

1999-01-01

280

How short rotation forest crops can be used for sustainable remediation of contaminated areas  

Energy Technology Data Exchange (ETDEWEB)

In large territories of the CIS, it becomes obvious from the factual consequences of the Chernobyl environmental contamination that no successful remediation actions can be achieved without considering realistic technical and economical issues. In these conditions, the Short Rotation Forestry concept for energy purposes is proposed as an alternative and integrated approach for the recovery of agricultural practices on waste farm land. This corrective option will be examined with respect to this ecological, economical, and social relevancy. Different aspects of the culture in contaminated areas and of energy production from biomass remain to be investigated, developed and validated in the light of radiation protection criteria. In particular, attention will be drawn on the opportunity of this new concept to be integrated in the development of the site remediation research activities at SCK.CEN.

Thiry, I.

1996-09-18

 
 
 
 
281

Cropping Systems to Improve Carbon Sequestration for Mitigation of Climate Change  

Directory of Open Access Journals (Sweden)

Full Text Available The recent trend of an increase in the concentration of greenhouse gases (GHGs) in the atmosphere has led to an ele-vated concern and urgency to adopt measures for carbon (C) sequestration to mitigate the climate change. Among all GHGs, carbon dioxide (CO2) is the most important one which occurs in the greatest concentration and has the strong-est radiative forcing among all. Reducing the release of CO2 to the atmosphere through “green energy” technologies or fossil fuel energy alternatives, such as wind, solar and hydraulic energies, is a major challenge. However, removal of atmospheric CO2 by terrestrial ecosystems via C sequestration and converting the sequestered C into the soil organic C has provided a great opportunity for shifting GHG emission to mitigate the climate change. Soil is an ideal reservoir for storage of organic C since soil organic C has been depleted due to land misuse and inappropriate management through the long history. To optimize the efficiency of C sequestration in agriculture, cropping systems, such as crop rotation, intercropping, cover cropping, etc., play a critical role by influencing optimal yield, total increased C sequestered with biomass, and that remained in the soil. As matter of fact, soil C sequestration is a multiple purpose strategy. It restores degraded soils, enhances the land productivity, improves the diversity, protects the environment and reduces the enrichment of atmospheric CO2, hence shifts emission of GHGs and mitigates climate change.

Qingren Wang; Yuncong Li; Ashok Alva

2010-01-01

282

Convective Heat and Mass Transfer in Rotating Disk Systems  

CERN Document Server

The book describes results of investigations of a series of convective heat and mass transfer problems in rotating-disk systems, namely, over free rotating disks, under conditions of transient heat transfer, solid- body rotation of fluid, orthogonal flow impingement onto a disk, swirl radial flow between parallel co-rotating disks, in cone-disk systems and for Prandtl and Schmidt numbers larger than unity. Methodology used included integral methods, self-similar and approximate analytical solutions, as well as CFD. The book is aimed at the professional audience of academic researchers, industr

Shevchuk, Igor V

2009-01-01

283

Assessing climate change effects on European crop yields using the Crop Growth Monitoring System and a weather generator  

UK PubMed Central (United Kingdom)

Climate change impacts on potential and rainfed crop yields on the European continent were studied using output of three General Circulation Models and the Crop Growth Monitoring System in combination with a weather generator. Climate change impacts differ per crop type and per CO2 emission scenario. Crops planted in autumn and winter (winter wheat) may benefit from the increasing CO2 concentration. Rainfall is sufficient and if the CO2 concentration increase is high, yields may increase up to 2090. If the CO2 increase is less, increasing temperatures result in declining or stagnating yields after 2050. Crops planted in spring (potato, sugar beet) initially benefit from the CO2 increase, however as time progresses the increasing temperatures reduce these positive effects. By the end of the century yields decline in southern Europe and production may only be possible if enough irrigation water is available. In northern Europe depending on the temperature and CO2 concentration increase, yields either stagnate or decline. However in some of the cooler regions yield increase is still possible. Crops planted in late spring and summer (maize) may suffer from droughts and high temperature in summer. By the end of the century, depending on the temperature rise, crop yields decline almost everywhere. If the temperature increase is less only in north western Europe yields remain stable.

Supit I; van Diepen CA; de Wit AJW; Wolf J; Kabat P; Baruth B; Ludwig F

2012-10-01

284

Net global warming potential and greenhouse gas intensity in irrigated cropping systems in northeastern Colorado.  

UK PubMed Central (United Kingdom)

The impact of management on global warming potential (GWP), crop production, and greenhouse gas intensity (GHGI) in irrigated agriculture is not well documented. A no-till (NT) cropping systems study initiated in 1999 to evaluate soil organic carbon (SOC) sequestration potential in irrigated agriculture was used in this study to make trace gas flux measurements for 3 yr to facilitate a complete greenhouse gas accounting of GWP and GHGI. Fluxes of CO2, CH4, and N2O were measured using static, vented chambers, one to three times per week, year round, from April 2002 through October 2004 within conventional-till continuous corn (CT-CC) and NT continuous corn (NT-CC) plots and in NT corn-soybean rotation (NT-CB) plots. Nitrogen fertilizer rates ranged from 0 to 224 kg N ha(-1). Methane fluxes were small and did not differ between tillage systems. Nitrous oxide fluxes increased linearly with increasing N fertilizer rate each year, but emission rates varied with years. Carbon dioxide efflux was higher in CT compared to NT in 2002 but was not different by tillage in 2003 or 2004. Based on soil respiration and residue C inputs, NT soils were net sinks of GWP when adequate fertilizer was added to maintain crop production. The CT soils were smaller net sinks for GWP than NT soils. The determinant for the net GWP relationship was a balance between soil respiration and N2O emissions. Based on soil C sequestration, only NT soils were net sinks for GWP. Both estimates of GWP and GHGI indicate that when appropriate crop production levels are achieved, net CO2 emissions are reduced. The results suggest that economic viability and environmental conservation can be achieved by minimizing tillage and utilizing appropriate levels of fertilizer.

Mosier AR; Halvorson AD; Reule CA; Liu XJ

2006-07-01

285

Effects of Residue Management and Cropping Systems on Wheat Yield Stability in a Semiarid Mediterranean Clay Soil  

Directory of Open Access Journals (Sweden)

Full Text Available Agriculture is the single biggest user of land and water in Morocco; however its performances are still low due to high rainfall variation and rates of soil productivity depletion. Increasing concerns about soil and environment quality degradation have raised the need to review existing tillage management systems and develop new systems for seed-bed preparation. Consequently, No-tillage is found a promising practice of soil management to improve simultaneously soil quality and wheat production in semiarid Morocco. However, residue management under No-tillage was Not yet studied in conjunction with wheat rotation. Therefore, a field study was conducted in the semiarid Chaouia Plain of Morocco during the period from 1994 to 2003, in order to evaluate the impacts of different tillage practices (conventional tillage (CT), No-tillage (NT)); No-tillage wheat residue management scenarios (total NTr, partial NTp and No-removal of residues NTm) and crop rotations (continuous wheat (CW), Wheat-Fallow (WF), Wheat-Maize-Fallow (WMF), Wheat-Lentil-Fallow (WLF) and Wheat-Barley-Fallow (WBF)) on wheat production. Over-years, conventional tillage system permitted lower yield of wheat while NT maintenance of crop residue at the surface is needed to increase it. Basically, NTp could be adopted in mixed crop-livestock systems of semiarid areas for the purpose of guarantying grain and feed. Wheat yields were the lowest under continuous wheat for all years. Wheat-fallow rotation is an important option in dry years or areas, while wheat-fallow-lentil or barley rotations are recommended in better environments. Stability analysis indicated that yields in the No-tillage system were less influenced by adverse growing conditions than conventional tillage system, particularly under low rainfall. These results indicate that improved soil quality under No-tillage enhanced wheat yield stability by reducing the impact of adverse growing conditions.

Rachid Mrabet

2011-01-01

286

Development of an airborne remote sensing system for crop pest management: System integration and verification  

Science.gov (United States)

Remote sensing along with Global Positioning Systems, Geographic Information Systems, and variable rate technology has been developed, which scientists can implement to help farmers maximize the economic and environmental benefits of crop pest management through precision agriculture. Airborne remo...

287

Desempenho de genótipos de algodoeiro na presença ou não de rotação de cultura com Crotalaria spectabilis, em área infestada com Meloidogyne incognita/ Performance of cotton genotypes in the presence or absence of crop rotation with Crotalaria spectabilis in an area infested with Meloidogyne incognita  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Em área naturalmente infestada com Meloidogyneincognita raça 3, localizada em Primavera do Leste-MT, foi estudado o desempenho de 21 genótipos de algodoeiro com níveis diversos de tolerância ao nematoide, com a adoção ou não de rotação de cultura com Crotalaria spectabilis. De modo geral a rotação diminuiu a severidade dos sintomas exibidos pelas plantas, devidos ao ataque do parasita, e promoveu aumento na produtividade de algodão. Entretanto, seu efeito nã (more) o foi suficiente para tornar eficaz o desempenho de genótipos de baixa tolerância ao nematoide, os quais, mesmo na presença da leguminosa, tiveram notas para sintomas 142% maiores e produtividades de algodão 57% menores do que as cultivares mais tolerantes. Alta correlação entre as médias de produção dos genótipos na seqüência ou não da leguminosa e ausência de interação genótipo x rotação, indicaram que, embora em patamar mais elevado de produção, a tendência de desempenho dos genótipos foi a mesma na presença e na ausência da crotalária. De tal modo que, na média, a produção dos três genótipos mais tolerantes, na ausência de rotação, foi, ainda assim, 48% superior à dos genótipos mais intolerantes, na presença da crotalária. As perdas mínimas possíveis na produção, atribuíveis ao uso de genótipos intolerantes, foram estimadas em 37% na ausência da rotação e em 29% com rotação. Abstract in english In an area naturally infested with Meloidogyne incognita race 3, located in Primavera do Leste, Mato Grosso State, Brazil, the performance of 21 cotton genotypes having different levels of tolerance to this parasitic nematode was studied, in the presence or absence of crop rotation with Crotalaria spectabilis. A general trend was observed for crop rotation to reduce the severity of symptoms exibited by plant sowing to nematode incidence, and lead to increased cotton yield (more) . However, its effect was not sufficient to increase the performance of genotypes with low tolerance to the parasite, which, even under the crop rotation schem, had disease sympton rates that were 142% higher and cotton yields that were 57% lower than those obtained for more tolerant genotypes. High correlation between average yield in the presence or absence of crop rotation, and absence of interaction between genotype and crop rotation, indicated that, although at higher yield level being achieved, the tendency of genotype performance remained the same in both systems. The yield of the three more tolerant genotypes in the absence of crop rotation was 48% superior to that of the three least tolerant genotypes under crop rotation. The minimum possible losses, attributable to the use of susceptible genotypes, were estimated at 37% and 29%, respectively, without crop rotation being used or under conditions of crop rotation.

Galbieri, Rafael; Fuzatto, Milton G.; Cia, Edivaldo; Welter, Adinara M.; Fanan, Sheila

2011-10-01

288

Influence of Cropping Systems on Soil Aggregate and Weed Seedbank Dynamics During the Organic Transition Period  

UK PubMed Central (United Kingdom)

Agronomic management during the 3-yr transition period to organic certification influences soil quality and the weed seedbank. We studied two cropping systems during the transition period and the first certified organic season. A 4-yr rotation of corn, soybean, wheat/alfalfa, corn (C-S-W/A-C) [Zea mays L., Glycine max (L.) Merr., Triticum aestivum L., Medicago sativa L.], produced under a more complex management that included manure and cover crop residue, was compared to a perennial based corn, alfalfa, alfalfa, corn (C-A-A-C) rotation. We compared soil aggregate size distribution and bulk density after Year 1 and on completion of the transition period. Weed seedbank populations were quantified through two seasons in the greenhouse. Weed surface density and aboveground weed biomass were quantified in the field. Over the course of the study, the percentage of large soil macroaggregates (>2000 ?m size class) had 2.7 and 3.4-fold increase for the C-A-A-C and C-S-W/A-C treatments, respectively. The C-S-W/A-C system generated a 4.5-fold increase in aggregates of this class when wheat that was interseeded with alfalfa was harvested as forage. Bulk density decreased 14 and 6% for the C-S-W/A-C and the C-A-A-C systems, respectively. There was a 60 to nearly 300% increase in total weed seeds germinated in the greenhouse for the C-S-W/A-C system. This same system had a 60 to more than 500% decreased weed seedbank density in the field. We conclude from this study that either strategy can improve soil quality while the weed seedbank was better managed in the more complicated C-S-W/A-C system.

Corbin AndrewT; Thelen KurtD; Robertson GP; Leep RichardH

2010-11-01

289

Demanda de tração em haste sulcadora na integração lavoura-pecuária com diferentes pressões de pastejo e sua relação com o estado de compactação do solo Draft requirement in direct drilling in crop and cattle rotation systems using different grazing pressures and its relation to soil compactness status  

Directory of Open Access Journals (Sweden)

Full Text Available Conduziu-se um experimento com integração lavoura-pecuária em Latossolo Vermelho distroférrico para avaliar o esforço de tração em hastes sulcadoras de adubo utilizadas em semeadura direta, atuando em diferentes profundidades e intensidades de pastejo, bem como o efeito desse último fator sobre o estado de compactação do solo. Os tratamentos principais foram constituídos pelas alturas da pastagem de inverno (aveia + azevém): 0,10; 0,20; 0,30 e 0,40 m e sem pastejo, obtidas variando-se a carga animal, e os tratamentos secundários foram duas profundidades de atuação da haste sulcadora de adubo: 0,12 e 0,15 m. A massa seca de raízes da pastagem, na camada de 0 a 0,12 m, aumentou com o incremento na intensidade de pastejo. Analisando os valores de resistência mecânica do solo à penetração, o efeito do pastejo foi detectado até 0,12 m, sendo crescentes com a intensidade de pastejo. A força de tração demandada pelas hastes aumentou de 1.900 para 4.300 N (120%), quando a profundidade de trabalho passou de 0,12 para 0,15 m. O esforço de tração nas hastes sulcadoras também foi maior quanto maior a carga de animais sobre a pastagem, embora as diferenças tenham sido significativas apenas entre os tratamentos sem pastejo e os mantidos a alturas de 0,10 e 0,20 m. Os valores de resistência do solo à penetração e de esforço de tração demandado pelas hastes sulcadoras apresentaram correlação significativa.An experiment was carried out with crop and cattle rotation in an Oxisoil, in Tupanciretã - RS, which aimed to evaluate the draft effort in fertilizer direct drillings used in direct seeding, working at different depths and intensities of fields under different grazing pressures. Grazing pressure effects on soil compactness were also assessed. The main treatments were grazing maintaining 0.10, 0.20, 0.30, 0.40 m pasture (Lolium multiflorum + Avena strigosa) without grazing, height (adjusting the number of cows on the plots) and two working depths of fertilizer shanks: 0.12 m and 0.15 m. Root dry matter in the superficial layer (0.0 - 0.12 m) was increased when higher grazing pressures were used. Soil resistance to a penetrometer showed increased values at higher grazing pressures; it was detected until 0.12 m depth. Draft requirement of fertilizer shanks increased from 1,900 to 4,300 N (120%) when the working depth changed from 0.12 m to 0.15 m condition. Draft demand by fertilizer shanks was higher on soils under higher pressures as well, but the absolute values showed that only treatments with remaining heights of 0.10 and 0.20 m were different from those found without grazing systems. Soil resistance to penetrometer and power demand by fertilizer shanks was closely related.

Osmar Conte; Renato Levien; Carlos R. Trein; Carla T. C. Cepik; Henrique Debiasi

2007-01-01

290

Organic and Conventional Production Systems in the Wisconsin Integrated Cropping Systems Trial: II. Economic and Risk Analysis 1993-2006  

UK PubMed Central (United Kingdom)

This article, the second in a series looking at the Wisconsin Integrated Cropping Systems Trial (WICST), reports on the profitability of six conventional and organic systems, with a focus on net returns and associated risk exposure. Several pricing scenarios were compared to evaluate the impact of government programs and organic price premiums. When net return estimates are made using only neighboring elevator prices (no government programs or organic price premiums), we found that the no-till corn-soybean system [Zea mays L. and Glycine max (L.) Merr.] was the most profitable grain system, and management intensive rotational grazing (MIRG) the most profitable forage system. When government programs and organic price premiums are included, returns increased by 85 to 110% for the organic grain system (corn-soybean-wheat + red clover (Triticum aestivum L. + Trifolium pratense L.) and 35 to 40% for the organic forage system [companion seeded alfalfa with oat + field pea (Medicago sativa L., Avena sativa L., and Pisum sativum L.), hay, and then corn]. This places both organic systems with higher returns than any of the Midwestern standards of no-till corn-soybean, continuous corn, or intensive alfalfa production. Also, the results indicate how risk exposure varied across systems. Interestingly, taking risk into consideration did not drastically affect the ranking among those systems. Our analysis shows that, under the market scenarios that prevailed between 1993 and 2006, intensive rotational grazing and organic grain and forage systems were the most profitable systems on highly productive land in southern Wisconsin.

Chavas Jean-Paul; Posner JoshuaL; Hedtcke JanetL

2009-03-01

291

A methodological approach for deriving regional crop rotations as basis for the assessment of the impact of agricultural strategies using soil erosion as example.  

Science.gov (United States)

Regarding increasing pressures by global societal and climate change, the assessment of the impact of land use and land management practices on land degradation and the related decrease in sustainable provision of ecosystem services gains increasing interest. Existing approaches to assess agricultural practices focus on the assessment of single crops or statistical data because spatially explicit information on practically applied crop rotations is mostly not available. This provokes considerable uncertainties in crop production models as regional specifics have to be neglected or cannot be considered in an appropriate way. In a case study in Saxony, we developed an approach to (i) derive representative regional crop rotations by combining different data sources and expert knowledge. This includes the integration of innovative crop sequences related to bio-energy production or organic farming and different soil tillage, soil management and soil protection techniques. Furthermore, (ii) we developed a regionalization approach for transferring crop rotations and related soil management strategies on the basis of statistical data and spatially explicit data taken from so called field blocks. These field blocks are the smallest spatial entity for which agricultural practices must be reported to apply for agricultural funding within the frame of the European Agricultural Fund for Rural Development (EAFRD) program. The information was finally integrated into the spatial decision support tool GISCAME to assess and visualize in spatially explicit manner the impact of alternative agricultural land use strategies on soil erosion risk and ecosystem services provision. Objective of this paper is to present the approach how to create spatially explicit information on agricultural management practices for a study area around Dresden, the capital of the German Federal State Saxony. PMID:23751946

Lorenz, Marco; Fürst, Christine; Thiel, Enrico

2013-06-07

292

Phase considerations in a rotating system  

International Nuclear Information System (INIS)

A neutron interferometer in constant absolute rotation will exhibit a certain phase-shift between its two beams, a phenomenon shared with the classic Sagnac or Michelson-Gale-Pearson experiments or with the modern laser-gyrocompass composed of lasers in a ring. To first order in the rotational frequency, it is possible to understand by employing only rudimentary theory, the essence of this phenomenon to any degree of relativistiness of the participating particle. This paper is mainly paedagogical, noting the similarity due to permanent rotation between photon-, electron and neutron-interferometers. Future experimentation, aside from corroborating well believed tenets, may hope with improving precision to bring new approaches to measurement of fundamental effects

1978-06-07

293

Plant nutrient and water balance studies under legume-cereal rotation systems  

International Nuclear Information System (INIS)

[en] A two-year cycle of crop rotation experiments with at least three main treatments of cereal-cereal, legume-cereal and fallow-cereal treatments was outlined. The water balance approach was utilized to estimate crop water consumption and to compare different crop rotation systems, in view of water conservation and of increasing efficient use of scarcely available water under rainfed areas of Middle-Eastern Countries, with low and erratic rainfall characteristics. The use of the neutron scattering technique was recommended for easy monitoring of changes in soil water storage, as one of the key field data required in the water balance equation. The use of 15N-labelled fertilizers provided a unique tool allowing to separately study the behaviour of N-fertilizer as well as soil N. In addition, the quantification of residual fertilizer N was possible. Also, the use of labelled N allowed to quantify the amount of biologically fixed N2. (author). 7 refs, 4 figs, 1 tab

1996-01-01

294

Soil carbon, after 3 years, under short-rotation woody crops grown under varying nutrient and water availability.  

Energy Technology Data Exchange (ETDEWEB)

Abstract Soil carbon contents were measured on a short-rotation woody crop study located on the US Department of Energy’s Savannah River Site outside Aiken, SC. This study included fertilization and irrigation treatments on five tree genotypes (sweetgum, loblolly pine, sycamore and two eastern cottonwood clones). Prior to study installation, the previous pine stand was harvested and the remaining slash and stumps were pulverized and incorporated 30 cm into the soil. One year after harvest soil carbon levels were consistent with preharvest levels but dropped in the third year below pre-harvest levels. Tillage increased soil carbon contents, after three years, as compared with adjacent plots that were not part of the study but where harvested, but not tilled, at the same time. When the soil response to the individual treatments for each genotype was examined, one cottonwood clone (ST66), when irrigated and fertilized, had higher total soil carbon and mineral associated carbon in the upper 30 cm compared with the other tree genotypes. This suggests that root development in ST66 may have been stimulated by the irrigation plus fertilization treatment.

Sanchez, Felipe, G.; Coleman, Mark; Garten, Charles, T., Jr.; Luxmoore, Robert, J.; Stanturf, John, A.; Wullschleger, Stan, D.

2007-07-01

295

Effect of Cropping System and Contouring or Download Sowing on Soil Water Erosion under no Tillage  

Science.gov (United States)

Water erosion is the main responsible factor of soil and water losses, thus also causing soil degradation, especially on agricultural land, and it is also one factor of degradation outside the place of the origin of erosion. No tillage agriculture has been practiced in the last few decades for the purposes of water erosion control in various regions of Brazil. However, it has been shown that no tillage does not adequately control water erosion unless other complementary conservationist practices such as contour tillage or terracement. Although the erosion problem is widely recognized, there are still difficulties in estimating their magnitude, the environmental impact and the economic consequences, especially when it occurs in a conservation system like no tillage. The aim of this study was to quantify runoff and soil losses by water erosion under five different soil tillage treatments at Santa Catarina State, Southern Brazil. A field study was carried out using a rotating-boom rainfall simulator with 64 mmh-1 rainfall intensity for 90 minutes. Four rainfall tests were applied over the experimental period, one in each of the successive soybean and maize crop stages. Both soil cover by surface crop residue and soil cover by soybean and maize plant canopy were measured immediately before each rainfall test. Soil and water losses were smaller when sowing in contour than when sowing downslope. Contouring has promoted an average reduction of 42% in soil losses and 20% in water losses. Maize crop has promoted an average reduction of 19% in soil losses and 12% in water losses, in relation to the soybean crop. Therefore runoff rates and soil losses were higher in the downslope plots and in the soybean crop. Soil cover by previous crop residue was an important factor for reducing soil losses. Runoff rates were influenced by the soil water content before each rainfall test (R2= 0.78). The highest runoff occurred during the third simulated rainfall test, with the 83% of the total rain applied; immediately before the test the soil moisture was 36%. The smallest losses occurred in the fourth test, with 55% of the total rain applied where the soil moisture immediately before the rainfall test was 25%.

Marioti, J.; Padilha, J.; Bertol, I.; Barbosa, F. T.; Ramos, J. C.; Werner, R. S.; Vidal Vázquez, E.; Tanaka, M. S.

2012-04-01

296

Influência do manejo do solo e da rotação de culturas na qualidade industrial do trigo Influence of soil management and crop rotation on characteristics that define the industrial quality of wheat  

Directory of Open Access Journals (Sweden)

Full Text Available A qualidade industrial do trigo é afetada por fatores genéticos e ambientais, como solo, clima, tratos culturais, e outros. O presente trabalho teve como finalidade avaliar o efeito de sistemas de manejo de solo e de rotação de culturas sobre características que definem a qualidade industrial de trigo (peso do hectolitro, peso de mil grãos, extração experimental de farinha, alveografia, teste de microssedimentação com lauril sulfato de sódio e número de queda). O delineamento experimental foi em blocos ao acaso, com parcelas subdivididas e três repetições. A parcela principal foi constituída pelos sistemas de manejo de solo (plantio direto, preparos convencionais de solo com arado de discos e de aivecas, e cultivo mínimo), e a subparcela, pelos sistemas de rotação de culturas (monocultura, um inverno e dois invernos sem trigo). O preparo convencional de solo com arado de discos e o cultivo mínimo reduziu o número de queda; o sistema de rotação com dois invernos sem trigo elevou o peso do hectolitro; a monocultura desse cereal reduziu o peso do hectolitro, elevou a força geral de glúten e a microssedimentação com lauril sulfato de sódio; a interação sistemas de manejo de solo, rotação de culturas e ano de cultivo afetou o peso de mil grãos e, o ano de cultivo teve grande influência em todas as características de qualidade industrial de trigo estudadas.Wheat quality is affected by genetic and environmental factors such as soil, climate and cultural traits. The objective of this study was to evaluate the effect of soil management and crop rotation systems on characteristics that define wheat industrial quality (hectoliter weight, thousand-kernel weight, milling quality, alveograph characteristics, sodium dodecyl sulphate microsedimentation test and falling number). The experimental design used was in complete randomized blocks, with split plots and three replications. Main plot consisted of the soil management systems (no-tillage system, conventional tillage with disc and moldboard plough and minimum tillage) and the subplot consisted of the crop rotation systems (monoculture, one winter and two winters without wheat). Conventional soil preparations with discs' plough reduced the falling number; the crop rotation systems with two winters without wheat increased the hectoliter weight; the monoculture of this cereal reduced the hectoliter weight, increased the gluten strength and the values obtained in the microsedimentation test with sodium lauril sulphate; the interaction of soil management, crop rotation system and year of management affected the weight of one-thousand grains and the year of cultivation had great influence in all characteristics of the industrial quality of wheat.

ELIANA MARIA GUARIENTI; HENRIQUE PEREIRA DOS SANTOS; JÚLIO CÉSAR BARRENECHE LHAMBY

2000-01-01

297

Efeitos do preparo do solo, plantio direto e de rotações de culturas sobre o rendimento e a economicidade do feijoeiro irrigado/ Agronomic effect of soil tillage, no-tillage and crop rotation on yield of irrigated common bean  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O objetivo deste trabalho foi identificar os efeitos de sistemas de preparo do solo e de rotações de culturas sobre o rendimento de grãos e economicidade da cultura do feijoeiro (Phaseolus vulgaris L.) irrigado pelo sistema pivô central. O trabalho foi conduzido durante seis anos consecutivos, na Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, localizado no Município de Santo Antônio de Goiás, GO, em Latossolo Vermelho-Escuro, de textura argilosa. O experim (more) ento consistiu de um fatorial 4 x 6, em delineamento inteiramente casualizado, com parcelas subdivididas. Os sistemas de preparo do solo foram: P1 arado de aiveca (novembro-dezembro) alternado com grade aradora (maio-junho); P2 arado de aiveca contínuo; P3 grade aradora contínua; P4 plantio direto; e as rotações de culturas: R1 arroz-feijão; R2 milho-feijão; R3 soja-trigo, R4 soja-trigo-soja-feijão-arroz-feijão; R5 arroz consorciado com calopogônio-feijão; e R6 milho-feijão-milho-feijão-arroz -feijão. As rotações R1, R2, R3 e R5 foram anuais, e as R4 e R6, trienais. Neste trabalho analisaram-se somente as rotações que continham feijão. O arroz, o milho e a soja foram semeados em novembro-dezembro (verão), e o feijão e o trigo, em maio-junho (inverno). Houve efeito do preparo do solo e das rotações de cultura sobre o rendimento de grãos do feijoeiro. A cultura produziu mais quando se utilizou no preparo do solo a combinação de arado de aiveca, nos cultivos de verão, e grade aradora nos de inverno. Os rendimentos do feijoeiro foram maiores quando a cultura foi implantada bienalmente na mesma área, nas rotações com arroz/calopogônio e arroz, e menores, nas rotações com milho. O feijoeiro irrigado, com relação ao preparo do solo e rotações de culturas, foi economicamente viável, propiciando taxas de retorno que variaram de 67% a 97%. Abstract in english The objective of this study was to evaluate the agronomic effect of soil tillage and crop rotation on grain yield of common bean (Phaseolus vulgaris L.) irrigated by central pivot. The study was conducted at the Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, in a Dark-Red Latosol with clay texture, during six consecutive years. Basic experiment was a 4 x 6 factorial, having a completely randomized block design with subdivided plots. Soil tillage systems were: P1 (more) moldboard plough (November-December), alternated with harrow disc (May-June); P2 moldboard plough; P3 harrow disc, and P4 no-tillage. The crop rotations used were: R1 rice-common bean; R2 corn-common bean; R3 soybean-wheat; R4 soybean-wheat-soybean-common bean-rice-common bean; R5 rice associated with Calopogonium mucunoides-common bean; and R6 corn-common bean-corn-common bean-rice-common bean. The crop rotations R1, R2, R3, and R5 were annual and R4 and R6 were triennial; in this study, only rotations with common bean were evaluated. Rice, corn and soybean were sown in November/December (summer) and common bean and wheat in May/June (winter). Grain yield of common bean was influenced by soil tillage and crop rotation. Yield was higher under soil prepared with moldboard plough in combination with summer sowing and prepared with harrow disc in winter sowing. Common bean grain yield was higher when biannual sowing was done in the same area in rotation with rice/C. mucunoides and rice, and lower in rotation with corn. Irrigated common bean crop was economically viable as a function of soil tillage and crop rotation and economic return varied from 67% to 97%.

Silveira, Pedro Marques da; Silva, Osmira Fátima da; Stone, Luis Fernando; Silva, José Geraldo da

2001-02-01

298

Efeitos do preparo do solo, plantio direto e de rotações de culturas sobre o rendimento e a economicidade do feijoeiro irrigado Agronomic effect of soil tillage, no-tillage and crop rotation on yield of irrigated common bean  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi identificar os efeitos de sistemas de preparo do solo e de rotações de culturas sobre o rendimento de grãos e economicidade da cultura do feijoeiro (Phaseolus vulgaris L.) irrigado pelo sistema pivô central. O trabalho foi conduzido durante seis anos consecutivos, na Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, localizado no Município de Santo Antônio de Goiás, GO, em Latossolo Vermelho-Escuro, de textura argilosa. O experimento consistiu de um fatorial 4 x 6, em delineamento inteiramente casualizado, com parcelas subdivididas. Os sistemas de preparo do solo foram: P1 arado de aiveca (novembro-dezembro) alternado com grade aradora (maio-junho); P2 arado de aiveca contínuo; P3 grade aradora contínua; P4 plantio direto; e as rotações de culturas: R1 arroz-feijão; R2 milho-feijão; R3 soja-trigo, R4 soja-trigo-soja-feijão-arroz-feijão; R5 arroz consorciado com calopogônio-feijão; e R6 milho-feijão-milho-feijão-arroz -feijão. As rotações R1, R2, R3 e R5 foram anuais, e as R4 e R6, trienais. Neste trabalho analisaram-se somente as rotações que continham feijão. O arroz, o milho e a soja foram semeados em novembro-dezembro (verão), e o feijão e o trigo, em maio-junho (inverno). Houve efeito do preparo do solo e das rotações de cultura sobre o rendimento de grãos do feijoeiro. A cultura produziu mais quando se utilizou no preparo do solo a combinação de arado de aiveca, nos cultivos de verão, e grade aradora nos de inverno. Os rendimentos do feijoeiro foram maiores quando a cultura foi implantada bienalmente na mesma área, nas rotações com arroz/calopogônio e arroz, e menores, nas rotações com milho. O feijoeiro irrigado, com relação ao preparo do solo e rotações de culturas, foi economicamente viável, propiciando taxas de retorno que variaram de 67% a 97%.The objective of this study was to evaluate the agronomic effect of soil tillage and crop rotation on grain yield of common bean (Phaseolus vulgaris L.) irrigated by central pivot. The study was conducted at the Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, in a Dark-Red Latosol with clay texture, during six consecutive years. Basic experiment was a 4 x 6 factorial, having a completely randomized block design with subdivided plots. Soil tillage systems were: P1 moldboard plough (November-December), alternated with harrow disc (May-June); P2 moldboard plough; P3 harrow disc, and P4 no-tillage. The crop rotations used were: R1 rice-common bean; R2 corn-common bean; R3 soybean-wheat; R4 soybean-wheat-soybean-common bean-rice-common bean; R5 rice associated with Calopogonium mucunoides-common bean; and R6 corn-common bean-corn-common bean-rice-common bean. The crop rotations R1, R2, R3, and R5 were annual and R4 and R6 were triennial; in this study, only rotations with common bean were evaluated. Rice, corn and soybean were sown in November/December (summer) and common bean and wheat in May/June (winter). Grain yield of common bean was influenced by soil tillage and crop rotation. Yield was higher under soil prepared with moldboard plough in combination with summer sowing and prepared with harrow disc in winter sowing. Common bean grain yield was higher when biannual sowing was done in the same area in rotation with rice/C. mucunoides and rice, and lower in rotation with corn. Irrigated common bean crop was economically viable as a function of soil tillage and crop rotation and economic return varied from 67% to 97%.

Pedro Marques da Silveira; Osmira Fátima da Silva; Luis Fernando Stone; José Geraldo da Silva

2001-01-01

299

Classification of the field drainage and wetness by using aerial photographs in irrigated paddy rice and upland crop rotation field  

Science.gov (United States)

Information about field drainage/wetness is useful for farmers to plan field management in irrigated paddy rice and upland crop rotation field. Wet injury is a loss to farmers in upland crop farming, experience is the most common way of approaching this risk. In this study, we propose to provide efficient and objective classify and mapping method of such field drainage information using aerial photography. Study area (500 ha) is located in Ibaraki Prefecture, Japan. In this area, we acquired multitemporalaerial photographs (ADS40) three times after the rain on winter. Digital Number (DN) of Blue, Green, Red and Near Infrared band were used to analyze. To analyze the relationship between each band DN and soil moisture, mass soil water content of 0-5cm depth was determined using the 100ml core sample at 22 sites on shooting date. And to verify our classification of the drainage and wetness, volumetric soil water content was monitored using TDR sensor (Decagon, ECH2O) at 5cm, 10cm and 20 cm depth at 16 sites. First, optimum band was selected from correlation analysis of mass soil water content and DN. Next, optimum band DN of three aerial photographs at field area was grouped by cluster analysis (ISODATA method). We found a good positive correlation between mass soil water content and red band DN, by selecting optimum bands. 17 groups were found from cluster analysis using three aerial photographs with different soil moisture conditions. After that, we classified them into five levels of field drainage based on red band DN values. We generated maps of drainage/wetness based on these results. We compared volumetric soil water content at the monitoring site for the "Dry" and "Wet" points, water was drained quickly at the "Dry" site but it needed more than 1 week the volume soil water content back to revert before rain at the "Wet" site. By the result, we positively verified our classification. We used three aerial photographs with different soil moisture conditions as proxy of top soil moisture content. It is thought to be an indication of drainage/wetness. Generally, estimating soil water content at field scale from a remote sensing data was difficult. But this method can classify the study area relatively. We think it is enough as a soil information for farmers.

Ritsuko, Fuchiyama; Takeshi, Ota; Michikazu, Fukuhara

2013-04-01

300

Comparative acute toxicity of neonicotinoid and pyrethroid insecticides to non-target crayfish (Procambarus clarkii) associated with rice-crayfish crop rotations.  

UK PubMed Central (United Kingdom)

BACKGROUND: Most insecticides used to control rice water weevil (Lissorhoptrus oryzophilus Kuscel) infestations are pyrethroids. However, pyrethroids are highly toxic to non-target crayfish associated with rice-crayfish crop rotations. One solution to the near-exclusive reliance on pyrethroids in a rice-crayfish pest management program is to incorporate neonicotinoid insecticides, which are insect specific and effective against weevils but not extremely toxic to crayfish. This study aimed to take the first step to assess neonicotinoids as alternatives to pyrethroids in rice-crayfish crop rotations by measuring the acute toxicities of three candidate neonicotinoid insecticides, clothianidin, dinotefuran and thiamethoxam, to juvenile Procambarus clarkii (Girard) crayfish and comparing them with the acute toxicities of two currently used pyrethroid insecticides, lambda-cyhalothrin and etofenprox. RESULTS: Neonicotinoid insecticides are at least 2-3 orders of magnitude less acutely toxic (96 h LC(50)) than pyrethroids to juvenile Procambarid crayfish: lambda-cyhalothrin (0.16 microg AI L(-1)) = etofenprox (0.29 microg AI L(-1)) >> clothianidin (59 microg AI L(-1)) > thiamethoxam (967 microg AI L(-1)) > dinotefuran (2032 microg AI L(-1)). CONCLUSION: Neonicotinoid insecticides appear to be much less hazardous alternatives to pyrethroids in rice-crayfish crop rotations. Further field-level neonicotinoid acute and chronic toxicity testing with crayfish is needed.

Barbee GC; Stout MJ

2009-11-01

 
 
 
 
301

Size and composition of weed seedbank in long-term organic and conventional low-input cropping systems  

UK PubMed Central (United Kingdom)

Long-term effects of organic (ORG) and conventional low-input (CONV) farming systems on size and composition of weed seedbank were assessed in 2007 in central Italy, in an on-farm experiment set up in 1996. In this experiment, six rotations (R1–R6) were considered, basically consisting on the same crop sequence with different starting points, i.e. (1) legume crop (soybean/field bean/common pea), (2) vegetable crop (pepper/melon), (3) winter cereal (soft/durum wheat), (4) summer cereal (maize) (5) industrial vegetable (processing tomato), (6) winter cereal (soft/durum wheat). All rotations were established both in ORG and in CONV, in strict adherence to EU regulations (ORG: EU reg. 2092/91; CONV: EU reg. 2078/92). Intercrops with green manuring purposes were included in ORG, while weed control was performed mechanically in ORG and chemically/mechanically in CONV. Weed seedbank was determined on 10 soil samples (0–0.30m depth) in each plot and seeds were directly extracted, identified and counted. In all rotations, the adoption of ORG resulted in a significant increase in weed seedbank density, particularly in the case of summer weed species (Portulaca oleracea L., Amaranthus retroflexus L. and Chenopodium album L.), which are more competitive and difficult to control in summer crops under organic farming systems in the Mediterranean climates. Small differences between ORG and CONV were found in terms of number of weed species (23 in ORG and 20 in CONV, on average), but the index of diversity in CONV was on average higher than in ORG. Furthermore, the most dominant weeds in CONV represented a lower percentage of total seedbank (40%, 23% and 5%, respectively, for P. oleracea, A. retroflexus and C. album in CONV and 56%, 32% and 4% for the same three weeds in ORG). These results confirm that the wider availability of effective weed control methods in integrated low-input farming systems (CONV) is helpful to maintain a low seedbank size, with a lower dominance structure. However, the adoption of ORG systems based on long rotation cycles, very competitive crops and accurate weed control, especially at the beginning of the ORG management, may be sustainable in the long run, in terms of potential weed infestation levels.

Graziani F; Onofri A; Pannacci E; Tei F; Guiducci M

2012-05-01

302

Energy crops for biogas plants. Mecklenburg-Western Pomerania; Energiepflanzen fuer Biogasanlagen. Mecklenburg-Vorpommern  

Energy Technology Data Exchange (ETDEWEB)

For agriculturists in Mecklenburg-Western Pomerania (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

Aurbacher, J.; Bull, I.; Formowitz, B. (and others)

2012-06-15

303

Energy crops for biogas plants. Saxony-Anhalt; Energiepflanzen fuer Biogasanlagen. Sachsen-Anhalt  

Energy Technology Data Exchange (ETDEWEB)

For agriculturists in Saxony-Anhalt (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

Boese, L.; Buttlar, C. von; Boettcher, K. (and others)

2012-07-15

304

Energy crops for biogas plants. Baden-Wuerttemberg; Energiepflanzen fuer Biogasanlagen. Baden-Wuerttemberg  

Energy Technology Data Exchange (ETDEWEB)

For agriculturists in Baden-Wuerttemberg (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

Butz, A.; Heiermann, M.; Herrmann, C. [and others

2013-05-01

305

Environmental assessment of two different crop systems in terms of biomethane potential production.  

UK PubMed Central (United Kingdom)

The interest in renewable energy sources has gained great importance in Europe due to the need to reduce fossil energy consumption and greenhouse gas emissions, as required by the Renewable Energy Directive (RED) of the European Parliament. The production of energy from energy crops appears to be consistent with RED. The environmental impact related to this kind of energy primarily originates from crop cultivation. This research aimed to evaluate the environmental impact of different crop systems for biomass production: single and double crop. The environmental performances of maize and maize plus wheat were assessed from a life cycle perspective. Two alternative scenarios considering different yields, crop management, and climatic conditions, were also addressed. One normal cubic metre of potential methane was chosen as a functional unit. Methane potential production data were obtained through lab experimental tests. For both of the crop systems, the factors that have the greatest influence on the overall environmental burden are: fertilizer emissions, diesel fuel emissions, diesel fuel production, and pesticide production. Notwithstanding the greater level of methane potential production, the double crop system appears to have the worse environmental performance with respect to its single crop counterpart. This result is due to the bigger quantity of inputs needed for the double crop system. Therefore, the greater amount of biomass (silage) obtained through the double crop system is less than proportional to the environmental burden that results from the bigger quantity of inputs requested for double crop.

Bacenetti J; Fusi A; Negri M; Guidetti R; Fiala M

2013-08-01

306

An ultrasonic system for weed detection in cereal crops.  

Science.gov (United States)

Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index) computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were assessed by discriminant analysis. The ultrasonic readings permitted the separation between weed infested zones and non-infested areas with up to 92.8% of success. This system will potentially reduce the cost of weed detection and offers an opportunity to its use in non-selective methods for weed control. PMID:23443401

Andújar, Dionisio; Weis, Martin; Gerhards, Roland

2012-12-13

307

Integrated soil-crop system management: reducing environmental risk while increasing crop productivity and improving nutrient use efficiency in China.  

UK PubMed Central (United Kingdom)

During the past 47 yr (1961-2007), Chinese cereal production has increased by 3.2-fold, successfully feeding 22% of the global human population with only 9% of the world's arable land, but at high environmental cost and resource consumption. Worse, crop production has been stagnant since 1996 while the population and demand for food continue to rise. New advances for sustainability of agriculture and ecosystem services will be needed during the coming 50 yr to reduce environmental risk while increasing crop productivity and improving nutrient use efficiency. Here, we advocate and develop integrated soil-crop system management (ISSM). In this approach, the key points are (i) to take all possible soil quality improvement measures into consideration, (ii) to integrate the utilization of various nutrient resources and match nutrient supply to crop requirements, and (iii) to integrate soil and nutrient management with high-yielding cultivation systems. Recent field experiments have shed light on how ISSM can lead to significant increases in crop yields while increasing nutrient use efficiency and reducing environmental risk.

Zhang F; Cui Z; Fan M; Zhang W; Chen X; Jiang R

2011-07-01

308

Atributos químicos de um Cambissolo Húmico após 12 anos sob preparo convencional e semeadura direta em rotação e sucessão de culturas/ Chemical properties of a Humic Dystrudept after 12 years under conventional and no tillage with crop succession and rotation  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O manejo adequado do solo é uma das bases para a sustentabilidade do sistema agrícola. O objetivo do estudo foi avaliar atributos químicos de um Cambissolo Húmico Alumínico após 12 anos em dois sistemas de preparo do solo, com rotação e sucessão de culturas. O experimento foi conduzido em Lages, SC, utilizando preparo convencional (PC) e semeadura direta (SD), sob rotação (r) e sucessão (s) de culturas. O delineamento experimental foi inteiramente casualizado (more) com quatro repetições. As sequências de cultivo foram: feijão-pousio-milho-pousio-soja-pousio no PCr; milho-pousio no PCs; feijão-aveia-milho-nabo-soja-ervilhaca na SDr; e milho-ervilhaca na SDs. As amostras de solo foram coletadas nas camadas 0-2,5; 2,5-5; 5-10; e 10-20cm. Avaliou-se carbono orgânico total (COT), cálcio, magnésio, alumínio trocável, fósforo, potássio, nitrogênio total (NT) e pH em água. A SD aumentou os teores de COT e nutrientes em comparação ao PC, especialmente na camada superficial do solo. O cultivo de milho e ervilhaca em sucessão aumentou os teores de COT e NT na camada superficial do solo em comparação com a rotação sob semeadura direta. Abstract in english Suitable soil management is one of the bases for sustainability in agricultural systems. The study aimed to evaluate chemical properties of a Humic Dystrudept for 12 years under two tillage systems, with crops rotation and succession. The experiment was carried out in Lages, SC, under conventional tillage (CT) and no-till (NT), with rotation (r) and succession (s) cropping systems, using crop sequences of beans-fallow-maize-fallow-soybean in CTr; maize-fallow in CTs; bean (more) s-oats-maize-fodder radish-soybean-vetch in NTr; and maize-vetch in NTs. The experimental design was completely randomized with four replicates. The soil samples were collected in the layers 0-2.5, 2.5-5, 5-10 and 10-20cm. The variables assessed were total organic carbon (TOC), calcium, magnesium, exchangeable aluminum, phosphorus, potassium, total nitrogen (TN) and water pH. The no-tillage system increased TOC and nutrient levels in comparison with conventional tillage, especially in the surface soil layer. Maize and vetch crop succession had higher TOC and TN contents in the surface soil layer compared to crop rotation under no-tillage.

Andrade, Andréia Patrícia; Mafra, Álvaro Luiz; Picolla, Cristiano Della; Albuquerque, Jackson Adriano; Bertol, Ildegardis

2012-05-01

309

Atributos químicos de um Cambissolo Húmico após 12 anos sob preparo convencional e semeadura direta em rotação e sucessão de culturas Chemical properties of a Humic Dystrudept after 12 years under conventional and no tillage with crop succession and rotation  

Directory of Open Access Journals (Sweden)

Full Text Available O manejo adequado do solo é uma das bases para a sustentabilidade do sistema agrícola. O objetivo do estudo foi avaliar atributos químicos de um Cambissolo Húmico Alumínico após 12 anos em dois sistemas de preparo do solo, com rotação e sucessão de culturas. O experimento foi conduzido em Lages, SC, utilizando preparo convencional (PC) e semeadura direta (SD), sob rotação (r) e sucessão (s) de culturas. O delineamento experimental foi inteiramente casualizado com quatro repetições. As sequências de cultivo foram: feijão-pousio-milho-pousio-soja-pousio no PCr; milho-pousio no PCs; feijão-aveia-milho-nabo-soja-ervilhaca na SDr; e milho-ervilhaca na SDs. As amostras de solo foram coletadas nas camadas 0-2,5; 2,5-5; 5-10; e 10-20cm. Avaliou-se carbono orgânico total (COT), cálcio, magnésio, alumínio trocável, fósforo, potássio, nitrogênio total (NT) e pH em água. A SD aumentou os teores de COT e nutrientes em comparação ao PC, especialmente na camada superficial do solo. O cultivo de milho e ervilhaca em sucessão aumentou os teores de COT e NT na camada superficial do solo em comparação com a rotação sob semeadura direta.Suitable soil management is one of the bases for sustainability in agricultural systems. The study aimed to evaluate chemical properties of a Humic Dystrudept for 12 years under two tillage systems, with crops rotation and succession. The experiment was carried out in Lages, SC, under conventional tillage (CT) and no-till (NT), with rotation (r) and succession (s) cropping systems, using crop sequences of beans-fallow-maize-fallow-soybean in CTr; maize-fallow in CTs; beans-oats-maize-fodder radish-soybean-vetch in NTr; and maize-vetch in NTs. The experimental design was completely randomized with four replicates. The soil samples were collected in the layers 0-2.5, 2.5-5, 5-10 and 10-20cm. The variables assessed were total organic carbon (TOC), calcium, magnesium, exchangeable aluminum, phosphorus, potassium, total nitrogen (TN) and water pH. The no-tillage system increased TOC and nutrient levels in comparison with conventional tillage, especially in the surface soil layer. Maize and vetch crop succession had higher TOC and TN contents in the surface soil layer compared to crop rotation under no-tillage.

Andréia Patrícia Andrade; Álvaro Luiz Mafra; Cristiano Della Picolla; Jackson Adriano Albuquerque; Ildegardis Bertol

2012-01-01

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Weed community response to contrasting integrated weed management systems for cool dryland annual crops  

UK PubMed Central (United Kingdom)

Contrasting approaches to integrated weed management (IWM) for prairie cropping systems were evaluated by measuring weed response to six IWM systems in a wheat-oilseed rape-barley-pea rotation at Saskatoon and Watrous, Saskatchewan, Canada. The six IWM systems (high herbicide/zero tillage; medium herbicide/zero tillage; low herbicide/zero tillage; low herbicide/low tillage; medium herbicide/medium tillage; no herbicide/high tillage) included various combinations of seeding rate and date, herbicide timing and rate, and tillage operations, in order to achieve similar weed management levels. Changes in weed communities were assessed over 4 years by monitoring species composition and abundance at various times during the growth season. Principal response curves indicated a gradual increase in Thlaspi arvense, Chenopodium album, Amaranthus retroflexus and Fallopia convolvulus in the no herbicide/high tillage system. Winter and early spring annuals and perennials increased in most systems, but particularly in the low herbicide/zero tillage and medium herbicide/zero tillage systems. Although five of the six IWM systems provided similar results, changes in weed communities would suggest that operations could be revised to improve the overall management of certain weed species and reduce seed return in the no herbicide/high tillage system and in systems with low herbicide inputs and zero tillage. This study confirms the potential of contrasting IWM