WorldWideScience

Sample records for sandy soil cropped

  1. IMPROVEMENT OF SANDY SOIL WITH WATER-CONSERVING MEMBRANE AND ITS EFFECT ON CROP GROWTH

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-jun; CUI Xiang-hao; LI Qu-sheng

    2005-01-01

    Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water-conserving membrane will obstruct capillary and increase viscidity of sandy soil, so as to decrease leakage and evaporation in sandy soil. The water-conserving membrane contains polyacrylic acid (PAA) and bentonite. When PAA concentration and Ph of solution are different, water-conserving membrane can be made in different depth of soil. This experiment shows that the solution with 0.2% PAA does not harm and poison the crops, on the contrary,promotes crop germination. The solution with 0.2% or 0.4% PAA can accelerate corn growth. Accordingly, different crops need the application of the different PAA concentrations in the cultivation. Therefore, on the basis of different vadose coefficient in sandy soil, the solution with different PAA concentration can improve sandy soil and increase its water-conserving competence very well. The solution can be used to improve sandy soil and control desert enlargement in arid, semi-arid and semi-humid areas.

  2. Assessment of physical and chemical indicators of sandy soil quality for sustainable crop production

    Science.gov (United States)

    Lipiec, Jerzy; Usowicz, Boguslaw

    2017-04-01

    Sandy soils are used in agriculture in many regions of the world. The share of sandy soils in Poland is about 55%. The aim of this study was to assess spatial variability of soil physical and chemical properties affecting soil quality and crop yields in the scale of field (40 x 600 m) during three years of different weather conditions. The experimental field was located on the post glacial and acidified sandy deposits of low productivity (Szaniawy, Podlasie Region, Poland). Physical soil quality indicators included: content of sand, silt, clay and water, bulk density and those chemical: organic carbon, cation exchange capacity, acidity (pH). Measurements of the most soil properties were done at spring and summer each year in topsoil and subsoil layer in 150 points. Crop yields were evaluated in places close to measuring points of the soil properties. Basic statistics including mean, standard deviation, skewness, kurtosis minimal, maximal and correlations between the soil properties and crop yields were calculated. Analysis of spatial dependence and distribution for each property was performed using geostatistical methods. Mathematical functions were fitted to the experimentally derived semivariograms that were used for mapping the soil properties and crop yield by kriging. The results showed that the largest variations had clay content (CV 67%) and the lowest: sand content (5%). The crop yield was most negatively correlated with sand content and most positively with soil water content and cation exchange capacity. In general the exponential semivariogram models fairly good matched to empirical data. The range of semivariogram models of the measured indicators varied from 14 m to 250 m indicate high and moderate spatial variability. The values of the nugget-to-sill+nugget ratios showed that most of the soil properties and crop yields exhibited strong and moderate spatial dependency. The kriging maps allowed identification of low yielding sub-field areas that

  3. Effect of biochar on aerobic processes, enzyme activity, and crop yields in two sandy loam soils

    DEFF Research Database (Denmark)

    Sun, Zhencai; Bruun, Esben; Arthur, Emmanuel

    2014-01-01

    of wood-based biochar on soil respiration, water contents, potential ammonia oxidation (PAO), arylsulfatase activity (ASA), and crop yields at two temperate sandy loam soils under realistic field conditions. In situ soil respiration, PAO, and ASA were not significantly different in quadruplicate field......, it was found that soil pH, rather than biochar rates, was a driving environmental variable. For ASA, the methodological approach was challenged by product sorption, but results did not suggest that biochar significantly stimulated the enzyme activity. Crop yields of maize in field experiments with 10–100 Mg...

  4. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia

    Directory of Open Access Journals (Sweden)

    WAHYU ASTIKO

    2016-01-01

    Full Text Available Abstract. Astiko W, Fauzi MT, Sukartono. 2016. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia. Nusantara Bioscience 8: 66-70. Inoculation of arbuscular mycorrhizal fungi (AMF on maize in sandy soil is expected to have positive implications for the improvement of AMF population and nutrient uptake. However, how many increases in the AMF population and nutrient uptake in the second cycle of a certain cropping system commonly cultivated by the farmers after growing their corn crop have not been examined. Since different cropping systems would indicate different increases in the populations of AMF and nutrient uptake. This study aimed to determine the population AMF and nutrient uptake on the second cropping cycle of corn-based cropping systems which utilized indigenous mycorrhizal fungi on sandy soil in dryland area of North Lombok, West Nusa Tenggara, Indonesia. For that purpose, an experiment was conducted at the Akar-Akar Village in Bayan Sub-district of North Lombok, designed according to the Randomized Complete Block Design, with four replications and six treatments of cropping cycles (P0 = corn-soybean as a control, in which the corn plants were not inoculated with AMF; P1 = corn-soybean, P2 = corn-peanut, P3 = corn-upland rice, P4 = corn-sorghum, and P5 = corn-corn, in which the first cycle corn plants were inoculated with AMF. The results indicated that the mycorrhizal populations (spore number and infection percentage were highest in the second cycle sorghum, achieving 335% and 226% respectively, which were significantly higher than those in the control. Increased uptake of N, P, K and Ca the sorghum plants at 60 DAS of the second cropping cycle reached 200%; 550%; 120% and 490% higher than in the control. The soil used in this experiment is rough-textured (sandy loam, so it is relatively low in water holding capacity and high porosity.

  5. Influence of legume crops on content of organic carbon in sandy soil

    Directory of Open Access Journals (Sweden)

    Hajduk Edmund

    2015-06-01

    Full Text Available The paper presents the results of a 3-year field experiment designed to evaluate the content of organic carbon in brown soil (Haplic Cambisol Dystric developed from a light loamy sand under legumes cultivation. Experimental factors were: species of legume crop (colorful-blooming pea (Pisum sativum, chickling vetch (Lathyrus sativus, narrow-leafed lupin (Lupinus angustifolius, methods of legumes tillage (legumes in pure culture and in mixture with naked oats and mineral N fertilization (0, 30, 60, 90 kg N·ha−1. Cultivation of legumes on sandy soil did not result in an increase of organic carbon content in the soil after harvest as compared to the initial situation, i.e. 7.39 vs. 7.76 g·kg−1 dry matter (DM, on average, respectively. However, there was the beneficial effect of this group of plants on soil abundance in organic matter, the manifestation of which was higher content of organic carbon in soils after legume harvest as compared to soils with oats grown (7.21 g·kg−1 DM, on average. Among experimental crops, cultivation of pea exerted the most positive action to organic carbon content (7.58 g·kg−1, after harvest, on average, whereas narrow-leaved lupin had the least effect on organic carbon content (7.23 g·kg−1, on average. Pure culture and greater intensity of legume cultivation associated with the use of higher doses of mineral nitrogen caused less reduction in organic carbon content in soils after harvest.

  6. Characterisation of phosphate solubilising bacteria in sandy loam soil under chickpea cropping system.

    Science.gov (United States)

    Singh, Machiavelli; Tejo Prakash, N

    2012-06-01

    With the aim to explore the possible role of phosphate-solubilizing bacteria (PSB) in phosphorus (P) cycling in agricultural soils, we isolated PSB inhabiting naturally in the sandy loam soils under chickpea cropping of Patiala (Punjab State). A total of 31 bacterial isolates showing solubilizing activities were isolated on Pikovskaya agar plates. The potent phosphate solubilizers were selected for further characterization. These isolates were shown to belong to the genera Pseudomonas and Serratia by partial sequencing analysis of their respective 16S rDNA genes. ERIC-PCR based fingerprinting was done for tracking the survival of introduced populations of the PSB during mass inoculation of these strains under chickpea plots. The results showed positive correlation (r(2) = 0.853) among soil phosphatase activity and phosphate solubilizers population, which was also positively correlated (r(2) = 0.730) to available phosphorus. Identification and characterization of soil PSB for the effective plant growth-promotion broadens the spectrum of phosphate solubilizers available for field application.

  7. Crop residues as driver for N2O emissions from a sandy loam soil

    DEFF Research Database (Denmark)

    Pugesgaard, Siri; Petersen, Søren O.; Chirinda, Ngonidzashe

    2017-01-01

    Nitrogen (N) cycling within agriculture constitutes a source of direct and indirect emissions of the potent greenhouse gas nitrous oxide (N2O). We analysed relationships between N2O emissions and C and N balances of four arable cropping systems under conventional or organic management within a long......-term experiment on a loamy sand soil at Foulum in Denmark. All cropping systems included winter wheat, a leguminous crop (faba bean or grass-clover), potato and spring barley grown in different 4-crop rotations varying in strategies for N supply (fertilizer/manure type and rate, use of catch crops and green...... manure). Crops in both organic and conventional systems received N at rates below the optimum for crop production. Soil N2O emissions were monitored in 2008–2009 in six selected crops which could be combined with data from other monitoring programs to calculate N2O emission factors for each of the 16...

  8. Phosphatase activity in sandy soil influenced by mycorrhizal and non-mycorrhizal cover crops

    Directory of Open Access Journals (Sweden)

    Alceu Kunze

    2011-06-01

    Full Text Available Cover crops may difffer in the way they affect rhizosphere microbiota nutrient dynamics. The purpose of this study was to evaluate the effect of mycorrhizal and non-mycorrhizal cover crops on soil phosphatase activity and its persistence in subsequent crops. A three-year experiment was carried out with a Typic Quartzipsamment. Treatments were winter species, either mycorrhizal black oat (Avena strigosa Schreb or the non-mycorrhizal species oilseed radish (Raphanus sativus L. var. oleiferus Metzg and corn spurry (Spergula arvensis L.. The control treatment consisted of resident vegetation (fallow in the winter season. In the summer, a mixture of pearl millet (Pennisetum americanum L. with sunnhemp (Crotalaria juncea L. or with soybean (Glycine max L. was sown in all plots. Soil cores (0-10 cm and root samples were collected in six growing seasons (winter and summer of each year. Microbial biomass P was determined by the fumigation-extraction method and phosphatase activity using p-nitrophenyl-phosphate as enzyme substrate. During the flowering stage of the winter cover crops, acid phosphatase activity was 30-35 % higher in soils with the non-mycorrhizal species oilseed radish, than in the control plots, regardless of the amount of P immobilized in microbial biomass. The values of enzyme activity were intermediate in the plots with corn spurry and black oat. Alkaline phosphatase activity was 10-fold lower and less sensitive to the treatments, despite the significant relationship between the two phosphatase activities. The effect of plant species on the soil enzyme profile continued in the subsequent periods, during the growth of mycorrhizal summer crops, after completion of the life cycle of the cover crops.

  9. Quantity and nature of water-extractable organic matter from sandy loam soils with potato cropping managements

    Science.gov (United States)

    Water-extractable organic matter (WEOM) is part of the soil labile organic matter components. In this work, we evaluated the level and nature of soil WEOM from a long-term (6-year) potato crop rotation field experiment. The contents of water-extractable organic C (WEOC) were higher in continuous pot...

  10. Soil precompression stress, penetration resistance and crop yields in relation to differently-trafficked, temperate-region sandy loam soils

    DEFF Research Database (Denmark)

    Schjønning, Per; Lamandé, Mathieu; Munkholm, Lars Juhl

    2016-01-01

    treatment (labelled M8-1), the soil was loaded only in the first year. A tricycle-like machine with a single pass of wide tyres each carrying 12 Mg (treatment S12) was included at one site. Traffic treatments were applied in a randomized block design with four replicates and with treatments repeated in four...... strength measure predicting resistance to subsoil compaction. The tyre inflation pressure and/or the mean ground pressure were the main predictors of PR in the upper soil layers. For deeper soil layers, PR correlated better to the wheel load. The number of wheel passes (M-treatments vs the S12 treatment......-pressure tyres by crab steering/dog-walk machinery....

  11. Nitrogen fertilization on soybean under crop-livestock system and sandy soil = Nitrogênio mineral na soja integrada com a pecuária em solo arenoso

    Directory of Open Access Journals (Sweden)

    Alvadi Antonio Balbinot Junior

    2016-07-01

    Full Text Available In Brazil, soybean has been introduced in areas with sandy soil and tropical climate, often under crop-livestock system. The use of nitrogen (N for this crop is supplied by the soil organic matter mineralization and the biological N fixation. However, there are questions about the effect of nitrogen fertilization in soybean crop under sandy soils with a high amount of straw. The aim of this study was to evaluate the agronomic performance of two soybean cultivars in different doses (20 and 45 kg N ha-1 and application times (sowing, at flowering or early grain filling of N in sandy soil with high amount of Urochloa brizantha straw. Two experiments were conducted in Northwest of Paraná state, Brazil, the first experiment with the BMX Potência RR cultivar and the second one with the BRS 360 RR cultivar, in a sandy soil (11% clay. The experiment were composed by seven treatments (interaction between factors and the control, settled in a randomized block design with four replications. In sandy soil, with high amount of U. brizantha straw, the nitrogen fertilizer applied at different doses and at soybean development stages, cultivars BMX Potência RR and BRS 360 RR, does not influence the photoassimilates partition between stem and leaves, foliar N concentration, yield, yield components, and the oil and protein content in the grains. = No Brasil, a soja tem sido introduzida em regiões que apresentam solos arenosos e clima tropical, sendo muitas vezes integrada com a pecuária. A demanda da oleaginosa por nitrogênio(N é suprida pela mineralização da matéria orgânica do solo e pela fixação biológica do N. No entanto, há questionamentos quanto ao efeito da adubação nitrogenada na cultura da soja cultivada em solos arenosos, com alta quantidade de palha de gramíneas. Objetivou-se com este trabalho avaliar o desempenho de duas cultivares de soja, em solo arenoso, após dois anos com pastagem de Urochloa brizantha, submetidas a diferentes

  12. Nitrate leaching from sandy loam soils under a double-cropping forage system estimated from suction-probe measurements.

    NARCIS (Netherlands)

    Trindade, H.; Coutinho, J.; Beusichem, van M.L.; Scholefield, D.; Moreira, N.

    1997-01-01

    Nitrate leaching from a double-cropping forage system was measured over a 2-year period (June 1994–May 1996) in the Northwest region of Portugal using ceramic cup samplers. The crops were grown for silage making and include maize (from May to September) and a winter crop (rest of the year)

  13. Measurement and Computation of Movement of Bromide Ions and Carbofuran in Ridged HUmic-Sandy Soil

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2010-01-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. R

  14. Organic matter dynamics in coarse sandy calcareous soils

    NARCIS (Netherlands)

    Pronk, A.A.; Reuler, van H.

    2011-01-01

    The decomposition of organic matter in coarse sandy calcareous soils (beach sand) is thought to be much higher than in acid fine sandy soils but relatively little research is performed on these soils. Laboratory incubation experiments in which the release of soil carbon (C) is determined may overest

  15. Factors affecting N immobilisation/mineralisation kinetics for cellulose-, glucose- and straw-amended sandy soils

    NARCIS (Netherlands)

    Vinten, A.J.A.; Whitmore, A.P.; Bloem, J.; Howard, R.; Wright, F.

    2002-01-01

    The kinetics of nitrogen immobilization/mineralization for cellulose-, glucose- and straw-amended sandy soils were investigated in a series of laboratory incubations. Three Scottish soils expected to exhibit a range of biological activity were used: aloamy sand, intensively cropped horticultural soi

  16. Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

    Science.gov (United States)

    Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

    2016-08-01

    A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

  17. Tillage System and Cover Crop Effects on Soil Quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    2014-01-01

    Information about the quantitative effect of conservation tillage combined with a cover crop on soil structure is still limited. This study examined the effect of these management practices on soil pore characteristics of a sandy loam soil in a long-term field trial. The tillage treatments (main...

  18. Compost amendment of sandy soil affects soil properties and greenhouse tomato productivity

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Cornelis, W.; Razzaghi, Fatemeh

    2012-01-01

    Sandy soils, with low productivity, could be improved by compost application to sustain crop production. This study aimed to examine the effect of three compost types (vegetable, fruit and yard waste compost, garden waste compost, and spent mushroom compost) on basic properties of a loamy sand...... and greenhouse tomato productivity. Disturbed and intact soil samples were taken from a decade-long compost field experiment on loamy sand with three compost types at application rate of 30 m3 ha-1 yr-1 (7.5 ton ha-1 yr-1). The soils were characterized for chemical and physical properties. Tomato was planted...... in a greenhouse using soil samples from the field and vegetative and yield parameters (plant height, stem diameter, leaf number, and fruit yield), water productivity, and harvest index were evaluated. All compost types significantly increased soil total carbon, total nitrogen, pH, electrical conductivity...

  19. Effects of water treatment residuals and coal combustion byproduct amendments on properties of a sandy soil and impact on crop production – A pot experiment

    Science.gov (United States)

    Byproducts of coal combustion (such as fly ash: FA), livestock industry (such as chicken manure: CM, or animal manure, etc), or water treatment residuals (such as sewage sludge: SS, or incinerated sewage sludge: ISS) can be used as amendments to agricultural soils, provided that these byproducts (ap...

  20. Response Of Wheat (Triticum aestivum L. Crop And Broad-Leaved Weeds To Different Water Requirements And Weed Management In Sandy Soils

    Directory of Open Access Journals (Sweden)

    El-Metwally Ibrahim M.

    2015-03-01

    Full Text Available Water scarcity is a major cause of crops yield reduction in many parts of the world. So, a more rational use of irrigation water should be adapted and deficit irrigation principles should be accepted with a certain level of reduction in yield level. To study the efficiency of four water requirements (100% whole season, 75% whole season, 50% whole season and 100% whole season while 50% at grain-filling stage and five weed-control treatments (three postemergence herbicides i.e., metosulam, tribenuron-methyl, and bromoxynil, hand weeding and unweeded check, and their interactive effects, two field experiments on wheat crop were conducted in two successive seasons at the agricultural experimental station of the National Research Centre, Nubaria, Egypt. Bromoxynil, tribenuron-methyl came in the first order for controlling total broad-leaved weeds. Application of 100% water requirement recorded the highest values compared to all other irrigation water treatments in term of flag-leaf area, chlorophyll content, plant height, number of spike/m2, spike weight, grains number/spike, weight of 1,000 grains, yield and yield attributes of wheat. Metosulam followed by bromoxynil, tribenuron-methyl and hand-weeding treatments gave higher values of grain yield/ha. The highest grain yield, protein and carbohydrates percentages of wheat grains were obtained from addition of 100% water requirement with metosulam treatment was used followed by 75% of water requirement combined with metosulam treatment without significant difference among these treatments.

  1. Soil-water characteristics of sandy soil and soil cement with and without vegetation

    OpenAIRE

    2014-01-01

    The use of soil cement as a growth medium was examined in this study. During the monitoring, green soil cement revealed diverse ecological values. The survival rates of plants in each soil conditions were higher than 80%,which was very promising. Furthermore, the survival rates dropped when the soil density reached95%, which means soil density might influence the survival rate of plant. Plant growth rates in sandy soil were higher than that in soil cement. In particular, low soil density faci...

  2. Compost amendment of sandy soil affects soil properties and greenhouse tomato productivity

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Cornelis, W.; Razzaghi, Fatemeh

    2012-01-01

    Sandy soils, with low productivity, could be improved by compost application to sustain crop production. This study aimed to examine the effect of three compost types (vegetable, fruit and yard waste compost, garden waste compost, and spent mushroom compost) on basic properties of a loamy sand...... and significantly decreased bulk density, with no effect on plant available water compared to the control. Fresh and dry fruit weights were significantly increased after compost addition. Plant height, leaf number, stem diameter, and total biomass did not significantly improve after compost addition. Spent mushroom...

  3. Sustainable long-term intensive application of manure to sandy soils without phosphorus leaching

    DEFF Research Database (Denmark)

    Asomaning, Samuel K.; Abekoe, Mark K.; Dowuona, G.N.N.

    2015-01-01

    Long-term application of manure to sandy soils to ensure high crop productivity may lead to phosphorus (P) leaching, which, in turn, may deteriorate the quality of recipient waters because of eutrophication. The risk of P leaching depends on contents of aluminum (Al) and iron (Fe) oxides...... soils, whereas in the deepest soil layers the P contents in the cultivated and uncultivated soils were almost the same indicating very limited downward P transport despite long-term manure application. This was supported by comparable P concentrations in groundwater taken under cultivated...

  4. Screening of cellulose decomposing fungi in sandy dune soil of Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    ShaoKun Wang; XueYong Zhao; XiaoAn Zuo; XinPing Liu; Hao Qu; Wei Mao; JianYing Yun

    2015-01-01

    Cellulose decomposing fungi play an important role in litter decomposition and are decisive in nutrient cycling in sandy land ecosystems. Thirty-one strains were isolated to select efficient cellulose decomposers, and four efficient cellulose decomposing fungi (NM3-1, NM3-2, NM3-3, and NM3-4) were screened using a CMC (carboxymethyl cellulose) carbon source in dune soil of Horqin Sandy Land. They were identified as Asperigillus calidoustus, Fusarium oxysporum, Fusarium solani, and Hypocrea lixii by rDNA-ITS molecular biological methods. Cloth decomposition rates were 15.71%, 15.89%, 17.29%, and 17.89%by the four efficient decomposers incubated for 30 days, respectively. Screening of efficient cellulose decomposers can not only increase the dune soil functional microbe bank, but can also accelerate litter decom-position and available nutrient input in the Horqin Sandy Land.

  5. Microfungi diversity isolation from sandy soil of Acapulco touristic beaches

    Science.gov (United States)

    Microscopic fungi diversity in marine sandy soil habitats is associated with key functions of beach ecosystems. There are few reports on their presence in Mexican beaches. Although standard methods to obtain the fungi from soil samples are established, the aim of this pilot study was to test the pla...

  6. The biogenic emission potential of nitric oxide from sandy soils

    Science.gov (United States)

    Yu, J. B.; Meixner, F. X.; Sun, Z. G.; Chen, X. B.; Mamtimin, B.

    2009-04-01

    There are about 160.9 Mha of sandy land in China, about 17.6% of total Chinese area, which mainly distributed in 35°-50° N. The western Songnen Plain, which located in the semi-arid region of Northeastern China, is one of the main sandy soil distribution regions. The changes of land use in sandy soil are accompanied by changes in biogeochemical cycles of nutrients, particularly of the air-surface exchange of trace gases like nitric oxide. Our study, based on results obtained by a laboratory incubation technique, focuses on (a) NO production and consumption in sandy soils from two types of land use as function of soil temperature and soil moisture, and (b) The biogenic emission potential of nitric oxide from sandy soils in semi-arid region. At 25˚C, average NO production (in terms of mass of N) was 0.016,and 0.013 ng kg-1s-1 in sandy soils from soybean land (SL) and man-made forest (MF), re¬spectively. NO consumption rate constant ranged from 0.26×10-6 to 7.28×10-6 m3 kg-1s-1. At 25˚C and under optimum soil moisture conditions for NO production, the NO compensation point mixing ratio was about 266 and 161 ug m-3 (465,and 281 ppb) for soils of SL and MF, respectively. Statistically sound relationships have been observed between NO fluxes and soil moisture (optimum curves). NO fluxes also increased exponentially with soil temperature at any given soil moisture. The optimum soil moisture for which maximum NO flux was observed was independent of soil temperature. The maximum of NO flux potentials for SL and MF soils (at 25°C) were 59.6 and 36.5 ng m-2s-1 at water-filled pore space (%WFPS) of 26 and 24, respectively. The NO flux potential was about 2 times larger for cropland soil than for man-made forest soils, most likely due to fertilizer application to the cropland soils.

  7. Exploring the potential of near-surface geophysical methods to delineate a shallow hardpan in a southeastern U.S. sandy coastal plain soil

    Science.gov (United States)

    A hardpan, which is a dense soil layer near the ground surface, is an undesirable feature of many soils in the Southeast U.S., especially sandy Coastal Plain soils. Shallow hardpans restrict root growth and water penetration through the soil profile, in turn reducing the effective crop root zone and...

  8. Soil N mineralization in a dairy production system with grass and forage crops

    NARCIS (Netherlands)

    Verloop, J.; Hilhorst, G.J.; Oenema, J.; Keulen, van H.; Sebek, L.B.J.; Ittersum, van M.K.

    2014-01-01

    This paper describes the dynamics of soil N mineralization in the experimental intensive dairy farming system ‘De Marke’ on a dry sandy soil in the Netherlands. We hypothesized that knowledge of the effects of crop rotation on soil N mineralization and of the spatial and temporal variability of soil

  9. Impacts of crop rotations on soil organic carbon sequestration

    Science.gov (United States)

    Gobin, Anne; Vos, Johan; Joris, Ingeborg; Van De Vreken, Philippe

    2013-04-01

    Agricultural land use and crop rotations can greatly affect the amount of carbon sequestered in the soil. We developed a framework for modelling the impacts of crop rotations on soil carbon sequestration at the field scale with test case Flanders. A crop rotation geo-database was constructed covering 10 years of crop rotation in Flanders using the IACS parcel registration (Integrated Administration and Control System) to elicit the most common crop rotation on major soil types in Flanders. In order to simulate the impact of crop cover on carbon sequestration, the Roth-C model was adapted to Flanders' environment and coupled to common crop rotations extracted from the IACS geodatabases and statistical databases on crop yield. Crop allometric models were used to calculate crop residues from common crops in Flanders and subsequently derive stable organic matter fluxes to the soil (REGSOM). The REGSOM model was coupled to Roth-C model was run for 30 years and for all combinations of seven main arable crops, two common catch crops and two common dosages of organic manure. The common crops are winter wheat, winter barley, sugar beet, potato, grain maize, silage maize and winter rapeseed; the catch crops are yellow mustard and Italian ryegrass; the manure dosages are 35 ton/ha cattle slurry and 22 ton/ha pig slurry. Four common soils were simulated: sand, loam, sandy loam and clay. In total more than 2.4 million simulations were made with monthly output of carbon content for 30 years. Results demonstrate that crop cover dynamics influence carbon sequestration for a very large percentage. For the same rotations carbon sequestration is highest on clay soils and lowest on sandy soils. Crop residues of grain maize and winter wheat followed by catch crops contribute largely to the total carbon sequestered. This implies that agricultural policies that impact on agricultural land management influence soil carbon sequestration for a large percentage. The framework is therefore

  10. Strategies to optimize allocation of limited nutrients to sandy soils of the Sahel: a case study from Niger, West Africa

    NARCIS (Netherlands)

    Gandah, M.; Brouwer, J.; Hiernaux, P.; Duivenbooden, van N.

    2003-01-01

    Soils used for rainfed cereal production in Niger are sandy, deficient in major nutrients (N and P), and also low in organic matter content. Scarce rainfall with an unpredictable distribution in space and time makes crop and nutrient management difficult. Observations were made in 1996 and 1997 on m

  11. Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Wulandari P.S.

    2010-01-01

    Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

  12. Measured and Estimated Volatilisation of Naphthalene from a Sandy Soil

    DEFF Research Database (Denmark)

    Lindhardt, Bo; Christensen, Thomas Højlund

    1994-01-01

    The non-steady-state fluxes of naphthalene from an artificially contaminated sandy soil at different water contents were measured in the laboratory, at 10°C. The soil contained 1.1% of organic carbon and the water content varied between 2.8 and 14% w/w. The diffusive flux of naphthalene from the ...... the fluxes by a factor of 1.5 to 6.4. The largest deviation between predicted and observed dynamic fluxes was found at high water contents. For the cover soil, half-life times of 1 to 2 days were estimated by the model for naphthalene degradation....

  13. Morphology of rain water channelization in systematically varied model sandy soils

    OpenAIRE

    Wei, Y.; Cejas, C. M.; Barrois, R.; Dreyfus, R.; Durian, D. J.

    2014-01-01

    We visualize the formation of fingered flow in dry model sandy soils under different raining conditions using a quasi-2d experimental set-up, and systematically determine the impact of soil grain diameter and surface wetting property on water channelization phenomenon. The model sandy soils we use are random closely-packed glass beads with varied diameters and surface treatments. For hydrophilic sandy soils, our experiments show that rain water infiltrates into a shallow top layer of soil and...

  14. Tillage System and Cover Crop Effects on Soil Quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    2014-01-01

    Optimal use of management systems including tillage and winter cover crops is recommended to improve soil quality and sustain agricultural production. The effects on soil properties of three tillage systems (as main plot) including direct drilling (D), harrowing to a depth of 8 to 10 cm (H......), and moldboard plowing (MP) with and without a cover crop were evaluated in a long-term experiment on a sandy loam soil in Denmark. Chemical, physical, and biological soil properties were measured in the spring of 2012. The field measurements included mean weight diameter (MWD) after the drop-shatter test......, penetration resistance, and visual evaluation of soil structure (VESS). In the laboratory, aggregate strength, water-stable aggregates (WSA), and clay dispersibility were measured. The analyzed chemical and biological properties included soil organic C (SOC), total N, microbial biomass C, labile P and K...

  15. Deep Compaction Control of Sandy Soils

    Directory of Open Access Journals (Sweden)

    Bałachowski Lech

    2015-02-01

    Full Text Available Vibroflotation, vibratory compaction, micro-blasting or heavy tamping are typical improvement methods for the cohesionless deposits of high thickness. The complex mechanism of deep soil compaction is related to void ratio decrease with grain rearrangements, lateral stress increase, prestressing effect of certain number of load cycles, water pressure dissipation, aging and other effects. Calibration chamber based interpretation of CPTU/DMT can be used to take into account vertical and horizontal stress and void ratio effects. Some examples of interpretation of soundings in pre-treated and compacted sands are given. Some acceptance criteria for compaction control are discussed. The improvement factors are analysed including the normalised approach based on the soil behaviour type index.

  16. Estimation of nitrogen pools in irrigated potato production on sandy soil using the model SUBSTOR.

    Directory of Open Access Journals (Sweden)

    Rishi Prasad

    Full Text Available Recent increases in nitrate concentrations in the Suwannee River and associated springs in northern Florida have raised concerns over the contributions of non-point sources. The Middle Suwannee River Basin (MSRB is of special concern because of prevalent karst topography, unconfined aquifers and sandy soils which increase vulnerability of the ground water contamination from agricultural operations--a billion dollar industry in this region. Potato (Solanum tuberosum L. production poses a challenge in the area due to the shallow root system of potato plants, and low water and nutrient holding capacity of the sandy soils. A four-year monitoring study for potato production on sandy soil was conducted on a commercial farm located in the MSRB to identify major nitrogen (N loss pathways and determine their contribution to the total environmental N load, using a partial N budget approach and the potato model SUBSTOR. Model simulated environmental N loading rates were found to lie within one standard deviation of the observed values and identified leaching loss of N as the major sink representing 25 to 38% (or 85 to 138 kg ha(-1 N of the total input N (310 to 349 kg ha(-1 N. The crop residues left in the field after tuber harvest represented a significant amount of N (64 to 110 kg ha(-1 N and posed potential for indirect leaching loss of N upon their mineralization and the absence of subsequent cover crops. Typically, two months of fallow period exits between harvest of tubers and planting of the fall row crop (silage corn. The fallow period is characterized by summer rains which pose a threat to N released from rapidly mineralizing potato vines. Strategies to reduce N loading into the groundwater from potato production must focus on development and adoption of best management practices aimed on reducing direct as well as indirect N leaching losses.

  17. Mitigation of Liquefaction in Sandy Soils Using Stone Columns

    Science.gov (United States)

    Selcuk, Levent; Kayabalı, Kamil

    2010-05-01

    Soil liquefaction is one of the leading causes of earthquake-induced damage to structures. Soil improvement methods provide effective solutions to reduce the risk of soil liquefaction. Thus, soil ground treatments are applied using various techniques. However, except for a few ground treatment methods, they generally require a high cost and a lot of time. Especially in order to prevent the risk of soil liquefaction, stone columns conctructed by vibro-systems (vibro-compaction, vibro-replacement) are one of the traditional geotechnical methods. The construction of stone columns not only enhances the ability of clean sand to drain excess pore water during an earthquake, but also increases the relative density of the soil. Thus, this application prevents the development of the excess pore water pressure in sand during earthquakes and keeps the pore pressure ratio below a certain value. This paper presents the stone column methods used against soil liquefaction in detail. At this stage, (a) the performances of the stone columns were investigated in different spacing and diameters of columns during past earthquakes, (b) recent studies about design and field applications of stone columns were presented, and (c) a new design method considering the relative density of soil and the capacity of drenage of columns were explained in sandy soil. Furthermore, with this new method, earthquake performances of the stone columns constructed at different areas were investigated before the 1989 Loma Prieta and the 1994 Northbridge earthquakes, as case histories of field applications, and design charts were compiled for suitable spacing and diameters of stone columns with consideration to the different sandy soil parameters and earhquake conditions. Key Words: Soil improvement, stone column, excess pore water pressure

  18. [Effects of land use and management on soil quality of Heerqin sandy land].

    Science.gov (United States)

    Su, Yongzhong; Zhao, Halin

    2003-10-01

    The changes of soil physical, chemical and biological properties under different land use and management lasted for 14 years were investigated on the Heerqin sandy land. The results showed that among various land use systems marked differences exhibited in soil quality indicators, including soil particle composition, porosity distribution, bulk density, water-holding capacity, organic matter and nutrient contents, pH, and enzyme activities. Most of these soil quality indicators were the highest in the orchard intercropped with crops and perennial grass (agroforestry systems), intermediate in the well-management irrigated farmland, and the lowest in the less-management dry farmland. Compared to the primary grassland soil, although some soil properties, including porosity distribution, water-holding capacity, phosphorus content, and enzyme activities, were improved in the well-management systems, soil organic matter and nitrogen contents were significantly lower. It suggested that a long-term input of organic matter was needed for the restoration and reestablishment of soil carbon and nitrogen pools in the seriously degraded ecosystem. Inappropriate land use and management could rapidly worsen soil quality, and hence, from a perspective of soil resource conservation, a preferable way for preventing soil degradation and achieving sustainable land use should be to give up the cultivation of degraded dry farmlands, and to adopt more effective and appropriate soil management and cultivation practices.

  19. Influence of biochar on the physical, chemical and retention properties of an amended sandy soil

    Science.gov (United States)

    Baiamonte, Giorgio; De Pasquale, Claudio; Parrino, Francesco; Crescimanno, Giuseppina

    2017-04-01

    Soil porosity plays an important role in soil-water retention and water availability to crops, potentially affecting both agricultural practices and environmental sustainability. The pore structure controls fluid flow and transport through the soil, as well as the relationship between the properties of individual minerals and plants. Moreover, the anthropogenic pressure on soil properties has produced numerous sites with extensive desertification process close to residential areas. Biochar (biologically derived charcoal) is produced by pyrolysis of biomasses under low oxygen conditions, and it can be applied for recycling organic waste in soils and increase soil fertility, improving soil structure and enhancing soil water storage and soil water movement. Soil application of biochar might have agricultural, environmental and sustainability advantages over the use of organic manures or compost, as it is a porous material with a high inner surface area. The main objectives of the present study were to investigate the possible application of biochar from forest residues, derived from mechanically chipped trunks and large branches of Abies alba M., Larix decidua Mill., Picea excelsa L., Pinus nigra A. and Pinus sylvestris L. pyrolysed at 450 °C for 48h, to improve soil structural and hydraulic properties (achieving a stabilization of soil). Different amount of biochar were added to a desertic sandy soil, and the effect on soil porosity water retention and water available to crops were investigated. The High Energy Moisture Characteristic (HEMC) technique was applied to investigate soil-water retention at high-pressure head levels. The adsorption and desorption isotherms of N2 on external surfaces were also determined in order to investigate micro and macro porosity ratio. Both the described model of studies on adsorption-desorption experiments with the applied isotherms model explain the increasing substrate porosity with a particular attention to the macro and micro

  20. EFFECTS OF ALKALINE SANDY LOAM ON SULFURIC SOIL ACIDITY AND SULFIDIC SOIL OXIDATION

    Directory of Open Access Journals (Sweden)

    Patrick S. Michael

    2015-08-01

    Full Text Available  In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM for general use of the soils. In acid sulfate soils (ASS, addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

  1. Trends in soil organic matter contents in Dutch grasslands and maize fields on sandy soils

    NARCIS (Netherlands)

    Hanegraaf, M.C.; Hoffland, E.; Kuikman, P.J.; Brussaard, L.

    2009-01-01

    There is considerable concern in Europe that soil organic matter (SOM) contents are declining, which would threaten both agriculture and the environment. We performed a trend analysis of SOM contents in sandy soils, using historic data from routine agricultural soil analyses. Data were selected from

  2. Measurement and computation of movement of bromide ions and carbofuran in ridged humic-sandy soil.

    Science.gov (United States)

    Leistra, Minze; Boesten, Jos J T I

    2010-07-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. Rainfall was supplemented by sprinkler irrigation. The distribution of the substances in the soil profile of the ridges and furrows was measured on three dates in the potato growing season. Separate ridge and furrow systems were simulated by using the pesticide emission assessment at regional and local scales (PEARL) model for pesticide behavior in soil-plant systems. The substances travelled deeper in the furrow soil than in the ridge soil, because of runoff from the ridges to the furrows. At 19 days after application, the peak of the bromide distribution was measured to be in the 0.1-0.2 m layer of the ridges, while it was in the 0.3-0.5 m layer of the furrows. After 65 days, the peak of the carbofuran distribution in the ridge soil was still in the 0.1 m top layer, while the pesticide was rather evenly distributed in the top 0.6 m of the furrow soil. The wide ranges in concentration measured with depth showed that preferential water flow and substance transport occurred in the sandy soil. Part of the bromide ion distribution was measured to move faster in soil than the computed wave. The runoff of water and pesticide from the ridges to the furrows, and the thinner root zone in the furrows, are expected to increase the risk of leaching to groundwater in ridged fields, in comparison with more level fields.

  3. Different Behavior of Enteric Bacteria and Viruses in Clay and Sandy Soils after Biofertilization with Swine Digestate

    Science.gov (United States)

    Fongaro, Gislaine; García-González, María C.; Hernández, Marta; Kunz, Airton; Barardi, Célia R. M.; Rodríguez-Lázaro, David

    2017-01-01

    Enteric pathogens from biofertilizer can accumulate in the soil, subsequently contaminating water and crops. We evaluated the survival, percolation and leaching of model enteric pathogens in clay and sandy soils after biofertilization with swine digestate: PhiX-174, mengovirus (vMC0), Salmonella enterica Typhimurium and Escherichia coli O157:H7 were used as biomarkers. The survival of vMC0 and PhiX-174 in clay soil was significantly lower than in sandy soil (iT90 values of 10.520 ± 0.600 vs. 21.270 ± 1.100 and 12.040 ± 0.010 vs. 43.470 ± 1.300, respectively) and PhiX-174 showed faster percolation and leaching in sandy soil than clay soil (iT90 values of 0.46 and 2.43, respectively). S. enterica Typhimurium was percolated and inactivated more slowly than E. coli O157:H7 (iT90 values of 9.340 ± 0.200 vs. 6.620 ± 0.500 and 11.900 ± 0.900 vs. 10.750 ± 0.900 in clay and sandy soils, respectively), such that E. coli O157:H7 was transferred more quickly to the deeper layers of both soils evaluated (percolation). Our findings suggest that E. coli O157:H7 may serve as a useful microbial biomarker of depth contamination and leaching in clay and sandy soil and that bacteriophage could be used as an indicator of enteric pathogen persistence. Our study contributes to development of predictive models for enteric pathogen behavior in soils, and for potential water and food contamination associated with biofertilization, useful for risk management and mitigation in swine digestate recycling. PMID:28197137

  4. The effect of different tillage and cover crops on soil quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    This paper examines the effect of different tillage treatments and cover crop on soil physical, chemical and biological properties of a sandy loam soil in a long-term field trial set up in 2007 at Foulum, Denmark. The experimental design is a split plot design with different tillage practices...

  5. Energizing marginal soils: A perennial cropping system for Sida hermaphrodita

    Science.gov (United States)

    Nabel, Moritz; Poorter, Hendrik; Temperton, Vicky; Schrey, Silvia D.; Koller, Robert; Schurr, Ulrich; Jablonowski, Nicolai D.

    2017-04-01

    As a way to avoid land use conflicts, the use of marginal soils for the production of plant biomass can be a sustainable alternative to conventional biomass production (e.g. maize). However, new cropping strategies have to be found that meet the challenge of crop production under marginal soil conditions. We aim for increased soil fertility by the use of the perennial crop Sida hermaphrodita in combination with organic fertilization and legume intercropping to produce substantial biomass yield. We present results of a three-year outdoor mesocosm experiment testing the perennial energy crop Sida hermaphrodita grown on a marginal model substrate (sand) with four kinds of fertilization (Digestate broadcast, Digestate Depot, mineral NPK and unfertilized control) in combination with legume intercropping. After three years, organic fertilization (via biogas digestate) compared to mineral fertilization (NPK), reduced the nitrate concentration in leachate and increased the soil carbon content. Biomass yields of Sida were 25% higher when fertilized organically, compared to mineral fertilizer. In general, digestate broadcast application reduced root growth and the wettability of the sandy substrate. However, when digestate was applied locally as depot to the rhizosphere, root growth increased and the wettability of the sandy substrate was preserved. Depot fertilization increased biomass yield by 10% compared to digestate broadcast fertilization. We intercropped Sida with various legumes (Trifolium repens, Trifolium pratense, Melilotus spp. and Medicago sativa) to enable biological nitrogen fixation and make the cropping system independent from synthetically produced fertilizers. We could show that Medicago sativa grown on marginal substrate fixed large amounts of N, especially when fertilized organically, whereas mineral fertilization suppressed biological nitrogen fixation. We conclude that the perennial energy crop Sida in combination with organic fertilization has great

  6. Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

    NARCIS (Netherlands)

    Rietkerk, M; Ouedraogo, T; Kumar, L; Sanou, S; van Langevelde, F; Kiema, A; van de Koppel, J; van Andel, J; Hearne, J; Skidmore, AK; de Ridder, N; Stroosnijder, L; Prins, HHT

    We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

  7. Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

    NARCIS (Netherlands)

    Rietkerk, M.G.; Ouedraogo, T.; Kumar, L.; Sanou, S.; Langevelde, F. van; Kiema, A.; Koppel, J. van de; Andel, J. van; Hearne, J.; Skidmore, A.K.; Ridder, N. de; Stroosnijder, L.; Prins, H.H.T.

    2002-01-01

    We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

  8. Nitrate leaching to groundwater at experimental farm "De Marke" and other Dutch sandy soils

    NARCIS (Netherlands)

    Hack-ten Broeke, M.J.D.

    2001-01-01

    This study focuses on nitrate leaching to the groundwater as a result of the land use system of experimental farm 'De Marke', translated to other sandy soils in the Netherlands. The land use was extrapolated to five major sandy soil map units, selected from the 1: 50 000 Soil Map of the Netherlands,

  9. Release behavior of copper and zinc from sandy soils

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-kui; XIA Yi-ping

    2005-01-01

    The concentrations and chemical forms of copper(Gu) and zinc(Zn) in surface soils directly influence the movement of Gu and Zn. In this study, thirteen sandy soil samples with a wide range of total Cu and Zn concentrations were collected for evaluating the relationships between Cu and Zn release and extraction time, ratio of soil to water, pH and electrolyte types. The results indicated that Cu released in batch extraction that represents long-term leaching was mainly from exchangeable, and carbonate bound Cu fractions, and Zn released in the batch extraction was mainly from its carbonate bound fraction. However, the Cu and Zn leached from the soils using the column leaching that represents short-term leaching were mainly from their exchangeable fractions. Soil column leaching at different pH values indicated that the amounts of leached Zn and Cu were greatly affected by pH. The Cu and Zn release experiments with varying extraction times and ratio of soil to water suggest that long-term water-logging in the soils after rain may increase contact time of the soils with water and the release of Cu and Zn to water from the soils, and total amounts of Cu or Zn released from the soils increase, but the Cu or Zn concentration in the surface runoff decrease with increasing rainfall intensity. The increased Ca concentration in soil solution increased stability of organic matter-mineral complexes and might decrease the dissolution of organic matter, and thus decreased the release of Cu-binding component of organic matter. However, high concentration of Na in the soil solution increased the dispersion of the organic matter-mineral complexes and increased dissolution of organic matter and the release of Cu from the soils.

  10. Remediation of sandy soils using surfactant solutions and foams.

    Science.gov (United States)

    Couto, Hudson J B; Massarani, Guilio; Biscaia, Evaristo C; Sant'Anna, Geraldo L

    2009-05-30

    Remediation of sandy soils contaminated with diesel oil was investigated in bench-scale experiments. Surfactant solution, regular foams and colloidal gas aphrons were used as remediation fluids. An experimental design technique was used to investigate the effect of relevant process variables on remediation efficiency. Soils prepared with different average particle sizes (0.04-0.12 cm) and contaminated with different diesel oil contents (40-80 g/kg) were used in experiments conducted with remediation fluids. A mathematical model was proposed allowing for the determination of oil removal rate-constant (k(v)) and oil content remaining in the soil after remediation (C(of)) as well as estimation of the percentage of oil removed. Oil removal efficiencies obtained under the central experimental design conditions were 96%, 88% and 35% for aphrons, regular foams and surfactant solutions, respectively. High removal efficiencies were obtained using regular foams and aphrons, demanding small amounts of surfactant.

  11. Extraction Efficiency of Belonolaimus longicaudatus from Sandy Soil.

    Science.gov (United States)

    McSorley, R; Frederick, J J

    1991-10-01

    Numbers of Belonolaimus longicaudatus extracted from sandy soils (91-92% sand) by sieving and centrifugation were only 40-55% of those extracted by sieving and incubation on a Baermann tray. Residues normally discarded at each step of the sieving plus Baermann tray extraction procedure were examined for nematodes to obtain estimates of extraction efficiencies. For third-stage and fourth-stage juveniles, males, and females, estimates of extraction efficiency ranged from 60 to 65% in one experiment and 73 to 82% in another. Estimated extraction efficiencies for second-stage juveniles were lower (33% in one experiment, 67% in another) due to losses during sieving. When sterilized soil was seeded with known numbers of B. longicaudatus, 60% of second-stage juveniles and 68-76% of other stages were recovered. Most stages of B. longicaudatus could be extracted from these soils by sieving plus Baermann incubation with an efficiency of 60-70%.

  12. Experiences of soil fertility management through legume based ...

    African Journals Online (AJOL)

    Mo

    either sandy soils or sandy loam soils to compare soil rehabilitation benefits of ... to incorporate the legume crop residues in order to maximize the residual nitrogen benefit to the cereal crop. ... different legume technologies either in rotation or.

  13. Imazaquin degradation and metabolism in a sandy loam soil amended with farm litters

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Imazaquin applied in legume crops has a long residual time in soil,which often impacts safety of the susceptible crops.To increase safety of imazaquin application,two composted litters,bovine manure (BM) and chicken manure (CM),were used to determine their effects on imazaquin environmental behavior by incorporating each kind of manure into the tested sandy loam soil at 10% (w/w).The degradation of imazaquin in BM- and CM-amended soil was about 2.4 and 1.5 times,respectively,faster than that in unamended soil.The half-lives of imazaquin in BM-amended soil varied between 6.7 and 15.4 d over the temperature range of 20 to 40℃,and the degradation rate constant (k) increased by a factor of about 1.5 for every 10℃ change.Higher mix ratio did not significantly increase the degradation,and the optimal active degradation of imazaquin was observed approximately at the mix ratio of 10:1 of soil to BM.The different moisture levels had negligible effect on imazaquin degradation.In both unamended and BM-amended treatments.two metabolites were observed at 5,10 and 30 d after treatment.One metabolite at retention time (RT) of 8.4 min was identified as 2-(4-hydroxyl-5-oxo-2-imidazolin-2-y1) quinoline acid,originating from the loss of isopropyl group and hydroxylation at the 4-position of imidazolinone ring.The other at RT of 12.9 min was identified as quinolinc-2,3-dicarboxylic anhydride,resulting from detachment of imidazolinone ring and the forming of dicarboxylic anhydride.This finding suggested that the addition of farm litters into soil might be a good management option since it can not only increase soil fertility but also contribute to increase safety of imazaquin application to the following susceptible crops.

  14. Maize productivity and mineral N dynamics following different soil fertility management practices on a depleted sandy soil in Zimbabwe

    NARCIS (Netherlands)

    Chikowo, R.; Mapfumo, P.; Nyamugafata, P.; Giller, K.E.

    2004-01-01

    There is a need for an improved understanding of nitrogen (N) dynamics in depleted sandy soils in southern Africa. A field experiment was conducted to evaluate the performance of different soil fertility improvement practices on a degraded granitic sandy soil in Zimbabwe. Legumes capable of accumula

  15. Leaching behaviour of azoxystrobin in sandy loam soil

    African Journals Online (AJOL)

    Mr HMM Mzimela

    2014-08-01

    Aug 1, 2014 ... harmful pesticide residues on the crops and in the soil. Recent studies have ... roots and translocate to stems and leaves via xylem, or through leaf ... Analysis of azoxystrobin was carried out on gas liquid chromatograph (GLC) ...

  16. Effect of Application of Increasing Concentrations of Contaminated Water on the Different Fractions of Cu and Co in Sandy Loam and Clay Loam Soils

    Directory of Open Access Journals (Sweden)

    John Volk

    2016-12-01

    Full Text Available This study aimed to establish the fate of copper (Cu and cobalt (Co in sandy loam and clay loam soils that had been irrigated with increasing concentrations of contaminated water. A sequential extraction procedure was used to determine the fractions of Cu and Co in these soils. The concentration of bioavailable Cu and Co on clay loam was 1.7 times that of sandy loam soil. Cu on sandy loam soil was largely in the organic > residual > exchangeable > water-soluble > carbonate fractions, whereas on clay loam soil the element was largely in organic > exchangeable > residual > carbonate > water-soluble fractions. Co was largely observed in the exchangeable, water-soluble, and carbonate fractions, but with no particular trend observed in both soil types. When crops are grown on sandy soils that have a low capacity to hold heavy metals, the resulting effect would be high uptake of the heavy metals in crop plants. Because the predominant forms of Cu and Co vary in soils, it is expected that the metals will behave differently in the soils.

  17. Quasi 3D modelling of water flow in the sandy soil

    Science.gov (United States)

    Rezaei, Meisam; Seuntjens, Piet; Joris, Ingeborg; Boënne, Wesley; De Pue, Jan; Cornelis, Wim

    2016-04-01

    Monitoring and modeling tools may improve irrigation strategies in precision agriculture. Spatial interpolation is required for analyzing the effects of soil hydraulic parameters, soil layer thickness and groundwater level on irrigation management using hydrological models at field scale. We used non-invasive soil sensor, a crop growth (LINGRA-N) and a soil hydrological model (Hydrus-1D) to predict soil-water content fluctuations and crop yield in a heterogeneous sandy grassland soil under supplementary irrigation. In the first step, the sensitivity of the soil hydrological model to hydraulic parameters, water stress, crop yield and lower boundary conditions was assessed after integrating models at one soil column. Free drainage and incremental constant head conditions were implemented in a lower boundary sensitivity analysis. In the second step, to predict Ks over the whole field, the spatial distributions of Ks and its relationship between co-located soil ECa measured by a DUALEM-21S sensor were investigated. Measured groundwater levels and soil layer thickness were interpolated using ordinary point kriging (OK) to a 0.5 by 0.5 m in aim of digital elevation maps. In the third step, a quasi 3D modelling approach was conducted using interpolated data as input hydraulic parameter, geometric information and boundary conditions in the integrated model. In addition, three different irrigation scenarios namely current, no irrigation and optimized irrigations were carried out to find out the most efficient irrigation regime. In this approach, detailed field scale maps of soil water stress, water storage and crop yield were produced at each specific time interval to evaluate the best and most efficient distribution of water using standard gun sprinkler irrigation. The results show that the effect of the position of the groundwater level was dominant in soil-water content prediction and associated water stress. A time-dependent sensitivity analysis of the hydraulic

  18. Effects of agricultural practices of three crops on the soil communities under Mediterranean conditions: field evaluation.

    Science.gov (United States)

    Leitão, Sara; José Cerejeira, Maria; Abreu, Manuela; Sousa, José Paulo

    2014-05-01

    Sustainable agricultural production relies on soil communities as the main actors in key soil processes necessary to maintain sustainable soil functioning. Soil biodiversity influences soil physical and chemical characteristics and thus the sustainability of crop and agro-ecosystems functioning. Agricultural practices (e.g.: soil tillage, pesticides and fertilizer applications, irrigation) may affects negatively or positively soil biodiversity and abundances by modifying the relationships between organisms in the soil ecosystem. The present study aimed to study the influence of agricultural practices of three crops (potato, onion and maize) under Mediterranean climate conditions on soil macro- and mesofauna during their entire crop cycles. Effects on soil communities were assessed at a higher tier of environmental risk assessment comprising field testing of indigenous edaphic communities in a selected study-site located in a major agriculture region of Central Portugal, Ribatejo e Oeste, neighbouring protected wetlands. A reference site near the agricultural field site was selected as a Control site to compare the terrestrial communities' composition and variation along the crop cycle. The field soil and Control site soil are sandy loam soils. Crops irrigation was performed by center-pivot (automated sprinkler that rotates in a half a circle area) and by sprinklers. Soil macro- and mesofauna were collected at both sites (field and Control) using two methodologies through pitfall trapping and soil sampling. The community of soil macro- and mesofauna of the three crops field varied versus control site along the crops cycles. Main differences were due to arachnids, coleopterans, ants and adult Diptera presence and abundance. The feeding activity of soil fauna between control site and crop areas varied only for potato and onion crops vs. control site but not among crops. Concentration of pesticides residues in soil did not cause apparent negative effects on the soil

  19. Biochar reduces copper toxicity in Chenopodium quinoa Willd. In a sandy soil.

    Science.gov (United States)

    Buss, Wolfram; Kammann, Claudia; Koyro, Hans-Werner

    2012-01-01

    Mining, smelting, land applications of sewage sludge, the use of fungicides containing copper (Cu), and other human activities have led to widespread soil enrichment and contamination with Cu and potentially toxic conditions. Biochar (BC) can adsorb several substances, ranging from herbicides to plant-inhibiting allelochemicals. However, the range of potential beneficial effects on early-stage plant growth with regard to heavy metal toxicity is largely unexplored. We investigated the ameliorating properties of a forestry-residue BC under Cu toxicity conditions on early plant growth. Young quinoa plants () were grown in the greenhouse in the presence of 0, 2, and 4% BC application (w/w) added to a sandy soil with 0, 50, or 200 μg g Cu supplied. The plants without BC showed severe stress symptoms and reduced growth shortly after Cu application of 50 μg g and died at 200 μg Cu g. Increasing BC concentrations in the growth medium significantly increased the plant performance without Cu toxicity or under Cu stress. At the 4% BC application rate, the plants with 200 μg g Cu almost reached the same biomass as in the control treatment. In the presence of BC, less Cu entered the plant tissues, which had reduced Cu concentrations in the order roots, shoots, leaves. The amelioration effect also was reflected in the plant-soil system CO gas exchange, which showed clear signs of improvement with BC presence. The most likely ameliorating mechanisms were adsorption of Cu to negatively charged BC surfaces and an improvement of the water supply. Overall, BC seems to be a beneficial amendment with the potential to ameliorate Cu toxicity in sandy soils. Further research with a broad spectrum of different soil types, BCs, and crop plants is required.

  20. Phosphorus fractions in sandy soils of vineyards in southern Brazil

    Directory of Open Access Journals (Sweden)

    Djalma Eugênio Schmitt

    2013-04-01

    Full Text Available Phosphorus (P applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm were collected from a native grassland area and two vineyards, after 14 years (vineyard 1 and 30 years (vineyard 2 of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO3, in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH, and in the non-labile fraction extracted by 1 mol L-1 HCl, indicating the possibility of water eutrophication. Phosphorus application and grapevine cultivation time increased the P content in the organic fraction extracted by NaHCO3 from the 0-5 cm layer, and especially in the moderately labile fraction extracted by 0.1 mol L-1 NaOH, down to a depth of 20 cm.

  1. Biochar application does not improve the soil hydrological function of a sandy soil

    NARCIS (Netherlands)

    Jeffery, S.; Meinders, M.B.C.; Stoof, C.R.; Bezemer, T.M.; Van de Voorde, T.F.J.; Mommer, L.; Van Groenigen, J.W.

    2015-01-01

    Biochar application to soil is currently being widely posited as a means to improve soil quality and thereby increase crop yield. Next to beneficial effects on soil nutrient availability and retention, biochar is assumed to improve soil water retention. However, evidence for such an effect in the

  2. Morphology of Rain Water Channeling in Systematically Varied Model Sandy Soils

    Science.gov (United States)

    Wei, Yuli; Cejas, Cesare M.; Barrois, Rémi; Dreyfus, Rémi; Durian, Douglas J.

    2014-10-01

    We visualize the formation of fingered flow in dry model sandy soils under different rain conditions using a quasi-2D experimental setup and systematically determine the impact of the soil grain diameter and surface wetting properties on the water channeling phenomenon. The model sandy soils we use are random closely packed glass beads with varied diameters and surface treatments. For hydrophilic sandy soils, our experiments show that rain water infiltrates a shallow top layer of soil and creates a horizontal water wetting front that grows downward homogeneously until instabilities occur to form fingered flows. For hydrophobic sandy soils, in contrast, we observe that rain water ponds on the top of the soil surface until the hydraulic pressure is strong enough to overcome the capillary repellency of soil and create narrow water channels that penetrate the soil packing. Varying the raindrop impinging speed has little influence on water channel formation. However, varying the rain rate causes significant changes in the water infiltration depth, water channel width, and water channel separation. At a fixed rain condition, we combine the effects of the grain diameter and surface hydrophobicity into a single parameter and determine its influence on the water infiltration depth, water channel width, and water channel separation. We also demonstrate the efficiency of several soil water improvement methods that relate to the rain water channeling phenomenon, including prewetting sandy soils at different levels before rainfall, modifying soil surface flatness, and applying superabsorbent hydrogel particles as soil modifiers.

  3. Effects of Soil properties on phosphorus subsurface migration in sandy soils

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-Kui

    2008-01-01

    The soil factors influencing the potential migration of dissolved and particulate phosphorus (P) from structurallyweak sandy subsoils were evaluated by means of soil column leaching experiments.Soil colloids were extracted from two types of soils to make the colloid-bound forms of P solution.Eight sandy soils with diverse properties were collected for packing soil columns.The effects of influent solutions varying in concentrations of colloids,P,and electrolyte,on the transport of P and quality of leachates were characterized.P migration in the soils was soil property-dependent.High soil electrical conductivity values retarded the mobility of colloids and transportability of colloid-associated P (particulate P).Soil electrical conductivity was negatively correlated with colloids and reactive particulate P (RPP) concentrations in the leachates,whereas,the total reactive P (TRP) and dissolved reactive P (DRP) concentrations in the leachates were mainly controlled by the P adsorption capacity and the P levels in the subsoil.The reactive particulate P in the leachates was positively correlated with the colloidal concentration.Increased colloidal concentration in the influent could significantly increase the colloidal concentration in the leachates.Elevated P concentration in the influent had little effect on P recovery in the leachates,but it resulted in significant increases in the absolute P concentration in the leachates.

  4. Organic fertilization for soil improvement in a vegetable cropping system

    Science.gov (United States)

    Verhaeghe, Micheline; De Rocker, Erwin; De Reycke, Luc

    2016-04-01

    Vegetable Research Centre East-Flanders Karreweg 6, 9770 Kruishoutem, Belgium A long term trial for soil improvement by organic fertilization was carried out in Kruishoutem from 2001 till 2010 in a vegetable rotation (carrots - leek - lettuce (2/year) - cauliflower (2/year) - leek - carrots - lettuce (2/year) - cauliflower (2/year) - leek and spinach). The trial compared yearly applications of 30 m²/ha of three types of compost (green compost, vfg-compost and spent mushroom compost) with an untreated object which did not receive any organic fertilization during the trial timescale. The organic fertilization was applied shortly before the cropping season. Looking at the soil quality, effects of organic fertilization manifest rather slow. The first four years after the beginning of the trial, no increase in carbon content of the soil is detectable yet. Although, mineralization of the soil has increased. The effect on the mineralization is mainly visible in crops with a lower N uptake (e.g. carrots) leading to a higher nitrate residue after harvest. Effects on soil structure and compaction occur rather slowly although, during the first two cropping seasons compost applications increase the water retention capacity of the soil. Compost increases the pH of the soil from the first year on till the end of the trial in 2010. Thus, organic fertilization impedes acidification in light sandy soils. Also soil fertility benefits from compost by an increase in K-, Ca- and Mg- content in the soil from the second year on. After 10 years of organic fertilization, yield and quality of spinach were increased significantly (porganic fertilization.

  5. Effects of cropping systems on soil biology

    Science.gov (United States)

    The need for fertilizer use to enhance soil nutrient pools to achieve good crop yield is essential to modern agriculture. Specific management practices, including cover cropping, that increase the activities of soil microorganisms to fix N and mobilize P and micronutrients may reduce annual inputs ...

  6. Heterogeneous water flow and pesticide transport in cultivated sandy soils : description of model concepts

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2011-01-01

    There is ample experimental evidence that complications in water flow and pesticide transport can occur in cultivated humic-sandy and loamy-sandy soils. As a result, pesticide leaching to groundwater and water courses can be higher than expected. We made an inventory of mechanistic/deterministic mod

  7. Effect of biochar and compost application on quantity, quality and stability of organic carbon in sandy soil

    Science.gov (United States)

    Holes, Annamaria; Szegi, Tamas; Fuchs, Marta; Micheli, Erika; Aleksza, Laszlo

    2014-05-01

    Nowadays the amount of waste is increasing as a consequence of civilization development. Significant proportion of municipal waste is biodegradable. For the treatment of these wastes composting and pyrolysis can be one solution. Many studies were published on the effects of composts in soils, but on combined application of biochars and composts only a limited number of articles are available. Total carbon content, water soluble organic carbon content and organic matter quality have decisive role in the utilization of soils. In our study the effects of combined application of biochars and compost on organic carbon quality, quantity and stability were measured in sandy soil. The sandy soil was mixed with different proportions (1w/w%, 2,5w/w%, 5w/w%, 10w/w%) of biochars. Two types of biochars produced by pyrolization were used: plant origin biochar (POB) and animal origin biochar (AOB). 20w/w% urban green compost was mixed into each sample in addition to biochars. After the 30 days of wet incubation soil organic carbon (SOC) content was determined by Walkley-Black method, while for the SOC quality measurements E4/E6 method was used. The dissolved organic carbon (DOC) was extracted from the soil samples by cold water, and determined by titrimetric method. The future purpose of our study is to find the optimal compost-biochar treatment in order to improve soil fertility and maximize crop yield.

  8. Temporal stability of the apparent electrical conductivity measured in seasonally dry sandy soil

    Science.gov (United States)

    Pedrera, Aura; Brevik, Eric C.; Giráldez, Juan V.; Vanderlinden, Karl

    2016-04-01

    Soil is spatially heterogeneous due to differences in parent material, climate, topography, time and management practices. The use of non-invasive and non-contact geophysical methods facilitates the exploration of natural landscapes or cropped areas. Electromagnetic induction (EMI) sensors which measure the soil apparent electrical conductivity (ECa) express soil spatial variability in terms of spatial soil ECa variability. In an agricultural context, knowledge and understanding of the soil spatial variability will allow us to delimit areas where precision agriculture techniques could be used to improve management practices. These practices enhance soil and water conservation, especially for sandy soils in Mediterranean climates where soils are dry for substantial periods of time. The first objective of this work was to apply principal component analysis (PCA) to see if a temporally stable component could be found. The second objective was to see if temporal stability information acquired from several ECa surveys could be used to better interpret results of a single survey in terms of relationships between ECa and soil water content (SWC). The experimental catchment, "La Manga", is located in SW Spain and covers 6.7 ha of a rainfed olive orchard. Soil profile samples were collected at 41 locations on a pseudo-regular grid. Samples were analyzed in the laboratory for soil texture, stone content, and bulk density (ρb). The catchment was sampled for gravimetric SWC at the 0-0.1 and 0.1-0.2 m depth intervals at the same 41 locations on 18 occasions. At the same 41 locations ECa was measured during 9 of the 18 SWC surveys using a DUALEM-21S EMI sensor. In addition, 7 field-wide ECa surveys were conducted. Soil ECa values were used to delimit three areas in the orchard, based on the spatial distribution of the first principal component (PC), which represented the spatial ECa pattern. Soil properties were studied within each area, and using analysis of variance

  9. Regional scale assessment of soil predictors of groundwater phosphate (P) levels in acidic sandy agricultural soils

    Science.gov (United States)

    Mabilde, Lisa

    2016-04-01

    Possible factors affecting the leaching of P to the groundwater in the Belgian sandy area are examined via regression analysis. The main objective is to investigate the dependency of phreatic groundwater phosphate concentrations (Flemish VMM monitoring net, monitoring period 2010-2013) on soil phosphate saturation degree (PSD) (1994-1997 mapping for Flemish Land Agency) (n = 1032). Additionally explored parameters include: depth distributions of Fe- and Al-oxides, sorbed P and phosphate sorption capacity (PSC) and soil pH. Interpolated data of these soil parameters in 3 depth layers (0-30, 30-60, 60-90 cm) were generated by ordinary kriging. Secondly, we assessed the significance of other edaphic factors potentially controlling the groundwater P: topsoil organic carbon content (OC %), soil clay content and fluctuation of the groundwater table. Overall, the mean PSD halved with each 30 cm depth layer (56 > 24 > 13 %) and was correlated to groundwater PO43- level. The statistical significance of the correlation with groundwater PO43- concentrations increased with depth layer. The poor correlation (R2 = 0.01) between PSD and groundwater phosphate concentration indicates that many factors, other than soil P status, control the transport of P from soil solution to the groundwater in Belgian sandy soils. A significant (PStructural equation modeling for example could be used to understand the practical importance of individual soil, management and hydrological potential predictors of groundwater PO4.

  10. Inhibiting water evaporation of sandy soil by the soil particles modified with Japanese wax

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zeng-Zhi; WANG Hong-Juan; Li Cui-Lan

    2009-01-01

    This study was conducted to resolve the problems of water conservation of sandy soil in desertification areas. The surface of soil particles was modified by molecules of natural Japanese wax through some specially screened surfactant. The modified particles were then well sprayed onto the sand, which was placed in an artificial climate box with simulating desert environment, to form a soil film with effect of suppressing water and gas-permeability. Structure of soil film was analyzed by means of X-ray diffraction (XRD) and infrared spectrometry (IR). And its mechanism of water inhibition was illustrated with DSC and TG curves. Its influence on grass-planting was tested through the instruments of water detector. The results show that sorbitol anhydride stearate(Span 80)could well disperse the Japanese wax and make it combine with the clay which is also dispersed. The pores among soil particles grew smaller and turned from hydrophilic into hydrophobic, in which way resistance to water penetrating through the film was increased. Experimental grass grows normally on sandy soil with the soil film in the artificial desert climate box, indicating that the soil particles modified with Japanese wax is an effective method to inhibit water evaporation.

  11. Cowpea N rhizodeposition and its below-ground transfer to a co-existing and to a subsequent millet crop on a sandy soil of the Sudano-Sahelian eco-zone

    DEFF Research Database (Denmark)

    Laberge, Guillaume; Haussmann, Bettina I.G.; Ambus, Per;

    2011-01-01

    Nitrogen (N) rhizodeposition by cowpea (Vigna unguiculata (L.) Walp) is potentially a large N source in cropping systems of Sub-Saharan Africa. A field experiment was conducted to measure cowpea N rhizodeposition under the conditions of the Sudano-Sahelian zone using direct 15N labelling techniques...

  12. Trade-offs between soil hydrology and plant disease effects after biochar amendment in sandy soil

    Science.gov (United States)

    Verheijen, Frank; Silva, Flavio; Amaro, Antonio; Pinto, Gloria; Mesquita, Raquel; Jesus, Claudia; Alves, Artur; Keizer, Jacob

    2015-04-01

    Biochar can affect multiple soil-based ecosystem services to varying extents, leading to trade-offs. Improvements in plant-available water have predominantly been found at high biochar application rates in sandy soils. Reductions in plant diseases after biochar application have been found in various horticultural plants, and trees such as maple and oak, mostly at relatively low biochar application rates. Serious damage to Eucalyptus globulus has been reported since 1999 when frequent and severe defoliation of young trees was observed, and eucalypts are the major tree species in commercial forestry plantations of Portugal, forming an important economic activity. Here we investigated simultaneous effects on plant available water and on disease suppression of eucalypt, in a completely randomised full factorial greenhouse pot experiment, using a range of woody feedstock biochar concentrations in sandy soil. Treatments included plant inoculation with the fungus Neofusicoccum kwambonambiense and cycles of acute drought stress. Preliminary results showed delayed wilting for plants treated with 3-6% biochar, but also increased stem lesion length. These results suggest a trade-off between effects on water availability and disease for Eucalyptus globulus plants in the selected sandy soil amended with this specific biochar, at the selected application rates.

  13. Quantitative Retrieval of Soil Nutrient in Sandy Land Based on BJ-1 Multispectral Image

    Science.gov (United States)

    Wu, Junjun; Li, Zengyuan; Gao, Zhihai; Wang, Bengyu; Bai, Lina; Sun, Bin; Li, Changlong; Ding, Xiangyuan

    2014-11-01

    To research an indicator for sandy information, this paper conducts a study on soil nutrient in sandy land. Firstly, the difference of soil nutrient between sandy land and the other was analyzed. Secondly, the correlation between soil nutrient index and band was studied. Then the best inversion band and model was determined and evaluated. Finally, the distribution of soil nutrient was obtained. As the result indicated that the divergence of total nitrogen in different land was the maximum among the three nutrient indicators. With the development of desertification, total nitrogen declined dramatically. The correlation coefficient between each band and total nitrogen was relatively higher, and it reached 0.6. In addition, taking the reciprocal for the sum of three bands as the independent variable was an excellent choice, it could reflect the sandy information better than the single band. The quantitative retrieval model was checked by independent sample, and RMSE was 0.0407.

  14. Effect of Particle Size and Soil Compaction on Gas Transport Parameters in Variably Saturated, Sandy Soils

    DEFF Research Database (Denmark)

    Hamamoto, Shoichiro; Møldrup, Per; Kawamoto, Ken

    2009-01-01

    the water retention curve), both exhibiting similar and exponential relationships with D50. Under variably saturated conditions, higher Dp and ka in coarser sand (larger D50) were observed due to rapid gas diffusion and advection through the less tortuous large-pore networks. In addition, soil compaction......The soil gas diffusion coefficient (Dp) and air permeability (ka) and their dependency on soil air content ( ) control gas diffusion and advection in soils. This study investigated the effects of average particle size (D50) and dry bulk density ( b) on Dp and ka for six sandy soils under variably...... saturated conditions. Data showed that particle size markedly affects the effective diameter of the drained pores active in leading gas through the sample at –100 cm H2O of soil water matric potential (calculated from Dp and ka) as well as the average pore diameter at half saturation (calculated from...

  15. Perennial crop phase effects on soil fertility

    Science.gov (United States)

    There is a need to develop agricultural management systems that enhance soil fertility and reduce reliance on external inputs. Perennial phases in crop rotations are effective at restoring soil fertility, though little information exists in the northern Great Plains regarding soil-based outcomes re...

  16. The fate of fresh and stored 15N-labelled sheep urine and urea applied to a sandy and a sandy loam soil using different application strategies

    DEFF Research Database (Denmark)

    Sørensen, P.; Jensen, E.S.

    1996-01-01

    .), or it was applied to ryegrass one month after sowing. In a sandy loam soil, 62% of the incorporated urine N and 78% of the incorporated urea N was recovered in three cuts of herbage after 5 months. In a sandy soil, 51-53% of the labelled N was recovered in the herbage and the distribution of labelled N in plant...... and soil was not significantly different for incorporated urine and urea. Almost all the supplied labelled N was accounted for in soil and herbage in the sandy loam soil, whereas 33-34% of the labelled N was unaccounted for in the sandy soil. When the stored urine was applied to the soil surface, 20...... unaccounted for was probably mainly lost by ammonia volatilization. Significantly more urine- than urea-derived N (36 and 19%, respectively) was immobilized in the sandy loam soil, whereas the immobilization of N from urea and urine was similar in the sandy soil (13-16%). The distribution of urine N, whether...

  17. Eleven years' effect of conservation practices for temperate sandy loams: I. Soil physical properties and topsoil carbon content

    DEFF Research Database (Denmark)

    Abdollahi, Lotfallah; Getahun, Gizachew Tarekegn; Munkholm, Lars Juhl

    2017-01-01

    experiments were conducted in 11- to 12-yr-old experiments on two Danish sandy loams at Foulum and Flakkebjerg. Three crop rotations/residue management treatments were compared and tillage was included as a splitplot factor. The tillage systems were moldboard plowing to a depth of 20 cm (MP), direct drilling...... their important role in soil structure formation and stabilization. Our study showed benefits of combining key CA elements, although longer-term studies are most likely needed to reveal the full potential....

  18. Solute leaching in a sandy soil with a water-repellent surface layer: a simulation.

    NARCIS (Netherlands)

    Rooij, de G.H.; Vries, de P.

    1996-01-01

    Many sandy soils in the Netherlands have a water-repellent surface layer covering a wettable soil with a shallow groundwater table. Fingers form in the water-repellent surface layer and rapidly transport water and solutes to the wettable soil in which the streamlines diverge. Although several field

  19. Overall assessment of soil quality on humid sandy loams: Effects of location, rotation and tillage

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Hansen, Elly Møller; Rickson, J.M.

    2015-01-01

    for each rotation: mouldboard ploughing to a depth of 20 cm (MP); harrowing to a depth of 8–10 cm (H); and direct drilling (D) at two experimental sites with a sandy loam soil and different water budgets in Denmark. The Muencheberg soil quality rating (M-SQR) method and simpler soil quality indices (i...

  20. Recharge in northern clime calcareous sandy soils: soil water chemical and carbon-14 evolution

    Science.gov (United States)

    Reardon, E. J.; Mozeto, A. A.; Fritz, P.

    1980-11-01

    Chemical analyses were performed on soil water extracted from two cores taken from a sandy calcareous soil near Delhi, Ontario. Calcite saturation is attained within the unsaturated zone over short distances and short periods of time, whereas dolomite undersaturation persists to the groundwater table. The progressive dissolution of dolomite by soil water, within the unsaturated zone, after calcite saturation is reached results in calcite supersaturation. Deposition of iron and manganese oxyhydroxide phases occurs at the carbonate leached/unleached zone boundary. This is a result of soil water neutralization due to carbonate dissolution during infiltration but may also reflect the increased rate of oxidation of dissolved ferrous and manganous ions at higher pH's. The role of bacteria in this process has not been investigated. The depth of the carbonate leached/unleached zone boundary in a calcareous soil has important implications for 14C groundwater dating. The depth of this interface at the study site (-2 m) does not appear to limit 14C diffusion from the root zone to the depth at which carbonate dissolution occurs. Thus, soil water achieves open system isotopic equilibrium with the soil CO 2 gas phase. It is calculated that in soils with similar physical properties to the study soil but with depths of leaching of 5 m or more, complete 14C isotopic equilibration of soil water with soil gas would not occur. Soil water, under these conditions would recharge to the groundwater exhibiting some degree of closed system 14C isotopic evolution.

  1. Impacts of crop growth dynamics on soil quality at the regional scale

    Science.gov (United States)

    Gobin, Anne

    2014-05-01

    Agricultural land use and in particular crop growth dynamics can greatly affect soil quality. Both the amount of soil lost from erosion by water and soil organic matter are key indicators for soil quality. The aim was to develop a modelling framework for quantifying the impacts of crop growth dynamics on soil quality at the regional scale with test case Flanders. A framework for modelling the impacts of crop growth on soil erosion and soil organic matter was developed by coupling the dynamic crop cover model REGCROP (Gobin, 2010) to the PESERA soil erosion model (Kirkby et al., 2009) and to the RothC carbon model (Coleman and Jenkinson, 1999). All three models are process-based, spatially distributed and intended as a regional diagnostic tool. A geo-database was constructed covering 10 years of crop rotation in Flanders using the IACS parcel registration (Integrated Administration and Control System). Crop allometric models were developed from variety trials to calculate crop residues for common crops in Flanders and subsequently derive stable organic matter fluxes to the soil. Results indicate that crop growth dynamics and crop rotations influence soil quality for a very large percentage. soil erosion mainly occurs in the southern part of Flanders, where silty to loamy soils and a hilly topography are responsible for soil loss rates of up to 40 t/ha. Parcels under maize, sugar beet and potatoes are most vulnerable to soil erosion. Crop residues of grain maize and winter wheat followed by catch crops contribute most to the total carbon sequestered in agricultural soils. For the same rotations carbon sequestration is highest on clay soils and lowest on sandy soils. This implies that agricultural policies that impact on agricultural land management influence soil quality for a large percentage. The coupled REGCROP-PESERA-ROTHC model allows for quantifying the impact of seasonal and year-to-year crop growth dynamics on soil quality. When coupled to a multi-annual crop

  2. Assessment of grass root effects on soil piping in sandy soils using the pinhole test

    Science.gov (United States)

    Bernatek-Jakiel, Anita; Vannoppen, Wouter; Poesen, Jean

    2017-04-01

    Soil piping is a complex land degradation process, which involves the hydraulic removal of soil particles by subsurface flow. This process is frequently underestimated and omitted in most soil erosion studies. However, during the last decades several studies reported the importance of soil piping in various climatic zones and for a wide range of soil types. Compared to sheet, rill and gully erosion, very few studies focused on the factors controlling piping and, so far, there is no research study dealing with the effects of plant roots on piping susceptibility of soils having a low cohesion. The objective of this study is therefore to assess the impact of grass root density (RD) on soil piping in sandy soils using the pinhole test. The pinhole test involves a water flow passing through a hole of 1 mm diameter in a soil specimen (sampled using a metal ring with a diameter of 5 cm and a length of 8 cm), under varying hydraulic heads (50 mm, 180 mm, 380 mm and 1020 mm; Nadal-Romero et al., 2011). To provide a quantitative assessment piping susceptibility of the soil sample, the pipeflow discharge (cm3 s-1) and the sediment discharge (g s-1) were measured every minute during a five minute test. Bare and root-permeated samples were tested, using a sandy soil with a sand, silt, clay content of respectively, 94%, 4% and 2%. The root-permeated topsoil samples were taken in field plots sown with a mixture of grasses with fibrous roots. All soil samples were placed on a sandbox with a 100 mm head for 24 hours to ensure a similar water content for all samples. In total, 67 pinhole tests (lasting 5 minutes each) were conducted, i.e. 43 root-permeated soil samples with RD ranging from 0.01 to 0.93 kg m-3 and 24 root-free soil samples as a reference. Clear piping erosion could be observed in 65% of the root-free soil samples, whereas only 17% of rooted soil samples revealed clear piping erosion during the tests. Statistical analyses show that there is a negative correlation (-0

  3. Copper Accumulation, Availability and Adsorption Capacity in Sandy Soils of Vineyards with Different Cultivation Duration

    Science.gov (United States)

    Mallmann, F. J. K.; Miotto, A.; Bender, M. A.; Gubiani, E.; Rheinheimer, D. D. S.; Kaminski, J.; Ceretta, C. A.; Šimůnek, J.

    2015-12-01

    Bordeaux mixture is a copper-based (Cu) fungicide and bactericide applied in vineyards to control plant diseases. Since it is applied several times per year, it accumulates in large quantities on plants and in soil. This study evaluates the Cu accumulation in, and desorption kinetics and adsorption capability of a sandy Ultisol in a natural field and in 3 vineyards for 5 (V1), 11 (V2), and 31 (V3) years in South of Brazil. Soil samples were collected in 8 depths (0-60 cm) of all four soil profiles, which all displayed similar soil properties. The following soil properties were measured: pH, organic matter (OM), soil bulk density, Cu total concentration, and Cu desorption and adsorption curves. A two first-order reactions model and the Langmuir isotherm were fitted to the desorption and adsorption curves, respectively. An increase in the total mass of Cu in the vineyards followed a linear regression curve, with an average annual increase of 7.15 kg ha-1. Cu accumulated down to a depth of 5, 20, and 30 cm in V1, V2 and V3, respectively, with the highest Cu content reaching 138.4 mg kg-1 in the 0-5 cm soil layer of V3. Cu desorption parameters showed a high correlation with its total concentration. Approximately 57 and 19% of total Cu were immediately and slowly available, respectively, indicating a high potential for plant absorption and/or downward movement. Cu concentrations extracted by EDTA from soil layers not affected by anthropogenic Cu inputs were very low. The maximum Cu adsorption capacity of the 0-5 and 5-10 cm soil layers increased with the vineyard age, reaching concentrations higher than 900 mg kg-1. This increase was highly related to OM and pH, which both increased with cultivation duration. Despite of low clay content of these soils, there is low risk of groundwater Cu contamination for actual conditions. However, high Cu concentrations in the surface layer of the long-term vineyards could cause toxicity problems for this and for companion crops.

  4. Soil erosion: perennial crop plantations

    NARCIS (Netherlands)

    Hartemink, A.E.

    2006-01-01

    Plantation agriculture is an important form of land-use in the tropics. Large areas of natural and regenerated forest have been cleared for growing oil palm, rubber, cocoa, coffee, and other perennial tree crops. These crops grown both on large scale plantations and by smallholders are important sou

  5. Water consumption and soil moisture distribution in melon crop with mulching and in a protected environment

    Directory of Open Access Journals (Sweden)

    Rodrigo Otávio Câmara Monteiro

    2013-06-01

    Full Text Available Mulching has become an important technique for land cover, but there are some technical procedures which should be adjusted for these new modified conditions to establish optimum total water depth. It is also important to observe the soil-water relations as soil water distribution and wetted volume dimensions. The objective of the present study was to estimate melon evapotranspiration under mulching in a protected environment and to verify the water spatial distribution around the melon root system in two soil classes. Mulching provided 27 mm water saving by reducing water evaporation. In terms of volume each plant received, on average, the amount of 175.2 L of water in 84 days of cultivation without mulching, while when was used mulching the water requirement was 160.2 L per plant. The use of mulching reduced the soil moisture variability throughout the crop cycle and allowed a greater distribution of soil water that was more intense in the clay soil. The clayey soil provided on average 43 mm more water depth retention in 0.50 m soil deep relative to the sandy loam soil, and reduced 5.6 mm the crop cycle soil moisture variation compared to sandy loam soil.

  6. Growth, Yield and WUE of Drip and Sprinkler Irrigated Okra Grown On Sandy Soil Under Semi-Arid Conditions in Southeast Ghana

    DEFF Research Database (Denmark)

    Plauborg, Finn

    Vegetable production systems at the Keta sand spit, Southeast Ghana, are typically managed with excessive amounts of irrigation water and fertilizers on sandy soils with low inherent water and nutrient retention capacities. The shallow groundwater which is the primary irrigation water resource...... is prone to salinization from the Keta lagoon, the Atlantic Ocean and brackish water underneath (Kortatsi and Agyeku, 1999). To ensure the sustainability of vegetable production at the Keta spit, introduction of water saving irrigation systems and improved irrigation management schemes are important. Thus...... for the drip irrigated okra crop was 269 mm compared to 379 mm for sprinkler. By adopting drip irrigation to okra, the seasonal crop water use could be reduced close to 30 %. From the results it is concluded that on rough textured sandy soil drip irrigation with frequent weekly fertigation resulted...

  7. [Effects of Different Residue Part Inputs of Corn Straws on CO2 Efflux and Microbial Biomass in Clay Loam and Sandy Loam Black Soils].

    Science.gov (United States)

    Liu, Si-yi; Liang, Ai-zhen; Yang, Xue-ming; Zhang, Xiao-ping; Jia, Shu-xia; Chen, Xue-wen; Zhang, Shi-xiu; Sun, Bing-jie; Chen, Sheng-long

    2015-07-01

    The decomposed rate of crop residues is a major determinant for carbon balance and nutrient cycling in agroecosystem. In this study, a constant temperature incubation study was conducted to evaluate CO2 emission and microbial biomass based on four different parts of corn straw (roots, lower stem, upper stem and leaves) and two soils with different textures (sandy loam and clay loam) from the black soil region. The relationships between soil CO2 emission, microbial biomass and the ratio of carbon (C) to nitrogen (N) and lignin of corn residues were analyzed by the linear regression. Results showed that the production of CO2 was increased with the addition of different parts of corn straw to soil, with the value of priming effect (PE) ranged from 215. 53 µmol . g-1 to 335. 17 µmol . g -1. Except for corn leaves, the cumulative CO2 production and PE of clay loam soil were significantly higher than those in sandy loam soil. The correlation of PE with lignin/N was obviously more significant than that with lignin concentration, nitrogen concentration and C/N of corn residue. The addition of corn straw to soil increased the contents of MBC and MBN and decreased MBC/MBN, which suggested that more nitrogen rather than carbon was conserved in microbial community. The augmenter of microbial biomass in sandy loam soil was greater than that in clay loam soil, but the total dissolved nitrogen was lower. Our results indicated that the differences in CO2 emission with the addition of residues to soils were primarily ascribe to the different lignin/N ratio in different corn parts; and the corn residues added into the sandy loam soil could enhance carbon sequestration, microbial biomass and nitrogen holding ability relative to clay loam soil.

  8. Improvement of Water Movement in an Undulating Sandy Soil Prone to Water Repellency

    NARCIS (Netherlands)

    Oostindie, K.; Dekker, L.W.; Wesseling, J.G.; Ritsema, C.J.

    2011-01-01

    The temporal dynamics of water repellency in soils strongly influence water flow. We investigated the variability of soil water content in a slight slope on a sandy fairway exhibiting water-repellent behavior. A time domain reflectometry (TDR) array of 60 probes measured water contents at 3-h

  9. Rain water transport and storage in a model sandy soil with hydrogel particle additives.

    Science.gov (United States)

    Wei, Y; Durian, D J

    2014-10-01

    We study rain water infiltration and drainage in a dry model sandy soil with superabsorbent hydrogel particle additives by measuring the mass of retained water for non-ponding rainfall using a self-built 3D laboratory set-up. In the pure model sandy soil, the retained water curve measurements indicate that instead of a stable horizontal wetting front that grows downward uniformly, a narrow fingered flow forms under the top layer of water-saturated soil. This rain water channelization phenomenon not only further reduces the available rain water in the plant root zone, but also affects the efficiency of soil additives, such as superabsorbent hydrogel particles. Our studies show that the shape of the retained water curve for a soil packing with hydrogel particle additives strongly depends on the location and the concentration of the hydrogel particles in the model sandy soil. By carefully choosing the particle size and distribution methods, we may use the swollen hydrogel particles to modify the soil pore structure, to clog or extend the water channels in sandy soils, or to build water reservoirs in the plant root zone.

  10. Contribution of individual sorbents to the control of heavy metal activity in sandy soil

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2001-01-01

    A multisurface model is used to evaluate the contribution of various sorption surfaces to the control of heavy metal activity in sandy soil samples at pH 3.7-6.1 with different sorbent contents. This multisurface model considers soil as a set of independent sorption surfaces, i.e. organic matter (NI

  11. Irrigation and nitrogen use efficiency of Thuja occidentalis grown on sandy soils

    NARCIS (Netherlands)

    Pronk, A.A.

    2004-01-01

    A combined conifer growth - soil water and nitrogen balance model was calibrated to simulate dry mass production and partitioning, water and nitrogen demand and nitrogen losses for Thuja occidentalis grown for two years on a sandy soil. Light interception was successfully described by the row-of-cub

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

    DEFF Research Database (Denmark)

    Chirinda, Ngonidzashe; Olesen, Jørgen Eivind; Porter, John Roy

    2010-01-01

    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...... 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...

  13. Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil Column Method

    Directory of Open Access Journals (Sweden)

    Sulakhudin

    2010-01-01

    Full Text Available Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil ColumnMethod (Sulakhudin, A Syukur, D Shiddieq and T Yuwono: In coastal sandy soil, mainly nitrogen losses due toleaching resulted to low fertilizer efficiency. Slow-release N fertilizers are proposed to minimize these losses, andhumic-calcium coated urea has been examined. A soil column method was used to compare the effects of coated ureawith humic-calcium on transformation and leaching loss of N in coastal sandy soil. The experiment aid to compare twokinds sources of humic substances (cow manure and peat which mixed with calcium as coated urea on transformation,vertical distribution and leaching N in coastal sandy soil. The concentration of humic-calcium coated urea i.e.1%, 5%and 10% based on their weight. The results showed that urea coated with humic-calcium from cow manure (UCHMand humic-calcium from peat (UCHP increased the N total and available N in the soil and decreased leaching loss ofN from the soil column. Compared to UCHP, UCHM in all concentration showed N-nitrate higher than N-ammonium onincubation length 2, 4 and 6 weeks. The N leached from a costal sandy soil with application coated urea with UCHMranged from 21.18% to 23.72% of the total N added as fertilizer, for coated urea with UCHP they ranged between21.44% and 23.25%, whereas for urea (control reached 29.48%. Leaching losses of mineral N were lower when ureacoated with UCHM compared to urea coated with UCHP or urea fertilizer. The study concluded that the UCHM isbetter than UCHP in decreasing N leached from coastal sandy soil

  14. Effects of Carboxymethylcelluloses (CMC) on Some Hydraulic Properties of Sandy Soil

    Institute of Scientific and Technical Information of China (English)

    ANDRY Henintsoa; INOUE Mitsuhiro; MORITANI Shigeoki; UZOMA Kingsley Chinyere

    2010-01-01

    The property of hydrophilic polymers capable absorbing huge volumes of water led to many practical applications of these new materials in arid regions for improving the water retention in sandy soils. Effects of four carboxymethylcelluloses (CMC), mixed at various rates with the sandy soil, on the water-holding capacity and hydraulic conductivity (Ks) when leached with distilled water (simulating rain), tap water, and saline water were evaluated. The maximum water absorption of CMCs ranged between 80 and 100 kg. kg-1 of polymer; however, the absorbent swelling capacity decreased significantly with increasing the salt concentration in the solution. The water absorption capacity of CMCs decreased significantly when incorporated in the sandy soil compared to that of the absorbent alone. Application of CMC increased significantly the available water content up to 3 ±0.5 times. All soils treated with CMCs showed a significant lower in Ks compared to the control soil. Meanwhile, Ks was found increased with increasing the salt concentration in the leaching solution. This understanding of characteristics of the absorbents and the interactions among absorbents, soil, and irrigation water quality would be of help in water management of sandy soil.

  15. Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil.

    Science.gov (United States)

    Zhuang, Wenhua; Li, Longguo; Liu, Chao

    2013-01-01

    Based on the laboratory study, the effects of sodium polyacrylate (SP) was investigated at 5 rates of 0, 0.08, 0.2, 0.5, and 1%, on water retention, saturated hydraulic conductivity(Ks), infiltration characteristic and water distribution profiles of a sandy soil. The results showed that water retention and available water capacity effectively increased with increasing SP rate. The Ks and the rate of wetting front advance and infiltration under certain pond infiltration was significantly reduced by increasing SP rate, which effectively reduced water in a sandy soil leaking to a deeper layer under the plough layer. The effect of SP on water distribution was obviously to the up layer and very little to the following deeper layers. Considering both the effects on water retention and infiltration capacity, it is suggested that SP be used to the sandy soil at concentrations ranging from 0.2 to 0.5%.

  16. [Monitoring of water and salt transport in silt and sandy soil during the leaching process].

    Science.gov (United States)

    Fu, Teng-Fei; Jia, Yong-Gang; Guo, Lei; Liu, Xiao-Lei

    2012-11-01

    Water and salt transport in soil and its mechanism is the key point of the saline soil research. The dynamic rule of water and transport in soil during the leaching process is the theoretical basis of formation, flush, drainage and improvement of saline soil. In this study, a vertical infiltration experiment was conducted to monitor the variation in the resistivity of silt and sandy soil during the leaching process by the self-designed automatic monitoring device. The experimental results showed that the peaks in the resistivity of the two soils went down and faded away in the course of leaching. It took about 30 minutes for sandy soil to reach the water-salt balance, whereas the silt took about 70 minutes. With the increasing leaching times, the desalination depth remained basically the same, being 35 cm for sandy soil and 10 cm for the silt from the top to bottom of soil column. Therefore, 3 and 7 leaching processes were required respectively for the complete desalination of the soil column. The temporal and spatial resolution of this monitoring device can be adjusted according to the practical demand. This device can not only achieve the remote, in situ and dynamic monitoring data of water and salt transport, but also provide an effective method in monitoring, assessment and early warning of salinization.

  17. Micronutrients in Soils, Crops, and Livestock

    Science.gov (United States)

    Gupta, Umesh C.; Wu, Kening; Liang, Siyuan

    Micronutrient concentrations are generally higher in the surface soil and decrease with soil depth. In spite of the high concentration of most micronutrients in soils, only a small fraction is available to plants. Micronutrients, also known as trace elements, are required in microquantities but their lack can cause serious crop production and animal health problems. Crops vary considerably in their response to various micronutrients. Brassicas and legumes are highly responsive to molybdenum (Mo) and boron (B), whereas corn and other cereals are more responsive to zinc (Zn) and copper (Cu). Micronutrient deficiencies are more common in humid temperate regions, as well as in humid tropical regions, because of intense leaching associated with high precipitation. Soil pH is one of the most important factors affecting the availability of micronutrients to plants. With increasing pH, the availability of these nutrients is reduced with the exception of Mo whose availability increases as soil pH increases. In most plant species, leaves contain higher amounts of nutrients than other plant parts. Therefore, whenever possible, leaves should be sampled to characterize the micronutrient status of crops. Deficiency symptoms for most micronutrients appear on the younger leaves at the top of the plant, whereas toxicity symptoms generally appear on the older leaves of plants. As summarized by Deckers and Steinnes, micronutrient deficiencies are widespread in developing countries, which have much poorer soil resources than the fertile soils of Europe and North America. Many of these areas lie in the humid tropics with extremely infertile, highly weathered, and/or highly leached soils, which are intensely deficient in nutrients. The rest of such soils are in the semiarid and areas adjacent to the latter, where alkaline and calcareous soil conditions severely limit the availability of micronutrients to plants. Frequently, the Cu, iron (Fe), manganese (Mn), Zn, and selenium (Se) levels

  18. Application of Wenner Configuration to Estimate Soil Water Content in Pine Plantations on Sandy Land

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To estimate the mean value of surface soil water content rapidly, accurately, and nonintrusively, field investigations on soil electrical resistivity (SER) with the Yokogawa 324400 earth resistivity meter and the surface (0-150 cm) soil water content (SWC) with time domain reflectometry (TDR), together with the abiotic factors including soil texture, structure,and salinity concentrations were conducted in the Mongolian pine (Pinus sylvestris var. mongolica) plantations on a sandy land. The measurement of SER was based on the 4-probe Wenner configuration method. Relationships between the values of SWC and SER were obtained based on analysis of the abiotic factors of the research site, which play a key role in affecting the soil electrical resistivity. Results indicate that the SER meter could be used to estimate the mean value of SWC in the Mongolian pine plantations on the sandy land during the growing seasons. The bulky nature of the equipment simplified the cumbersome measurements of soil water content with the general methods. It must be noted that the Wenner configuration method could only provide the mean values of the SWC, and the soil texture, structure,temperature, and solute concentrations influenced the SER and further affected the estimation of the SWC by the SER meter. Therefore, the results of this study could be applied on a sandy land during the growing seasons only. However,the SWC of other soil types also may be obtained according to the individual soil types using the procedures of this study.

  19. Experiments on the movement of pesticides in sandy soils to groundwater : prospects of testing preferential transport models

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2012-01-01

    Many agricultural areas with humic-sandy and loamy-sandy soils are used also for the extraction of water for drinking-water supply. Model concepts have been developed for the fast preferential transport of plant protection products (pesticides) in such soils, e.g. by fingered and funneled flow. An i

  20. Effect of Land Cover Change on Soil Phosphorus Fractions in Southeastern Horqin Sandy Land, Northern China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qiong; ZENG De-Hui; FAN Zhi-Ping; D.K.LEE

    2008-01-01

    In the past 50 years, large areas of the Horqin sandy land were afforested to prevent desertification. Although the afforestation policy appears successful, many people now doubt whether it is suitable to plant trees with high density on the poor soils in semiarid regions. Little is known about the impacts of afforestation on the sandy soil properties, although the evaluation of these impacts is fundamental to judge the rationality of afforestation policy. Soil phosphorus (P) fractions, acid phosphomonoesterase activities, and other soil chemical properties were compared among five adjoining typical ecosystems on poor sandy soils in southeastern Horqin sandy land. The ecosystems studied are natural elm savanna, degraded grassland, Mongolian pine (Pinus sylvestris var. Mongolica) plantation, Chinese pine (Pinus tabulaeformis) plantation, and mixed plantation of Mongolian pine and poplar (Populus simonii). The results showed that organic P dominated soil P (47%-65%) was the principal source of available P. The degradation of elm savanna to grassland significantly reduced soil pH and resulted in an overall reduction in soil fertility, although slightly increased labile inorganic P. Grassland afforestation had no significant influence on soil pH, organic carbon, and total N but significantly reduced total P. Impacts of grassland afforestation on soil P fractions depended on tree species. Natural elm savanna had higher soil P conserving ability than artificial plantations. Therefore, with the aim of developing a sustainable ecosystem, we suggested that vegetations with low nutrient demand (particularly P) and efficient nutrient cycling would be more suitable for ecosystem restoration in the semiarid region.

  1. Soil Inorganic Nitrogen and Microbial biomass Carbon and Nitrogen Under Pine Plantations in Zhanggutai Sandy Soil

    Institute of Scientific and Technical Information of China (English)

    YU Zhan-Yuan; CHEN Fu-Sheng; ZENG De-Hui; ZHAO Qiong; CHEN Guang-Sheng

    2008-01-01

    The dynamics of soil inorganic nitrogen (NH+4-N and NO-3N) and microbial biomass carbon (Cmic) and nitrogen (Nmic) under 30-year-old fenced Pinus sylvestris L. var. mongolica Litvin (SF), unfenced P. sylvestris L. var. mongolica Litvin (SUF), and unfenced Pinus densiflora Siebold et Zucc. (DUF) plantations in the Zhanggutai sandy soil of China were studied during Apr. to Oct. 2004 by the in situ closed-top core incubation method. All mentioned C and N indices in each stand type fluctuated over time. The ranges of inorganic N, Cmic, and Nmic contents in the three stand types were 0.7-2.6, 40.0-128.9, and 5.4-15.2 μg g-1, respectively. The average contents of soil NH+4-N and Cmic under the three 30-year-old pine plantations were not different. However, soil NO-3-N and total inorganic N contents decreased in the order of SUF > SF > DUF, the Nmic content was in the order of SF = SUF > DUF, and the Cmic:Nmic ratio was in the order of SUF = DUF > SF. Seasonal variations were observed in soil inorganic N, microbial biomass, and plant growth. These seasonal variations had certain correlations with microbe and plant N use in the soil, and their competition for NH+4-N was mostly regulated by soil N availability. The influence of tree species on inorganic N and Nmic were mainly because of differences in litter quality. Lack of grazing decreased the Cmic:N ratio owing to decreased carbon output and increased the ability of soil to supply N. The soil N supply under the P. sylvestris var. mongolica plantation was lower than under the P. densiflora plantation.

  2. Distribution of transformed organic matter in structural units of loamy sandy soddy-podzolic soil

    Science.gov (United States)

    Kogut, B. M.; Yashin, M. A.; Semenov, V. M.; Avdeeva, T. N.; Markina, L. G.; Lukin, S. M.; Tarasov, S. I.

    2016-01-01

    The effect of land use types and fertilizing systems on the structural and aggregate composition of loamy sandy soddy-podzolic soil and the quantitative parameters of soil organic matter has been studied. The contribution of soil aggregates 2-1 mm in size to the total Corg reserve in the humus horizon is higher than the contributions of other aggregates by 1.3-4.2 times. Reliable correlations have been revealed between the contents of total (Corg), labile (Clab), and active (C0) organic matter in the soil. The proportion of C0 is 44-70% of Clab extractable by neutral sodium pyrophosphate solution. The contributions of each of the 2-1, 0.5-0.25, and humus horizon of loamy sandy soddy-podzolic soil, the active, slow, and passive pools contain 6-11, 34-65, and 26-94% of the total Corg, respectively.

  3. Water and nutrient productivity in melon crop by fertigation under subsurface drip irrigation and mulching in contrasting soils

    Directory of Open Access Journals (Sweden)

    Rodrigo Otávio Câmara Monteiro

    2014-01-01

    Full Text Available Cropping intensification and technical, economic and environmental issues require efficient application of production factors to maintain the soil productive capacity and produce good quality fruits and vegetables. The production factors, water and NPK nutrients, are the most frequent limiting factors to higher melon yields. The objective of the present study was to identify the influence of subsurface drip irrigation and mulching in a protected environment on the water and NPK nutrients productivity in melon cropped in two soil types: sandy loam and clay. The melon crop cultivated under environmental conditions with underground drip irrigation at 0.20m depth, with mulching on sandy loam soil increased water and N, P2O5 and K use efficiency.

  4. Plant functional diversity enhances associations of soil fungal diversity with vegetation and soil in the restoration of semiarid sandy grassland.

    Science.gov (United States)

    Zuo, Xiaoan; Wang, Shaokun; Lv, Peng; Zhou, Xin; Zhao, Xueyong; Zhang, Tonghui; Zhang, Jing

    2016-01-01

    The trait-based approach shows that plant functional diversity strongly affects ecosystem properties. However, few empirical studies show the relationship between soil fungal diversity and plant functional diversity in natural ecosystems. We investigated soil fungal diversity along a restoration gradient of sandy grassland (mobile dune, semifixed dune, fixed dune, and grassland) in Horqin Sand Land, northern China, using the denaturing gradient gel electrophoresis of 18S rRNA and gene sequencing. We also examined associations of soil fungal diversity with plant functional diversity reflected by the dominant species' traits in community (community-weighted mean, CWM) and the dispersion of functional trait values (FD is). We further used the structure equation model (SEM) to evaluate how plant richness, biomass, functional diversity, and soil properties affect soil fungal diversity in sandy grassland restoration. Soil fungal richness in mobile dune and semifixed dune was markedly lower than those of fixed dune and grassland (P functional diversity explained nearly 70% variances of soil fungal richness. Strong association of soil fungal richness with the dominant species in the community supported the mass ratio hypothesis. Our results clearly highlight the role of plant functional diversity in enhancing associations of soil fungal diversity with community structure and soil properties in sandy grassland ecosystems.

  5. Cover crop effects on soil carbon and nitrogen under bioenergy sorghum crops

    Science.gov (United States)

    Cover crops can increase soil C and N storage and reduce the potential for N leaching under agronomic crops, but information on their benefits under bioenergy crops is scanty due to the removal of aboveground biomass. The objective of the study was to evaluate the effect of cover crops on soil organ...

  6. Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas

    Science.gov (United States)

    Irrigation initiation timing was evaluated in furrow-irrigated soybean field with sandy soils in Mississippi County, AR. A major objective of this 2015 study was to validate and expand irrigation timing recommendations that pair plant growth measures with weather cues including use of local weather ...

  7. Effects of DCD addition to slurry on nitrate leaching in sandy soils

    NARCIS (Netherlands)

    Corré, W.J.; Zwart, K.B.

    1995-01-01

    The effects of the addition of the nitrification inhibitor dicyandiamide (DCD) to cattle slurry, applied in autumn to an arable sandy soil, were investigated in a three-year field experiment in the Netherlands. Treatments included application of slurry with DCD in November and December, application

  8. Transport of water and solutes in wettable and water repellent sandy soils

    NARCIS (Netherlands)

    Ritsema, C.J.; Dekker, L.W.

    1996-01-01

    The research yielded the following conclusions and results: preferential flow can be expected in recently deposited, loosely packed, wettable dune sands; preferential flow is common in most water-repellent sandy soils; distribution flow in topsoils isa process of major importance, resulting in a

  9. Improvement of Faba Bean Yield Using Rhizobium/Agrobacterium Inoculant in Low-Fertility Sandy Soil

    Directory of Open Access Journals (Sweden)

    Sameh H. Youseif

    2017-01-01

    Full Text Available Soil fertility is one of the major limiting factors for crop’s productivity in Egypt and the world in general. Biological nitrogen fixation (BNF has a great importance as a non-polluting and a cost-effective way to improve soil fertility through supplying N to different agricultural systems. Faba bean (Vicia faba L. is one of the most efficient nitrogen-fixing legumes that can meet all of their N needs through BNF. Therefore, understanding the impact of rhizobial inoculation and contrasting soil rhizobia on nodulation and N2 fixation in faba bean is crucial to optimize the crop yield, particularly under low fertility soil conditions. This study investigated the symbiotic effectiveness of 17 Rhizobium/Agrobacterium strains previously isolated from different Egyptian governorates in improving the nodulation and N2 fixation in faba bean cv. Giza 843 under controlled greenhouse conditions. Five strains that had a high nitrogen-fixing capacity under greenhouse conditions were subsequently tested in field trials as faba bean inoculants at Ismaillia Governorate in northeast Egypt in comparison with the chemical N-fertilization treatment (96 kg N·ha−1. A starter N-dose (48 kg N·ha−1 was applied in combination with different Rhizobium inoculants. The field experiments were established at sites without a background of inoculation under low fertility sandy soil conditions over two successive winter growing seasons, 2012/2013 and 2013/2014. Under greenhouse conditions, inoculated plants produced significantly higher nodules dry weight, plant biomass, and shoot N-uptake than non-inoculated ones. In the first season (2012/2013, inoculation of field-grown faba bean showed significant improvements in seed yield (3.73–4.36 ton·ha−1 and seed N-yield (138–153 Kg N·ha−1, which were higher than the uninoculated control (48 kg N·ha−1 that produced 2.97 Kg·ha−1 and 95 kg N·ha−1, respectively. Similarly, in the second season (2013

  10. Biochar and Mill Ash Use as Soil Amendments to Grow Sugarcane in Sandy Soils of South Florida

    Science.gov (United States)

    Alvarez-Campos, O.; Lang, T. A.; Bhadha, J. H.; McCray, M.; Gao, B.; Glaz, B.; Daroub, S. H.

    2015-12-01

    The use of agricultural and urban organic residues as amendments provides an option to improve sugarcane production in sandy soils located northwest of the Everglades Agricultural Area, while reducing waste. This study was conducted to determine the effect of mill ash and three biochars on sugarcane yield and sandy soil properties. Mill ash and biochars produced from hardwood yard waste (HY), barn shavings with horse manure (HM), and rice hulls (RH) were incorporated at 1% and 2% (by weight) to sandy soils in a lysimeter experiment. A control without amendment and an often-used commercial practice of mill ash applied at 6% (AS6) were also included. Results showed that RH2 and AS6 produced greater biomass and sucrose yield compared with the control. According to critical nutrient level analysis, RH and AS amendments also resulted in the highest silicon content, which had a positive correlation with increasing sugarcane yield. In addition, RH2 and AS6 increased total phosphorus, Mehlich-3 phosphorus, and cation exchange capacity (CEC) compared with the control. While CEC remained constant with AS2 and AS6 applications, CEC significantly increased over time with RH2. Moreover, higher amendment applications increased soil organic matter compared with the control and did not decrease over time, which suggests a positive influence for long term carbon sustainability and nutrient cycling in sandy soils. Overall, RH2 and AS6 have the most potential to be used as amendments in sandy soils of South Florida due to their positive effects on soil properties, which improved sugarcane yield. However, no negative consequences were found with the application of any other amendment in terms of sugarcane growth and soil quality. Future research should focus on the use of RH and AS amendments on long-term field-scale studies, and the economic feasibility of a single year application on plant and ratoon cane yields.

  11. Use of arsenic contaminated irrigation water for lettuce cropping: effects on soil, groundwater, and vegetal.

    Science.gov (United States)

    Beni, Claudio; Marconi, Simona; Boccia, Priscilla; Ciampa, Alessandra; Diana, Giampietro; Aromolo, Rita; Sturchio, Elena; Neri, Ulderico; Sequi, Paolo; Valentini, Massimiliano

    2011-10-01

    The present study investigated the effects of using arsenic (As) contaminated irrigation water in Lactuca sativa L. cropping. Two different arsenic concentrations, i.e., 25 and 85 μg L(-1) and two different soils, i.e., sandy and clay loam, were taken into account. We determined the arsenic mobility in the different soil fractions, its amount in groundwater, and the phytotoxicity and genotoxicity. Nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP) were used to assess the lettuce metabolic profile changes and the arsenic uptake by the plant, respectively, as a function of the various conditions studied, i.e., As content and type of soil. Data indicated that at both concentrations in sandy soil, arsenic is in part quickly leached and thus present in groundwater and in part absorbed by the vegetable, being therefore readily available for assimilation by consumption. NMR results reported a large modification of the metabolic pattern, which was depending on the pollutant amount. In clay loam soil, the groundwater had a low As content with respect to sandy soil, and NMR and ICP performed on the lettuce did not reveal severe changes related to As, most likely because the metalloid is bound to the colloidal fraction.

  12. Temporal stability of electrical conductivity in a sandy soil

    Science.gov (United States)

    Pedrera-Parrilla, Aura; Brevik, Eric C.; Giráldez, Juan V.; Vanderlinden, Karl

    2016-07-01

    Understanding of soil spatial variability is needed to delimit areas for precision agriculture. Electromagnetic induction sensors which measure the soil apparent electrical conductivity reflect soil spatial variability. The objectives of this work were to see if a temporally stable component could be found in electrical conductivity, and to see if temporal stability information acquired from several electrical conductivity surveys could be used to better interpret the results of concurrent surveys of electrical conductivity and soil water content. The experimental work was performed in a commercial rainfed olive grove of 6.7 ha in the `La Manga' catchment in SW Spain. Several soil surveys provided gravimetric soil water content and electrical conductivity data. Soil electrical conductivity values were used to spatially delimit three areas in the grove, based on the first principal component, which represented the time-stable dominant spatial electrical conductivity pattern and explained 86% of the total electrical conductivity variance. Significant differences in clay, stone and soil water contents were detected between the three areas. Relationships between electrical conductivity and soil water content were modelled with an exponential model. Parameters from the model showed a strong effect of the first principal component on the relationship between soil water content and electrical conductivity. Overall temporal stability of electrical conductivity reflects soil properties and manifests itself in spatial patterns of soil water content.

  13. Cumulative and residual effects of potato cropping system management strategies on crop and soil health parameters

    Science.gov (United States)

    Soil and crop management practices can greatly affect parameters related to soil health, as well as crop productivity and disease development, and may provide options for more sustainable production. Different 3-yr potato cropping systems focused on specific management goals of soil conservation (SC...

  14. Retention of pesticides in sandy soil columns modified with a wood barrier

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Martin, M. J.; Rodriguez-Cruz, M. S.; Ordax, J. M.; Arienzo, M.

    2009-07-01

    Wood residues can be used as low-cost potential sorbents of hydrophobic pesticides in technologies aimed to prevent soil and water contamination and reduce the risk of environmental pollution produced by point pollution sources of these compounds. The objective of this work was to study the effect of a pine or oak sawdust barrier on the retention of Iinuron, alachlor and metalaxyl, with different hydrophobic character, in a sandy soil. (Author)

  15. Parameters of the occurrence of internal erosion processes in salty-sandy soils

    OpenAIRE

    Gajić Grozdana

    2005-01-01

    The study was aimed at defining the conditions of the occurrence of internal erosion in silty-sandy soils. The susceptibility of this soil to internal erosion depends on the porosity, particle-size composition and hydro-geo-mechanical parameters. Internal erosion stability was analyzed by the introduction of the coefficient of particle composition as the critical particle-size condition, which is in fact the coefficient of internal erosion (Kue). Based on the study results, mathematical model...

  16. Investigating the Effect of Soil Texture and Fertility on Evapotranspiration and Crop Coefficient of Maize Forage

    Directory of Open Access Journals (Sweden)

    M. Ghorbanian Kerdabadi

    2017-02-01

    Full Text Available Introduction: Crop coefficient varies in different environmental conditions, such as deficit irrigation, salinity and intercropping. The effect of soil fertility and texture of crop coefficient and evapotranspiration of maize was investigated in this study. Low soil fertility and food shortages as a stressful environment for plants that makes it different evapotranspiration rates of evapotranspiration calculation is based on the FAO publication 56. Razzaghi et al. (2012 investigate the effect of soil type and soil-drying during the seed-filling phase on N-uptake, yield and water use, a Danish-bred cultivar (CV. Titicaca was grown in field lysimeters with sand, sandy loam and sandy clay loam soil. Zhang et al (2014 were investigated the Effect of adding different amounts of nitrogen during three years (from 2010 to 2012 on water use efficiency and crop evapotranspiration two varieties of winter wheat. The results of their study showed. The results indicated the following: (1 in this dry land farming system, increased N fertilization could raise wheat yield, and the drought-tolerant Changhan No. 58 showed a yield advantage in drought environments with high N fertilizer rates; (2 N application affected water consumption in different soil layers, and promoted wheat absorbing deeper soil water and so increased utilization of soil water; and (3 comprehensive consideration of yield and WUE of wheat indicated that the N rate of 270 kg/ha for Changhan No. 58 was better to avoid the risk of reduced production reduction due to lack of precipitation; however, under conditions of better soil moisture, the N rate of 180 kg/ha was more economic. Materials and Methods: The study was a factorial experiment in a completely randomized design with three soil texture treatment, including silty clay loam, loam and sandy-loam soil and three fertility treatment, including without fertilizer, one and two percent fertilizer( It was conducted at the experimental farm in

  17. Fire impacts on water repellency of sandy soils in SW Spanish coast

    Science.gov (United States)

    Jordán, Antonio; Zavala, Lorena M.; Gordillo-Rivero, Ángel J.; Muñoz-Rojas, Miriam; Keesstra, Saskia; Cerdá, Artemi

    2017-04-01

    Although water repellency of sandy soils from dune areas and their consequences (irregular wetting front, preferential flow pathways) are well studied, there is not much information about the effect of fire on hydrophobicity and its consequences in these areas. In this paper we study the in-depth variation of water repellency of burnt sandy soils from south-western Spain. Generally, it was observed that water repellency from unburnt forest soils is relatively higher than in shrublands and grasslands (where the lowest values were observed). However, the impact of fire caused a strong increase of hydrophobicity in the first two cases, with no major differences between them. This study confirms the presence of natural water repellency in sandy soils, as well as some of its consequences (irregular infiltration or increased surface water flow) depending on the type of vegetation, although the differences observed in burnt soils suggest that, although the composition of vegetation is important in the formation of natural water repellency, organic matter content is much more important in the case of burnt soils.

  18. Impact of biochar addition on thermal properties of a sandy soil: modelling approach

    Science.gov (United States)

    Usowicz, Boguslaw; Lipiec, Jerzy; Lukowski, Mateusz; Bis, Zbigniew; Marczewski, Wojciech; Usowicz, Jerzy

    2017-04-01

    Adding biochar can alter soil thermal properties and increase the water holding capacity and reduce the mineral soil fertilization. Biochar in the soil can determine the heat balance on the soil surface and the temperature distribution in the soil profile through changes in albedo and the thermal properties. Besides, amendment of soil with biochar results in improvement of water retention, fertility and pH that are of importance in sandy and acid soils, widely used in agriculture. In this study we evaluated the effects of wood-derived biochar (0, 10, 20, and 40 Mg ha-1) incorporated to a depth of 0-15 cm on the thermal conductivity, heat capacity, thermal diffusivity and porosity in sandy soil under field conditions. In addition, soil-biochar mixtures of various percentages of biochar were prepared to determine the thermal properties in function of soil water status and density in laboratory. It was shown that a small quantity of biochar added to the soil does not significantly affect all the thermal properties of the soil. Increasing biochar concentration significantly enhanced porosity and decreased thermal conductivity and diffusivity with different rate depending on soil water status. The soil thermal conductivity and diffusivity varied widely and non-linearly with water content for different biochar content and soil bulk density. However, the heat capacity increased with biochar addition and water content linearly and was greater at higher than lower soil water contents. The measured and literature thermal data were compared with those obtained from the analytic model of Zhang et al. (2013) and statistical-physical model (Usowicz et al., 2016) based on soil texture, biochar content, bulk density and water content.

  19. Soil erosion rates by wind-driven rain from a sandy soil in Denmark

    Science.gov (United States)

    Fister, W.; Kuhn, N. J.; Itin, N.; Tesch, S.; Heckrath, G.; Ries, J. B.

    2012-04-01

    Soil erosion by wind and water is able to cause severe soil loss from agricultural fields. Laboratory studies in recent years have shown that wind most probably has an increasing effect on soil erosion rates by water. However, field studies have so far not been able to quantify and proof this assumption explicitly. Especially the differentiation between the influence of windless and wind-driven erosion seems to be the major issue. The objectives of this study were, therefore, to explicitly investigate the importance of wind-driven rain in relation to erosion rates without the effect of wind by applying a newly developed Portable Wind and Rainfall Simulator (PWRS) that is able to simulate the processes both separately and simultaneously. The PWRS was used on bare sandy soil near Viborg, Denmark. Prior to simulation the soil was ploughed and after consolidation harrowed to create surface structures and roughness representing typical conditions after seed bed preparation. To facilitate the separation of specific influences by wind-driven rain and to avoid systematic errors a defined order of four consecutive test runs was established: 0) single wind test run for 10 min, 1) single rainfall test run on dry soil, 2) single rainfall test run on moist soil, 3) simultaneous wind and rainfall test run (wind-driven rainfall). Each rainfall simulation lasted for 30 minutes with a 30 min break in between to allow for initial drainage of the soil and for remounting sediment catchers. By utilizing a gutter in combination with wedge-shaped sediment traps it was possible to separate between splash and runoff erosion from the 2.2 m2 plot. The results show a wide range of soil detachment raging from zero up to more than 500 g m-2 in 30 minutes. Five out of nine test sequences support the theory that wind-driven rain causes more erosion than windless rain. The relation between the two processes is therefore not as clear as expected and seems to be dominated by the natural variability

  20. Vertical distribution of soil moisture and surface sandy soil wind erosion for different types of sand dune on the southeastern margin of the Mu Us Sandy Land, China

    Institute of Scientific and Technical Information of China (English)

    ChaoFeng Fu; JingBo Zhao; FanMin Mei; TianJie Shao; Jun Zuo

    2015-01-01

    Soil moisture is a critical state affecting a variety of land surface and subsurface processes. We report investigation results of the factors controlling vertical variation of soil moisture and sand transport rate of three types of dunes on the south-eastern margin of the Mu Us Sandy Land. Samples were taken from holes drilled to a depth of 4 m at different topographic sites on the dunes, and were analyzed for soil moisture, grain-size distribution and surface sediment discharge. The results show that: (1) The average soil moisture varies in different types of dunes, with the following sequences ordered from highest to lowest: in the shrubs-covered dunes and the trees-covered dunes the sequence is from inter-dunes lowland to windward slope to leeward slope. The average moisture in the bare-migratory sand dunes is sequenced from inter-dunes lowland to leeward slope to windward slope. (2) Vegetation form and surface coverage affect the range of soil moisture of different types of dunes in the same topographic position. The coefficient of variation of soil moisture for shrubs-covered dunes is higher than that of other types of dune. (3) The effect of shrubs on dune soil moisture is explained in terms of the greater ability of shrubs to trap fine-grained atmospheric dust and hold moisture. (4) The estimated sand transport rates over sand dunes with sparse shrubs are less than those over bare-migratory dunes or sand dunes with sparse trees, indi-cating that shrubs are more effective in inhibiting wind erosion in the sandy land area.

  1. Soil and plant nitrogen dynamics of a tomato crop under different fertilization strategies

    DEFF Research Database (Denmark)

    Doltra, Jordi; Muñoz, P; Antón, A

    2010-01-01

    A field experiment was conducted in 2007 to investigate the effects of the N fertilizer source on the soil and plant N dynamics of a tomato crop grown in a sandy loam soil. The fertilization treatments were: mineral N-fertilization applied by fertigation (TM); organic N-fertilization (TO) with co......A field experiment was conducted in 2007 to investigate the effects of the N fertilizer source on the soil and plant N dynamics of a tomato crop grown in a sandy loam soil. The fertilization treatments were: mineral N-fertilization applied by fertigation (TM); organic N-fertilization (TO......) with compost obtained from the organic fraction of urban waste (OFUW); and a combined treatment (TC) with half organic and half mineral N. Compost was incorporated in November 2006. Plants were drip irrigated with well water. The nitrate concentrations in the irrigation solutions were determined on a weekly....... The model was calibrated using data from a previous experiment. No differences between treatments were observed with respect to yield or N content in marketable fruits. The amount of N left in the field at the end of the cropping period was significantly lower in TO than in TC and TM. Simulated plant growth...

  2. Parameters of the occurrence of internal erosion processes in salty-sandy soils

    Directory of Open Access Journals (Sweden)

    Gajić Grozdana

    2005-01-01

    Full Text Available The study was aimed at defining the conditions of the occurrence of internal erosion in silty-sandy soils. The susceptibility of this soil to internal erosion depends on the porosity, particle-size composition and hydro-geo-mechanical parameters. Internal erosion stability was analyzed by the introduction of the coefficient of particle composition as the critical particle-size condition, which is in fact the coefficient of internal erosion (Kue. Based on the study results, mathematical models and the functional correlation between water regime and resistant characteristics of silty-sandy soils, we defined the parameters of the occurrence of initial internal erosion and analyzed the effects of the practical application of the study results.

  3. Competition between n-alkane-assimilating yeasts and bacteria during colonization of sandy soil microcosms.

    Science.gov (United States)

    Schmitz, C; Goebel, I; Wagner, S; Vomberg, A; Klinner, U

    2000-07-01

    An n-alkane-assimilating strain of Candida tropicalis was selected in sandy soil inoculated with microorganisms from contaminated sites. Competition experiments with n-alkane utilizers from different strain collections confirmed that yeasts overgrow bacteria in sandy soil. Acidification of the soil is one of the colonization factors useful for the yeasts. It can be counteracted by addition of bentonite, a clay mineral with high ion exchange capacity, but not, however, by kaolin. Strains of different yeast species showed different levels of competitiveness. Strains of Arxula adeninivorans, Candida maltosa, and Yarrowia lipolytica overgrew strains of C. tropicalis, C. shehatae or Pichia stipitis. Two strains of C. maltosa and Y. lipolytica coexisted during several serial transfers under microcosm conditions.

  4. Volatilisation of o-Xylene from Sandy Soil

    DEFF Research Database (Denmark)

    Lindhardt, Bo; Christensen, Thomas Højlund; Brun, Adam

    1994-01-01

    The diffusive release of o-xylene from two soils with different contents of organic carbon (1.1 % and 0.11 % TOC) and with two different water contents (app. 5 % w/w and 15 % w/w was studied in the laboratory. The soils were spiked with o-xylene in the laboratory. The fluxes were measured over...

  5. Fit-for-purpose phosphorus management: do riparian buffers qualify in catchments with sandy soils?

    Science.gov (United States)

    Weaver, David; Summers, Robert

    2014-05-01

    Hillslope runoff and leaching studies, catchment-scale water quality measurements and P retention and release characteristics of stream bank and catchment soils were used to better understand reasons behind the reported ineffectiveness of riparian buffers for phosphorus (P) management in catchments with sandy soils from south-west Western Australia (WA). Catchment-scale water quality measurements of 60 % particulate P (PP) suggest that riparian buffers should improve water quality; however, runoff and leaching studies show 20 times more water and 2 to 3 orders of magnitude more P are transported through leaching than runoff processes. The ratio of filterable reactive P (FRP) to total P (TP) in surface runoff from the plots was 60 %, and when combined with leachate, 96 to 99 % of P lost from hillslopes was FRP, in contrast with 40 % measured as FRP at the large catchment scale. Measurements of the P retention and release characteristics of catchment soils (bank soil (bank soils suggest that catchment soils contain more P, are more P saturated and are significantly more likely to deliver FRP and TP in excess of water quality targets than stream bank soils. Stream bank soils are much more likely to retain P than contribute P to streams, and the in-stream mixing of FRP from the landscape with particulates from stream banks or stream beds is a potential mechanism to explain the change in P form from hillslopes (96 to 99 % FRP) to large catchments (40 % FRP). When considered in the context of previous work reporting that riparian buffers were ineffective for P management in this environment, these studies reinforce the notion that (1) riparian buffers are unlikely to provide fit-for-purpose P management in catchments with sandy soils, (2) most P delivered to streams in sandy soil catchments is FRP and travels via subsurface and leaching pathways and (3) large catchment-scale water quality measurements are not good indicators of hillslope P mobilisation and transport

  6. Use of dolomite phosphate rock (DPR) fertilizers to reduce phosphorus leaching from sandy soil.

    Science.gov (United States)

    Chen, G C; He, Z L; Stoffella, P J; Yang, X E; Yu, S; Calvert, D

    2006-01-01

    There is increasing concern over P leaching from sandy soils applied with water-soluble P fertilizers. Laboratory column leaching experiments were conducted to evaluate P leaching from a typical acidic sandy soil in Florida amended with DPR fertilizers developed from dolomite phosphate rock (DPR) and N-Viro soil. Ten leaching events were carried out at an interval of 7 days, with a total leaching volume of 1,183 mm equivalent to the mean annual rainfall of this region during the period of 2001-2003. Leachates were collected and analyzed for total P and inorganic P. Phosphorus in the leachate was dominantly reactive, accounting for 67.7-99.9% of total P leached. Phosphorus leaching loss mainly occurred in the first three leaching events, accounting for 62.0-98.8% of the total P leached over the whole period. The percentage of P leached (in the total P added) from the soil amended with water-soluble P fertilizer was higher than those receiving the DPR fertilizers. The former was up to 96.6%, whereas the latter ranged from 0.3% to 3.8%. These results indicate that the use of N-Viro-based DPR fertilizers can reduce P leaching from sandy soils.

  7. Changes in physical properties of sandy soil after long-term compost treatment

    Science.gov (United States)

    Aranyos, József Tibor; Tomócsik, Attila; Makádi, Marianna; Mészáros, József; Blaskó, Lajos

    2016-07-01

    Studying the long-term effect of composted sewage sludge application on chemical, physical and biological properties of soil, an experiment was established in 2003 at the Research Institute of Nyíregyháza in Hungary. The applied compost was prepared from sewage sludge (40%), straw (25%), bentonite (5%) and rhyolite (30%). The compost was ploughed into the 0-25 cm soil layer every 3rd year in the following amounts: 0, 9, 18 and 27 Mg ha-1 of dry matter. As expected, the compost application improved the structure of sandy soil, which is related with an increase in the organic matter content of soil. The infiltration into soil was improved significantly, reducing the water erosion under simulated high intensity rainfall. The soil compaction level was reduced in the first year after compost re-treatment. In accordance with the decrease in bulk density, the air permeability of soil increased tendentially. However, in the second year the positive effects of compost application were observed only in the plots treated with the highest compost dose because of quick degradation of the organic matter. According to the results, the sewage sludge compost seems to be an effective soil improving material for acidic sandy soils, but the beneficial effect of application lasts only for two years.

  8. Phosphorus leaching from a sandy soil in the presence of modified and un-modified adsorbents.

    Science.gov (United States)

    Moharami, Somayeh; Jalali, Mohsen

    2014-10-01

    Phosphorus (P) leaching from a sandy soil was investigated in the presence of modified and unmodified clay minerals and nanoparticles (NPs). Compared with control soil, amended soil with NPs had the highest percentage of P retention than amended soil with clay minerals. Among the adsorbents used, the highest percentage of P retention was produced by Al₂O₃-chitosan while the lowest percentage of P retention was by zeolite. Data measured for P leaching after using adsorbents were used to predict P leaching using transport model. PHREEQC model was able to model P leaching from control and amended soil. After leaching, P values in control and amended soil were fractionated by a sequential extraction procedure. Concentration of P in Ca-bound fraction (HCl-P) after application of modified and unmodified clay minerals and NPs (except TiO₂ and Al₂O₃) increased and decreased, respectively. Saturation indices (SIs) and P speciation were assessed using the Visual MINTEQ version 2.3 program. According to the SIs, leaching P from control and amended soil with different adsorbent was controlled by dissolution of hydroxyapatite. The results indicated that used adsorbents can reduce P leaching from the sandy soil. Thus, retention of P by amended soil reduced a risk in terms of groundwater contamination with P.

  9. Effects of Soil Texture, Moisture Condition and Cropping Systems on Soil Friability

    Directory of Open Access Journals (Sweden)

    A. Safadoust

    2016-10-01

    Full Text Available Introduction: Soil friability is defined as the tendency of a mass of unconfined intact soil in bulk to crumble and break up under applied stress into similar fragments, aggregates and individual soil particles with specific size range. Tensile strength is a term which defined as the stress, or force per unit area, required to cause soil to fail in tension. The stated parameters are almost considered as the key physical properties of agricultural soils, because the friable condition is a desirable feature for establishing adequate seedbeds during tillage practice. In spite of the relevance of the subject, information on the effects of intrinsic soil properties on the tensile strength and friability is limited in Iran. The objective of this study was to quantify and to relate tensile strength and friability of two texturally different soils of clay loam and sandy loam under two different cropping systems of wheat and alfalfa. Materials and methods: The soil samples were collected from the 0–30 cm horizon of two sites of sandy loam (SL and clay loam (CL soils which were located inHamadan province in western Iran. Each soil had been under cultivation of either wheat (conventionally tilled or alfalfa for 11 years. At the laboratory, the soils were gently dry-sieved to separate 8-10, 15-25 and 30-38 mm fractions. The tensile strength was calculated as suggested by Dexter and Kroesbergen, (1985 and the soil friability was calculated through the coefficient of variation method as proposed by Watts and Dexter (1998. The experiment was carried out at the air-dry water content and soil matric suctions of 80 and 50 kPa for three ranges of aggregate size (8-10 mm, 15-25 mm and 30-38 mm. Then the impacts of soil texture (clay loam and sandy loam and cultivation types (alfalfa and wheat were assessed in a factorial design at each water content. Regression analyses were carried out to evaluate the relationship between soil intrinsic properties (clay content

  10. Plant functional diversity enhances associations of soil fungal diversity with vegetation and soil in the restoration of semiarid sandy grassland

    OpenAIRE

    Zuo, Xiaoan; Wang, Shaokun; Lv, Peng; Zhou, Xin; Zhao, Xueyong; Zhang, Tonghui; Zhang, Jing

    2015-01-01

    Abstract The trait‐based approach shows that plant functional diversity strongly affects ecosystem properties. However, few empirical studies show the relationship between soil fungal diversity and plant functional diversity in natural ecosystems. We investigated soil fungal diversity along a restoration gradient of sandy grassland (mobile dune, semifixed dune, fixed dune, and grassland) in Horqin Sand Land, northern China, using the denaturing gradient gel electrophoresis of 18S rRNA and gen...

  11. Nitrogen fertilization in the growth phase of 'Chardonnay' and 'Pinot Noir' vines and nitrogen forms in sandy soil of the Pampa Biome

    Directory of Open Access Journals (Sweden)

    Felipe Lorensini

    Full Text Available ABSTRACT Information on nitrogen fertilization in growing vines is still a very limited subject, especially for crops on sandy soils in the Pampa Biome in Rio Grande do Sul, where viticulture has expanded considerably in the last decade. This study aimed to assess the impact of N doses on growth of young plants of Chardonnay and Pinot Noir vines and N forms present in sandy soil in the Pampa Biome. The experiment was conducted from October 2011 to December 2012 in a vineyard in Santana do Livramento, in Southern Rio Grande do Sul State, in soil with 82 g kg-1 clay in the 0-20 cm layer. Vines of Chardonnay and Pinot Noir varieties were subjected to applications of 0, 10, 20, 40, 60, and 80 kg N ha-1 year-1. Total N in leaves, SPAD readings, stem diameter, plant height, and dry matter of the pruned material were evaluated in two growth cycles and three times. Soil samples were collected at 0-10 and 10-20 cm depths at four crop growth stages, in which N-NH4 +, N-NO3 -, and total N were analyzed and the mineral N was calculated. The N levels applied to young vines, although they did not provide relevant changes in the N-NH4 +, N-NO3 -, and mineral N contents in the soil, were able to increase the N content in the leaves, increasing plant vigor. because the reason is that there was an increase in stem diameter, plant height, and dry matter of pruned material in most evaluation periods. These parameters suggest better growth patterns and uniformity of young grapevines with possible positive effects in anticipation of production, demonstrating the importance of nitrogen fertilization strategies to the growing vines in the sandy soil conditions of the Pampa Biome.

  12. Reduced nitrogen leaching by intercropping maize with red fescue on sandy soils in North Europe

    DEFF Research Database (Denmark)

    Manevski, Kiril; Børgesen, Christen Duus; Andersen, Mathias Neumann

    2015-01-01

    Aim To study maize (Zea mays L.) growth and soil nitrogen (N) dynamics in monocrop and intercropped systems in a North European climate and soil conditions with the support of a simulation model. Methods Field data for 3 years at two sites/soil types in Denmark and three main factors: (i) cropping...

  13. Effects of residual disinfectant on soil and lettuce crop irrigated with chlorinated water.

    Science.gov (United States)

    Lonigro, A; Montemurro, N; Laera, G

    2017-04-15

    The accidental or continuous release of residual chlorine in water reclaimed for irrigational purposes could compromise the crop yield and increase the load of toxic organo-halogenated compounds, posing additional risks for environment and human health. This study was aimed at assessing the consequences of using chlorinated water for irrigating lettuce crops grown in pots with two different types of soil. The results show that the accumulation of extractable organo-halogenated compounds (EOX) in soil, roots and leaves is directly related to the chlorine concentration in the irrigation water. The accumulation of EOX in sandy soils is not significant, while it reached up to 300% of the control in the silty-clay soil, demonstrating that the phenomenon is linked to the organic matter content in the soil. The accumulation of EOX in the soil appears to play a significant role in subsequent bioaccumulation in cultures irrigated with tap water (long term memory effect). Chloramines also demonstrated to have similar impacts as the free chlorine from hypochlorite. The consistent bioaccumulation of 400-700μgClkg(-1) of EOX in the leaves of crops irrigated with just 0.2mgClL(-1) of residual chlorine, as compared to levels below the detection limit of 75μgClkg(-1) in the control crops, evidences the potential impact on food chain and human health. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Using humic acid for remediation of sandy soils contaminated by heavy metal

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper presents the development of a new remediation technology for contaminated sandy soil using humic acid (HA). Distribution of amount of Cr (VI) in the aqueous or solid system containing humic acid and sandy soil, was studied using batch experiments, es-pecially for effects of reaction time, pH, concentrations, temperature and irradiation on the reduction of Cr (VI), and the optimum reaction conditions. The results indicated a significant increase of the adsorption of Cr (VI) because of the complexion reaction between HA and Cr (VI) that occurred under acidic condition. The reaction mechanisms of HA with chromium on sand surfaces were certified. Thus it came to a conclusion that HA could be used effectively on remediation of Cr (VI)-contaminated soil and groundwater in a wide range of pH, with or without sunlight. These results suggest that the organic-inorganic complex-such as sandy soils coated with humic substances-is important as a metal reservoir in the environment.

  15. Evaluation Of Onion Production On Sandy Soils By Use Of Reduced Tillage And Controlled Traffic Farming With Wide Span Tractors

    Directory of Open Access Journals (Sweden)

    Pedersen Hans Henrik

    2015-09-01

    Full Text Available Growing of vegetables is often characterised by intensive field traffic and use of heavy machines. By implementing controlled traffic farming (CTF, compaction of the growth zone can be avoided. An experiment was established in an onion field on a coarse sandy loam. Treatments were applied in the field that for five years had been managed by seasonal CTF (SCTF, where harvest is performed by random traffic due to lack of suitable harvest machines. The main treatment was compaction with a fully loaded potato harvester. The split treatment in the crossed split plot design was mechanical loosening. Bulk density, macroporosity, penetration resistance, water retention characteristics and yield were measured. Mechanical loosening caused improvements in the physical soil measurements and more roots were found in the upper soil layers. The highest yield was however found in the CTF simulation plots (19% higher than in the SCTF simulated plots. Using wide span tractors as a harvest platform will enable CTF in vegetable production. Avoidance of compaction will enable reduced tillage intensity and productivity can be improved both through higher yield of the area that is cropped and by a larger percentage of fields can be cropped area as less area will be needed for tracks.

  16. Spatial patterns of wetting characteristics in grassland sandy soil

    Directory of Open Access Journals (Sweden)

    Orfánus Tomáš

    2016-06-01

    Full Text Available In grasslands where organic and inorganic resources are alternating at scales of individual plants, the transient character is given to certain wetting properties of soil, which then become highly variable both in space and in time. The objective of presented study was to study wetting pattern within two soil horizons at 5-cm and 10-cm depths respectively and to examine how the wetting patterns relate to hydraulic conductivity determined by Minidisc infiltrometer at suction −2 cm, K(−2 cm. This characteristics is implicitly independent on antecedent soil water content (SWC since it relates to steady infiltration phase but can be influenced by present soil water repellency (SWR. Field measurements were performed on July 27–28, 2010 on the grassland experimental site located near the village Sekule in Southwest Slovakia. The water drop penetration time (WDPT, SWC and tension Minidisc infiltration measurements were carried out on the 0.64 m2 plot in a regular 8 × 8 grid. The results showed that SWR and SWC influence each other and cause correlation between spatial patterns of studied soil wetting characteristics and between characteristics measured at the two soil depths. Further, it was found out, that calculation of K(−2 cm according to Zhang may cause apparent correlation of K(−2 cm with antecedent SWC, which is the artificial effect of sorptivity parameter in the equation on steady stage of infiltration process. This pseudocorrelation has disappeared after adopting of Minasny and McBratney (2000 approaches by calculation of K(−2 cm.

  17. Soil residual nitrogen under various crop rotations and cultural practices

    Science.gov (United States)

    Crop rotation and cultural practice may influence soil residual N available for environmental loss due to crop N uptake and N immobilization. We evaluated the effects of stacked vs. alternate-year crop rotations and cultural practices on soil residual N (NH4-N and NO3-N contents) at the 0-125 cm dep...

  18. Response of corn silage (Zea mays L.) to zinc fertilization on a sandy soil under field and

    National Research Council Canada - National Science Library

    Saad Drissi; Abdelhadi Aït Houssa; Ahmed Bamouh; Mohamed Benbella

    2017-01-01

    The purpose of the experiments was to evaluate zinc (Zn) fertilization effect on growth, yield and yield components of corn silage grown on a sandy soil under field and outdoor container conditions...

  19. Effect of Corn Residue Biochar on the Hydraulic Properties of Sandy Loam Soil

    Directory of Open Access Journals (Sweden)

    Avanthi Deshani Igalavithana

    2017-02-01

    Full Text Available Biochar has an ability to alter the biological, chemical, and physical properties of soil due to its physicochemical properties such as surface area, porosity, nutrient retention ability, available nutrient contents, aromaticity, etc. The present study was designed to evaluate the impact of physical properties and application rate of biochar on the hydraulic properties of a sandy loam soil in the short term. Biochar was produced at 500 °C from dried corn residue (BC500. The BC500 was incorporated at the rates of 0, 2.5%, 5.0%, 7.5%, and 10% (w·w−1 into the sandy loam soil and filled up to a height of 4 cm, in cores having 5 cm diameter and height. Each treatment was performed in triplicate and equilibrated for 30 days. Then saturated hydraulic conductivity (Ksat, water holding capacity (WHC, and bulk density were determined in each sample after four days of saturation at room temperature in a water bath. The BC500 particle size distribution, pores, and surface functional groups were assessed. The Ksat exhibited a highly significant exponential reduction from 0% to 7.5% of BC500 application and approached an asymptote at 10% BC500. Bulk density showed a significant negative correlation to biochar application rate. The WHC and BC500 application rate illustrated a strong positive relationship. Biochar surface was free from hydrophobic functional groups. The addition of BC500 has a positive influence on soil hydraulic properties, primarily due to the increased soil porosity. The BC500 is composed of a microporous structure and hydrophilic surface that retain water in sandy textured soils. The application of BC500 would be a wise investment to maximize the water use efficiency in soils for agricultural production.

  20. Effects of vegetable oil residue after soil extraction on physical-chemical properties of sandy soil and plant growth.

    Science.gov (United States)

    Gong, Zongqiang; Li, Peijun; Wilke, B M; Alef, Kassem

    2008-01-01

    Vegetable oil has the ability to extract polycyclic aromatic hydrocarbons (PAHs) from contaminated sandy soil for a remediation purpose, with some of the oil remaining in the soil. Although most of the PAHs were removed, the risk of residue oil in the soil was not known. The objective of this study was to evaluate the effects of the vegetable oil residue on higher plant growth and sandy soil properties after soil extraction for a better understanding of the soil remediation. Addition of sunflower oil and column experiment were performed on a PAH contaminated soil and/or a control soil, respectively. Soils were incubated for 90 d, and soil pH was measured during the soil incubation. Higher plant growth bioassays with Avena sativa L. (oat) and Brassica rapa L. (turnip) were performed after the incubation, and then soil organic carbon contents were measured. The results show that both the nutrient amendment and the sunflower oil degradation resulted in the decrease of soil pH. When these two process worked together, their effects were counteracted due to the consumption of the nutrients and oil removal, resulting in different pH profiles. Growth of A. sativa was adversely affected by the sunflower oil, and the nutrient amendments stimulated the A. sativa growth significantly. B. rapa was more sensitive to the sunflower oil than A. sativa. Only 1% sunflower oil addition plus nutrient amendment stimulated B. rapa growth. All the other treatments on B. rapa inhibited its growth significantly. The degradation of the sunflower oil in the soils was proved by the soil organic carbon content.

  1. Toxicity of Nitro-Heterocyclic and Nitroaromatic Energetic Materials to Folsomia candida in a Natural Sandy Loam Soil

    Science.gov (United States)

    2015-04-01

    FOLSOMIA CANDIDA IN A NATURAL SANDY LOAM SOIL ECBC-TR-1272 Carlton T. Phillips Ronald T. Checkai Roman G. Kuperman Michael Simini Jan E...SUBTITLE Toxicity of Nitro-Heterocyclic and Nitroaromatic Energetic Materials to Folsomia candida in a Natural Sandy Loam Soil 5a. CONTRACT NUMBER 5b...2,4-dinitrotoluene (2,4-DNT) Folsomia candida octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) 2,6-dinitrotoluene

  2. Towards improved nitrogen management in silage maize production on sandy soils.

    NARCIS (Netherlands)

    Schroder, J.J.

    1998-01-01

    Maize has become a highly appreciated crop in Dutch dairy farming during the last 25 years. The current cropping technique, however, is associated with a low recovery of soil mineral nitrogen (N) and serious losses of N to the environment. This gave rise to the research described in this thesis whic

  3. Effect of pore-size distribution on the collapse behaviour of anthropogenic sandy soil deposits

    Directory of Open Access Journals (Sweden)

    Baille Wiebke

    2016-01-01

    Full Text Available In the former open-pit mines of the Lusatian region in Germany, several liquefaction events have occurred during the recent years in the anthropogenic deposits made of very loose sandy soils. These events are related to the rising ground water table after the stop of controlled ground water lowering. The very loose state is due to the formation of sand aggregates (pseudo-grains during the deposition process. The pseudo-grains enclose larger voids of dimension greater than the single sand grain. Wetting induced collapse of the pseudo-grains is presumed to be one of the possible mechanisms triggering liquefaction. In the present study, the effect of larger voids on the wetting induced deformation behaviour of sandy soils is experimentally investigated by laboratory box tests. The deformation field in the sample during wetting was measured using Digital Image Correlation (DIC technique. The results show that the observed deformations are affected by the pore size distribution, thus the amount of voids between the pseudo-grains (macro-void ratio and the voids inside the pseudo-grains (matrix void ratio. The global void ratio of a sandy soil is not sufficient as single state parameter, but the pore size distribution has to be taken into account, experimentally as well as in modelling.

  4. The potential of cover crops for improving soil function

    Science.gov (United States)

    Stoate, Chris; Crotty, Felicity

    2017-04-01

    Cover crops can be grown over the autumn and winter ensuring green cover throughout the year. They have been described as improving soil structure, reducing soil erosion and potentially even a form of grass weed control. These crops retain nutrients within the plant, potentially making them available for future crops, as well as increasing soil organic matter. Over the last three years, we have investigated how different cover crop regimes affect soil quality. Three separate experiments over each autumn/winter period have investigated how different cover crops affect soil biology, physics and chemistry, with each experiment building on the previous one. There have been significant effects of cover crops on soil structure, as well as significantly lower weed biomass and increased yields in the following crop - in comparison to bare stubble. For example, the effect of drilling the cover crops on soil structure in comparison to a bare stubble control that had not been driven on by machinery was quantified, and over the winter period the soil structure of the cover crop treatments changed, with compaction reduced in the cover crop treatments, whilst the bare stubble control remained unchanged. Weeds were found in significantly lower biomass in the cover crop mixes in comparison to the bare stubble control, and significantly lower weed biomass continued to be found in the following spring oat crop where the cover crops had been, indicating a weed suppressive effect that has a continued legacy in the following crop. The following spring oats have shown similar results in the last two years, with higher yields in the previous cover crop areas compared to the bare stubble controls. Overall, these results are indicating that cover crops have the potential to provide improvements to soil quality, reduce weeds and improve yields. We discuss the economic implications.

  5. Assessment of Fate of Thiodicarb Pesticide in Sandy Clay Loam Soil

    Directory of Open Access Journals (Sweden)

    M. A. Bajeer

    2015-06-01

    Full Text Available In present study the fate of thiodicarb pesticide in sandy clay loam soil was investigated through its adsorption and leaching using HPLC. Experimental results revealed that thiodicarb follows first order kinetic with rate constant value of 0.711 h-1 and equilibrium study showed that Freundlich model was best fitted with multilayer adsorption capacity 3.749 mol/g and adsorption intensity 1.009. Therefore, adsorption of thiodicarb was multilayer, reversible and non-ideal. Leaching study has indicated intermediate mobility of thiodicarb with water due to its solubility, while field study showed the non-leacher nature. However both adsorption and leaching were heavily affected by soil characteristics. As the soil taken was sandy clay loam hence due to clay texture adsorption was higher because of vacant sites existing and greater surface area. For this the pesticide has remained adsorbed in above 20 cm soil layer as clearly seen from field study, minor amount was recorded in third layer of soil having 21-30 cm depth. The leached amount of thiodicarb in first and last part of water was 1.075 and 0.003 ng/µl. The general trend observed for adsorption in column and field soil was decreased downwards from 2.027 to 0.618 and 5.079 to 0.009 ng/µl.

  6. Gas diffusion-derived tortuosity governs saturated hydraulic conductivity in sandy soils

    DEFF Research Database (Denmark)

    Masis Melendez, Federico; Deepagoda Thuduwe Kankanamge Kelum, Chamindu; de Jonge, Lis Wollesen

    2014-01-01

    Accurate prediction of saturated hydraulic conductivity (Ksat) is essential for the development of better distributed hydrological models and area-differentiated risk assessment of chemical leaching. The saturated hydraulic conductivity is often estimated from basic soil properties such as particle...... size distribution or, more recently, soil-air permeability. However, similar links to soil gas diffusivity (Dp/Do) have not been fully explored even though gas diffusivity is a direct measure of connectivity and tortuosity of the soil pore network. Based on measurements for a coarse sandy soil....../Do model to measured data, and subsequently linked to the cementation exponent of the wellestablished Revil and Cathles predictive model for saturated hydraulic conductivity. Furthermore, a two-parameter model, analogue to the Kozeny-Carman equation, was developed for the Ksat - Dp/Do relationships. All 44...

  7. Effects of biochar and manure amendments on water vapor sorption in a sandy loam soil

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Tuller, Markus; Moldrup, Per;

    2015-01-01

    properties of soils, especially on water retention at low matric potentials. To overcome this knowledge gap, the effects of combined BC (0 to 100 Mg ha-1) and manure (21 and 42 Mg ha-1) applications on water vapor sorption and specific surface area was investigated for a sandy loam soil. In addition......, potential impacts of BC aging were evaluated. All considered BC-amendment rates led to a distinct increase of water retention, especially for low matric potentials. The observed increases were attributed to a significant increase of soil organic matter contents and specific surface areas in BCamended soils......Over the last few years, the application of biochar (BC) as a soil amendment to sequester carbon and mitigate global climate change has received considerable attention. While positive effects of biochar on plant nutrition are well documented, little is known about potential impacts on the physical...

  8. Effect of pH on bacteriophage transport through sandy soils

    Science.gov (United States)

    Kinoshita, Takashi; Bales, Roger C.; Maguire, Kimberley M.; Gerba, Charles P.

    1993-01-01

    Effects of pH and hydrophobicity on attachment and detachment of PRD-1 and MS-2 in three different sandy soils were investigated in a series of laboratory-column experiments. Concentrations of the lipid-containing phage PRD-1 decreased 3–4 orders of magnitude during passage through the 10–15-cm-long columns. Attachment of the lipid-containing phage PRD-1 was insensitive to pH and was apparently controlled by hydrophobic interactions in soil media. The less-hydrophobic phage MS-2 acted conservatively; it was not removed in the columns at pH's 5.7–8.0. The sticking efficiency (α) in a colloid-filtration model was between 0.1 and 1 for PRD-1, indicating a relatively high removal efficiency. Phage attachment was reversible, but detachment under steady-state conditions was slow. An increase in pH had a moderate effect on enhancing detachment. Still, these soils should continue to release phage to virus-free water for days to weeks following exposure to virus-containing water. In sandy soils with a mass-fraction organic carbon as low as a few hundredths of a percent, pH changes in the range 5.7–8.0 should have little effect on retention of more-hydrophobic virus (e.g., PRD-1), in that retardation will be dominated by hydrophobic effects. Sharp increases in pH should enhance detachment and transport of virus previously deposited on soil grains. A more hydrophilic virus (e.g., MS-2) will transport as a conservative tracer in low-carbon sandy soil.

  9. Mobilization and Mobility of Colloidal Phosphorus in Sandy Soils

    OpenAIRE

    Ilg, Katrin

    2007-01-01

    erschienen in: Journal of Environmental Quality. - 2005(34)3, S. 926-935; Soil Science Society of America Journal. - 2007(71)2, S. 298-305 Die Auswaschung von Phosphor (P) trägt zur Verlagerung von P aus terrestrischen in aquatische Ökosysteme bei. Neben der gelösten Form kann P im Sickerwasser auch an Kolloide gebunden auftreten. Die Sorption von P an potentiell dispergierbare Bestandteile der Bodenmatrix, z.B. Eisen- und Aluminiumoxide und -hydroxide, beeinflusst deren Oberflächenladung ...

  10. Relationships between water infiltration and oil spill migration in sandy soils

    Science.gov (United States)

    Kessler, Avner; Rubin, Hillel

    1987-06-01

    This article summarizes a study directed towards the prediction of oil spill migration in sandy soils. Such a prediction is needed for the design of remedial measures against soil and groundwater contamination. The geneal approach in this study is to convert available data concerning water infiltration into equivalent unknown data concerning oil spillage. This information is then fed into a numerical model by which the oil spill migration is simulated. Laboratory measurements including retention curve, hydraulic conductivity and infiltration rate, were made separately for water and kerosene in order to evaluate and confirm the suggested approach.

  11. Evaluation of Soil Quality Indicators in Sugarcane Management in Sandy Loam Soil

    Institute of Scientific and Technical Information of China (English)

    S.A.C.SANT'ANNA; M.F.FERNANDES; W.M.P.M.IVO; J.L.S.COSTA

    2009-01-01

    An important factor for the sustainability of soils highly susceptible to degradation is the use of monitoring tools that promptly and realistically reflect changes imposed on soil by different cropping systems.To select soil quality indicator variables in sugarcane (Saccharum offcinarum L.) production areas that fulfill the criteria of sensitivity to management practices and between-season consistency in the management discrimination,ten composite soil samples (0-10 cm) were collected in July 2005 (rainy season) and again in March 2006 (dry season) from areas under cultivation of organic sugarcane (OS),green sugarcane (GS),burned sugarcane (BS) and from an adjacent native forest (NF) area at Usina Triunfo,Boca da Mata,Alagoas,Brazil.Microbial biomass-C (MBC),total organic C (TOC),soil enzyme activity expressed as the rate of fluorescein diacetate (FDA) hydrolysis,mean weight diameter of water-stable soil aggregates (MWD),and percentage of water-stable macroaggregates (PWSA) were analyzed.Although MBC and TOC were higher in NF than in the cultivated areas,no differences were observed in these C pools between the three sugarcane systems.The response of FDA to the site management was dependent on the sampling time.In the rainy period,the activity followed the order:NF > OS > GS > BS,whereas in the dry season,only NF differed from the other treatments.Irrespective of the sampling time,MWD and PWSA decreased in the order NF > OS = GS > BS.The variables MWD and PWSA are quite sensitive for discriminating between site management histories regardless the sampling season.

  12. Soil coverage evolution and wind erosion risk on summer crops under contrasting tillage systems

    Science.gov (United States)

    Mendez, Mariano J.; Buschiazzo, Daniel E.

    2015-03-01

    The effectiveness of wind erosion control by soil surface conditions and crop and weed canopy has been well studied in wind tunnel experiments. The aim of this study is to assess the combined effects of these variables under field conditions. Soil surface conditions, crop and weed coverage, plant residue, and non-erodible aggregates (NEA) were measured in the field between the fallow start and the growth period of sunflower (Helianthus annuus) and corn (Zea mays). Both crops were planted on a sandy-loam Entic Haplustoll with conventional-(CT), vertical-(VT) and no-till (NT) tillage systems. Wind erosion was estimated by means of the spreadsheet version the Revised Wind Erosion Equation and the soil coverage was measured each 15 days. Results indicated that wind erosion was mostly negligible in NT, exceeding the tolerable levels (estimated between 300 and 1400 kg ha-1 year-1 by Verheijen et al. (2009)) only in an year with high climatic erosivity. Wind erosion exceeded the tolerable levels in most cases in CT and VT, reaching values of 17,400 kg ha-1. Wind erosion was 2-10 times higher after planting of both crops than during fallows. During the fallows, the soil was mostly well covered with plant residues and NEA in CT and VT and with residues and weeds in NT. High wind erosion amounts occurring 30 days after planting in all tillage systems were produced by the destruction of coarse aggregates and the burying of plant residues during planting operations and rains. Differences in soil protection after planting were given by residues of previous crops and growing weeds. The growth of weeds 2-4 weeks after crop planting contributed to reduce wind erosion without impacting in crops yields. An accurate weeds management in semiarid lands can contribute significantly to control wind erosion. More field studies are needed in order to develop management strategies to reduce wind erosion.

  13. Accounting for soil biotic effects on soil health and crop productivity in the design of crop rotations.

    Science.gov (United States)

    Dias, Teresa; Dukes, Angela; Antunes, Pedro M

    2015-02-01

    There is an urgent need for novel agronomic improvements capable of boosting crop yields while alleviating environmental impacts. One such approach is the use of optimized crop rotations. However, a set of measurements that can serve as guiding principles for the design of crop rotations is lacking. Crop rotations take advantage of niche complementarity, enabling the optimization of nutrient use and the reduction of pests and specialist pathogen loads. However, despite the recognized importance of plant-soil microbial interactions and feedbacks for crop yield and soil health, this is ignored in the selection and management of crops for rotation systems. We review the literature and propose criteria for the design of crop rotations focusing on the roles of soil biota and feedback on crop productivity and soil health. We consider that identifying specific key organisms or consortia capable of influencing plant productivity is more important as a predictor of soil health and crop productivity than assessing the overall soil microbial diversity per se. As such, we propose that setting up soil feedback studies and applying genetic sequencing tools towards the development of soil biotic community databases has a strong potential to enable the establishment of improved soil health indicators for optimized crop rotations. © 2014 Society of Chemical Industry.

  14. Soil Chemistry Factors Confounding Crop Salinity Tolerance—A Review

    Directory of Open Access Journals (Sweden)

    Pichu Rengasamy

    2016-10-01

    Full Text Available The yield response of various crops to salinity under field conditions is affected by soil processes and environmental conditions. The composition of dissolved ions depend on soil chemical processes such as cation or anion exchange, oxidation-reduction reactions, ion adsorption, chemical speciation, complex formation, mineral weathering, solubility, and precipitation. The nature of cations and anions determine soil pH, which in turn affects crop growth. While the ionic composition of soil solution determine the osmotic and ion specific effects on crops, the exchangeable ions indirectly affect the crop growth by influencing soil strength, water and air movement, waterlogging, and soil crusting. This review mainly focuses on the soil chemistry processes that frustrate crop salinity tolerance which partly explain the poor results under field conditions of salt tolerant genotypes selected in the laboratory.

  15. Crop growth and two dimensional modeling of soil water transport in drip irrigated potatoes

    DEFF Research Database (Denmark)

    Plauborg, Finn; Iversen, Bo Vangsø; Mollerup, Mikkel

    2009-01-01

    Drip irrigation can be an effective way to improve water and nitrogen use efficiency in soil and hence to reduce the environmental pollution. In the EU project SAFIR ( http://www.safir4eu.org/ ) a potato experiment was carried out in lysimeters on three different soil types: coarse sand, loamy sand...... and sandy loam. An automatic roof was used to exclude the lysimeters from natural precipitation. The potatoes were drip irrigated following different strategies: Fully irrigated (FI), deficit irrigation (65% FI), and partial root zone drying (PRD). Gas exchange measurements were carried as well as sampling...... of abscisic acid (ABA). Model outputs from the mechanistic simulation model Daisy, in SAFIR developed to include 2D soil processes and gas exchange processes based on Ball et al. and Farquhar were compared with measured crop dynamics, final DM yield and volumetric water content in the soil measured by TDR...

  16. Soil and plant nitrogen dynamics of a tomato crop under different fertilization strategies

    DEFF Research Database (Denmark)

    Doltra, Jordi; Muñoz, P; Antón, A

    2010-01-01

    ) with compost obtained from the organic fraction of urban waste (OFUW); and a combined treatment (TC) with half organic and half mineral N. Compost was incorporated in November 2006. Plants were drip irrigated with well water. The nitrate concentrations in the irrigation solutions were determined on a weekly......A field experiment was conducted in 2007 to investigate the effects of the N fertilizer source on the soil and plant N dynamics of a tomato crop grown in a sandy loam soil. The fertilization treatments were: mineral N-fertilization applied by fertigation (TM); organic N-fertilization (TO...... basis. Soil samples were taken before planting and at harvest from depths of up to 90 cm in order to determine moisture and N-NO3- levels. The estimated amounts of total N-NO3- available in the different treatments, including the initial content in the 0-90 cm soil layer, were 560 (TC), 570 (TO) and 610...

  17. Impact of paper mill wastewater on soil properties and crop yield through lysimeter studies.

    Science.gov (United States)

    Singh, P K; Ladwani, K; Ladwani, K; Deshbhratar, P B; Ramteke, D S

    2013-01-01

    Paper and pulp industries produce large quantities of wastewater which can have adverse effects on the receiving water systems. In the present study lysimeters were used and filled with different soils replicating natural soil horizons and provided with a leachate collection system. The physico-chemical characteristics of the soil in each lysimeter and the quality of wastewater before leaching were assessed. Treated wastewater was evaluated for crop irrigation, and was categorized according to the irrigation water class 'Increasing Problem to Severe Problem' with respect to salinity and specific ion toxicity. Sandy loam soils showed 96% chemical oxygen demand (COD) removal while clay loam soils removed 99% of COD, and the colour removal in both the cases was found to be 100%. Application of wastewater resulted in an increase of pH value, ranging from 6.2-7.6; the electrical conductivity (ECe) of saturated extracts was found to be 0.6-1.7 dS m(-1), and exchangeable sodium percentage (ESP) ranged from 7.8-11.1% in soils. Similarly, an increase in the organic carbon, available nitrogen, phosphorus and potash content of soils was observed when irrigated with wastewater. Wastewater irrigation showed increased grain and straw yield of jowar, wheat and moong. These results permit successful utilization of pulp and paper mill wastewater for crop production without damaging the soils.

  18. Grape yield, and must compounds of 'Cabernet Sauvignon' grapevine in sandy soil with potassium contents increasing

    Directory of Open Access Journals (Sweden)

    Marlise Nara Ciotta

    2016-08-01

    Full Text Available ABSTRACT: Content of exchangeable potassium (K in t soil may influence on its content in grapevines leaves, grape yield, as well as, in must composition. The study aimed to assess the interference of exchangeable K content in the soil on its leaf content, production and must composition of 'Cabernet Sauvignon' cultivar. In September 2011, in Santana do Livramento (RS five vineyards with increasing levels of exchangeable K in the soil were selected. In the 2012/13 and 2013/14 harvests, the grape yield, yield components, total K content in the leaves in full bloom and berries veraison were evaluated. Values of total soluble sugar (TSS, pH, total titratable acidity (TTA, total polyphenols and anthocyanins were evaluated in the must. Exchangeable K content increase in soil with sandy surface texture increased its content in leaves collected during full flowering and in berries and must pH; however, it did not affect production of the 'Cabernet Sauvignon'.

  19. Transfer of cadmium from a sandy acidic soil to man: A population study

    Energy Technology Data Exchange (ETDEWEB)

    Staessen, J.A.; Celis, H.G.; Fagard, R.H.; Lijnen, P.J.; Thijs, L.B.; Amery, A.K. (Univ. of Leuven (Belgium)); Vyncke, G. (Ministry of the Flemish Community, Hasselt (Belgium)); Lauwerys, R.R.; Roels, H.A. (Univ. of Louvain, Brussels (Belgium)); Claeys, F. (Ministry of Health and Social Affairs, Brussels (Belgium)); Dondeyne, F. (Ministry of the Flemish Community, Brussels (Belgium)); Ide, G. (LISEC Research Centre for Ecology and Forestry, Genk (Belgium)); Rondia, D.; Sartor, F. (Univ. of Liege, (Belgium))

    1992-06-01

    This population study included 230 subjects (age range 20-83 years) who consumed vegetables grown in kitchen gardens on a sandy acidic soil (mean pH {approximately}6.3). The study investigated the association between the Cd (cadmium) levels in blood and urine and the Cd concentration in the soil (range 0.2-44 ppm). Seventy-six subjects were current smokers and 122 participants lived in a district with known Cd pollution. Urinary Cd in the 230 subjects averaged 8.7 nmole/24 hr, (range 1.3 to 47 nmole/24 hr) after age adjustment positively correlated with the Cd level in the soil; a twofold increase of the Cd concentration in the soil was accompanied by a 7% rise in urinary Cd in men and by a 4% rise in women. Blood Cd averaged 11.5 nmole/liter (range 1.8-41 nmole/liter) and was negatively associated with the Cd level in the soil. After adjustment for significant covariates (smoking and serum {gamma}-glutamyl transpeptidase in both sexes, and age and serum ferritin in women), a twofold increase in the Cd concentration in the soil was accompanied by a 6% decrease in blood Cd in men and by a 10% decrease in women. In conclusion, in a rural population, consuming vegetables grown on a sandy acidic soil, 2 to 4% of the variance of urinary Cd was directly related to the Cd level in the soil. The negative correlation with blood Cd, a measure of more recent exposure, was biased by the implementation of preventive measures in the polluted district.

  20. Toluene removal from sandy soils via in situ technologies with an emphasis on factors influencing soil vapor extraction.

    Science.gov (United States)

    Amin, Mohammad Mehdi; Hatamipour, Mohammad Sadegh; Momenbeik, Fariborz; Nourmoradi, Heshmatollah; Farhadkhani, Marzieh; Mohammadi-Moghadam, Fazel

    2014-01-01

    The integration of bioventing (BV) and soil vapor extraction (SVE) appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC) and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE) including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5%) of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing) after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.

  1. Toluene Removal from Sandy Soils via In Situ Technologies with an Emphasis on Factors Influencing Soil Vapor Extraction

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2014-01-01

    Full Text Available The integration of bioventing (BV and soil vapor extraction (SVE appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5% of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.

  2. Toluene Removal from Sandy Soils via In Situ Technologies with an Emphasis on Factors Influencing Soil Vapor Extraction

    Science.gov (United States)

    Amin, Mohammad Mehdi; Hatamipour, Mohammad Sadegh; Nourmoradi, Heshmatollah; Farhadkhani, Marzieh; Mohammadi-Moghadam, Fazel

    2014-01-01

    The integration of bioventing (BV) and soil vapor extraction (SVE) appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC) and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE) including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5%) of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing) after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater. PMID:24587723

  3. Zeolite and Hucalcia as Coating Material for Improving Quality of NPK Fertilizer in Costal Sandy Soil

    Directory of Open Access Journals (Sweden)

    Sulakhudin

    2011-05-01

    Full Text Available he growth and yield of plants are mainly a function of the quantity of fertilizer and water. In coastal sandy soil, nutrient losses and dry soils are seriously problems. The objective of the research was to study effect of zeolite and hucalci concentrations as NPK coating materials on NPK qualities i.e. water adsorption and release of N, P and K. The research used a coastal sandy soil as media. It was conducted in a laboratory of Soil Science Department, Gadjah Mada University from July to August 2009. Experimental design used was a factorial in a completely randomized design. The first factor was hucalci concentration, consisted of 10% (H1, 20% (H2, and 30% (H3. The second factor was zeolite concentration, consisted of 25% (Z1, 50% (Z2, 75% (Z3, and 100% (Z4. NPK fertilizer (without coating used as a control. The results showed that hucalci and zeolite had a capability to increase water adsorption and to retard the release of N, P, K. The coated NPK with hucalci 30% and zeolite 100% had the highest quality in water absorption, water retention and release of nutrients.

  4. Nitrogen Amendment Stimulated Decomposition of Maize Straw-Derived Biochar in a Sandy Loam Soil: A Short-Term Study.

    Directory of Open Access Journals (Sweden)

    Weiwei Lu

    Full Text Available This study examined the effect of nitrogen (N on biochar stability in relation to soil microbial community as well as biochar labile components using δ13C stable isotope technology. A sandy loam soil under a long-term rotation of C3 crops was amended with biochar produced from maize (a C4 plant straw in absence (BC0 and presence (BCN of N and monitored for dynamics of carbon dioxide (CO2 flux, phospholipid fatty acids (PLFAs profile and dissolved organic carbon (DOC content. N amendment significantly increased the decomposition of biochar during the first 5 days of incubation (P < 0.05, and the proportions of decomposed biochar carbon (C were 2.30% and 3.28% in BC0 and BCN treatments, respectively, during 30 days of incubation. The magnitude of decomposed biochar C was significantly (P < 0.05 higher than DOC in biochar (1.75% and part of relatively recalcitrant biochar C was mineralized in both treatments. N amendment increased soil PLFAs concentration at the beginning of incubation, indicating that microorganisms were N-limited in test soil. Furthermore, N amendment significantly (P < 0.05 increased the proportion of gram-positive (G+ bacteria and decreased that of fungi, while no noticeable changes were observed for gram-negative (G- bacteria and actinobacteria at the early stage of incubation. Our results indicated that N amendment promoted more efficiently the proliferation of G+ bacteria and accelerated the decomposition of relatively recalcitrant biochar C, which in turn reduced the stability of maize straw-derived biochar in test soil.

  5. Response of the microbial community to copper oxychloride in acidic sandy loam soil.

    Science.gov (United States)

    Du Plessis, K R; Botha, A; Joubert, L; Bester, R; Conradie, W J; Wolfaardt, G M

    2005-01-01

    Determining the response of different microbial parameters to copper oxychloride in acidic sandy loam soil samples using cultivation-dependent and direct microscopic techniques. Culturable microbial populations were monitored for 245 days in a series of soil microcosms spiked with different copper oxychloride concentrations. Microbial populations responded differently to additional Cu. Protistan numbers and soil metabolic potential decreased. Experiments with more soil samples revealed that metabolic potential was not significantly affected by protista was noted in soil containing only 15 mg kg(-1) EDTA-extractable Cu. The negative impact on protistan numbers was less severe in soils with a higher phosphorous and zinc content. Bacterial populations responded differently, and protista were most sensitive to elevated Cu levels. Protistan numbers in soil from uncultivated land were higher and seemed to be more sensitive to additional Cu than the numbers of these organisms in soil originating from cultivated land. Protistan sensitivity to small increases in Cu levels demonstrates the vulnerability of the soil ecosystem to Cu perturbations, especially when the importance of protista as link in the flow of energy between trophic levels is considered.

  6. Does thermal carbonization (Biochar of organic material increase more merits for their amendments of sandy soil?

    Directory of Open Access Journals (Sweden)

    Y. Wu

    2014-02-01

    Full Text Available Organic materials (e.g. furfural residue are generally believed to improve the physical and chemical properties of the soils with low fertility. Recently, biochar have been received more attention as a possible measure to improve the carbon balance and improve soil quality in some degraded soils. However, little is known about their different amelioration of a sandy saline soil. In this study, 56d incubation experiment was conducted to evaluate the influence of furfural and its biochar on the properties of saline soil. The results showed that both furfural and biochar greatly reduced pH, increased soil organic carbon (SOC content and cation exchange capacity (CEC, and enhanced the available phosphorus (P in the soil. Furfural is more efficient than biochar in reducing pH: 5% furfural lowered the soil pH by 0.5–0.8 (soil pH: 8.3–8.6, while 5% biochar decreased by 0.25–0.4 due to the loss of acidity in pyrolysis process. With respect to available P, 5% of the furfural addition increased available P content by 4–6 times in comparison to 2–5 times with biochar application. In reducing soil exchangeable sodium percentage (ESP, biochar is slightly superior to furfural because soil ESP reduced by 51% and 43% with 5% furfural and 5% biochar addition at the end of incubation. In addition, no significant differences were observed between furfural and biochar about their capacity to retain N, P in leaching solution and to increase CEC in soil. These facts may be caused by the relatively short incubation time. In general, furfural and biochar have different amendments depending on soil properties: furfural was more effectively to decrease pH and to increase available P, whereas biochar played a more important role in increasing SOC and reducing ESP of saline soil.

  7. Effects of vegetable oil residue after soil extraction on physical-chemical properties of sandy soil and plant growth

    Institute of Scientific and Technical Information of China (English)

    GONG Zongqiang; LI Peijun; B.M.Wilke; Kassem Alef

    2008-01-01

    Vegetable oil has the ability to extract polycyclic aromatic hydrocarbons (PAHs) from contaminated sandy soft for a remediation purpose, with some of the oft remaining in the soil. Although most of the PAHs were removed, the risk of residue oil in the soft was not known. The objective of this study was to evaluate the effects of the vegetable oil residue on higher plant growth and sandy soft properties after soil extraction for a better understanding of the soil remediation. Addition of sunflower oil and column experiment were performed on a PAH contaminated soil and/or a control soft, respectively. Soils were incubated for 90 d, and soil pH was measured during the soil incubation. Higher plant growth bioassays with Avena sativa L. (oat) and Brassica rapa L. (turnip) were performed after the incubation, and then soil organic carbon contents were measured. The results show that both the nutrient amendment and the sunflower oil degradation resulted in the decrease of soil pH. When these two process worked together, their effects were counteracted due to the consumption of the nutrients and oil removal, resulting in different pH profiles. Growth ofA. sativa was adversely affected by the sunflower oil, and the nutrient amendments stimulated the A. sativa growth significantly. B. rapa was more sensitive to the sunflower oil than A. sativa. Only 1% sunflower oft addition plus nutrient amendment stimulated B. rapa growth. All the other treatments on B. rapa inhibited its growth significantly. The degradation of the sunflower oft in the soils was proved by the soft organic carbon content.

  8. Nano chitosan-NPK fertilizer enhances the growth and productivity of wheat plants grown in sandy soil

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Aziz, H.M.M.; Hasaneen, M.N.A.; Ome, A.M.

    2016-11-01

    Nanofertilizers have become a pioneer approach in agriculture research nowadays. In this paper we investigate the delivery of chitosan nanoparticles loaded with nitrogen, phosphorus and potassium (NPK) for wheat plants by foliar uptake. Chiotsan-NPK nanoparticles were easily applied to leaf surfaces and entered the stomata via gas uptake, avoiding direct interaction with soil systems. The uptake and translocation of nanoparticles inside wheat plants was investigated by transmission electron microscopy. The results revealed that nano particles were taken up and transported through phloem tissues. Treatment of wheat plants grown on sandy soil with nano chitosan-NPK fertilizer induced significant increases in harvest index, crop index and mobilization index of the determined wheat yield variables, as compared with control yield variables of wheat plants treated with normal non-fertilized and normal fertilized NPK. The life cycle of the nano-fertilized wheat plants was shorter than normal-fertilized wheat plants with the ratio of 23.5% (130 days compared with 170 days for yield production from date of sowing). Thus, accelerating plant growth and productivity by application of nanofertilizers can open new perspectives in agricultural practice. However, the response of plants to nanofertilizers varies with the type of plant species, their growth stages and nature of nanomaterials. (Author)

  9. Nano chitosan-NPK fertilizer enhances the growth and productivity of wheat plants grown in sandy soil

    Directory of Open Access Journals (Sweden)

    Mohammed N. A. Hasaneen

    2016-03-01

    Full Text Available Nanofertilizers have become a pioneer approach in agriculture research nowadays. In this paper we investigate the delivery of chitosan nanoparticles loaded with nitrogen, phosphorus and potassium (NPK for wheat plants by foliar uptake. Chiotsan-NPK nanoparticles were easily applied to leaf surfaces and entered the stomata via gas uptake, avoiding direct interaction with soil systems. The uptake and translocation of nanoparticles inside wheat plants was investigated by transmission electron microscopy. The results revealed that nano particles were taken up and transported through phloem tissues. Treatment of wheat plants grown on sandy soil with nano chitosan-NPK fertilizer induced significant increases in harvest index, crop index and mobilization index of the determined wheat yield variables, as compared with control yield variables of wheat plants treated with normal non-fertilized and normal fertilized NPK. The life cycle of the nano-fertilized wheat plants was shorter than normal-fertilized wheat plants with the ratio of 23.5% (130 days compared with 170 days for yield production from date of sowing. Thus, accelerating plant growth and productivity by application of nanofertilizers can open new perspectives in agricultural practice. However, the response of plants to nanofertilizers varies with the type of plant species, their growth stages and nature of nanomaterials.

  10. Soil total carbon and crop yield affected by crop rotation and cultural practice

    Science.gov (United States)

    Stacked crop rotation and improved cultural practice have been used to control pests, but their impact on soil organic C (SOC) and crop yield are lacking. We evaluated the effects of stacked vs. alternate-year rotations and cultural practices on SOC at the 0- to 125-cm depth and annualized crop yiel...

  11. Mitigation of Water Stress on Apple Trees under Rotational Irrigation Conditions by Increasing the Application Rate of Organic Fertilizers to Sandy Soils

    Science.gov (United States)

    Hamed, Lamy Mamdoh Mohamed; Ramadan Eid, Abdelraouf; Mohsmed Rabie Abdellatif Abdelaziz, Adel; Fathy Abdelsalam Essa, El-Sayed

    2016-04-01

    Egypt, as part of Mediterranean regions, is characterized by irregular and low rainfall amount which varies between (30-150 mm.year-1), and characterized also by high temperature which increase the rate of evapotranspiration from the cultivated soil. On the other hand, New reclaimed soils are mostly occupies around 84 % of total area of Egypt, which is mainly sandy soils. These soils generally characterized by low water capacity holding, soil organic matter, and weak in nutrients retention. Under these conditions which have a great influence on crop production, there is a great needing to increase the crop water use efficiency and increasing of nutrient retention in sandy soils. In this context, two field experiments were carried out on sand soil located in north Cairo-Egypt at the experimental farm of National Research Center, El-NUBARIA, (latitude 30° 30' N, and longitude 30° 19' E). The effect of compost rates on soil hydraulic characteristics, fruit yields, quality traits, and water use efficiency and productivity of apple tree (Apple Anna Cultivar), was studied under deficit irrigation conditions. Four rates of compost [I1: control, I2: 12 ton.ha-1., I3: 24 ton.ha-1., I4: 36 ton.ha-1. and I5:48 ton.ha-1.] were applied under irrigation frequencies of (IF1 :once per week; IF2 :twice per week, IF3 :three times per week). The obtained results indicated that by increasing the application rate of compost, the available water capacity and saturated water content of sandy soil have been enhanced. In the same time, the fruit yield, quality traits and water productivity were increased by increasing the application rate of compost. It is worthy to mention that the I5IF3 treatment gave the highest values of fruit yield, quality traits and water productivity, whereas I1IF1 treatment gave the lowest values of all the above mentioned variables. As result, for apple cultivation in El-NUBARIA region, the recommended rate of compost is 48 ton.ha-1 and irrigation frequency

  12. Cumulative effects of sewage sludge and effluent mixture application on soil properties of a sandy soil under a mixture of star and kikuyu grasses in Zimbabwe

    Science.gov (United States)

    Madyiwa, S.; Chimbari, M.; Nyamangara, J.; Bangira, C.

    Although sewage effluent and sludge provides nutrients for plant growth, its continual use over extended periods can result in the accumulation of heavy metals in soils and in grass to levels that are detrimental to the food chain. This study was carried in 2001 out at Firle farm, owned by the Municipality of Harare, to assess heavy metal loading on a sandy soil and uptake of the metals by pasture grass consisting of a mixture of Cynodon nlemfuensis (star grass) and Pennisetum clandestinum Chiov (kikuyu grass) following sewage effluent and sludge application for 29 years. Firle Farm receives treated effluent and sludge emanating from domestic and industrial sources. Soil and grass samples were taken from the study area, consisting of 3 ha of non-irrigated area (control) and 1.3 ha of irrigated area. Both the soil and grass samples were tested for Cu, Zn, Ni and Pb using atomic absorption spectrophotometry. Sewage sludge addition resulted in high levels of soil pollution, especially in the 20 cm horizon, in the irrigated area when compared to the control. Grasses took up moderate levels of Cu and Zn, and limited levels of Pb. Nickel was not detectable in grasses despite high levels in the irrigated soil. Copper uptake was several times higher than the suggested potentially toxic level of 12 mg/kg [Soil Science Society of America, Micronutrients in agriculture, second ed., Wisconsin, USA, 1991]. Lead uptake averaged 1.0 mg/kg, which was below 10 mg/kg the suggested limit for agronomic crops [E.M. Seaker, Zinc, copper, cadmium and lead in minespoil, water and plants from reclaimed mine land amended with sewage sludge, 1991]. Cu and Zn showed relatively higher mobility down the soil profile than Ni and Pb. Even then, the concentrations in the lower soil layers were very small, suggesting that the metals were unlikely to contaminate groundwater. There was no direct correlation between metal levels in soils and grasses. It was postulated that it is the bio

  13. Toxicity of iron oxide nanoparticles to grass litter decomposition in a sandy soil

    Science.gov (United States)

    Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Imran, Muhammad; Dhavamani, Jeyakumar; Ismail, Iqbal M. I.; Basahi, Jalal M.; Almeelbi, Talal

    2017-01-01

    We examined time-dependent effect of iron oxide nanoparticles (IONPs) at a rate of 2000 mg kg−1 soil on Cynodon dactylon litter (3 g kg−1) decomposition in an arid sandy soil. Overall, heterotrophic cultivable bacterial and fungal colonies, and microbial biomass carbon were significantly decreased in litter-amended soil by the application of nanoparticles after 90 and 180 days of incubation. Time dependent effect of nanoparticles was significant for microbial biomass in litter-amended soil where nanoparticles decreased this variable from 27% after 90 days to 49% after 180 days. IONPs decreased CO2 emission by 28 and 30% from litter-amended soil after 90 and 180 days, respectively. These observations indicated that time-dependent effect was not significant on grass-litter carbon mineralization efficiency. Alternatively, nanoparticles application significantly reduced mineral nitrogen content in litter-amended soil in both time intervals. Therefore, nitrogen mineralization efficiency was decreased to 60% after 180 days compared to that after 90 days in nanoparticles grass-litter amended soil. These effects can be explained by the presence of labile Fe in microbial biomass after 180 days in nanoparticles amendment. Hence, our results suggest that toxicity of IONPs to soil functioning should consider before recommending their use in agro-ecosystems. PMID:28155886

  14. Toxicity of iron oxide nanoparticles to grass litter decomposition in a sandy soil

    Science.gov (United States)

    Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Imran, Muhammad; Dhavamani, Jeyakumar; Ismail, Iqbal M. I.; Basahi, Jalal M.; Almeelbi, Talal

    2017-02-01

    We examined time-dependent effect of iron oxide nanoparticles (IONPs) at a rate of 2000 mg kg‑1 soil on Cynodon dactylon litter (3 g kg‑1) decomposition in an arid sandy soil. Overall, heterotrophic cultivable bacterial and fungal colonies, and microbial biomass carbon were significantly decreased in litter-amended soil by the application of nanoparticles after 90 and 180 days of incubation. Time dependent effect of nanoparticles was significant for microbial biomass in litter-amended soil where nanoparticles decreased this variable from 27% after 90 days to 49% after 180 days. IONPs decreased CO2 emission by 28 and 30% from litter-amended soil after 90 and 180 days, respectively. These observations indicated that time-dependent effect was not significant on grass-litter carbon mineralization efficiency. Alternatively, nanoparticles application significantly reduced mineral nitrogen content in litter-amended soil in both time intervals. Therefore, nitrogen mineralization efficiency was decreased to 60% after 180 days compared to that after 90 days in nanoparticles grass-litter amended soil. These effects can be explained by the presence of labile Fe in microbial biomass after 180 days in nanoparticles amendment. Hence, our results suggest that toxicity of IONPs to soil functioning should consider before recommending their use in agro-ecosystems.

  15. Cropping sequence and nitrogen fertilization impact on surface residue, soil carbon sequestration, and crop yields

    Science.gov (United States)

    Information is needed on the effect of management practices on soil C storage for obtaining C credit. The effects of tillage, cropping sequence, and N fertilization were evaluated on dryland crop and surface residue C and soil organic C (SOC) at the 0-120 cm depth in a Williams loam from 2006 to 201...

  16. Soil carbon and crop yields affected by irrigation, tillage, crop rotation, and nitrogen fertilization

    Science.gov (United States)

    Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

  17. A Bioassay Technique to Study Clomazone Residues in Sandy Loam Soil

    Directory of Open Access Journals (Sweden)

    Jelena Gajić Umiljendić

    2013-01-01

    Full Text Available A bioassay test was conducted to evaluate the sensitivity of maize, sunflower and barley toclomazone residues in sandy loam soil. Clomazone was applied at different rates from 0.12 to12 mg a.i./kg of soil. The parameters measured 14 days after treatment were: shoot height, freshand dry weight, and content of pigments (carotenoids, chlorophyll a and chlorophyll b. Theresults showed that the lowest clomazone concentration caused a significant reduction in allmeasured parameters for barley and sunflower shoots. Fresh weight of maize shoots was notsensitive to clomazone residual activity in soil while the other parameters were highly inhibited.Nomenclature: clomazone (2-(2-chlorbenzyl-4,4-dimethyl-1,2-oxazolidin-3-one, maize(Zea mays L., sunflower (Helianthus annuus L., barley (Hordeum vulgare L.

  18. Transport of humic and fulvic acids in relation to metal mobility in a copper-contaminated acid sandy soil

    NARCIS (Netherlands)

    Weng, L.; Fest, E.P.M.J.; Filius, J.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2002-01-01

    The transport of inorganic and organic pollutants in water and soil can be strongly influenced by the mobility of natural dissolved organic matter (DOM). In this paper, the transport of a humic acid (HA) and a fulvic acid (FA) in a copper-contaminated acid sandy soil was studied. The data showed

  19. A Leguminous Shrub (Caragana microphylla) in Semiarid Sandy Soils of North China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tong-Hui; SU Yong-Zhong; CUI Jian-Yuan; ZHANG Zhi-Hui; CHANG Xue-Xiang

    2006-01-01

    Caragana microphylla Lam., a pioneer leguminous shrub species for vegetation re-establishment, is widely distributed in the semi-fixed and fixed sandy lands of the Horqin region. Some soil chemical and physical properties were measured under the canopy of C. microphylla and in the adjacent open areas to determine the effects of individual shrubs on soil properties. The influence of isolated C. microphylla on chemical and physical properties of the topsoil was significantly different between plots under the shrub canopy and in the shrub interspaces. Beneath the shrub canopy greater amounts of fine particle fractions, a higher water-holding capacity, and a lower bulk density, as well as higher aboveground and belowground litter biomass were found. Soil organic C and total N concentrations were 23%-31.6% and 14%-27.2% higher under the shrub canopies than in the shrub interspaces, respectively, giving rise to "islands of fertility". In a desertified sandy grassland ecosystem, C. microphylla was believed to play a major role in organic C sequestration, N accumulation, and the hydrologic cycle. Additionally, it has been found to be of ecological importance for vegetative restoration and reversal of desertification.

  20. Aggregate-associated carbon and nitrogen in reclaimed sandy loam soils

    Energy Technology Data Exchange (ETDEWEB)

    Wick, A.F.; Stahl, P.D.; Ingram, L.J. [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States)

    2009-11-15

    Minimal research has been conducted on aggregate, C, and N in coarse-textured soils used to reclaim surface coal mine lands. Furthermore, little is known about the contribution different plant communities make to the recovery of aggregation in these soils. Two chronosequences of semiarid reclaimed sites with sandy loam soils were sampled under shrub- and grass-dominated communities. Aggregation, aggregate fractions, and associated C and N were measured. No definitive trends of increasing macroaggregates between sites were observed undershrubs; however, macro- and microaggregation was greater in the 16-yr-old (0.20 and 0.23 kg aggregate kg{sup -1} soil, respectively) than in the 5-yr-old soils (0.02 and 0.08 kg aggregate kg{sup -1} soil, respectively) under grasses. Although C and N concentrations were drastically reduced (50-75%) with mining activity between the <1-yr-old and native soils, aggregate C and N concentrations tinder shrubs and grasses were similar to each other and to the native soils in the 5-yr-old site. Sods under grass in the 16-yr-old site had lower available and aggregate-occluded C and N concentrations than the 5-yr-old site, while C and N concentrations did not change between 5- and 16-yr-old soils under shrubs. Conversely, aggregate C and N pool sizes under shrubs and grasses both increased with site age to conditions similar to those observed in the native soil. Reclaimed shrub site soils had consistently higher C concentrations in the older reclaimed sites (10 and 16 yr old) than the soils under grasses, indicating greater accumulation and retention of C and N in organic material under shrub than grass communities in semiarid reclaimed sites.

  1. Contribution of individual sorbents to the control of heavy metal activity in sandy soil.

    Science.gov (United States)

    Weng, L; Temminghoff, E J; Van Riemsdijk, W H

    2001-11-15

    A multisurface model is used to evaluate the contribution of various sorption surfaces to the control of heavy metal activity in sandy soil samples at pH 3.7-6.1 with different sorbent contents. This multisurface model considers soil as a set of independent sorption surfaces, i.e. organic matter (NICA-Donnan), clay silicate (Donnan), and iron hydroxides (DDL, CD-MUSIC). The activities of Cu2+, Cd2+, Zn2+, Ni2+, and Pb2+ in equilibrium with the soil have been measured using a Donnan membrane technique. The metal activities predicted by the model agree with those measured reasonably well over a wide concentration range for all the metals of interest except for Pb. The modeling results suggest that soil organic matter is the most important sorbent that controls the activity of Cu2+, Cd2+, Zn2+, and Ni2+ in these sandy soils. When metal loading is high in comparison with soil organic matter content, the contribution of clay silicates to metal binding becomes more important. Adsorption to iron hydroxides is found not significant in these samples for Cu, Cd, Zn, and Ni. However, for Pb the model estimates strong adsorption on iron hydroxides. The model predicts that acidification will not only lead to increased solution concentrations but also to a shift toward more nonspecific cation-exchange type binding especially for the metals Cd, Zn, and Ni. Lowering the pH has led to a loss of 56% of Cd, 69% of Zn, and 66% of Ni during 16 years due to increased leaching.

  2. Influence of manganese fertilizer on efficiency of grapes on sandy soils of the Chechen Republic

    Directory of Open Access Journals (Sweden)

    Batukaev A.A.

    2014-01-01

    Full Text Available As a result of the studies, there has been obtained new information about the manganese influence on productivity of grape plantations, on sandy soils of the Chechen Republic. Manganese fertilizing of 4 kg active ingredient per 1 ha, against the background of nitrogen 90 kg, phosphorus 90 kg and potassium 90 kg/ha, made it into a phase of grape sap flow, which contributes to higher yields, increase of the sugar content of the berries and a significant decrease in juice acidity, in comparison with other options.

  3. Effect of pore-size distribution on the collapse behaviour of anthropogenic sandy soil deposits

    OpenAIRE

    Baille Wiebke; Jebeli Alireza; Schanz Tom

    2016-01-01

    In the former open-pit mines of the Lusatian region in Germany, several liquefaction events have occurred during the recent years in the anthropogenic deposits made of very loose sandy soils. These events are related to the rising ground water table after the stop of controlled ground water lowering. The very loose state is due to the formation of sand aggregates (pseudo-grains) during the deposition process. The pseudo-grains enclose larger voids of dimension greater than the single sand gra...

  4. Cover crops and crop residue management under no-till systems improve soils and environmental quality

    Science.gov (United States)

    Kumar, Sandeep; Wegner, Brianna; Vahyala, Ibrahim; Osborne, Shannon; Schumacher, Thomas; Lehman, Michael

    2015-04-01

    Crop residue harvest is a common practice in the Midwestern USA for the ethanol production. However, excessive removal of crop residues from the soil surface contributes to the degradation of important soil quality indicators such as soil organic carbon (SOC). Addition of a cover crop may help to mitigate these negative effects. The present study was set up to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators and surface greenhouse gas (GHG) fluxes. The study was being conducted on plots located at the North Central Agricultural Research Laboratory (NCARL) in Brookings, South Dakota, USA. Three plots of a corn and soybean (Glycine max (L.) Merr.) rotation under a no-till (NT) system are being monitored for soils and surface gas fluxes. Each plot has three residue removal (high residue removal, HRR; medium residue removal, MRR; and low residue removal, LRR) treatments and two cover crops (cover crops and no cover crops) treatments. Both corn and soybean are represented every year. Gas flux measurements were taken weekly using a closed static chamber method. Data show that residue removal significantly impacted soil quality indicators while more time was needed for an affect from cover crop treatments to be noticed. The LRR treatment resulted in higher SOC concentrations, increased aggregate stability, and increased microbial activity. The LRR treatment also increased soil organic matter (SOM) and particulate organic matter (POM) concentrations. Cover crops used in HRR (high corn residue removal) improved SOC (27 g kg-1) by 6% compared to that without cover crops (25.4 g kg-1). Cover crops significantly impacted POM concentration directly after the residue removal treatments were applied in 2012. CO2 fluxes were observed to increase as temperature increased, while N2O fluxes increased as soil moisture increased. CH4 fluxes were responsive to both increases in temperature and moisture. On average, soils under

  5. Microbial activity in soil cultivated with different summer legumes in coffee crop

    Directory of Open Access Journals (Sweden)

    Elcio Liborio Balota

    2011-02-01

    Full Text Available A field experiment was conducted for ten years in a sandy soil in the north part of the Paraná State, Brazil. The soil samples were collected at 0-10 cm depth, both under the coffee canopy and in the inter row space between the coffee plants, in the following treatments: Control, Leucaena leucocephala, Crotalaria spectabilis, Crotalaria breviflora, Mucuna pruriens, Mucuna deeringiana, Arachis hypogaea and Vigna unguiculata. The legume crops influenced the microbial activity, both under the coffee canopy and in the inter row space. The cultivation of Leucaena leucocephala increased the microbial biomass C, N and P. Although L. leucocephala and Arachis hypogaea provided higher microbial biomass, the qCO2 decreased by up to 50% under the coffee canopy and by about 25% in the inter row space. The soil microbial biomass was enriched in N and P due to green manure residue addition.

  6. Phytotoxicity and uptake of nitroglycerin in a natural sandy loam soil.

    Science.gov (United States)

    Rocheleau, Sylvie; Kuperman, Roman G; Dodard, Sabine G; Sarrazin, Manon; Savard, Kathleen; Paquet, Louise; Hawari, Jalal; Checkai, Ronald T; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I

    2011-11-15

    Nitroglycerin (NG) is widely used for the production of explosives and solid propellants, and is a soil contaminant of concern at some military training ranges. NG phytotoxicity data reported in the literature cannot be applied directly to development of ecotoxicological benchmarks for plant exposures in soil because they were determined in studies using hydroponic media, cell cultures, and transgenic plants. Toxicities of NG in the present studies were evaluated for alfalfa (Medicago sativa), barnyard grass (Echinochloa crusgalli), and ryegrass (Lolium perenne) exposed to NG in Sassafras sandy loam soil. Uptake and degradation of NG were also evaluated in ryegrass. The median effective concentration values for shoot growth ranged from 40 to 231 mg kg(-1) in studies with NG freshly amended in soil, and from 23 to 185 mg kg(-1) in studies with NG weathered-and-aged in soil. Weathering-and-aging NG in soil did not significantly affect the toxicity based on 95% confidence intervals for either seedling emergence or plant growth endpoints. Uptake studies revealed that NG was not accumulated in ryegrass but was transformed into dinitroglycerin in the soil and roots, and was subsequently translocated into the ryegrass shoots. The highest bioconcentration factors for dinitroglycerin of 685 and 40 were determined for roots and shoots, respectively. Results of these studies will improve our understanding of toxicity and bioconcentration of NG in terrestrial plants and will contribute to ecological risk assessment of NG-contaminated sites.

  7. Variation in soil water content to rainfall under Caragana microphylla shrub in Horqin Sandy Land

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to investigate the spatio-temporal variability of soil water content to rainfall under Caragana microphylla shrub in Horqin Sandy Land,a plot of 25 m × 25 m,where there were 6 shrub canopies of C. microphylla,was sited for measuring soil water content at two soil layers of 0-20 cm (top layer) and 20-40 cm (lower layer). Soil water content was measured on the 1st,5th,10th and 15th day after a 42 mm rainfall in Naiman of Inner Mongolia. The results showed that soil water contents at both layers under C. microphylla shrub were gradually decreased after the rain. Soil water content at the top layer outside the shrub canopy was higher than that inside the shrub canopy within 5 days,and became similar inside and outside the shrub canopy on the 10th day after the 42 mm rainfall,and it was lower outside than that inside the shrub canopy on the 15th day. The soil water content at lower layer in the area without shrubs was higher than that under shrub canopy all along. All the measured values of soil water content can be fitted to a variogram model. There was significant autocorrelation of the values of soil water content between top layer and lower layer,except for the fourth measured values of soil water content at top layer. The range and spatial dependence of soil water content at top layer were lower than that at lower layer.

  8. Assessing crop N status of fertigated vegetable crops using plant and soil monitoring techniques.

    Science.gov (United States)

    Peña-Fleitas, M T; Gallardo, M; Thompson, R B; Farneselli, M; Padilla, F M

    2015-11-01

    Evaluation of crop N status will assist optimal N management of intensive vegetable production. Simple procedures for monitoring crop N status such as petiole sap [NO 3(-)-N], leaf N content and soil solution [NO 3(-)] were evaluated with indeterminate tomato and muskmelon. Their sensitivity to assess crop N status throughout each crop was evaluated using linear regression analysis against nitrogen nutrition index (NNI) and crop N content. NNI is the ratio between the actual and the critical crop N contents (critical N content is the minimum N content necessary to achieve maximum growth), and is an established indicator of crop N status. Nutrient solutions with four different N concentrations (treatments N1-N4) were applied throughout each crop. Average applied N concentrations were 1, 5, 13 and 22 mmol L(-1) in tomato, and 2, 7, 13 and 21 mmol L(-1) in muskmelon. Respective rates of N were 23, 147, 421 and 672 kg N ha(-1) in tomato, and 28, 124, 245 and 380 kg N ha(-1) in muskmelon. For each N treatment in each crop, petiole sap [NO 3(-)-N] was relatively constant throughout the crop. During both crops, there were very significant (P 1. Relationships between petiole sap [NO 3(-)-N] with crop N content, and leaf N content with both NNI and crop N content had variable slopes and intercept values during the indeterminate tomato and the muskmelon crops. Soil solution [NO 3(-)] in the root zone was not a sensitive indicator of crop N status. Of the three systems examined for monitoring crop/soil N status, petiole sap [NO 3(-)-N] is suggested to be the most useful because of its sensitivity to crop N status and because it can be rapidly analysed on the farm.

  9. Eleven years' effect of conservation practices for temperate sandy loams: II. Soil pore characteristics

    DEFF Research Database (Denmark)

    Abdollahi, Lotfallah; Munkholm, Lars Juhl

    2017-01-01

    Conservation agriculture (CA) is regarded by many as a sustainable intensification strategy. Minimal soil disturbance in combination with residue retention are important CA components. This study examined the long-term effects of crop rotation, residue retention, and tillage on soil pore characte......Conservation agriculture (CA) is regarded by many as a sustainable intensification strategy. Minimal soil disturbance in combination with residue retention are important CA components. This study examined the long-term effects of crop rotation, residue retention, and tillage on soil pore......, the volume of pores > 30 μm was more than 0.03 m3 m-3 larger for MP than for D in spring 2014 at the 4- to 8-cm depth. At the 18- to 27-cm depth, direct drilling resulted in a better air permeability and pore continuity index (e.g., air permeability of 18.2 and 11.2 mm2 for D and MP, respectively at −10 k...

  10. Recurring fingered flow pathways in a water repellent sandy field soil

    Directory of Open Access Journals (Sweden)

    C. J. Ritsema

    1997-01-01

    Full Text Available Field evidence of finger formation and reformation during Successive rain events over an eight months' observation period from June 1994 until January 1995 is presented. Fingered flow pathways were monitored in a no-tilled, grass-covered water repellent sandy field soil using an automated, stand-alone TDR device. Within a 2 m long and 0.7 m deep transect, 98 three-wire probes were installed horizontally at depths of 4, 12, 20, 30, 40, 55, and 70 cm. The horizontal distance between two adjacent probes was IS cm. Finger formation occurred during distinct rainy periods and was most pronounced under heavy rainfall with initially wet topsoil conditions. The percentage of water infiltrated and transported preferentially through the fingers to the deep subsoil varied between 0 and 80%, depending on the wetting history of the soil and the rainfall characteristics.

  11. Amelioration of sandy soils in drought stricken areas through use of ...

    African Journals Online (AJOL)

    ACSS

    moisture retention, pH, N, P, Ca and Mg content, and subsequently, maize dry matter yield. Averaged over 2 ... increased soil quality persisted for at least. 3 years. ..... improve its ability to support a growing crop. ... A combination of these.

  12. Influence of tebuconazole and copper hydroxide on phosphatase and urease activities in red sandy loam and black clay soils

    OpenAIRE

    B. Anuradha; Rekhapadmini, A.; Rangaswamy, V.

    2016-01-01

    The efficacy of two selected fungicides i.e., tebuconazole and coppoer hydroxide, was conducted experiments in laboratory and copper hydroxide on the two specific enzymes phosphatase and urease were determined in two different soil samples (red sandy loam and black clay soils) of groundnut (Arachis hypogaea L.) from cultivated fields of Anantapuramu District, Andhra Pradesh. The activities of the selected soil enzymes were determined by incubating the selected fungicides-treated (1.0, 2.5, 5....

  13. Retention and transport of mecoprop on acid sandy-loam soils

    Science.gov (United States)

    Paradelo Núñez, Remigio; Conde Cid, Manuel; Abad, Elodie Martin; Fernández Calviño, David; Nóvoa Muñoz, Juan Carlos; Arias Estévez, Manuel

    2017-04-01

    Interaction with soil components is one of the key processes governing the fate of agrochemicals in the environment. In this work, we have studied the adsorption/desorption and transport of mecoprop in four acid sandy-loam soils with different organic matter contents. Kinetics of adsorption and adsorption/desorption at equilibrium have been studied in batch experiments, whereas transport was studied in laboratory columns. Adsorption and desorption are linear or nearly-linear. The kinetics of mecoprop adsorption are relatively fast in all cases (less than 24 h). Adsorption and desorption were adequately described by the linear and Freundlich models, with KF values that ranged from 0.7 to 8.8 Ln µmol1-n kg-1 and KD values from 0.3 to 3.6 L kg-1. High desorption percentages (>50%) were found, indicative of a high reversibility of the adsorption process. The results of the transport experiments showed that the retention of mecoprop by soil was very low (less than 6.2%). The retention of mecoprop by the soils in all experiments increased with organic matter content. Overall, it was observed that mecoprop was weakly adsorbed by the soils, what would result in a high risk of leaching of this compound.

  14. Impact of diverse soil microbial communities on crop residues decomposition

    Science.gov (United States)

    Mrad, Fida; Bennegadi-Laurent, Nadia; Ailhas, Jérôme; Leblanc, Nathalie; Trinsoutrot-Gattin, Isabelle; Laval, Karine; Gattin, Richard

    2017-04-01

    Soils provide many basic ecosystem services for our society and most of these services are carried out by the soil communities, thus influencing soils quality. Soil organic matter (SOM) can be considered as one of the most important soil quality indices for it plays a determinant role in many physical, chemical and biological processes, such as soil structure and erosion resistance, cation exchange capacity, nutrient cycling and biological activity (Andrews et al., 2004). Since a long time, exogenous organic inputs are largely used for improving agricultural soils, affecting highly soil fertility and productivity. The use of organic amendments such as crop residues influences the soil microbial populations' diversity and abundance. In the meantime, soil microbial communities play a major role in the organic matter degradation, and the effect of different microbial communities on the decomposition of crop residues is not well documented. In this context, studying the impact of crop residues on soil microbial ecology and the processes controlling the fate of plant residues in different management practices is essential for understanding the long-term environmental and agronomic effects on soil and organic matters. Our purpose in the present work was to investigate the decomposition by two contrasting microbial communities of three crop residues, and compare the effect of different residues amendments on the abundance and function of each soil microbial communities. Among the main crops which produce large amounts of residues, we focused on three different plants: wheat (Triticum aestivum L.), rape (Brassica napus) and sunflower (Helianthus annuus). The residues degradation in two soils of different management practices and the microbial activity were evaluated by: microbial abundance (microbial carbon, culturable bacteria, total DNA, qPCR), in combination with functional indicators (enzymatic assays and Biolog substrate utilization), kinetics of C and N

  15. [Effects of degraded sandy grassland afforestation on soil quality in semi-arid area of northern China].

    Science.gov (United States)

    Hu, Ya-lin; Zeng, De-hui; Fan, Zhi-ping; Ai, Gui-yan

    2007-11-01

    By the methods of field survey and incubation test, this paper studied the effects of degraded sandy grassland afforestation with Mongolian pine on the soil physical, chemical and biological properties in 0-10 cm layer on Keerqin sandy land. The results showed that after 32 years afforestation, soil organic C, total N and total P decreased by 21%, 42% and 45%, respectively. In May and November, soil NH4+ -N content was significantly higher under Mongolian pine plantation than under grassland (P = 0.001; P = 0.019), but in May, August and November, soil NO3- -N content was in adverse (P soil C mineralization rate was higher under Mongolian pine plantation than under grassland, but the difference in N mineralization rate was not significant (P > 0.05). In May and August, soil microbial biomass C under Mongolian pine plantation and grassland had little difference, but in November, it was significantly higher under Mongolian pine plantation than under grassland. Soil nutrients- and moisture contents were the important factors affecting soil microbial biomass C. Soil urease and invertase activities decreased but catalase activity increased under Mongolian pine plantation, compared with those under grassland. It was suggested that 32 years afforestation of degraded sandy grassland with Mongolian pine on Keerqin sandy land led to a definite degradation of soil quality. Owing to the changes of vegetation, the test indicators of soil quality had different seasonal dynamic characteristics under Mongolian pine plantation and grassland. As a means of degraded ecosystem restoration in semi-arid area of Northern China, afforestation had its definite limitations.

  16. Considering temperature dependence of thermo-physical properties of sandy soils in two scenarios of oil pollution

    Institute of Scientific and Technical Information of China (English)

    Aleksey V.Malyshev; Anatoly M.Timofeev

    2014-01-01

    We analyzed the heat conductivity and volumetric heat capacity of sandy soil contaminated in two scenarios of oil pollu tion, and also determined the temperature dependencies of these changed thermophysical properties. In the first pollution scenario, the oil product was introduced into wet river sand, and in the second case, dry sand was contaminated by the oil product and was then moistened with water. By considering these two scenarios as multicomponent dispersion systems with varying degrees of contamination and humidity, and by using a polystructural granular model with pore spaces and closed inclusions, we calculated that the heat conductivity of the sandy soil increased under the first pollution scenario and decreased under the second, but the change in the volumetric heat capacity of the sandy soil was proportional only to the amount of oil pollution, not the manner in which it was introduced. We also determined the temperature dependencies of these two thermophysical properties of sandy soil when polluted by oil, of which information will be useful for future containment and remediation of oil contaminated soil.

  17. Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

    Directory of Open Access Journals (Sweden)

    Antônio Ocimar Manzi

    2011-04-01

    Full Text Available Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundwater chemistry and soil CO2 respiration were studied in forests on sandy soils, whereas drought sensitivity of poorly-drained valley soils was investigated in an artificial drainage experiment. Slightly changes in litter decomposition or water chemistry were observed as a consequence of artificial drainage. Riparian plots did experience higher litter decomposition rates than campina forest. In response to a permanent lowering of the groundwater level from 0.1 m to 0.3 m depth in the drainage plot, topsoil carbon and nitrogen contents decreased substantially. Soil CO2 respiration decreased from 3.7±0.6 µmol m-2 s-1 before drainage to 2.5±0.2 and 0.8±0.1 µmol m-2 s-1 eight and 11 months after drainage, respectively. Soil respiration in the control plot remained constant at 3.7±0.6 µmol m-2 s-1. The above suggests that more frequent droughts may affect topsoil carbon and nitrogen content and soil respiration rates in the riparian ecosystem, and may induce a transition to less diverse campinarana or short-statured campina forest that covers areas with strongly-leached sandy soil.

  18. [Effects of transgenic crops on soil microorganisms: a review].

    Science.gov (United States)

    Zhang, Yan-Jun; Xie, Ming; Peng, De-Liang

    2013-09-01

    The worldwide cultivation of transgenic crops not only provides tremendous economic benefits, but also induces the concern about the potential risks of transgenic crops on soil ecosystem in which microorganisms are involved. The potential effects of transgenic crops on soil microorganisms include the direct effects of the transgenic proteins on non-target soil microorganisms, and the indirect effects of the unintentional changes in the chemical compositions of root exudates induced by the introduction of the exogenous transgenic proteins. Most of the studies on transgenic crops suggested that transgenic crops could affect the quantity and structure of soil microbial populations. However, the perceivable effects on the soil microorganisms are inconsistent, with some in significant and others in non-significant, or some with persistent and others with non-persistent. This paper summarized the effects of different transgenic crops on soil microorganisms, and discussed the factors affecting the assessment reliability, including the species of transgenic crops and the experimental technologies and principles. Some issues needed to be paid special attention to in the future studies were put forward.

  19. The Experimental Study on Application Effect of BGA Soil Conditioner in Aeolian Sandy Soil%BGA土壤调理剂在风沙土上的施用效果研究

    Institute of Scientific and Technical Information of China (English)

    杨建国; 纪立东; 樊丽琴; 谢华; 孙权; 李明; 尚红莺; 李淑玲

    2012-01-01

    In order to solve the problem of land desertification in Ningxia, improve aeolian sandy soil quality and increase land productivity, the application effect of BGA soil conditioner on aeolian sandy soil and crops was studied and evaluated through field plot experiment. The results showed that, compared with no fertilizer, BGA soil conditioner improved physical and chemical properties of aeolian sandy soil, promoted the growth of wine grape, cherry tomato and liquorice, increased significantly the yield of wine grape and cherry tomato, improved the quality of wine grape and liquorice. Compared with balanced fertilization, BGA soil conditioner improved physical and chemical properties of aeolian sandy soil, promoted the growth of wine grape and cherry tomato, decreased significantly the yield of liquorice, improved the quality of wine grape. The application of BGA soil conditioner greatly increased the investment cost of production. It was proposed to reduce production cost of BGA soil conditioner and combine application of BGA soil conditioner with chemical fertilizers.%为了解决宁夏土地沙化问题,提高风沙土土壤质量和土地生产力,通过田间试验研究了BGA土壤调理剂对风沙土土壤理化性质和作物生长发育的影响,评价了BGA土壤调理剂的施用效果.研究结果表明,与不施肥相比,施用BGA土壤调理剂改善了风沙土土壤理化性质,促进了酿酒葡萄、樱桃番茄和甘草的生长发育,显著提高了酿酒葡萄和樱桃番茄的产量,改善了酿酒葡萄和甘草品质;与配方施肥相比,施用BGA土壤调理剂改善了风沙土土壤理化性质,促进了酿酒葡萄和樱桃番茄的生长发育,显著降低了甘草产量,改善了酿酒葡萄品质.施用BGA土壤调理剂大幅度增加了生产投入成本,建议进一步降低BGA土壤调理剂的生产成本或与化肥配合施用.

  20. Leaching and ponding of viral contaminants following land application of biosolids on sandy-loam soil.

    Science.gov (United States)

    Wong, Kelvin; Harrigan, Tim; Xagoraraki, Irene

    2012-12-15

    Much of the land available for application of biosolids is cropland near urban areas. Biosolids are often applied on hay or grassland during the growing season or on corn ground before planting or after harvest in the fall. In this study, mesophilic anaerobic digested (MAD) biosolids were applied at 56,000 L/ha on a sandy-loam soil over large containment lysimeters seeded to perennial covers of orchardgrass (Dactylis glomerata L.), switchgrass (Panicum virgatum), or planted annually to maize (Zea mays L.). Portable rainfall simulators were to maintain the lysimeters under a nearly saturated (90%, volumetric basis) conditions. Lysimeter leachate and surface ponded water samples were collected and analyzed for somatic phage, adenoviruses, and anionic (chloride) and microbial (P-22 bacteriophage) tracers. Neither adenovirus nor somatic phage was recovered from the leachate samples. P-22 bacteriophage was found in the leachate of three lysimeters (removal rates ranged from 1.8 to 3.2 log(10)/m). Although the peak of the anionic tracer breakthrough occurred at a similar pore volume in each lysimeter (around 0.3 pore volume) the peak of P-22 breakthrough varied between lysimeters (worm holes or other natural phenomena. The concentration of viral contaminants collected in ponded surface water ranged from 1 to 10% of the initial concentration in the applied biosolids. The die off of somatic phage and P-22 in the surface water was fit to a first order decay model and somatic phage reached background level at about day ten. In conclusion, sandy-loam soils can effectively remove/adsorb the indigenous viruses leached from the land-applied biosolids, but there is a potential of viral pollution from runoff following significant rainfall events when biosolids remain on the soil surface.

  1. Biochar effects on wet and dry regions of the soil water retention curve of a sandy loam

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Sun, Zhencai;

    2014-01-01

    Reported beneficial effects of biochar on soil physical properties and processes include decreased soil density, and increased soil water transport, water holding capacity and retention (mainly for the wet region). Research is limited on biochar effects on the full soil water retention curve (wet...... and dry regions) for a given soil and biochar amendment scenarios. This study evaluates how biochar applied to a sandy loam field at rates from 0 to 50 Mg ha−1 yr–1 in 2011, 2012, or both years (2011+2012) influences the full water retention curve. Inorganic fertilizer and pig slurry were added to all...... region-water retention curve increased with increasing biochar rates....

  2. Uncertainty of Deardorff’s soil moisture model based on continuous TDR measurements for sandy loam soil

    Directory of Open Access Journals (Sweden)

    Brandyk Andrzej

    2016-03-01

    Full Text Available Knowledge on soil moisture is indispensable for a range of hydrological models, since it exerts a considerable influence on runoff conditions. Proper tools are nowadays applied in order to gain in-sight into soil moisture status, especially of uppermost soil layers, which are prone to weather changes and land use practices. In order to establish relationships between meteorological conditions and topsoil moisture, a simple model would be required, characterized by low computational effort, simple structure and low number of identified and calibrated parameters. We demonstrated, that existing model for shallow soils, considering mass exchange between two layers (the upper and the lower, as well as with the atmosphere and subsoil, worked well for sandy loam with deep ground water table in Warsaw conurbation. GLUE (Generalized Likelihood Uncertainty Estimation linked with GSA (Global Sensitivity Analysis provided for final determination of parameter values and model confidence ranges. Including the uncertainty in a model structure, caused that the median soil moisture solution of the GLUE was shifted from the one optimal in deterministic sense. From the point of view of practical model application, the main shortcoming were the underestimated water exchange rates between the lower soil layer (ranging from the depth of 0.1 to 0.2 m below ground level and subsoil. General model quality was found to be satisfactory and promising for its utilization for establishing measures to regain retention in urbanized conditions.

  3. Proposal of new convenient extractant for assessing phytoavailability of heavy metals in contaminated sandy soil.

    Science.gov (United States)

    Korzeniowska, Jolanta; Stanislawska-Glubiak, Ewa

    2017-06-01

    The aim of the study was to compare the usefulness of 1 M HCl with aqua regia, EDTA, and CaCl2 for the extraction of phytoavailable forms of Cu, Ni, and Zn on coarse-textured soils contaminated with these metals. Two microplot experiments were used for the studies. Reed canary grass (Phalaris arundinacea), maize (Zea mays), willow (Salix viminalis), spartina (Spartina pectinata), and miscanthus (Miscanthus × giganteus) were used as test plants. They were grown on soil artificially spiked with Cu, Ni, and Zn. The experimental design included a control and three increasing doses of metals. Microplots (1 m(2) × 1 m deep) were filled with sandy soil (clay-6%, pH 5.5, Corg-0.8%). Metals in the form of sulfates were dissolved in water and applied to the plot using a hand liquid sprayer. During the harvest, samples were collected from aboveground parts, roots, and the soil and then tested for their Cu, Zn, and Ni contents. The metal content of the soil was determined using four tested extractants. It was found that Cu and Ni were accumulated in roots in bigger amounts than Zn. The usefulness of the extractants was evaluated based on the correlation between the content of metals in the soil and the plant (n = 32). This study demonstrated that 1 M HCl, aqua regia, and EDTA were more efficient or equally useful for the assessment of the phytoavailability of Cu, Ni, and Zn as CaCl2. Due to the ease of performing determinations and their low cost, 1 M HCl can be recommended to assess the excess of Cu, Ni, and Zn in the coarse-textured soils.

  4. Multiple benefits of manure: the key to maintenance of soil fertility and restoration of depleted sandy soils on African smallholder farms

    NARCIS (Netherlands)

    Zingore, S.; Delve, R.J.; Nyamangara, J.; Giller, K.E.

    2008-01-01

    Manure is a key nutrient resource on smallholder farms in the tropics, especially on poorly buffered sandy soils, due to its multiple benefits for soil fertility. Farmers preferentially apply manure to fields closest to homesteads (homefields), which are more fertile than fields further away (outfie

  5. Chemical contamination of soils in the New York City area following Hurricane Sandy.

    Science.gov (United States)

    Mandigo, Amy C; DiScenza, Dana J; Keimowitz, Alison R; Fitzgerald, Neil

    2016-10-01

    This paper presents a unique data set of lead, arsenic, polychlorinated biphenyl (PCB), and polycyclic aromatic hydrocarbon (PAH) concentrations in soil samples collected from the metropolitan New York City area in the aftermath of Hurricane Sandy. Initial samples were collected by citizen scientists recruited via social media, a relatively unusual approach for a sample collection project. Participants in the affected areas collected 63 usable samples from basements, gardens, roads, and beaches. Results indicate high levels of arsenic, lead, PCBs, and PAHs in an area approximately 800 feet south of the United States Environmental Protection Agency (US EPA) Superfund site at Newtown Creek. A location adjacent to the Gowanus Canal, another Superfund site, was found to have high PCB concentrations. Areas of high PAH contamination tended to be near high traffic areas or next to sites of known contamination. While contamination as a direct result of Hurricane Sandy cannot be demonstrated conclusively, the presence of high levels of contamination close to known contamination sites, evidence for co-contamination, and decrease in number of samples containing measureable amounts of semi-volatile compounds from samples collected at similar locations 9 months after the storm suggest that contaminated particles may have migrated to residential areas as a result of flooding.

  6. Environmental adaptability of Canavalia virosa and Flemingia congesta to sandy ash soil of Merapi Volcano, Java

    Directory of Open Access Journals (Sweden)

    S. S. Wardoyo

    2016-07-01

    Full Text Available Studies on volcanic ash of Mount Merapi erupted in 2010 are limited to only characterization of mineralogical, physical, chemical, and biological properties of the volcanic ash. In order to speed up rehabilitation of soils affected by the volcanic ash, it is necessary to study the application of suitable plant species, which is called bio-mechanic conservation. The purpose of this study was to test the environmental adaptability of Canavalia virosa and Flemingia congesta in sandy soil covered by volcanic ash of Mount Merapi. This study was carried out using 2x4 Split-plot randomized block design with three replicates. The main plot of the design was plant species (Canavalia virosa and Flemingia congesta, while the sub plot was the dose of organic matter application (0, 20, 40, and 60 t / ha. Soil parameters measured were N-total, P-total, available P, available K, and organic matter contents. Plant parameters measured were plant dry weight and plant height. The results showed no significant differences in soil N, P and K contents of all treatments tested in this study after 9 weeks, except C organic content. Canavalia virosa grew well until 9 weeks, whereas Flemingia congesta started to die a 9 weeks after planting.

  7. Tillage and cover cropping effects on soil properties and crop production in Illinois

    Science.gov (United States)

    Cover crops (CCs) have been heralded for their potential to improve soil properties, retain nutrients in the field, and increase subsequent crop yields yet support for these claims within the state of Illinois remains limited. We assessed the effects of integrating five sets of CCs into a corn-soybe...

  8. Effect of Plant-derived Hydrophobic Compounds on Soil Water. Repellency in Dutch Sandy Soils

    NARCIS (Netherlands)

    Mao, J.|info:eu-repo/dai/nl/363508287; Dekker, S.C.|info:eu-repo/dai/nl/203449827; Nierop, K.G.J.|info:eu-repo/dai/nl/182329895

    2013-01-01

    Soil water repellency or hydrophobicity is a common and important soil property, which may diminish plant growth and promotes soil erosion leading to environmentally undesired situations. Hydrophobic organic compounds in the soil are derived from vegetation (leaves, roots, mosses) or microorganisms

  9. Effect of Plant-derived Hydrophobic Compounds on Soil Water. Repellency in Dutch Sandy Soils

    NARCIS (Netherlands)

    Mao, J.; Dekker, S.C.; Nierop, K.G.J.

    2013-01-01

    Soil water repellency or hydrophobicity is a common and important soil property, which may diminish plant growth and promotes soil erosion leading to environmentally undesired situations. Hydrophobic organic compounds in the soil are derived from vegetation (leaves, roots, mosses) or microorganisms

  10. Modelling of soil salinity and halophyte crop production

    NARCIS (Netherlands)

    Vermue, E.; Metselaar, K.; Zee, van der S.E.A.T.M.

    2013-01-01

    In crop modelling the soil, plant and atmosphere system is regarded as a continuum with regard to root water uptake and transpiration. Crop production, often assumed to be linearly related with transpiration, depends on several factors, including water and nutrient availability and salinity. The

  11. Cadmium in fertilizers, soil, crops and foods - the Swedish situation

    Energy Technology Data Exchange (ETDEWEB)

    Hellstrand, S.; Landner, L. [Swedish Environmental Research Group (MFG)

    1998-03-01

    The aim of this report is to review available information on the fluxes of cadmium (Cd) to agricultural soils and crops in Sweden from phosphorus fertilizers (P-fertilizer) and other sources, and to discuss how the content of Cd in soil, crops and human food may be influenced by the specific environmental conditions in Sweden, as well as by the agricultural practices used in the country 62 refs, 15 figs, 18 tabs. With 5 page summary in Swedish

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  13. Tomato nitrogen accumulation and fertilizer use efficiency on a sandy soil, as affected by nitrogen rate and irrigation scheduling

    NARCIS (Netherlands)

    Zotarelli, L.; Dukes, M.D.; Scholberg, J.M.S.; Munoz-Carpena, R.; Icerman, J.

    2009-01-01

    Tomato production systems in Florida are typically intensively managed with high inputs of fertilizer and irrigation and on sandy soils with low inherent water and nutrient retention capacities; potential nutrient leaching losses undermine the sustainability of such systems. The objectives of this 3

  14. Soil Organic Carbon Pools Under Switchgrass Grown as a Bioenergy Crop Compared to Other Conventional Crops

    Institute of Scientific and Technical Information of China (English)

    F.G.DOU; F.M.HONS; W.R.OCUMPAUGH; J.C.READ; M.A.HUSSEY; J.P.MUIR

    2013-01-01

    Switchgrass (Panicum virgatum L.) has been proposed as a sustainable bioenergy crop because of its high yield potential,adaptation to marginal sites,and tolerance to water and nutrient limitations.A better understanding of the potential effects of biomass energy crop production practices on soil biological properties and organic matter dynamics is critical to its production.Our objective was to evaluate changes in C pools under a warm-season perennial switchgrass in different soils compared to typically-grown crops collected at College Station,Dallas,and Stephenville,TX in February 2001.Sampling depths were 0-5,5-15,and 15-30 cm.Switchgrass increased soil organic C (SOC),soil microbial biomass C (SMBC),mineralizable C,and particulate organic matter C (POM-C) compared to conventional cropping systems.Soil C concentrations were in the order:long-term coastal bermudagrass [Cynodon dactylon (L.) Pers.] > switchgrass or kleingrass (Panicum coloratum L.) planted in 1992 > switchgrass 1997 > conventional cropping systems.Soil C concentrations tended to increase with increasing clay content.Greater microbial biomass C followed the order of Dallas >College Station > Stephenville,and ranged from approximately 180 mg C kg-1 soil at Stephenville to 1900 mg C kg-1 soil at Dallas.Particulate organic C was more sensitive than other fractions to management,increasing as much as 6-fold under long-term coastal bermudagrass compared to conventional cropping systems.Our study indicated that conversion of conventional cropping systems into switchgrass production can sequestrate more SOC and improve soil biological properties in the southern USA.

  15. Relating soil biochemistry to sustainable crop production

    Science.gov (United States)

    Amino acids, amino sugars, carbohydrates, phenols, and fatty acids together comprise appreciable proportions of soil organic matter (SOM). Their cycling contribute to soil processes, including nitrogen availability, carbon sequestration and aggregation. For example, soil accumulation of phenols has ...

  16. Grass Cover Influences Hydrophysical Parameters and Heterogeneity of Water Flow in a Sandy Soil

    Institute of Scientific and Technical Information of China (English)

    L. LICHNER; D. J. ELDRIDGE; K. SCHACHT; N. ZHUKOVA; L. HOLKO; M. (S)(I)R; J. PECHO

    2011-01-01

    Vegetation cover has a major effect on water flow in soils.Two sites,separated by distance of about 50 m,were selected to quantify the influence of grass cover on hydrophysical parameters and heterogeneity of water flow in a sandy soil emerging during a heavy rain following a long hot,dry period.A control soil (pure sand) with limited impact of vegetation or organic matter was obtained by sampling at 50 cm depth beneath a glade area,and a grassland soil was covered in a 10 cm thick humic layer and colonised by grasses.The persistence of water repellency was measured using the water drop penetration time test,sorptivity and unsaturated hydraulic conductivity using a mini disk infiltrometer,and saturated hydraulic conductivity using a double-ring infiltrometer.Dye tracer experiments were used to assess the heterogeneity of water flow,and both the modified method for estimating effective cross section and an original method for assessing the degree of preferential flow were used to quantify this heterogeneity from the images of dyed soil profiles.Most hydrophysical parameters were substantially different between the two surfaces.The grassland soil had an index of water repellency about 10 times that of pure sand and the persistence of water repellency almost 350 times that of pure sand.Water and ethanol sorptivities in the grassland soil were 7% and 43%,respectively,of those of the pure sand.Hydraulic conductivity and saturated hydraulic conductivities in the grassland soil were 5% and 16% of those of the pure sand,respectively.Dye tracer experiments revealed a stable flow with "air-draining" condition in pure sand and well-developed preferential flow in grassland soil,corresponding to individual grass tussocks and small micro-depressions.The grassland soil was substantially more water repellent and had 3 times the degree of preferential flow compared to pure sand.The results of this study reinforce our view that the consequences of any change in climate

  17. Soil water retention, air flow and pore structure characteristics after corn cob biochar application to a tropical sandy loam

    DEFF Research Database (Denmark)

    Amoakwah, Emmanuel; Frimpong, Kwame Agyei; Okae-Anti, D

    2017-01-01

    Soil structure is a key soil physical property that affects soil water balance, gas transport, plant growth and development, and ultimately plant yield. Biochar has received global recognition as a soil amendment with the potential to ameliorate the structure of degraded soils. We investigated how...... corn cob biochar contributed to changes in soil water retention, air flow by convection and diffusion, and derived soil structure indices in a tropical sandy loam. Intact soil cores were taken from a field experiment that had plots without biochar (CT), and plots each with 10 t ha− 1 (BC-10), 20 t ha...... to significant increase in soil water retention compared to the CT and BC-10 as a result of increased microporosity (pores biochar had minimal impact. No significant influence of biochar was observed for ka and Dp/D0 for the BC treatments compared to the CT despite...

  18. Soil resistance and resilience to mechanical stresses for three differently managed sandy loam soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Schjønning, Per; Møldrup, Per;

    2012-01-01

    carbon (CCC resistance and resilience of the three soils to compaction using air permeability (ka), void ratio (e) and air-filled porosity (ε) as functional indicators and to characterise aggregate stability, strength and friability. Aggregate tensile...... at both soil-water potentials than the MCC and CCC soils possibly due to higher biotic binding of soil particles by the greater organic carbon content. The water dispersible clay was negatively correlated with the level of clay saturation by organic carbon. The resistance of the soils to compaction......, quantified by both the compression index and a proposed functional index, was significantly greater for the MFC soil compared to the other two soils. The change in compression index with initial void ratio was significantly less for the MFC than the other soils. Plastic reorganisation of the soil particles...

  19. Soil Organic Nitrogen and Its Contribution to Crop Production

    Institute of Scientific and Technical Information of China (English)

    LI Sheng-xiu; WANG Zhao-hui; MIAO Yan-fang; LI Shi-qing

    2014-01-01

    Plant growth and crop production depend to a large extent on soil N supplying capacity (SNSC):The higher the SNSC, the higher the dependence of crops on soil and the lower the N fertilizer recovery. Of the SNSC, soil organic N (ON) played a key role in supplying N nutrient to crop production and still does in many subsistence and low-input farming systems. In this paper, soil ON contents, types, chemical components and its contribution to plant production are reviewed up to date in details, the characteristics of ON in dryland soils discussed together with its chemical components, and the mineralization and availability to plants of some important chemical components are emphasized at the last part for practical considerations.

  20. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    Science.gov (United States)

    Ladoni, Moslem; Kravchenko, Alexandra N; Robertson, G Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop

  1. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    Directory of Open Access Journals (Sweden)

    Moslem Ladoni

    Full Text Available Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover and non-leguminous (winter rye cover crops on potentially mineralizable N (PMN and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management

  2. Effect of soil pH on sorption of salinomycin in clay and sandy soils

    African Journals Online (AJOL)

    use

    Full Length Research Paper. Effect of ... In this study, sorption of salinomycin was measured in four agricultural soils, a clay soil with low organic ... Key words: Salinomycin, sorption, pH, desorption, environmental pollution, phosphate buffer.

  3. Controlled release fertilizer increased phytoremediation of petroleum-contaminated sandy soil.

    Science.gov (United States)

    Cartmill, Andrew D; Cartmill, Donita L; Alarcón, Alejandro

    2014-01-01

    A greenhouse experiment was conducted to determine the effect of the application of controlled release fertilizer [(CRF) 0, 4,6, or 8 kg m(-3)] on Lolium multiflorum Lam. survival and potential biodegradation of petroleum hydrocarbons (0, 3000, 6000, or 15000 mg kg(-1)) in sandy soil. Plant adaptation, growth, photosynthesis, total chlorophyll, and proline content as well as rhizosphere microbial population (culturable heterotrophic fungal and bacterial populations) and total petroleum hydrocarbon (TPH)-degradation were determined. Petroleum induced-toxicity resulted in reduced plant growth, photosynthesis, and nutrient status. Plant adaptation, growth, photosynthesis, and chlorophyll content were enhanced by the application of CRF in contaminated soil. Proline content showed limited use as a physiological indicator of petroleum induced-stress in plants. Bacterial and filamentous fungi populations were stimulated by the petroleum concentrations. Bacterial populations were stimulated by CRF application. At low petroleum contamination, CRF did not enhance TPH-degradation. However, petroleum degradation in the rhizosphere was enhanced by the application of medium rates of CRF, especially when plants were exposed to intermediate and high petroleum contamination. Application of CRF allowed plants to overcome the growth impairment induced by the presence of petroleum hydrocarbons in soils.

  4. Cations extraction of sandy-clay soils from cavado valley, portugal, using sodium salts solutions

    Directory of Open Access Journals (Sweden)

    Silva João Eudes da

    2002-01-01

    Full Text Available Cases of contamination by metals in the water wells of the Cavado Valley in north-west Portugal can be attributed to the heavy leaching of clay soils due to an excess of nitrogen resulting from the intensive use of fertilisers in agricultural areas. This work focuses on the natural weathering characteristics of soils, particularly the clay material, through the study of samples collected near the River Cavado. Samples taken from various sites, after physico-chemical characterisation, were subjected to clay dissolution tests, using sodium salts of different ionic forces, to detect the relationship between certain physico-chemical parameters of water, such as pH, nitrate, chloride and sulphate content, in the dissolution of clay and the subsequent extraction of such cations as Al, Fe and K. In acidic sandy clay soils, the mineralogical composition of which was characterised by a predominance of quartz, micas, kaolinite and K-feldspars, decreases of the clay material/water pH ratio increases dissolution of the micaceous and K-feldspars phases. The presence of nitrates in the aqueous solution apparently advanced the extraction of all three cations Al, Fe and K. The specific surface area of the clay material showed a significant correlation with the main kinetic parameters of cation extraction.

  5. Dissolved Organic Carbon Dynamics Along Terrestrial-aquatic Flowpaths in a Catchment Dominated by Sandy Soils

    Science.gov (United States)

    Wickland, K.; Walker, J. F.; Hood, K.; Butler, K. D.

    2015-12-01

    Aquatic systems receive significant amounts of terrestrially-derived dissolved organic carbon (DOC) from their watersheds. The amount and nature received depends on terrestrial carbon source strength, processing and losses of carbon during transport, and hydrologic connectivity between terrestrial and aquatic systems. While much research has been done on terrestrial DOC dynamics along terrestrial-aquatic flowpaths, there is still considerable uncertainty in many areas including the importance of different carbon sources, microbial metabolism and sorption of DOC, and processing of carbon in groundwater. Here we investigate DOC dynamics in soils, groundwater, and stream waters at the USGS Water, Energy, and Biogeochemical (WEBB) Program research site in northern Wisconsin. This site is well-suited for studying DOC dynamics as soils are sandy and homogenous with small DOC sorption potential, and previous work has characterized the hydrology of the region in detail. We collected water samples over two years from soil pit lysimeters along a series of hillslope transects, from shallow and deep groundwater wells, and from a first-order stream receiving these waters. We measured DOC concentration, DOC optical properties, and biodegradability of DOC. Combined with historical DOC and companion water chemistry data we characterize DOC generation and loss along the following flowpaths: 1) infiltration through the unsaturated zone to the groundwater table, 2) shallow groundwater flow, and 3) long groundwater flowpaths of different origin (lake-derived vs. terrestrial-derived water).

  6. Visual soil assessment: field guide for cropping

    OpenAIRE

    Shepherd, Graham

    2000-01-01

    Visual assessments provide an immediate diagnostic tool to evaluate soil quality, as many physical, biological (and to a lesser degree chemical) soil characteristics show up as visual characteristics. Results are easy to interpret and understand. The Visual Soil Assessment (VSA) method has been developed to help land managers assess soil quality easily, quickly, reliably and cheaply on a paddock scale. It requires little equipment, training or technical skills. Part I, “VSA of soil qu...

  7. Potassium Supplying Power of Soils in Heilongjiang Province and the Effect of Potassium Application on Resistance of Crops to Adverse Conditions

    Institute of Scientific and Technical Information of China (English)

    ChenKuiqing; WangErli; 等

    1995-01-01

    The total potassium(K)content of soils in Heilongjiang was relatively high in general and the available potassium content on soils was quite different for different soil types.The results of electro-ultra-filtration(EUF)analysis showed that the dark brown forest soils and the black soils in the northern part contained relatively high EUF-K,ranged from 12.5 to 15.7 mg per 100g soil.In the black soils in the southern part,the EUF-K ranged from 8 to 9mg per 100g soil.The albic and aeolian sandy soils contained low EUF-K,ranged from 3.2 to 4.8mg per 100g soil.Field experiment in 1982 indicated that potassium fertilizer in soils with medium or low EUF-K,increased soybean yield by 17%-34%,and obviously prevented the epidemic of meadow moth and soybean mosaic virus.Application of potassium fertilizer increased the protein and total sugar content of the plants,promoted transportation of nutrients,speeded up the growth of the plants,improved the resistance of crops to adverse conditions.Application of potassium fertilizer resulted in early maturity of crops(4-7 days earlier than cotrol),which had great significance for preventing crops from early frost damage.Hence,in order to keep nutrients balance in the soil and to increase soil fertility.potassium fertilizer or materials containing potassium must be applied to soils with medium and low EUF-K,such as black soils in the south part,ablic soils and aeolian sandy soils in Heilongjiang Province.

  8. Transport and Retention of Toxoplasma gondii Oocysts in Loamy Sand and Sandy Loam Soils

    Science.gov (United States)

    Kinsey, E. N.; Korte, C.; L'Ollivier, C.; Dubey, J. P.; Aurélien, D.; Darnault, C. J. G.

    2016-12-01

    Toxoplasma gondii is one of the most prevalent parasites affecting warm-blooded animals and humans. It has a complex life cycle that involves a wide variety of intermediate hosts with felids as a definitive host. Humans may contract it through consumption of infected, undercooked meat or by water or food sources contaminated with the oocyst form of the parasite. Infection of pregnant women can cause stillbirth, neurological effects or blindness. Because of the prevalence of cats, including on farms where oocyst-contaminated cat feces, animal feed, soil and water have been found, T. gondii is spread almost throughout the entire globe. It has been implicated or suspected in waterborne infections since the 1990s. This study aims to characterize the transport and retention of T. gondii oocysts in field soils. The four soils used were collected from fallow and cultivated fields in Illinois and Utah, USA. They are classified as loamy sands and sandy loams. Soil columns were subjected to continuous artificial rainfall until they reached steady state at which point pulses that included 2.5 million T. gondii oocysts (Me49 strain) and KBr as a tracer were added. After the pulse infiltrated, continuous rainfall was resumed. Rain applied all columns was a 1 mM KCl solution. Leachate samples were collected, analyzed using qPCR for T. gondii and bromide ions and breakthrough curves were produced. Soil was sliced into 1 to 2 cm sections, for which water content and T. gondii concentration were measured to access degree of saturation and oocyst retention.

  9. PCDD/PCDF behavior in low-temperature pyrolysis of PCP-contaminated sandy soil.

    Science.gov (United States)

    Thuan, Ngo Thi; Dien, Nguyen Thanh; Chang, Moo Been

    2013-01-15

    This study investigates the behavior of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) formation, dechlorination and destruction in PCP-contaminated sandy soil by low-temperature thermal treatment. Experimental tests were carried out in a nitrogen atmosphere in the temperature range of 200-400 °C with a treatment time of 30 min. 70% of PCP removal from the soil was achieved, resulting in 1436±230 ng/kg, the highest PCDD/F formation at 250 °C; however, the highest toxic concentration was measured around 4.20±0.62 ng TEQ/kg at 300 °C with 80% PCP removal from the soil. Further analysis has revealed that OCDD is the most dominant congener that is supposed to be formed from the pyrolysis of PCP, while OCDF is the second prevailing congener, possibly due to pyrolysis of 2,3,4,5-TeCP being a main byproduct of PCP pyrolysis. Detection of less chlorinated dioxins and furans over 300 °C indicates the dechlorination of highly chlorinated dioxins and furans, especially octachlorinated dibenzo-p-dioxin (OCDD) at 350 °C and 400 °C. Desorption from soil was supposed as a main mechanism for the distribution of PCDD/Fs in the gaseous phase, and not much difference in dioxins and furan levels was observed at 350 °C and 400 °C in the gaseous phase. Therefore, 350 °C is the most appropriate temperature to remove most PCP and PCDD/Fs from soil, as well as to meet PCDD/F emission standards (0.1 ng I-TEQ/Nm(3)). Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Effects of freeze-thaw on soil nitrogen and phosphorus availability at the Keerqin Sandy Lands, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qiong; ZENG De-hui; FAN Zhi-ping

    2008-01-01

    A laboratory simulated freeze-thaw was conducted to determine the effects of freeze-thaw on soil nutrient availability in temperate semi-arid regions. Soil samples were collected from sandy soils (0-20 cm) of three typical ecosystems (grassland, Mongolian pine plantation and poplar plantation) in southeastern Keerqin Sandy Lands of China and subjected to freeze-thaw treatment (-12℃ for 10 days, then 20℃ for 10 days) or incubated at constant temperature (20℃ for 20 days). Concentrations of the soil NO3--N, NH4+-N, NaHCO3 extractable inorganic P (LPi) and microbial biomass P (MBP) were determined on three occasions: at the start of the incubation, immediate post-thawing and at the 10th day post-thawing. The results showed that soil net nitrification and N mineralization rates at three sites were negatively affected by freeze-thaw treatment, and decreased by 50%-85% as compared to the control, of which the greatest decline occurred in the soil collected from poplar plantation. In contrast, the concentration of soil NH4+-N, NaHCO3 extractable inorganic P (LPi) and microbial biomass P were insignificantly influenced by freeze-thaw except that LPi and NH4+-N showed a slight increase immediate post-thawing. The effects of freeze-thaw on soil N transformation were related to soil biological processes and the relatively constant available P was ascribed to severe soil aridity.

  11. An integrated crop- and soil-based strategy for variable-rate nitrogen management in corn

    Science.gov (United States)

    Roberts, Darrin F.

    developed by Solari (2006), identification of soil variables for MZ delineation, and the possible integration of MZ and active sensors for N application. Crop response (sensor measured sufficiency index and yield) had the highest correlation with soil optical reflectance readings in sandy fields and with apparent soil electrical conductivity in silt loam fields with eroded slopes. Therefore, using these soil variables to delineate MZ allowed characterization of spatial patterns in both in-season crop response (sufficiency index) and yield. Compared to uniform N application, integrating MZ and sensor-based N application resulted in substantial N savings (˜40--120 kg ha-1) and increases in partial factor productivity (˜13--75 kg grain (kg N applied)-1) for fine-textured soils with eroded slopes. However, for coarser texture soils the current sensor-based N application algorithm may require further calibration, and for fields with no spatial variability there appears to be no benefit to using the algorithm. Collectively, results from these studies show promise for integrating active sensor-based N application and static soil-based MZ to increase NUE and economic return for producers over current N management strategies, but further research is needed to explore how best to integrate these two N management strategies.

  12. Biochar effects on wet and dry regions of the soil water retention curve of a sandy loam

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Sun, Zhencai

    2014-01-01

    Reported beneficial effects of biochar on soil physical properties and processes include decreased soil density, and increased soil water transport, water holding capacity and retention (mainly for the wet region). Research is limited on biochar effects on the full soil water retention curve (wet...... and dry regions) for a given soil and biochar amendment scenarios. This study evaluates how biochar applied to a sandy loam field at rates from 0 to 50 Mg ha−1 yr–1 in 2011, 2012, or both years (2011+2012) influences the full water retention curve. Inorganic fertilizer and pig slurry were added to all...... treatments. Six months after the last biochar application, intact and disturbed soil samples were collected for analyses. Soil water retention was measured from −1 kPa to −100 kPa using tension tables and ceramic plates and from −10 MPa to −480 MPa using a Vapor Sorption Analyzer. Soil specific area...

  13. Effects of organic fertilizers and biochar/organic fertilizer combinations on fertility and organic matter dynamics of a sandy soil in north-west Germany

    Science.gov (United States)

    Greenberg, Isabel; Kaiser, Michael; Polifka, Steven; Wiedner, Katja; Glaser, Bruno; Ludwig, Bernard

    2017-04-01

    % compared to the mineral fertilizer treatment. The magnitude of the demonstrated positive effect of biochar application on crop yield depends on the type and amount of the biochar+organic fertilizer mixture and the cultivated plant species. Besides benefiting biomass production, applications of 10 to 40 t/ha of biochar+fertilizer mixtures seem to result in increased bulk soil and aggregate protected OC contents, indicating a longer lasting positive effect on the OC storage and the structural stability of this sandy soil. Cost/benefit wise, the 10 t/ha composted biochar treatment seems to be most promising for improving soil properties and crop yield, while the compost treatment seems to be the best alternative for sandy soils where biochar is either unavailable or prohibitively expensive.

  14. Growth, Yield and WUE of Drip and Sprinkler Irrigated Okra Grown On Sandy Soil Under Semi-Arid Conditions in Southeast Ghana

    DEFF Research Database (Denmark)

    Plauborg, Finn

    Vegetable production systems at the Keta sand spit, Southeast Ghana, are typically managed with excessive amounts of irrigation water and fertilizers on sandy soils with low inherent water and nutrient retention capacities. The shallow groundwater which is the primary irrigation water resource......, the main aim of our study was to explore the water sa ving potential of drip irrigation in order to save the shallow groundwater from over exploitation. A two season study (minor dry season, 2011 and major dry season, 2012) were carried out to determine the okra crop response to the following treatments: 1...... is prone to salinization from the Keta lagoon, the Atlantic Ocean and brackish water underneath (Kortatsi and Agyeku, 1999). To ensure the sustainability of vegetable production at the Keta spit, introduction of water saving irrigation systems and improved irrigation management schemes are important. Thus...

  15. [Effects of long-term fertilization on pH buffer system of sandy loam calcareous fluvor-aquic soil].

    Science.gov (United States)

    Wang, Ji-Dong; Qi, Bing-Jie; Zhang, Yong-Chun; Zhang, Ai-Jun; Ning, Yun-Wang; Xu, Xian-Ju; Zhang, Hui; Ma, Hong-Bo

    2012-04-01

    Soil samples (0-80 cm) were collected from a 30-year fertilization experimental site in Xuzhou, Jiangsu Province of East China to study the variations of the pH, calcium carbonate and active calcium carbonate contents, and pH buffer capacity of sandy loam calcareous fluvor-aquic soil under different fertilization treatments. Thirty-year continuous application of different fertilizers accelerated the acidification of topsoil (0-20 cm), with the soil pH decreased by 0.41-0.70. Under different fertilization, the soil pH buffer capacity (pHBC) varied from 15.82 to 21.96 cmol x kg(-1). As compared with no fertilization, single N fertilization decreased the pHBC significantly, but N fertilization combined with organic fertilization could significantly increase the pHBC. The soil pHBC had significant positive correlations with soil calcium carbonate and active calcium carbonate contents, but less correlation with soil organic matter content and soil cation exchange capacity, suggesting that after a long-term fertilization, the sandy loam calcareous fluvor-aquic soil was still of an elementary calcium carbonate buffer system, and soil organic matter and cation exchange capacity contributed little to the buffer system. The soil calcium carbonate and active calcium carbonate contents were greater in 0-40 cm than in 40-80 cm soil layer. Comparing with soil calcium carbonate, soil active calcium carbonate was more sensitive to reflect the changes of soil physical and chemical properties, suggesting that the calcium carbonate buffer system could be further classified as soil active calcium carbonate buffer system.

  16. Evaluation of Crops Sensitivity to Atrazine Soil Residual

    Directory of Open Access Journals (Sweden)

    E Izadi

    2012-02-01

    Full Text Available Abstract In order to study the sensitivity of 9 crops to atrazine soil residual, two separate experiments were conducted in field and greenhouse conditions. First experiment was conducted in a field with treated soil by atrazine based on split plot and the results evaluated in greenhouse conditions. Treatments in the field experiment included two organic manure application rates (0 and 50 t/ha as main plots and 2 atrazine application rates (2 and 4 kg/ha atrazine a.i. as sob plots. After corn harvesting soil was sampled at 0-15 cm surface layer in each plots in 15 points, after mixing the samples. Wheat, barley, sugar beet, pea, lens and colza planted in pots at greenhouse. Second experiment conducted in greenhouse conditions for evaluation of atrazine soil residual in completely randomized design. Treatments included atrazine soil residual concentrations (0, 0.2, 0.5, 1, 5, 10 and 15 mg/kg soil and crops included wheat, barley, sugar beet, pea, lens, rape, bean and tomato. Results showed that atrazine residue had no effect on crops growth in field experiment treated with atrazine. It seems that atrazine residue in filed soil is lower that its damage threshold for crops or maybe for its fast removal in field than in control conditions. But in bioassay experiment (greenhouse experiment crops response to atrazine residues were different. Results showed that onion and pea were most susceptible ant tolerant crops between studied species and based of ED50 parameter the other crops tolerance to total residue ranked as: pea< bean< lentil< sugar beet< tomato< barley< wheat< rape< onion. Keywords: Atrazine residue, Pea, Bean, Lentil, Sugar beet, Barley, Wheat, Rape, Tomato

  17. The critical soil P levels for crop yield, soil fertility and environmental safety in different soil types

    NARCIS (Netherlands)

    Bai, Z.H.; Li, H.G.; Yang, X.Y.; Zhou, B.K.; Shi, X.J.; Wang, B.R.; Li, D.C.; Shen, J.B.; Chen, Q.; Qin, W.; Oenema, O.; Zhang, F.S.

    2013-01-01

    Sufficient soil phosphorus (P) is important for achieving optimal crop production, but excessive soil P levels may create a risk of P losses and associated eutrophication of surface waters. The aim of this study was to determine critical soil P levels for achieving optimal crop yields and minimal P

  18. Using a local-interaction model to determine the resistance to penetration of projectiles into sandy soil

    Science.gov (United States)

    Kotov, V. L.; Balandin, V. V.; Bragov, A. M.; Linnik, E. Yu.; Balandin, V. V.

    2013-07-01

    A local-interaction model describing the penetration of axisymmetric projectiles into sandy soil at a constant velocity is studied experimentally and theoretically. Two approaches to the determination of the parameters of the quadratic local-interaction model are considered. The first approach is based on the use of the solution of the problem of spherical-cavity expansion taking into account the dynamic compressibility and shear resistance of soil. In the second approach, model parameters are determined based on the experimental dependence of the resistance to penetration of conical projectiles into a sandy soil on the impact velocity. Good agreement was obtained between the results of experiments, two-dimensional numerical calculations, and calculations for the local interaction model based on the solution of the spherical-cavity expansion problem and used to determine the maximum resistance to penetration of conical and spherical projectiles.

  19. Artificial Management Improves Soil Moisture, C, N and P in an Alpine Sandy Meadow of Western China

    Institute of Scientific and Technical Information of China (English)

    WU Gao-Lin; LI Wei; ZHAO Ling-Ping; SHI Zhi-Hua

    2011-01-01

    Regeneration of degraded grassland ecosystems is a significant issue in restoration ecology globally.To understand the effects of artificial management measures on alpine meadows, we surveyed topsoil properties including moisture, organic carbon (SOC), nitrogen (N), and phosphorus (P) contents five years after fencing and fencing + reseeding management practices in a sandy meadow in the eastern Qinghai-Tibetan Plateau, northwestern China.Both the fencing and fencing + reseeding management practices significantly increased soil moisture storage, SOC, total N, available N, total P, and available P, as compared to the unmanaged control.Fencing plus reseeding was more effective than fencing alone for improving soil C, N, and P contents.These suggested that rehabilitation by reseeding and fencing generally had favorable effects on the soil properties in degraded sandy alpine meadows, and was an effective approach for restoration of degraded meadow ecosystems of the Qinghai-Tibetan Plateau.

  20. Physical-hydraulic properties of a sandy loam typic paleudalf soil under organic cultivation of 'montenegrina' mandarin (Citrus deliciosa Tenore¹

    Directory of Open Access Journals (Sweden)

    Caroline Valverde dos Santos

    2014-12-01

    Full Text Available Citrus plants are the most important fruit species in the world, with emphasis to oranges, mandarins and lemons. In Rio Grande do Sul, Brazil, most fruit production is found on small properties under organic cultivation. Soil compaction is one of the factors limiting production and due to the fixed row placement of this crop, compaction can arise in various manners in the interrows of the orchard. The aim of this study was to evaluate soil physical properties and water infiltration capacity in response to interrow management in an orchard of mandarin (Citrus deliciosa Tenore 'Montenegrina' under organic cultivation. Interrow management was performed through harrowing, logs in em "V", mowing, and cutting/knocking down plants with a knife roller. Soil physical properties were evaluated in the wheel tracks of the tractor (WT, between the wheel tracks (BWT, and in the area under the line projection of the canopy (CLP, with undisturbed soil samples collected in the 0.00-0.15, 0.15-0.30, 0.30-0.45, and 0.45-0.60 m layers, with four replicates. The soil water infiltration test was performed using the concentric cylinder method, with a maximum time of 90 min for each test. In general, soil analysis showed a variation in the physical-hydraulic properties of the Argissolo Vermelho-Amarelo distrófico arênico (sandy loam Typic Paleudalf in the three sampling sites in all layers, regardless of the management procedure in the interrows. Machinery traffic leads to heterogeneity in the soil physical-hydraulic properties in the interrows of the orchard. Soil porosity and bulk density are affected especially in the wheel tracks of the tractor (WT, which causes a reduction in the constant rate of infiltration and in the accumulated infiltration of water in this sampling site. The use of the disk harrow and mower leads to greater harmful effects on the soil, which can interfere with mandarin production.

  1. Conventional crop management effects on soil organic matter characteristics

    OpenAIRE

    2003-01-01

    International audience; A Mediterranean soil affected by long-term crop management systems was evaluated to identify the best indicators of its quality. Selected characteristics included total soil organic carbon (TOC), light fraction carbon (LFC), acid hydrolyzable and water-soluble carbohydrates carbon (AHG-C and WSC-C), phenolic carbon (PC), mineralizable carbon (Q), microbial biomass carbon (MB-C) and metabolic quotients (qCO$_2$ and qD). Soil samples were taken under natural grass (NG), ...

  2. Amendment of Acid Soils with Crop Residues and Biochars

    Institute of Scientific and Technical Information of China (English)

    YUAN Jin-Hua; XU Ren-Kou; WANG Ning; LI Jiu-Yu

    2011-01-01

    The liming potential of some crop residues and their biochars on an acid Ultisol was investigated using incubation experiments. Rice hulls showed greater liming potential than rice hull biochar, while soybean and pea straws had less liming potential than their biochars. Due to their higher alkalinity, biochars from legume materials increased soil pH much compared to biochars from non-legume materials. The alkalinity of biochars was a key factor affecting their liming potential,and the greater alkalinity of biochars led to greater reductions in soil acidity. The incorporation of biochars decreased soil exchangeable acidity and increased soil exchangeable base cations and base saturation, thus improving soil fertility.

  3. The nematicidal effect of some bacterial biofertilizers on Meloidogyne incognita in sandy soil

    Directory of Open Access Journals (Sweden)

    M.E El-Hadad

    2011-03-01

    Full Text Available In a greenhouse experiment, the nematicidal effect of some bacterial biofertilizers including the nitrogen fixing bacteria (NFB Paenibacillus polymyxa (four strains, the phosphate solubilizing bacteria (PSB Bacillus megaterium (three strains and the potassium solubilizing bacteria (KSB B. circulans (three strains were evaluated individually on tomato plants infested with the root-knot nematode Meloidogyne incognita in potted sandy soil. Comparing with the uninoculated nematode-infested control, the inoculation with P. polymyxa NFB7, B. megaterium PSB2 and B. circulans KSB2, increased the counts of total bacteria and total bacterial spores in plants potted soil from 1.2 to 2.6 folds estimated 60 days post-inoculation. Consequently, the inoculation with P. polymyxa NFB7 increased significantly the shoot length (cm, number of leaves / plant, shoot dry weight (g / plant and root dry weight (g / plant by 32.6 %, 30.8 %, 70.3 % and 14.2 %, respectively. Generally, the majority treatments significantly reduced the nematode multiplication which was more obvious after 60 days of inoculation. Among the applied strains, P. polymyxa NFB7, B. megaterium PSB2 and B. circulans KSB2 inoculations resulted in the highest reduction in nematode population comparing with the uninoculated nematode-infested control. They recorded the highest reduction in numbers of hatched juveniles/root by 95.8 %, females/root by 63.75 % and juveniles/1kg soil by 57.8 %. These results indicated that these bacterial biofertilizers are promising double purpose microorganisms for mobilizing of soil nutrients (nitrogen, phosphate and potassium and for the biological control of M. incognita.

  4. Crop residue decomposition, residual soil organic matter and nitrogen mineralization in arable soils with contrasting textures

    NARCIS (Netherlands)

    Matus, F.J.

    1994-01-01

    To evaluate the significance of cropping, soil texture and soil structure for the decomposition of 14C- and 15N-labelled crop residues, a study was conducted in a sand and a

  5. Conservation tillage impacts on soil, crop and the environment

    Directory of Open Access Journals (Sweden)

    Mutiu Abolanle Busari

    2015-06-01

    Full Text Available There is an urgent need to match food production with increasing world population through identification of sustainable land management strategies. However, the struggle to achieve food security should be carried out keeping in mind the soil where the crops are grown and the environment in which the living things survive. Conservation agriculture (CA, practising agriculture in such a way so as to cause minimum damage to the environment, is being advocated at a large scale world-wide. Conservation tillage, the most important aspect of CA, is thought to take care of the soil health, plant growth and the environment. This paper aims to review the work done on conservation tillage in different agro-ecological regions so as to understand its impact from the perspectives of the soil, the crop and the environment. Research reports have identified several benefits of conservation tillage over conventional tillage (CT with respect to soil physical, chemical and biological properties as well as crop yields. Not less than 25% of the greenhouse gas effluxes to the atmosphere are attributed to agriculture. Processes of climate change mitigation and adaptation found zero tillage (ZT to be the most environmental friendly among different tillage techniques. Therefore, conservation tillage involving ZT and minimum tillage which has potential to break the surface compact zone in soil with reduced soil disturbance offers to lead to a better soil environment and crop yield with minimal impact on the environment.

  6. Enhanced retention of linuron, alachlor and metalaxyl in sandy soil columns intercalated with wood barriers.

    Science.gov (United States)

    Rodríguez-Cruz, M S; Ordax, J M; Arienzo, M; Sánchez-Martín, M J

    2011-03-01

    A study has been made of the effect a reactive barrier made of pine (softwood) or oak (hardwood) wood intercalated in a sandy soil column has on the retention of linuron, alachlor and metalaxyl (pesticides with contrasting physicochemical characteristics). The leaching of pesticides has been carried out under a saturated flow regime and breakthrough curves (BTCs) have been obtained at flow rates of 1 m Lmin(-1) (all pesticides) and 3 m Lmin(-1) (linuron). The cumulative curves in the unmodified soil indicate a leaching of pesticides >80% of the total amount of compound added. After barrier intercalation, linuron leaching decreases significantly and a modification of the leaching kinetics of alachlor and metalaxyl has been observed. The theoretical R factors increased ∼2.6-3.3, 1.2-1.6-fold, and 1.4-1.7-fold and the concentration of the maximum peak decreased ∼6-12-fold, 2-4-fold and 1.2-2-fold for linuron, alachlor and metalaxyl, respectively. When considering the three pesticides, significant correlations have been found between the theoretical retardation factor (R) and the pore volume corresponding to the maximum peaks of the BTCs (r=0.77; pmetalaxyl. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Predicting the Grouting Ability of Sandy Soils by Artificial Neural Networks Based On Experimental Tests

    Directory of Open Access Journals (Sweden)

    Mahmoud Hassanlourad

    2014-12-01

    Full Text Available In this paper, the grouting ability of sandy soils is investigated by artificial neural networks based on the results of chemical grout injection tests. In order to evaluate the soil grouting potential, experimental samples were prepared and then injected. The sand samples with three different particle sizes (medium, fine, and silty and three relative densities (%30, %50, and %90 were injected with the sodium silicate grout with three different concentrations (water to sodium silicate ratio of 0.33, 1, and 2. A multi-layer Perceptron type of the artificial neural network was trained and tested using the results of 138 experimental tests. The multi-layer Perceptron included one input layer, two hidden layers and one output layer. The input parameters consisted of initial relative densities of grouted samples, the average size of particles (D50, the ratio of the grout water to sodium silicate and the grout pressure. The output parameter was the grout injection radius. The results of the experimental tests showed that the radius of grout injection is a complicated function of the mentioned parameters. In addition, the results of the trained artificial neural network showed to be reasonably consistent with the experimental results.

  8. Desorption kinetics of benzene in a sandy soil in the presence of powdered activated carbon.

    Science.gov (United States)

    Choi, J-W; Kim, S-B; Kim, D-J

    2007-02-01

    Desorption kinetics of benzene was investigated with a modified biphasic desorption model in a sandy soil with five different powdered activated carbon (PAC) contents (0, 1, 2, 5, 10% w/w) as sorbents. Sorption experiments followed by series dilution desorption were conducted for each sorbent. Desorption of benzene was successively performed at two stages using deionized water and hexane. Modeling was performed on both desorption isotherm and desorption rate for water-induced desorption to elucidate the presence of sorption-desorption hysteresis and biphasic desorption and if present to quantify the desorption-resistant fraction (q (irr)) and labile fraction (F) of desorption site responsible for rapid process. Desorption isotherms revealed that sorption-desorption exhibited a severe hysteresis with a significant fraction of benzene being irreversibly adsorbed onto both pure sand and PAC, and that desorption-resistant fraction (q (irr)) increased with PAC content. Desorption kinetic modeling showed that desorption of benzene was biphasic with much higher (4-40 times) rate constant for rapid process (k (1)) than that for slow process (k (2)), and that the difference in the rate constant increased with PAC content. The labile fraction (F) of desorption site showed a decreasing tendency with PAC. The experimental results would provide valuable information on remediation methods for soils and groundwater contaminated with BTEX.

  9. Microbiological parameters as indicators of soil quality under various soil management and crop rotation systems in southern Brazil

    OpenAIRE

    FRANCHINI, J. C.; Crispino, C.C.; de Souza, R. A.; Torres, E; HUNGRIA, M.

    2007-01-01

    Metadata only record This article attempts to recognize soil parameters that can be used to monitor soil quality under different crop and soil management systems. The rates of CO2 emissions (soil respiration) were affected by variations in the sampling period, as well as in soil management and crop rotation. Considering all samples, CO2 emissions were 21% greater in conventional tillage. Soil microbial biomass was also influenced by sampling period and soil management, but not by crop rota...

  10. Effects of Nitramine Explosive CL-20 on the Soil Microinvertebrate Community in a Sandy Loam Soil

    Science.gov (United States)

    2013-09-01

    by individually combining and gently mixing CL-20- amended soil concentrates with clean SSL field soil in a plastic bag . This approach ensured that...Hawari, J.; Spain, J.C. Biodegradation of the Nitramine Explosive CL- 20. Appl. Environ. Microbiol. 2003, 69, 1871–1874. U.S. Department of

  11. Microstructure and stability of two sandy loam soils with different soil management

    NARCIS (Netherlands)

    Bouma, J.

    1969-01-01

    A practical problem initiated this study. In the Haarlemmermeer, a former lake reclaimed about 1850, several farmers had difficulties with soil structure. Land, plowed in autumn, was very wet in spring. Free water was sometimes present on the soil surface. Planting and seeding were long delayed in

  12. Effects of nitrogen fertilizer sources and temperature on soil CO2 efflux in Italian ryegrass crop under Mediterranean conditions

    Directory of Open Access Journals (Sweden)

    Roberto Lai

    2012-06-01

    Full Text Available We report the results of a study that aimed to assess the dynamics of total and heterotrophic soil respiration and its relationships with soil temperature or soil moisture of an Italian ryegrass haycrop managed with different nitrogen (N fertilizer sources. The field experiment was carried out in the Nitrate Vulnerable Zone of the dairy district of Arborea, a reclaimed wetland in central-western Sardinia, Italy. This is an area characterized by sandy soils, shallow water table and intensive dairy cattle farming systems. Italian ryegrass is grown for hay production in the context of a double cropping rotation with silage maize. We analyzed the effects of N fertilizer treatments on soil carbon dioxide (CO2 efflux, soil water content and soil temperature: i farmyard manure; ii cattle slurry; iii mineral fertilizer; iv 70 kg ha-1 from slurry and 60 kg ha-1 from mineral fertilizer that corresponds to the prescriptions of the vulnerable zone management plan. During the monitoring period, soil water content never fell below 8.6% vol., corresponding to approximately -33 kPa matric potential. Total and heterotrophic soil respiration dynamics were both influenced by soil temperature over winter and early spring, reaching a maximum in the first ten days of April in manure and slurry treatments. In the last 30 days of the Italian ryegrass crop cycle, total soil respiration decreased and seemed not to be affected by temperature. The analysis of covariance with soil temperature as covariate showed that average respiration rates were significantly higher under the manure treatment and lower with mineral fertilizer than the slurry and slurry+mineral treatments, but with similar rates of respiration per unit increase of soil temperature for all treatments. The average soil respiration rates were significantly and positively related to the soil carbon (C inputs derived from fertilizers and preceding crop residuals. We concluded that: i the fertilizer source

  13. Effect of nitrogen and water availability of three soil types on yield, radiation use efficiency and evapotranspiration in field-grown quinoa

    DEFF Research Database (Denmark)

    Razzaghi, Fatemeh; Plauborg, Finn; Jacobsen, Sven-Erik

    2012-01-01

    in field lysimeters with sand, sandy loam and sandy clay loam soil. Despite application of the same amount of nitrogen (120 kg N ha−1) to all plots, there were large differences in crop nitrogen-uptake for sandy clay loam (134 kg ha−1), sandy loam (102 kg ha−1) and sand (77 kg ha−1) under full irrigation...

  14. Field performance of nine soil water content sensors on a sandy loam soil in new brunswick, maritime region, Canada.

    Science.gov (United States)

    Chow, Lien; Xing, Zisheng; Rees, Herb W; Meng, Fanrui; Monteith, John; Stevens, Lionel

    2009-01-01

    An in situ field test on nine commonly-used soil water sensors was carried out in a sandy loam soil located in the Potato Research Center, Fredericton, NB (Canada) using the gravimetric method as a reference. The results showed that among the tested sensors, regardless of installation depths and soil water regimes, CS615, Trase, and Troxler performed the best with the factory calibrations, with a relative root mean square error (RRMSE) of 15.78, 16.93, and 17.65%, and a r(2) of 0.75, 0.77, and 0.65, respectively. TRIME, Moisture Point (MP917), and Gopher performed slightly worse with the factory calibrations, with a RRMSE of 45.76, 26.57, and 20.41%, and a r(2) of 0.65, 0.72, and 0.78, respectively, while the Gypsum, WaterMark, and Netafim showed a frequent need for calibration in the application in this region.

  15. Field Performance of Nine Soil Water Content Sensors on a Sandy Loam Soil in New Brunswick, Maritime Region, Canada

    Directory of Open Access Journals (Sweden)

    Lionel Stevens

    2009-11-01

    Full Text Available An in situ field test on nine commonly-used soil water sensors was carried out in a sandy loam soil located in the Potato Research Center, Fredericton, NB (Canada using the gravimetric method as a reference. The results showed that among the tested sensors, regardless of installation depths and soil water regimes, CS615, Trase, and Troxler performed the best with the factory calibrations, with a relative root mean square error (RRMSE of 15.78, 16.93, and 17.65%, and a r2 of 0.75, 0.77, and 0.65, respectively. TRIME, Moisture Point (MP917, and Gopher performed slightly worse with the factory calibrations, with a RRMSE of 45.76, 26.57, and 20.41%, and a r2 of 0.65, 0.72, and 0.78, respectively, while the Gypsum, WaterMark, and Netafim showed a frequent need for calibration in the application in this region.

  16. Thallium dynamics in contrasting light sandy soils--soil vulnerability assessment to anthropogenic contamination.

    Science.gov (United States)

    Vanek, Ales; Chrastný, Vladislav; Komárek, Michael; Galusková, Ivana; Drahota, Petr; Grygar, Tomás; Tejnecký, Václav; Drábek, Ondrej

    2010-01-15

    The influence of different soil conditions and the presence of LMWOA (Low Molecular Weight Organic Acids) on anthropogenic Tl dynamics were discussed in this study. A shift from the "labile" to the residual fraction during the ageing was identified, indicating Tl incorporation into stable phases (e.g., illite and/or amorphous silicates). The increased water-soluble Tl concentration (1.8-fold, in maximum) after the split application of LMWOA (simulating root exudation) was observed in all soils; partial dissolution of relatively "insoluble" Tl-bearing phases (silicates and eventually oxides) in the presence of LMWOA is suggested. Thermodynamic modeling showed that Tl mobilization in the presence of citric and oxalic acids was indirect and could be attributed to complexation of major elements (Ca, Mg, Al) originating from the dissolution of various soil phases. On the contrary, H(+)-promoted dissolution by acetic acid was assumed as the predominant mechanism of Tl mobilization. Manganese(III,IV) oxides, illite and probably amorphous silicates were evaluated as the dominant phases responsible for Tl retention in the soils. In carbonate-rich soils, Tl coprecipitation with the newly formed carbonates seems to be an important factor influencing Tl release. Therefore, we suggest data on CEC, pH(ZPC) and soil mineralogy to be critical for assessment of Tl behavior in soil systems.

  17. Energy crop (Sida hermaphrodita) fertilization using digestate under marginal soil conditions: A dose-response experiment

    Science.gov (United States)

    Nabel, Moritz; Bueno Piaz Barbosa, Daniela; Horsch, David; Jablonowski, Nicolai David

    2014-05-01

    The global demand for energy security and the mitigation of climate change are the main drivers pushing energy-plant production in Germany. However, the cultivation of these plants can cause land use conflicts since agricultural soil is mostly used for plant production. A sustainable alternative to the conventional cultivation of food-based energy-crops is the cultivation of special adopted energy-plants on marginal lands. To further increase the sustainability of energy-plant cultivation systems the dependency on synthetic fertilizers needs to be reduced via closed nutrient loops. In the presented study the energy-plant Sida hermaphrodita (Malvaceae) will be used to evaluate the potential to grow this high potential energy-crop on a marginal sandy soil in combination with fertilization via digestate from biogas production. With this dose-response experiment we will further identify an optimum dose, which will be compared to equivalent doses of NPK-fertilizer. Further, lethal doses and deficiency doses will be observed. Two weeks old Sida seedlings were transplanted to 1L pots and fertilized with six doses of digestate (equivalent to a field application of 5, 10, 20, 40, 80, 160t/ha) and three equivalent doses of NPK-fertilizer. Control plants were left untreated. Sida plants will grow for 45 days under greenhouse conditions. We hypothesize that the nutrient status of the marginal soil can be increased and maintained by defined digestate applications, compared to control plants suffering of nutrient deficiency due to the low nutrient status in the marginal substrate. The dose of 40t/ha is expected to give a maximum biomass yield without causing toxicity symptoms. Results shall be used as basis for further experiments on the field scale in a field trial that was set up to investigate sustainable production systems for energy crop production under marginal soil conditions.

  18. Crop residue management in arable cropping systems under a temperate climate. Part 2: Soil physical properties and crop production. A review

    Directory of Open Access Journals (Sweden)

    Hiel, MP.

    2016-01-01

    Full Text Available Introduction. Residues of previous crops provide a valuable amount of organic matter that can be used either to restore soil fertility or for external use. A better understanding of the impact of crop residue management on the soil-water-plant system is needed in order to manage agricultural land sustainably. This review focuses on soil physical aspects related to crop residue management, and specifically on the link between soil structure and hydraulic properties and its impact on crop production. Literature. Conservation practices, including crop residue retention and non-conventional tillage, can enhance soil health by improving aggregate stability. In this case, water infiltration is facilitated, resulting in an increase in plant water availability. Conservation practices, however, do not systematically lead to higher water availability for the plant. The influence of crop residue management on crop production is still unclear; in some cases, crop production is enhanced by residue retention, but in others crop residues can reduce crop yield. Conclusions. In this review we discuss the diverse and contrasting effects of crop residue management on soil physical properties and crop production under a temperate climate. The review highlights the importance of environmental factors such as soil type and local climatic conditions, highlighting the need to perform field studies on crop residue management and relate them to specific pedo-climatic contexts.

  19. Zinc oxide nanoparticles affect carbon and nitrogen mineralization of Phoenix dactylifera leaf litter in a sandy soil.

    Science.gov (United States)

    Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Ismail, Iqbal M I; Shah, Ghulam Mustafa; Almeelbi, Talal

    2017-02-15

    We investigated the impact of zinc oxide nanoparticles (ZnO NPs; 1000mgkg(-1) soil) on soil microbes and their associated soil functions such as date palm (Phoenix dactylifera) leaf litter (5gkg(-1) soil) carbon and nitrogen mineralization in mesocosms containing sandy soil. Nanoparticles application in litter-amended soil significantly decreased the cultivable heterotrophic bacterial and fungal colony forming units (cfu) compared to only litter-amended soil. The decrease in cfu could be related to lower microbial biomass carbon in nanoparticles-litter amended soil. Likewise, ZnO NPs also reduced CO2 emission by 10% in aforementioned treatment but this was higher than control (soil only). Labile Zn was only detected in the microbial biomass of nanoparticles-litter applied soil indicating that microorganisms consumed this element from freely available nutrients in the soil. In this treatment, dissolved organic carbon and mineral nitrogen were 25 and 34% lower respectively compared to litter-amended soil. Such toxic effects of nanoparticles on litter decomposition resulted in 130 and 122% lower carbon and nitrogen mineralization efficiency respectively. Hence, our results entail that ZnO NPs are toxic to soil microbes and affect their function i.e., carbon and nitrogen mineralization of applied litter thus confirming their toxicity to microbial associated soil functions.

  20. Effect of silver nano-particles on soil microbial growth, activity and community diversity in a sandy loam soil.

    Science.gov (United States)

    Samarajeewa, A D; Velicogna, J R; Princz, J I; Subasinghe, R M; Scroggins, R P; Beaudette, L A

    2017-01-01

    Silver nano-particles (AgNPs) are widely used in a range of consumer products as a result of their antimicrobial properties. Given the broad spectrum of uses, AgNPs have the potential for being released to the environment. As a result, environmental risks associated with AgNPs need to be assessed to aid in the development of regulatory guidelines. Research was performed to assess the effects of AgNPs on soil microbial activity and diversity in a sandy loam soil with an emphasis on using a battery of microbial tests involving multiple endpoints. The test soil was spiked with PVP coated (0.3%) AgNPs at the following concentrations of 49, 124, 287, 723 and 1815 mg Ag kg(-1) dry soil. Test controls included an un-amended soil; soil amended with PVP equivalent to the highest PVP concentration of the coated AgNP; and soil amended with humic acid, as 1.8% humic acid was used as a suspension agent for the AgNPs. The impact on soil microbial community was assessed using an array of tests including heterotrophic plate counting, microbial respiration, organic matter decomposition, soil enzyme activity, biological nitrification, community level physiological profiling (CLPP), Ion Torrent™ DNA sequencing and denaturing gradient gel electrophoresis (DGGE). An impact on microbial growth, activity and community diversity was evident from 49 to 1815 mg kg(-1) with the median inhibitory concentrations (IC50) as low as 20-31 mg kg(-1) depending on the test. AgNP showed a notable impact on microbial functional and genomic diversity. Emergence of a silver tolerant bacterium was observed at AgNP concentrations of 49-287 mg kg(-1) after 14-28 days of incubation, but not detectable at 723 and 1815 mg kg(-1). The bacterium was identified as Rhodanobacter sp. The study highlighted the effectiveness of using multiple microbial endpoints for inclusion to the environmental risk assessment of nanomaterials.

  1. Spatial and temporal variation of nitrogen exported by runoff from sandy agricultural soils

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The eutrophication problem has drawn attention to nutrient leaching from agricultural soils.and an understanding of spatial and temporal variability is needed to develop decision-making tools.Thus,eleven sites were selected to monitor,over a two-year period,spatial and temporal variation of runoff discharge and various forms of N in surface runoff in sandy agricultural soils.Factors influencing the variation of runoff discharge and various forms of N in surface runoff were analyzed.Variation of annual rainfall was small among 11 situs.especially between 2001 and 2002.However,variation of annual discharge was significant among the sites.The results suggest that rainfall patterns and land usc had significant effect on discharge.The concentrations of total N,total kjeldahl N (TKN),organic matter-associated N (OM-N),NO3--N,and NH4+-N in the runoff ranged widely from 0.25 to 54.1,0.15 to 20.3,0.00 to 14.6,0.00 to 45.3,and 0.00 to 19.7 mg/L,respectively.Spatial and temporal variations in the N concentration and runoff discharge were noted among the different sites.Annual loads of N in the runoff varied widely among monitoring sites and depend mainly on runoff discharge.High loads of total N,OM-N,NO3--N,and NH4+-N in the runoff either in citrus groves or on vegetable farms occurred from June to October for each year,which coincided with the rainy season in the region.This study found that N in surface runoff was related to rainfall intensity,soil N level,and fertilizer use.

  2. Spatial and temporal variation of nitrogen exported by runoff from sandy agricultural soils.

    Science.gov (United States)

    Zhang, Ming-Kui; Wang, Li-Ping; He, Zhen-Li

    2007-01-01

    The eutrophication problem has drawn attention to nutrient leaching from agricultural soils, and an understanding of spatial and temporal variability is needed to develop decision-making tools. Thus, eleven sites were selected to monitor, over a two-year period, spatial and temporal variation of runoff discharge and various forms of N in surface runoff in sandy agricultural soils. Factors influencing the variation of runoff discharge and various forms of N in surface runoff were analyzed. Variation of annual rainfall was small among 11 sites, especially between 2001 and 2002. However, variation of annual discharge was significant among the sites. The results suggest that rainfall patterns and land use had significant effect on discharge. The concentrations of total N, total kjeldahl N (TKN), organic matter-associated N (OM-N), NO3(-)-N, and NH4(+)-N in the runoff ranged widely from 0.25 to 54.1, 0.15 to 20.3, 0.00 to 14.6, 0.00 to 45.3, and 0.00 to 19.7 mg/L, respectively. Spatial and temporal variations in the N concentration and runoff discharge were noted among the different sites. Annual loads of N in the runoff varied widely among monitoring sites and depend mainly on runoff discharge. High loads of total N, OM-N, NO3(-)-N, and NH4(+)-N in the runoff either in citrus groves or on vegetable farms occurred from June to October for each year, which coincided with the rainy season in the region. This study found that N in surface runoff was related to rainfall intensity, soil N level, and fertilizer use.

  3. Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence.

    Science.gov (United States)

    Sainju, Upendra M; Allen, Brett L; Caesar-TonThat, Thecan; Lenssen, Andrew W

    2015-01-01

    Information on the effect of long-term management on soil nutrients and chemical properties is scanty. We examined the 30-year effect of tillage frequency and cropping sequence combination on dryland soil Olsen-P, K, Ca, Mg, Na, SO4-S, and Zn concentrations, pH, electrical conductivity (EC), and cation exchange capacity (CEC) at the 0-120 cm depth and annualized crop yield in the northern Great Plains, USA. Treatments were no-till continuous spring wheat (Triticum aestivum L.) (NTCW), spring till continuous spring wheat (STCW), fall and spring till continuous spring wheat (FSTCW), fall and spring till spring wheat-barley (Hordeum vulgare L., 1984-1999) followed by spring wheat-pea (Pisum sativum L., 2000-2013) (FSTW-B/P), and spring till spring wheat-fallow (STW-F, traditional system). At 0-7.5 cm, P, K, Zn, Na, and CEC were 23-60% were greater, but pH, buffer pH, and Ca were 6-31% lower in NTCW, STCW, and FSTW-B/P than STW-F. At 7.5-15 cm, K was 23-52% greater, but pH, buffer pH, and Mg were 3-21% lower in NTCW, STCW, FSTCW, FSTW-B/P than STW-F. At 60-120 cm, soil chemical properties varied with treatments. Annualized crop yield was 23-30% lower in STW-F than the other treatments. Continuous N fertilization probably reduced soil pH, Ca, and Mg, but greater crop residue returned to the soil increased P, K, Na, Zn, and CEC in NTCW and STCW compared to STW-F. Reduced tillage with continuous cropping may be adopted for maintaining long-term soil fertility and crop yields compared with the traditional system.

  4. Can Novel Management Practice Improve Soil and Environmental Quality and Sustain Crop Yield Simultaneously?

    Science.gov (United States)

    Sainju, Upendra M

    2016-01-01

    Little is known about management practices that can simultaneously improve soil and environmental quality and sustain crop yields. The effects of novel and traditional management practices that included a combination of tillage, crop rotation, and N fertilization on soil C and N, global warming potential (GWP), greenhouse gas intensity (GHGI), and malt barley (Hordeum vulgarie L.) yield and quality were examined under non-irrigated and irrigated cropping systems from 2008 to 2011 in eastern Montana and western North Dakota, USA. In loamy soil under non-irrigated condition in eastern Montana, novel and traditional management practices were no-till malt barley-pea (Pisum sativum L.) with 80 kg N ha(-1) and conventional till malt barley-fallow with 80 kg N ha(-1), respectively. In sandy loam soil under irrigated and non-irrigated conditions in western North Dakota, novel and traditional management practices included no-till malt barley-pea with 67 (non-irrigated) to 134 kg N ha(-1) (irrigated) and conventional till malt barley with 67 (non-irrigated) to 134 kg N ha(-1) (irrigated), respectively. Compared with the traditional management practice, soil organic C (SOC) and total N (STN) at 0-120 cm were 5% greater with the novel management practice under non-irrigated condition in eastern Montana and under irrigated condition in western North Dakota, but were not different under non-irrigated condition in western North Dakota. In both places under irrigated and non-irrigated conditions, total applied N rate, residual soil NO3-N content at 0-120 cm, global warming potential (GWP), and greenhouse gas intensity (GHGI) were 15 to 70% lower with the novel than the traditional management practice. Malt barley yield and quality were not different between the two practices in both places. Novel management practices, such as no-till malt barley-pea with reduced N rate, can simultaneously enhance soil and environmental quality, reduce N input, and sustain crop yield compared with

  5. Can Novel Management Practice Improve Soil and Environmental Quality and Sustain Crop Yield Simultaneously?

    Directory of Open Access Journals (Sweden)

    Upendra M Sainju

    Full Text Available Little is known about management practices that can simultaneously improve soil and environmental quality and sustain crop yields. The effects of novel and traditional management practices that included a combination of tillage, crop rotation, and N fertilization on soil C and N, global warming potential (GWP, greenhouse gas intensity (GHGI, and malt barley (Hordeum vulgarie L. yield and quality were examined under non-irrigated and irrigated cropping systems from 2008 to 2011 in eastern Montana and western North Dakota, USA. In loamy soil under non-irrigated condition in eastern Montana, novel and traditional management practices were no-till malt barley-pea (Pisum sativum L. with 80 kg N ha(-1 and conventional till malt barley-fallow with 80 kg N ha(-1, respectively. In sandy loam soil under irrigated and non-irrigated conditions in western North Dakota, novel and traditional management practices included no-till malt barley-pea with 67 (non-irrigated to 134 kg N ha(-1 (irrigated and conventional till malt barley with 67 (non-irrigated to 134 kg N ha(-1 (irrigated, respectively. Compared with the traditional management practice, soil organic C (SOC and total N (STN at 0-120 cm were 5% greater with the novel management practice under non-irrigated condition in eastern Montana and under irrigated condition in western North Dakota, but were not different under non-irrigated condition in western North Dakota. In both places under irrigated and non-irrigated conditions, total applied N rate, residual soil NO3-N content at 0-120 cm, global warming potential (GWP, and greenhouse gas intensity (GHGI were 15 to 70% lower with the novel than the traditional management practice. Malt barley yield and quality were not different between the two practices in both places. Novel management practices, such as no-till malt barley-pea with reduced N rate, can simultaneously enhance soil and environmental quality, reduce N input, and sustain crop yield compared

  6. The Effect of Gasification Biochar on Soil Carbon Sequestration, Soil Quality and Crop Growth

    DEFF Research Database (Denmark)

    Hansen, Veronika

    have been raised about the potential negative impacts of incorporating bioenergy residuals (biochar) in soil and increasing the removal of crop residues such as straw, possibly reducing important soil functions and services for maintaining soil quality. Therefore, a combination of incubation studies...... and pot and field experiments was used to study the effect of straw and wood biochar on carbon sequestration, soil quality and crop growth. Overall, the biochar amendment improved soil chemical and physical properties and plant growth and showed a potential for soil carbon sequestration without having any...... negative impact on soil biota. However, the effects of biochar on soil quality and plant growth differed according to the biochar properties and the soil type used. Furthermore, the positive impact on some soil structural properties observed after straw incorporation was not achieved with biochar amendment...

  7. The Effect of Gasification Biochar on Soil Carbon Sequestration, Soil Quality and Crop Growth

    DEFF Research Database (Denmark)

    Hansen, Veronika

    have been raised about the potential negative impacts of incorporating bioenergy residuals (biochar) in soil and increasing the removal of crop residues such as straw, possibly reducing important soil functions and services for maintaining soil quality. Therefore, a combination of incubation studies...... negative impact on soil biota. However, the effects of biochar on soil quality and plant growth differed according to the biochar properties and the soil type used. Furthermore, the positive impact on some soil structural properties observed after straw incorporation was not achieved with biochar amendment...... and pot and field experiments was used to study the effect of straw and wood biochar on carbon sequestration, soil quality and crop growth. Overall, the biochar amendment improved soil chemical and physical properties and plant growth and showed a potential for soil carbon sequestration without having any...

  8. Belowground environmental effects of transgenic crops: a soil microbial perspective.

    Science.gov (United States)

    Turrini, Alessandra; Sbrana, Cristiana; Giovannetti, Manuela

    2015-04-01

    Experimental studies investigated the effects of transgenic crops on the structure, function and diversity of soil and rhizosphere microbial communities playing key roles in belowground environments. Here we review available data on direct, indirect and pleiotropic effects of engineered plants on soil microbiota, considering both the technology and the genetic construct utilized. Plants modified to express phytopathogen/phytoparasite resistance, or traits beneficial to food industries and consumers, differentially affected soil microorganisms depending on transformation events, experimental conditions and taxa analyzed. Future studies should address the development of harmonized methodologies by taking into account the complex interactions governing soil life. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  9. A genetic-algorithm approach for assessing the liquefaction potential of sandy soils

    Directory of Open Access Journals (Sweden)

    G. Sen

    2010-04-01

    Full Text Available The determination of liquefaction potential is required to take into account a large number of parameters, which creates a complex nonlinear structure of the liquefaction phenomenon. The conventional methods rely on simple statistical and empirical relations or charts. However, they cannot characterise these complexities. Genetic algorithms are suited to solve these types of problems. A genetic algorithm-based model has been developed to determine the liquefaction potential by confirming Cone Penetration Test datasets derived from case studies of sandy soils. Software has been developed that uses genetic algorithms for the parameter selection and assessment of liquefaction potential. Then several estimation functions for the assessment of a Liquefaction Index have been generated from the dataset. The generated Liquefaction Index estimation functions were evaluated by assessing the training and test data. The suggested formulation estimates the liquefaction occurrence with significant accuracy. Besides, the parametric study on the liquefaction index curves shows a good relation with the physical behaviour. The total number of misestimated cases was only 7.8% for the proposed method, which is quite low when compared to another commonly used method.

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

    Directory of Open Access Journals (Sweden)

    Ewelina Szydełko-Rabska

    2015-01-01

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

  11. Genotypic Differences of Forage Crop Tolerance to Acid Soils

    Institute of Scientific and Technical Information of China (English)

    YANGYUAI; CHUXIANGYUN; 等

    1998-01-01

    Twenty eight species of forage crops were planted on acid soils derived from Quaternary red clay(pH4.16) and red sandstone(pH4.55) to study genotypic differences of the forage crops in tolerance to acid soils as affected by liming,phosporus and potassium fertilizer application.Eight forage species,Lolium nultiflorum L., Brachiaria decumbens,Digitaria sumtisii,Melinis minutiflora,Paspalum dilatatum,Paspalum wettsteinii,Sataria viridis Beanv and Shcep's Festuca,were highly toleran to acid soils,and grew relatively well in the tested soils without lime application,whereas most of the other 20 tested forage species such as Lolium perenne L., Meadow Festuca and Trifolium praense L. were intolerant to acid soil ,showing retarded growth when the soil pH was below 5.5 and significant increase in dry matter yields by phosphrus fertilizer application at soil pH 6.0 Results showed that large differences in tolerance to acid soils existed among the forage species,and tolerance of the froage species to acid soils might be closely associated with their tolerance to Al and P efficiency.

  12. Crop diversity effects on soil health

    Science.gov (United States)

    Concurrent demands for abundant, healthy food, thriving rural economies, and an unpolluted physical environment represents a significant agricultural challenge in the 21st century. Trends in human population growth and changing weather patterns will make this challenge exceedingly difficult. Soil ...

  13. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  14. Soil C sequestration and agronomic yield of diverse crop rotations under no-till soil management

    Science.gov (United States)

    Diversified crop rotations, which reduce risk associated with adoption of no-till soil management, may influence soil C sequestration and soil quality. This study measured effects of corn-soybean (C-S), corn-soybean-oat/pea hay (C-S-H), or corn-soybean-oat/pea hay-alfalfa-alfalfa (C-S-H-A-A) annual ...

  15. Soil greenhouse gas emissions affected by irrigation, tillage, crop rotation, and nitrogen fertilization.

    Science.gov (United States)

    Sainju, Upendra M; Stevens, William B; Caesar-Tonthat, Thecan; Liebig, Mark A

    2012-01-01

    Management practices, such as irrigation, tillage, cropping system, and N fertilization, may influence soil greenhouse gas (GHG) emissions. We quantified the effects of irrigation, tillage, crop rotation, and N fertilization on soil CO, NO, and CH emissions from March to November, 2008 to 2011 in a Lihen sandy loam in western North Dakota. Treatments were two irrigation practices (irrigated and nonirrigated) and five cropping systems (conventional-tilled malt barley [ L.] with N fertilizer [CT-N], conventional-tilled malt barley with no N fertilizer [CT-C], no-tilled malt barley-pea [ L.] with N fertilizer [NT-PN], no-tilled malt barley with N fertilizer [NT-N], and no-tilled malt barley with no N fertilizer [NT-C]). The GHG fluxes varied with date of sampling and peaked immediately after precipitation, irrigation, and/or N fertilization events during increased soil temperature. Both CO and NO fluxes were greater in CT-N under the irrigated condition, but CH uptake was greater in NT-PN under the nonirrigated condition than in other treatments. Although tillage and N fertilization increased CO and NO fluxes by 8 to 30%, N fertilization and monocropping reduced CH uptake by 39 to 40%. The NT-PN, regardless of irrigation, might mitigate GHG emissions by reducing CO and NO emissions and increasing CH uptake relative to other treatments. To account for global warming potential for such a practice, information on productions associated with CO emissions along with NO and CH fluxes is needed.

  16. SOIL FUNGISTASIS AGAINST FUSARIUM GRAMINEARUM UNDER DIFFERENT CROP MANAGEMENT SYSTEMS

    Directory of Open Access Journals (Sweden)

    Bruno Brito Lisboa

    2015-02-01

    Full Text Available Soil management, in terms of tillage and cropping systems, strongly influences the biological properties of soil involved in the suppression of plant diseases. Fungistasis mediated by soil microbiota is an important component of disease-suppressive soils. We evaluated the influence of different management systems on fungistasis against Fusarium graminearum, the relationship of fungistasis to the bacterial profile of the soil, and the possible mechanisms involved in this process. Samples were taken from a long-term experiment set up in a Paleudult soil under conventional tillage or no-tillage management and three cropping systems: black oat (Avena strigose L. + vetch (Vicia sativa L./maize (Zea mays L. + cowpea (Vigna sinensis L., black oat/maize, and vetch/maize. Soil fungistasis was evaluated in terms of reduction of radial growth of F. graminearum, and bacterial diversity was assessed using ribosomal intergenic spacer analysis (RISA. A total of 120 bacterial isolates were obtained and evaluated for antibiosis, and production of volatile compounds and siderophores. No-tillage soil samples showed the highest level of F. graminearum fungistasis by sharply reducing the development of this pathogen. Of the cropping systems tested, the vetch + black oat/maize + cowpea system showed the highest fungistasis and the oat/maize system showed the lowest. The management system also affected the genetic profile of the bacteria isolated, with the systems from fungistatic soils showing greater similarity. Although there was no clear relationship between soil management and the characteristics of the bacterial isolates, we may conclude that antibiosis and the production of siderophores were the main mechanisms accounting for fungistasis.

  17. Soil carbon and nitrogen fractions and crop yields affected by residue placement and crop types.

    Science.gov (United States)

    Wang, Jun; Sainju, Upendra M

    2014-01-01

    Soil labile C and N fractions can change rapidly in response to management practices compared to non-labile fractions. High variability in soil properties in the field, however, results in nonresponse to management practices on these parameters. We evaluated the effects of residue placement (surface application [or simulated no-tillage] and incorporation into the soil [or simulated conventional tillage]) and crop types (spring wheat [Triticum aestivum L.], pea [Pisum sativum L.], and fallow) on crop yields and soil C and N fractions at the 0-20 cm depth within a crop growing season in the greenhouse and the field. Soil C and N fractions were soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), microbial biomass C and N (MBC and MBN), potential C and N mineralization (PCM and PNM), NH4-N, and NO3-N concentrations. Yields of both wheat and pea varied with residue placement in the greenhouse as well as in the field. In the greenhouse, SOC, PCM, STN, MBN, and NH4-N concentrations were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow. In the field, MBN and NH4-N concentrations were greater in no-tillage than conventional tillage, but the trend reversed for NO3-N. The PNM was greater under pea or fallow than wheat in the greenhouse and the field. Average SOC, POC, MBC, PON, PNM, MBN, and NO3-N concentrations across treatments were higher, but STN, PCM and NH4-N concentrations were lower in the greenhouse than the field. The coefficient of variation for soil parameters ranged from 2.6 to 15.9% in the greenhouse and 8.0 to 36.7% in the field. Although crop yields varied, most soil C and N fractions were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow in the greenhouse than the field within a crop growing season. Short-term management effect on soil C and N fractions were readily obtained with reduced variability under controlled soil and

  18. Partitioning of organic matter and heavy metals in a sandy soil: Effects of extracting solution, solid to liquid ratio and pH

    NARCIS (Netherlands)

    Fest, P.M.J.; Temminghoff, E.J.M.; Comans, R.N.J.; Riemsdijk, van W.H.

    2008-01-01

    In sandy soils the behavior of heavy metals is largely controlled by soil organic matter (solid and dissolved organic matter; SOC and DOC). Therefore, knowledge of the partitioning of organic matter between the solid phase and soil solution is essential for adequate predictions of the total dissolve

  19. Matrices to Revise Crop, Soil, and Environmental Sciences Undergraduate Curricula

    Science.gov (United States)

    Savin, Mary C.; Longer, David; Miller, David M.

    2005-01-01

    Undergraduate curricula for natural resource and agronomic programs have been introduced and revised during the past several decades with a desire to stay current with emerging issues and technologies relevant to constituents. For the past decade, the Department of Crop, Soil, and Environmental Sciences (CSES) faculty at the University of Arkansas…

  20. Dieldrin uptake by vegetable crops grown in contaminated soils.

    Science.gov (United States)

    Donnarumma, Lucia; Pompi, Valter; Faraci, Alessandro; Conte, Elisa

    2009-06-01

    The aim of these trials was to study the distribution of dieldrin in soil and its translocation to roots and the aerial parts of vegetable crops grown in greenhouses and fields. The main objectives were to characterize dieldrin accumulation in plant tissues in relation to the levels of soil contamination; uptake capability among plants belonging to different species, varieties and cultivars. The presence of the contaminant was quantified by gas chromatography-electron capture detector (GC-ECD) and confirmed by gas chromatography-mass spectrometer (GC-MS). The results showed a translocation of residues in cucurbitaceous fruits and flowers confirming that zucchini, cucumber and melon are crops with high uptake capability. The maximum level of dieldrin residue at 0.01 mg/kg was found to be a threshold value to safeguard the quality production of cucurbits. Tomato, lettuce and celery were identified as substitute crops to grow in contaminated fields.

  1. Effects of peat and weathered coal on the growth of Pinus sylvestris var. Mongolica seedlings on aeolian sandy soil

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The experiment was conducted at the Ganqika Sandy Land Ecological Station in Ke'erqinzuoyihouqi County, Inner Mongolia, in a growing season from April 28 to October 28, 2001. Peat and weathered coal wereadded to the aeolian sandy soil in different ratios. Two-year-old Pinus sylvestris var. Mongolica seedlings and plastic pots wereused in the experiment. The experimental results indicat ed that: 1) the peat and weathered coal could significantly improve the physical and chemical properties of aeolian sandy soil, and thus promoted the growth of seedlings;2) the effect of peat on seedling growth, including height, base diam eter, root length and biomass, presented an order of 8%>10%>5%>2%>0 in terms of peat contents, and the effect of weathered coal on seedling growth presented an order of 5%>8%>10%>2%>0 in terms of weathered coal contents for height and basal diameter, 5%>8%>2% >10%>0 for root length, and 5%>2%>8% >10%>0 for biomass;3) the effects of peat were generally greater than that of weathered coal. Meanwhile, 8% peat was the best treatment to promote the growth of P. Sylvestris var. Mo ngolica seedlings.

  2. Soil development in OSL dated sandy dune substrates under Quercus robur Forest (Netherlands)

    Science.gov (United States)

    van Mourik, J. M.; Nierop, Ir. K.; Verstraten, J. M.

    2009-04-01

    Coastal dune landscapes are very dynamic. The present distribution of vegetation and soil is the result of over 2000 years of natural processes and human management. The initial soil development was controlled by an increase of the organic matter content, which consisted mainly of decomposed roots of grasses (rhizomull), and a decrease of the soil pH to 3-4 by decalcification. This stage was followed by the development of a deciduous forest, which was dominated by Quercus robur. Since 1600 AD, a large part of the deciduous forest that dominated the east side of the coastal dune landscape transferred in expensive residential areas and urbanizations. Nevertheless some parts of the oak forest belt remained. The present forest soils are acid and the controlling soil processes are leaching of sesquioxides and storage of organic matter in mormoder humus forms. The sustainability of ecosystems is closely related to the quality of the humus form, controlling nutrient cycling and water supply. Therefore, improve of knowledge of humus form development and properties is important. We applied soil micromorphology and pyrolysis-gas chromatography/mass spectrometry (GC/MS) to investigate more details of humus form development at two locations (Duivendrift and Hoek van Klaas) in the coastal dune area of the Amsterdamse Waterleidingduinen (near Haarlem, the Netherlands). However, to understand forest soil development, including the organic matter composition in the humus form, the age of the substrate and the forest is required. Therefore, we used tradition techniques as pollen analysis and radiocarbon dating but also the recently introduced optical stimulated luminescence (OSL) dating technique. OSL dating works excellent for aeolian sandy deposits with a high percentage of quartz grains. The OSL age is defined as the time after the last bleaching by solar radiation of mineral grains. Or in other words, the start of a stable period without sand drifting. In the Ah horizons we

  3. Selenium status in soil, water and essential crops of Iran

    Directory of Open Access Journals (Sweden)

    Nazemi Lyly

    2012-11-01

    Full Text Available Abstracts As a contributing factor to health, the trace element selenium (Se is an essential nutrient of special interest for humans and all animals. It is estimated that 0.5 to 1 billion people worldwide suffer from Se deficiency. In spite of the important role of Se, its concentrations in soil, water and essential crops have not been studied in Iran. Therefore, the main aim of the current study was to determine the Se content of soil, water, and essential crops (rice in North, wheat in Center, date, and pistachio in South of different regions of Iran. Sampling was performed in the North, South, and Central regions of Iran. In each selected area in the three regions, 17 samples of surface soil were collected; samples of water and essential crops were also collected at the same sampling points. Upon preliminary preparation of all samples, the Se concentrations were measured by ICP-OES Model Varian Vista-MPX. The amount of soil-Se was found to be in the range between 0.04 and 0.45 ppm in the studied areas; the Se content of soil in the central region of Iran was the highest compared to other regions (p

  4. Cacao Crop Management Zones Determination Based on Soil Properties and Crop Yield

    Directory of Open Access Journals (Sweden)

    Perla Silva Matos de Carvalho

    Full Text Available ABSTRACT: The use of management zones has ensured yield success for numerous agricultural crops. In spite of this potential, studies applying precision agricultural techniques to cacao plantations are scarce or almost nonexistent. The aim of the present study was to delineate management zones for cacao crop, create maps combining soil physical properties and cacao tree yield, and identify what combinations best fit within the soil chemical properties. The study was conducted in 2014 on a cacao plantation in a Nitossolo Háplico Eutrófico (Rhodic Paleudult in Bahia, Brazil. Soil samples were collected in a regular sampling grid with 120 sampling points in the 0.00-0.20 m soil layer, and pH(H2O, P, K+, Ca2+, Mg2+, Na+, H+Al, Fe, Zn, Cu, Mn, SB, V, TOC, effective CEC, CEC at pH 7.0, coarse sand, fine sand, clay, and silt were determined. Yield was measured in all the 120 points every month and stratified into annual, harvest, and early-harvest cacao yields. Data were subjected to geostatistical analysis, followed by ordinary kriging interpolation. The management zones were defined through a Fuzzy K-Means algorithm for combinations between soil physical properties and cacao tree yield. Concordance analysis was carried out between the delineated zones and soil chemical properties using Kappa coefficients. The zones that best classified the soil chemical properties were defined from the early-harvest cacao yield map associated with the clay or sand fractions. Silt content proved to be an inadequate variable for defining management zones for cacao production. The delineated management zones described the spatial variability of the soil chemical properties, and are therefore important for site-specific management in the cacao crop.

  5. Lignin biochemistry and soil N determine crop residue decomposition and soil priming

    Science.gov (United States)

    Cropping history can affect soil properties, including available N, but little is known about the interactive effects of residue biochemistry, temperature and cropping history on residue decomposition. A laboratory incubation examined the role of residue biochemistry and temperature on the decomposi...

  6. 7 CFR 205.203 - Soil fertility and crop nutrient management practice standard.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Soil fertility and crop nutrient management practice... Requirements § 205.203 Soil fertility and crop nutrient management practice standard. (a) The producer must... nutrients and soil fertility through rotations, cover crops, and the application of plant and animal...

  7. Seasonal fluctuations in water repellency and infiltration in a sandy loam soil after a forest fire in Galicia (NW Spain

    Directory of Open Access Journals (Sweden)

    M. Rodríguez-Alleres

    2013-05-01

    Full Text Available The aim of this work was to analyze, after a wildfire of moderate severity, the temporal fluctuations in water repellency and infiltration in a sandy loam soil under a mixed plantation of pine and eucalyptus and the comparison with an adjacent area not affected by the fire. In the burnt area and in a neighboring area not affected by the fire were collected during one year (1, 4, 6, 8 and 12 months after the fire 10 soil samples along a transect of 18 m at four depths: 0-2, 2-5, 5-10 and 10-20 cm. Soil water repellency was determined using the water drop penetration time test (WDPT test and the infiltration was measured with a mini-disc infiltrometer (pressure head h0 = -2 cm.The results show a temporal pattern of soil water repellency in the burnt and unburnt areas. Significant correlations between water repellency and soil moisture were observed, with higher correlation coefficients in the unburned area and in the surface soil layer.Soil water infiltration was significantly lower than would be expected by the coarse texture of the soil in both burnt and unburnt areas. Temporal fluctuations in unburnt soil infiltration seem to be clearly related to the transient nature of the soil water repellency, with no infiltration in samples extremely repellent. In the burned area, the soil infiltration showed much more variability and temporal fluctuations appear to be less dependent on the persistence of water repellency and more dependent on environmental conditions.The unburnt area show significant and negative correlations of soil water repellency with hydraulic conductivity and sorptivity and positive of these two parameters with soil moisture. These relationships were not observed in the burnt area. The temporal fluctuations of soil water repellency have an evident impact on soil infiltration and seem to be more influent than the effects of fire.

  8. Linear spectral unmixing to monitor crop growth in typical organic and inorganic amended arid soil

    Science.gov (United States)

    El Battay, A.; Mahmoudi, H.

    2016-06-01

    The soils of the GCC countries are dominantly sandy which is typical of arid regions such as the Arabian Peninsula. Such soils are low in nutrients and have a poor water holding capacity associated with a high infiltration rate. Soil amendments may rehabilitate these soils by restoring essential soil properties and hence enable site revegetation and revitalization for crop production, especially in a region where food security is a priority. In this study, two inorganic amendments; AustraHort and Zeoplant pellet, and one organic locally produced compost were tested as soil amendments at the experimental field of the International Center for Biosaline Agriculture in Dubai, UAE. The main objective is to assess the remote sensing ability to monitor crop growth, for instance Okra (Abelmoschus esculentus), having these amendments, as background with the soil. Three biomass spectral vegetation indices were used namely; NDVI, TDVI and SAVI. Pure spectral signatures of the soil and the three amendments were collected, using a field spectroradiometer, in addition to the spectral signatures of Okra in two growing stages (vegetative and flowering) in the field with a mixed F.O.V of the plant and amended soil during March and May 2015. The spectral signatures were all collected using the FieldSpec® HandHeld 2 (HH2) in the spectral range 325 nm - 1075 nm over 12 plots. A set of 4 plots were assigned for each of the three amendments as follow: three replicates of a 1.5 by 1.5 meter plot with 3kg/m2 of each amendment and 54 plants, one plot as control and all plots were given irrigation treatments at 100% based on ETc. Spectra collected over the plots were inversed in the range of 400-900 nm via a Linear Mixture Model using pure soil and amendments spectral signatures as reference. Field pictures were used to determine the vegetation fraction (in term of area of the F.O.V). Hence, the Okra spectral signatures were isolated for all plots with the three types of amendments. The

  9. Comprehensive evaluation of multiple cropping systems on upland red soil

    Institute of Scientific and Technical Information of China (English)

    Guoqin HUANG; Xiuying LIU; Longwang LIU; Fang YE; Mingling ZHANG; Yanhong SHU

    2008-01-01

    According to the principles and methods of ecology and system engineering,we set up an evaluation indicator system for multi-component and multiple crop-ping systems,evaluated the comprehensive benefits of multi-component and multiple cropping systems using grey relation clustering analysis and screened out the opti-mized model based on research done in the upland red soil in Jiangxi Agricultural University from 1984 to 2004.The results show that the grey relation degree of "cabbage/ potato/maize-sesame" was the highest among 23 multi-component and multiple cropping systems and was clustered into the optimized system.This indicates that "cabbage/potato/maize - sesame" can bring the best social,economic and ecological benefits,increase product yield and farmers' income and promote sustainable development of agricultural production.Therefore,it is suitable for promotion on upland red soil.The grey rela-tion degree of "canola/Chinese milk vetch/maize/mung bean/maize" was second,which is suitable for imple-mentation at the city outskirts.In conclusion,these two planting patterns are expected to play important roles in the reconstruction of the planting structure and optimiza-tion of the planting patterns on upland red soil.

  10. Impact of crop rotation and soil amendments on long-term no-tilled soybean yields

    Science.gov (United States)

    Continuous cropping systems without cover crops are perceived as unsustainable for long-term yield and soil health. To test this, cropping sequence and cover crop effects on soybean (Glycine max L.) yields were assessed. Main effects were 10 cropping sequences of soybean, corn (Zea mays L.), and co...

  11. Residue and soil carbon sequestration in relation to crop yield as affected by irrigation, tillage, cropping system and nitrogen fertilization

    Science.gov (United States)

    Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

  12. Soil biological quality after 36 years of ley-arable cropping, permanent grassland and permanent arable cropping

    NARCIS (Netherlands)

    Eekeren, van N.J.M.; Bommele, L.; Bloem, J.; Schouten, T.; Rutgers, M.; Goede, de R.G.M.; Brussaard, L.; Reheul, D.

    2008-01-01

    Insight is needed into how management influences soil biota when sustainable grassland systems are developed. A crop rotation of grass and maize can be sustainable in terms of efficient nutrient use. However, there is lack of information on the effect of such a crop rotation on soil biological

  13. Using Biochar composts for improving sandy vineyard soils while reducing the risk of

    Science.gov (United States)

    Kammann, Claudia; Mengel, Jonathan; Mohr, Julia; Muskat, Stefan; Schmidt, Hans-Peter; Löhnertz, Otmar

    2016-04-01

    In recent years, biochar has increasingly been discussed as an option for sustainable environmentalmanagement, combining C sequestration with the aim of soil fertility improvement. Biochar has shownpositive effects in viticulture before (Genesio et al. 2015) which were largely attributed to improved water supply to the plants. However, in fertile temperate soils, the use of pure, untreated biochar does not guarantee economic benefits on the farm level (Ruysschaert et al., 2016). Hence, recent approaches started introducing biochar in management of nutrient-rich agricultural waste, e.g. in compost production (Kammann et al. 2015). Compost is frequently used in German vineyards for humus buildup and as a slow-release organic fertilizer. This, and increasingly mild, precipitation-rich winters, promoting mineralization, increase the risk of unwanted nitrate leaching losses into surface and ground waters during winter. To investigate if biochar pure, or biochar-compost mixtures and -products may have the potential to reduce nitrate leaching, we set up the following experiment: Either 30 or 60 t ha-1 of the following additives were mixed into the top 30 cm of sandy soil in large (120 L) containers, and planted with oneRiesling grapevine (Clone 198-30 GM) per container: Control (no addition), pure woody biochar, pure compost, biochar-compost (produced from the same organic feedstock than the compost, with 20 vol. - % of a woody biochar added), and pure compost plus pure biochar (same mixing ratio as in the former product). Once monthly, containers were exposed to simulated heavy rainfall that caused drainage. Leachates were collected from an outlet at the bottom of the containers, and analyzed for nutrients. The nutrient-rich additives containing compost all improved grape biomass and yield, most markedly pure compost and biochar-compost; same amendments were not significantly different. However,while the addition of the lower amount (30 t ha-1) of compost reduced nitrate

  14. Factors driving the carbon mineralization priming effect in a sandy loam soil amended with different types of biochar

    Science.gov (United States)

    Cely, P.; Tarquis, A. M.; Paz-Ferreiro, J.; Méndez, A.; Gascó, G.

    2014-06-01

    The effect of biochar on the soil carbon mineralization priming effect depends on the characteristics of the raw materials, production method and pyrolysis conditions. The goal of the present study is to evaluate the impact of three different types of biochar on physicochemical properties and CO2 emissions of a sandy loam soil. For this purpose, soil was amended with three different biochars (BI, BII and BIII) at a rate of 8 wt% and soil CO2 emissions were measured for 45 days. BI is produced from a mixed wood sieving from wood chip production, BII from a mixture of paper sludge and wheat husks and BIII from sewage sludge. Cumulative CO2 emissions of biochars, soil and amended soil were well fit to a simple first-order kinetic model with correlation coefficients (r2) greater than 0.97. Results show a negative priming effect in the soil after addition of BI and a positive priming effect in the case of soil amended with BII and BIII. These results can be related to different biochar properties such as carbon content, carbon aromaticity, volatile matter, fixed carbon, easily oxidized organic carbon or metal and phenolic substance content in addition to surface biochar properties. Three biochars increased the values of soil field capacity and wilting point, while effects over pH and cation exchange capacity were not observed.

  15. Soil Moisture Eff ects on Sand Saltation and Dust Emission Observed over the Horqin Sandy Land Area in China

    Institute of Scientific and Technical Information of China (English)

    LI Xiaolan; ZHANG Hongsheng

    2014-01-01

    In this study, the eff ects of soil moisture on sand saltation and dust emission over the Horqin Sandy Land area are investigated, based on observations of three dust events in 2010. The minimum friction velocity initiating the motion of surface particles, namely, the threshold friction velocity, is estimated to be 0.34, 0.40, and 0.50 m s−1 under the very dry, dry, and wet soil conditions, respectively. In comparison with the observations during the dust events under the very dry and dry soil conditions, the dust emission fl ux during the wet event is smaller, but the saltation activities of sand particles (d≧50 µm) are stronger. The size distributions of airborne dust particles (0.1≦d≦20 µm) show that concentrations of the fi ner dust particles (0.1≦d≦0.3 µm) have a secondary peak under dry soil conditions, while they are absent under wet soil conditions. This suggests that the surface soil particle size distribution can be changed by soil moisture. Under wet soil conditions, the particles appear to have a larger size, and hence more potential saltating particles are available. This explains the occurrence of stronger saltation processes observed under wet soil conditions.

  16. Threshold dynamics in soil carbon storage for bioenergy crops.

    Science.gov (United States)

    Woo, Dong K; Quijano, Juan C; Kumar, Praveen; Chaoka, Sayo; Bernacchi, Carl J

    2014-10-21

    Because of increasing demands for bioenergy, a considerable amount of land in the midwestern United States could be devoted to the cultivation of second-generation bioenergy crops, such as switchgrass and miscanthus. The foliar carbon/nitrogen ratio (C/N) in these bioenergy crops at harvest is significantly higher than the ratios in replaced crops, such as corn or soybean. We show that there is a critical soil organic matter C/N ratio, where microbial biomass can be impaired as microorganisms become dependent upon net immobilization. The simulation results show that there is a threshold effect in the amount of aboveground litter input in the soil after harvest that will reach a critical organic matter C/N ratio in the soil, triggering a reduction of the soil microbial population, with significant consequences in other microbe-related processes, such as decomposition and mineralization. These thresholds are approximately 25 and 15% of aboveground biomass for switchgrass and miscanthus, respectively. These results suggest that values above these thresholds could result in a significant reduction of decomposition and mineralization, which, in turn, would enhance the sequestration of atmospheric carbon dioxide in the topsoil and reduce inorganic nitrogen losses when compared to a corn-corn-soybean rotation.

  17. Litter Inputs and Soil Aggregation in Midwestern Biofuel Crops

    Science.gov (United States)

    Kantola, I. B.; Masters, M. D.; Smyth, E. M.; DeLucia, E. H.

    2014-12-01

    Perennial C4 grasses represent alternatives to corn for the production of ethanol because of low management costs and high biomass production. To evaluate the effects of perennial grasses on the agricultural soils of the Midwest, native switchgrass and a sterile hybrid of the Asian grass Miscanthus were planted at the University of Illinois Energy Farm in 2008. Through five years of growth, above and belowground plant biomass, litter, and soil were compared with soils in plots growing a corn-corn-soy rotation typical of the area. Above- and belowground plant biomass in Miscanthus and switchgrass averaged higher than corn/soy following two years of perennial establishment, with belowground biomass exceeding corn/soy by approximately 5-fold in the year after establishment (2010) and 25-fold by 2012. Measurements of root distribution and turnover rates indicate that roots are the primary contribution of new carbon to soils under perennial crops. Physical fractionation of the soils into water stable aggregates showed 4-14% increases in macroaggregate fractions under perennial crops; the large aggregates are adhered together by organic material and indicative of the increased presence of labile carbon forms like plant roots, fungi, and plant and microbial exudates. Carbon and nitrogen analyses of the fractions show that while overall carbon has not increased significantly in whole soil, soils under perennial grasses are concentrating carbon by 5-17% in the macroaggregates after just 5 years. Native switchgrass roots (buried) and litter (surface-applied) decompose faster than Miscanthus roots and litter, but slower than corn roots and litter buried to simulate incorporation by tillage. Switchgrass soil shows the highest degree of macroaggregate formation, pointing to a high rate of litter and root decomposition and incorporation into soil structure. While macroaggregates are relatively labile soil structures compared to microaggregates and free silt and clay, they offer

  18. Influence of tebuconazole and copper hydroxide on phosphatase and urease activities in red sandy loam and black clay soils.

    Science.gov (United States)

    Anuradha, B; Rekhapadmini, A; Rangaswamy, V

    2016-06-01

    The efficacy of two selected fungicides i.e., tebuconazole and coppoer hydroxide, was conducted experiments in laboratory and copper hydroxide on the two specific enzymes phosphatase and urease were determined in two different soil samples (red sandy loam and black clay soils) of groundnut (Arachis hypogaea L.) from cultivated fields of Anantapuramu District, Andhra Pradesh. The activities of the selected soil enzymes were determined by incubating the selected fungicides-treated (1.0, 2.5, 5.0, 7.5 and 10.0 kg ha(-1)) and -untreated groundnut soil samples at 10 day intervals. By determining the effective concentration, the rate of selected enzyme activity was estimated by adding the suitable substrate at 10, 20, 30 and 40 days of soil incubation. Both the enzyme activities were increased up to 5.0 kg ha(-1) level of fungicide in both soil samples significantly at 10 days of soil incubation and further enhanced up to 20 days of incubation. The activity of the phosphatase and urease decreased progressively at 30 and 40 days of incubation. From overall studies, higher concentrations (7.5 and 10.0 kg ha(-1)) of both tebuconazole and copper hydroxide were toxic to phosphatase and urease activities, respectively, in both soil samples.

  19. Soil Erosion: Advanced Crop and Soil Science. A Course of Study.

    Science.gov (United States)

    Miller, Larry E.

    The course of study represents the last of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil erosion. Upon completion of the two day lesson, the student will be able to: (1) define conservation, (2) understand how erosion takes place, and (3) list ways of controlling wind and water erosion.…

  20. Soil organic carbon assessments in cropping systems using isotopic techniques

    Science.gov (United States)

    Martín De Dios Herrero, Juan; Cruz Colazo, Juan; Guzman, María Laura; Saenz, Claudio; Sager, Ricardo; Sakadevan, Karuppan

    2016-04-01

    Introduction of improved farming practices are important to address the challenges of agricultural production, food security, climate change and resource use efficiency. The integration of livestock with crops provides many benefits including: (1) resource conservation, (2) ecosystem services, (3) soil quality improvements, and (4) risk reduction through diversification of enterprises. Integrated crop livestock systems (ICLS) with the combination of no-tillage and pastures are useful practices to enhance soil organic carbon (SOC) compared with continuous cropping systems (CCS). In this study, the SOC and its fractions in two cropping systems namely (1) ICLS, and (2) CCS were evaluated in Southern Santa Fe Province in Argentina, and the use of delta carbon-13 technique and soil physical fractionation were evaluated to identify sources of SOC in these systems. Two farms inside the same soil cartographic unit and landscape position in the region were compared. The ICLS farm produces lucerne (Medicago sativa Merrill) and oat (Avena sativa L.) grazed by cattle alternatively with grain summer crops sequence of soybean (Glicine max L.) and corn (Zea mays L.), and the farm under continuous cropping system (CCS) produces soybean and corn in a continuous sequence. The soil in the area is predominantly a Typic Hapludoll. Soil samples from 0-5 and 0-20 cm depths (n=4) after the harvest of grain crops were collected in each system and analyzed for total organic carbon (SOC, 0-2000 μm), particulate organic carbon (POC, 50-100 μm) and mineral organic carbon (MOC, <50 μm). Delta carbon-13 was determined by isotopic ratio mass spectrometry. In addition, a site with natural vegetation (reference site, REF) was also sampled for delta carbon-13 determination. ANOVA and Tukey statistical analysis were carried out for all data. The SOC was higher in ICLS than in CCS at both depths (20.8 vs 17.7 g kg-1 for 0-5 cm and 16.1 vs 12.7 g kg-1 at 0-20 cm, respectively, P<0.05). MOC was

  1. Impact of rapeseed cropping on the soil carbon balance

    Science.gov (United States)

    Moffat, Antje Maria; Herbst, Mathias; Huth, Vytas; Andres, Monique; Augustin, Jürgen

    2015-04-01

    Winter oilseed rape is the dominant biofuel crop in the young moraine landscape in Northern Germany. Since the cultivation of biofuel crops requires sustainability compared to fossil fuels by law, detailed knowledge about their green house gas (GHG) balance is necessary. The soil carbon balance is one of the key contributors to the total GHG balance and also very important for the assessment of soil fertility. However, the knowledge about the impact of different management practices on the soil carbon balance is very limited up to now. Therefore, we investigated the carbon fluxes of winter oilseed rape at field plots near Dedelow/Uckermark in NE Germany with different treatments of fertilization (mineral versus organic) and tillage (no-till and mulch-till versus ploughing). The dynamics of the carbon fluxes are mainly driven by the current climatic conditions but the overall response depends strongly on the ecosystem state (with its physiological and microbiological properties) which is affected by management. To get the full carbon flux dynamics but also the impact of the different management practices, two different approaches were used: The eddy covariance technique to get continuous fluxes throughout the year and the manual chamber technique to detect flux differences between specific management practices. The manual chamber measurements were conducted four-weekly as all-day campaigns using a flow-through non-steady-state closed chamber system. The fluxes in-between campaigns were gap-filled based on functional relationships with soil and air temperature (for the ecosystem respiration) and photosynthetic active radiation (for the gross primary production). All results presented refer to the cropping season 2012-2013. The combination of the two measurement techniques allows the evaluation of chamber fluxes including an independent estimate of the error on the overall balances. Despite the considerable errors, there are significant differences in the soil carbon

  2. ECOGEN - Soil ecological and economic evaluation of genetically modified crops

    DEFF Research Database (Denmark)

    Krogh, P. H

    2007-01-01

    ECOGEN is a project funded by the EU under the 6th Framework Programme. Based on results obtained from soil biodiversity studies and economic evaluations, ECOGEN assessed the impact on soil organisms of different agricultural management practices, including those involving genetically modified (GM...... where non-GM conventional maize (8 different varieties) was planted. In addition, economic assessments of the GM crop were performed by quantifying the differences in variable costs, revenues and external effects in comparison with the conventional variety. The implications for the EU Common Agriculture...... corn borer, was chosen as the model GM crop since it has been approved for planting in the EU and been available to growers in Europe since 2003 (introduced first in Spain), with commercial plantings being conducted in five Member States in 2006 on more than 63,000 ha. MON 810 maize was first...

  3. SOIL ECOLOGY AS KEY TO SUSTAINABLE CROP PRODUCTION.

    Science.gov (United States)

    De Deyn, G B

    2015-01-01

    Sustainable production of food, feed and fiberwarrants sustainable soil management and crop protection. The tools available to achieve this are both in the realm of the plants and of the soil, with a key role for plant-soil interactions. At the plant level we have vast knowledge of variation within plant species with respect to pests and diseases, based on which we can breed for resistance. However, given that systems evolve this resistance is bound to be temporarily, hence also other strategies are needed. Here I plea for an integrative approach for sustainable production using ecological principles. Ecology, the study of how organisms interact with their environment, teaches us that diversity promotes productivity and yield stability. These effects are thought to be governed through resource use complementarity and reduced build-up of pests and diseases both above- and belowground. In recent years especially the role of soil biotic interactions has revealed new insights in how plant diversity and productivity are related to soil biodiversity and the functions soil biota govern. In our grassland biodiversity studies we found that root feeders can promote plant diversity and succession without reducing plant community productivity, this illustrates the role of diversity to maintain productivity. Also diversity within species offers scope for sustainable production, for example through awareness of differences between plant genotypes in chemical defense compounds that can attract natural enemies of pests aboveground- and belowground thereby providing plant protection. Plant breeding can also benefit from using complementarity between plant species in the selection for new varieties, as our work demonstrated that when growing in species mixtures plant species adapt to each other over time such that their resource acquisition traits become more complementing. Finally, in a recent meta-analysis we show that earthworms can stimulate crop yield with on average 25%, but

  4. Toxicity of naturally-contaminated manganese soil to selected crops.

    Science.gov (United States)

    Kováčik, Jozef; Štěrbová, Dagmar; Babula, Petr; Švec, Pavel; Hedbavny, Josef

    2014-07-23

    The impact of manganese excess using naturally contaminated soil (Mn-soil, pseudototal Mn 6494 vs 675 μg g(-1) DW in control soil) in the shoots of four crops was studied. Mn content decreased in the order Brassica napus > Hordeum vulgare > Zea mays > Triticum aestivum. Growth was strongly depressed just in Brassica (containing 13696 μg Mn g(-1) DW). Some essential metals (Zn, Fe) increased in Mn-cultured Brassica and Zea, while macronutrients (K, Ca, Mg) decreased in almost all species. Toxic metals (Ni and Cd) were rather elevated in Mn-soil. Microscopy of ROS, NO, lipid peroxidation, and thiols revealed stimulation in all Mn-cultured crops, but changes were less visible in Triticum, a species with low shoot Mn (2363 μg g(-1) DW). Antioxidative enzyme activities were typically enhanced in Mn-cultured plants. Soluble phenols increased in Brassica only while proteins rather decreased in response to Mn excess. Inorganic anions (chloride, sulfate, and phosphate) were less accumulated in almost all Mn-cultured crops, while the nitrate level rather increased. Organic anions (malate, citrate, oxalate, acetate, and formate) decreased or remained unaffected in response to Mn-soil culture in Brassica, Hordeum, and Triticum but not in Zea. However, the role of organic acids in Mn uptake in these species is not assumed. Because control and Mn-soil differed in pH (6.5 and 3.7), we further studied its impact on Mn uptake in solution culture (using Mn concentration ∼5 mM deducted from water-soluble fraction of Mn-soil). Shoot Mn contents in Mn-treated plants were similar to those observed in soil culture (high in Brassica and low in Triticum) and pH had negligible impact. Fluorescence indicator of "general ROS" revealed no extensive or pH-dependent impact either in control or Mn-cultured roots. Observed toxicity of Mn excess to common crops urges for selection of cultivars with higher tolerance.

  5. The impact of genetically modified crops on soil microbial communities.

    Science.gov (United States)

    Giovannetti, Manuela; Sbrana, Cristiana; Turrini, Alessandra

    2005-01-01

    Genetically modified (GM) plants represent a potential benefit for environmentally friendly agriculture and human health. Though, poor knowledge is available on potential hazards posed by unintended modifications occurring during genetic manipulation. The increasing amount of reports on ecological risks and benefits of GM plants stresses the need for experimental works aimed at evaluating the impact of GM crops on natural and agro-ecosystems. Major environmental risks associated with GM crops include their potential impact on non-target soil microorganisms playing a fundamental role in crop residues degradation and in biogeochemical cycles. Recent works assessed the effects of GM crops on soil microbial communities on the basis of case-by-case studies, using multimodal experimental approaches involving different target and non-target organisms. Experimental evidences discussed in this review confirm that a precautionary approach should be adopted, by taking into account the risks associated with the unpredictability of transformation events, of their pleiotropic effects and of the fate of transgenes in natural and agro-ecosystems, weighing benefits against costs.

  6. Effects of grazing strategy on limiting nitrate leaching in grazed grass-clover pastures on coarse sandy soil

    DEFF Research Database (Denmark)

    Hansen, Elly Møller; Eriksen, Jørgen; Søegaard, Karen;

    2012-01-01

    Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006–2007 and 2007–2008. In both years, precipitation was above the long-term...... mean. The experiment was initiated in a 4-yr-old grass-clover sward in south Denmark. Three treatments were as follows grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm...

  7. PARTICULAR ASPECTS OF APPLICABILITY OF PROVISIONS OF THE PHYSICAL AND CHEMICAL THEORY OF EFFECTIVE STRESSES TO SANDY SOILS

    Directory of Open Access Journals (Sweden)

    Potapov Aleksandr Dmitrievich

    2012-10-01

    V.I. Osipov. The analysis of several genetic types of quaternary sands, performed by the authors, makes it possible to use the number of contacts to identify the morphology of sand grains within the framework of the analysis of soils. The authors demonstrate that the employment of the formulas developed by academician V.I. Osipov in the calculation of the number of contacts between particles in natural sandy soils is virtually impossible due to the fact that no natural sand particles can boast an ideal spherical shape. The number of contacts between the sand particles may increase due to the defects of their shape and the nature of the particle surface. In this study, the shape and nature of the surface of sand grains represent those of the sands of various origins. The authors have employed a composite index of morphology that takes account of the shape and nature of the surface throughout the amount of sand under research. Similar calculations that take account of the morphology of grains were performed for selected fractions of sands to eliminate the influence of grain size on the packing of sands. The analysis of provisions of the physical and chemical theory of effective stresses of soils and the study of multiple types of natural sands demonstrate that further research of formation and phases of coagulation contacts between particles of soil requires a detailed study of structural features of sands. These structural features include the grain size, homogeneity, the shape and nature of the surface of sand grains. Both individual particles of sand and sandy soil are to be subjected to morphological assessments. The parameters to be assessed will include density and composition of sandy soils, as the soil porosity affects the formation of true contacts between particles of sand and determines their number. Mineral composition is an important factor affecting the shape and nature of the surface of sand grains. The research performed by the authors contemplates

  8. NEW TRENDS IN AGRICULTURE - CROP SYSTEMS WITHOUT SOIL

    Directory of Open Access Journals (Sweden)

    Ioan GRAD

    2014-04-01

    Full Text Available The paper studied new system of agriculture - crop systems without soil. The culture systems without soil can be called also the hydroponic systems and now in Romania are not used only sporadically. In other countries (USA, Japan, the Netherlands, France, UK, Denmark, Israel, Australia, etc.. they represent the modern crop technology, widely applied to vegetables, fruits, fodder, medicinal plants and flowers by the experts in this area. In the world, today there are millions of hectares hydroponics, most of the vegetables, herbs, fruits of hypermarkets are coming from the culture systems without soil. The process consists of growing plants in nutrient solutions (not in the ground, resorting to an complex equipment, depending on the specifics of each crop, so that the system can be applied only in the large farms, in the greenhouses, and not in the individual households. These types of culture systems have a number of advantages and disadvantages also. Even if today's culture systems without soil seem to be the most modern and surprising technology applied in plant growth, the principle is very old. Based on him were built The Suspended Gardens of the Semiramis from Babylon, in the seventh century BC, thanks to him, the population from the Peru”s highlands cultivates vegetables on surfaces covered with water or mud. The peasant households in China, even today use the millenary techniques of the crops on gravel. .This hydroponic agriculture system is a way of followed for Romanian agriculture too, despite its high cost, because it is very productive, ecological, can cover, by products, all market demands and it answer, increasingly, constraints of urban life. The concept of hydroponics agriculture is known and appreciated in Romania also, but more at the theory level.

  9. Microcalorimetric study the toxic effect of hexavalent chromium on microbial activity of Wuhan brown sandy soil: an in vitro approach.

    Science.gov (United States)

    Yao, Jun; Tian, Lin; Wang, Yanxin; Djah, Atakora; Wang, Fei; Chen, Huilun; Su, Chunli; Zhuang, Rensheng; Zhou, Yong; Choi, Martin M F; Bramanti, Emilia

    2008-02-01

    A multi-channel thermal activity monitor was applied to study soil microbial activity in Wuhan brown sandy soil in the presence of different concentrations of hexavalent chromium (K(2)Cr(2)O(7)). In order to stimulate the soil microbial activity, 5.0mg of glucose and 5.0mg of ammonium sulfate were added to a 1.20-g soil sample under a controlled humidity of 35%. The results show that the poisonous species of K(2)Cr(2)O(7) at an half inhibitory concentration (IC(50)) value of 4.27 microg mL(-1) against soil microbe, and an increase of the amount of hexavalent chromium is associated to a decrease in the microbial activity of the soil, probably due to an increase in the toxicity of hexavalent chromium, affecting strongly the life in this soil microbial environment. Our work also suggests that microcalorimetry is a fast, simple and more sensitive method that can be easily performed to study the toxicity of different species of heavy metals on microorganism compared to other biological methods.

  10. Carbon supply and storage in tilled and nontilled soils as influenced by cover crops and nitrogen fertilization.

    Science.gov (United States)

    Sainju, Upendra M; Singh, Bharat P; Whitehead, Wayne F; Wang, Shirley

    2006-01-01

    Soil carbon (C) sequestration in tilled and nontilled areas can be influenced by crop management practices due to differences in plant C inputs and their rate of mineralization. We examined the influence of four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secale cereale L.)], biculture of legume and nonlegume (vetch and rye), and no cover crops (or winter weeds)} and three nitrogen (N) fertilization rates (0, 60 to 65, and 120 to 130 kg N ha(-1)) on C inputs from cover crops, cotton (Gossypium hirsutum L.), and sorghum [Sorghum bicolor (L.) Moench)], and soil organic carbon (SOC) at the 0- to 120-cm depth in tilled and nontilled areas. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic Plinthic Paleudults) from 1999 to 2002 in central Georgia. Total C inputs to the soil from cover crops, cotton, and sorghum from 2000 to 2002 ranged from 6.8 to 22.8 Mg ha(-1). The SOC at 0 to 10 cm fluctuated with C input from October 1999 to November 2002 and was greater from cover crops than from weeds in no-tilled plots. In contrast, SOC values at 10 to 30 cm in no-tilled and at 0 to 60 cm in chisel-tilled plots were greater for biculture than for weeds. As a result, C at 0 to 30 cm was sequestered at rates of 267, 33, -133, and -967 kg C ha(-1) yr(-1) for biculture, rye, vetch, and weeds, respectively, in the no-tilled plot. In strip-tilled and chisel-tilled plots, SOC at 0 to 30 cm decreased at rates of 233 to 1233 kg C ha(-1) yr(-1). The SOC at 0 to 30 cm increased more in cover crops with 120 to 130 kg N ha(-1) yr(-1) than in weeds with 0 kg N ha(-1) yr(-1), regardless of tillage. In the subtropical humid region of the southeastern United States, cover crops and N fertilization can increase the amount of C input and storage in tilled and nontilled soils, and hairy vetch and rye biculture was more effective in sequestering C than monocultures or no cover crop.

  11. Diffusion and emissions of 1,3-dichloro propene in Florida sandy soil in microplots affected by soil moisture, organic matter, and plastic film.

    Science.gov (United States)

    Thomas, John E; Allen, L Hartwell; McCormack, Leslie A; Vu, Joseph C; Dickson, Donald W; Ou, Li-Tse

    2004-04-01

    The main objective of this study was to determine the influence of soil moisture, organic matter amendment and plastic cover (a virtually impermeable film, VIF) on diffusion and emissions of (Z)- and (E)-1,3-dichloropropene (1,3-D) in microplots of Florida sandy soil (Arredondo fine sand). Upward diffusion of the two isomers in the Arredondo soil without a plastic cover was greatly influenced by soil-water content and (Z)-1,3-D diffused faster than (E)-1,3-D. In less than 5 h after 1,3-D injection to 30 cm depth, (Z)- and (E)-1,3-D in air dry soil had diffused to a 10 cm depth, whereas diffusion for the two isomers was negligible in near-water-saturated soil, even 101 h after injection. The diffusion rate of (Z)- and (E)-1,3-D in near-field-capacity soil was between the rates in the two water regimes. Yard waste compost (YWC) amendment greatly reduced diffusion of (Z)- and (E)-1,3-D, even in air-dry soil. Although upward diffusion of (Z)- and (E)-1,3-D in soil with VIF cover was slightly less than in the corresponding bare soil; the cover promoted retention of vapors of the two isomers in soil pore air in the shallow subsurface. More (Z)-1,3-D vapor was found initially in soil pore air than (E)-1,3-D although the difference declined thereafter. As a result of rapid upward movement in air-dry bare soil, (Z)- and (E)-1,3-D were rapidly volatilized into the atmosphere, but emissions from the near-water-saturated soil were minimal. Virtually impermeable film and YWC amendment retarded emissions. This study indicated that adequate soil water in this sandy soil is needed to prevent rapid emissions, but excess soil water slows diffusion of (Z)- and (E)-1,3-D. Thus, management for optimum water in soil is critical for pesticidal efficacy and the environment.

  12. Effect of different crops on soil organic matter and biological activity in Oxisols under three different crops

    Science.gov (United States)

    Toledo, Diana Marcela; Arzuaga, Silvia; Dalurzo, Humberto; Zornoza, Raúl; Vazquez, Sara

    2015-04-01

    The objective of this work was to evaluate changes in soil organic matter in Oxisols under different crops compared to native rainforest, and to assess if acid phosphatase activity (APA) could be a good indicator for SOC changes and soil quality. The experimental design consisted of four completely randomized blocks with four treatments: subtropical rainforest (F); yerba mate crop (I) (Ilex paraguariensis SH.); citrus crop (C) (Citrus unshiu Marc); and tobacco crop (T) (Nicotiana tabacum L.). Soil samples were taken at 0-10; 10-20 and 20-30 cm depths. The variables measured were soil organic carbon (SOC), APA, clay content, pH, total nitrogen (Nt), available phosphorus (P) and CO2 emissions. All data were analyzed by ANOVA to assess the effects of land-use changes. The treatment means were compared through Duncan's multiple range tests (psoils showed an acid reaction and their clay content was over 650 g kg-1 for the three depths. SOC and N contents were higher in native soils, intermediate for the citrus crop, and lower under both tobacco and yerba mate crops. CO2 emissions were higher in the rainforest (47.32 kg ha-1 of CO2) than in cultivated soils, which indicates that biological activity is enhanced in rainforest soils where substrates for soil biota and fauna are more readily available. The variability of 76% in APA was explained by total nitrogen, which is closely related to soil organic matter, and by available P. Conversion of subtropical rainforests into agricultural lands reduced SOC content and acid phosphatase activity, thereby lowering soil quality. In this study, acid phosphatase activity proved to be a sensitive indicator to detect changes from pristine to cropped soils, but it failed to distinguish differences among crop systems.

  13. Reclamation of Sodic-Saline Soils. Barley Crop Response

    Directory of Open Access Journals (Sweden)

    Giovanna Cucci

    2008-12-01

    Full Text Available The research was aimed at assessing the salinity and sodicity effects of two soil types submitted to correction on barley crop. The two soils, contained in cylindrical pots (0.40 m in size and 0.60 m h supplied with a bottom valve for the collection of drainage water and located under shed to prevent the leaching action of rainfall, were clay-textured and saline and sodic-saline at barley seeding, as they had been cultivated for 4 consecutive years with different herbaceous species irrigated with 9 types of brackish water. In 2002-2003 the 2 salinized and sodium-affected soils (ECe and ESP ranging respectively from 5.84-20.27 dSm-1 to 2.83-11.19%, submitted to correction, were cultivated with barley cv Micuccio, and irrigated with fresh water (ECw = 0.5 dS m-1 and SAR = 0.45 whenever 30% of the maximum soil available moisture was lost by evapotranspiration. Barley was shown to be a salt-tolerant species and did not experience any salt stress when grown in soils with an initial ECe up to 11 dS m-1. When it was grown in more saline soils (initial ECe of about 20 dS m-1, despite the correction, it showed a reduction in shoot biomass and kernel yield by 26% and 36% respectively, as compared to less saline soils.

  14. [Effects of transgenic Bt crops on non-target soil animals].

    Science.gov (United States)

    Yuan, Yi-gang; Ge, Feng

    2010-05-01

    Transgenic Bt crops are widely planted around the world. With the quick development and extension of genetically modified crops, it is needed to make a deep study on the effects of Bt crops on soil ecosystem. This paper reviewed the research progress on the effects of transgenic Bt crops on the population dynamics and community structure of soil animals, e.g., earthworm, nematode, springtail, mite, and beetle, etc. The development history of Bt crops was introduced, the passway the Bt protein comes into soil as well as the residual and degradation of Bt protein in soil were analyzed, and the critical research fields about the ecological risk analysis of transgenic Bt crops on non-target soil animals in the future were approached, which would provide a reference for the research of the effects of transgenic Bt crops on non-target soil animals.

  15. Metal availability and soil toxicity after repeated croppings of Thlaspi caerulescens in metal contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Catherine; Hammer, Daniel

    2004-09-01

    Metal phytoextraction with hyperaccumulating plants could be a useful method to decontaminate soils, but it is not fully validated yet. In order to quantify the efficiency of Cd and Zn extraction from a calcareous soil with and without Fe amendment and an acidic soil, we performed a pot experiment with three successive croppings of Thlaspi caerulescens followed by 3 months without plant and 7 weeks with lettuce. We used a combined approach to assess total extraction efficiency (2 M HNO{sub 3}-extractable metals), changes in metal bio/availability (0.1 M NaNO{sub 3}-extractable metals and lettuce uptake) and toxicity (lettuce biomass and the BIOMETreg] biosensor). The soil solution was monitored over the whole experiment. In the calcareous soil large Cu concentrations were probably responsible for chlorosis symptoms observed on T. caerulescens. When this soil was treated with Fe, the amount of extracted metal by T. caerulescens increased and metal availability and soil toxicity decreased when compared to the untreated soil. In the acidic soil, T. caerulescens was most efficient: Cd and Zn concentrations in plants were in the range of hyperaccumulation and HNO{sub 3}-extractable Cd and Zn, metal bio/availability, soil toxicity, and Cd and Zn concentrations in the soil solution decreased significantly. However, a reduced Cd concentration measured in the third T. caerulescens cropping indicated a decrease in metal availability below a critical threshold, whereas the increase of dissolved Cd and Zn concentrations after the third cropping may be the early sign of soil re-equilibration. This indicates that phytoextraction efficiency must be assessed by different approaches in order not to overlook any potential hazard and that an efficient phytoextraction scheme will have to take into account the different dynamics of the soil-plant system.

  16. Study on Obstacles to Continuous Cropping of Vegetables and Soil Remediation Technology

    Institute of Scientific and Technical Information of China (English)

    Pingsheng FAN; Gang CHEN; Deli XU; Weimin FENG; Yuyu LU; Anqin GUAN

    2016-01-01

    Firstly,this paper analyzes the cause of obstacles to continuous cropping of vegetables,and then introduces the soil ecological remediation technology used for overcoming obstacles to continuous cropping of vegetables. Finally,this paper analyzes the effect of applying soil ecological remediation technology in overcoming obstacles to continuous cropping of vegetables.

  17. Chemistry and microbial functional diversity differences in biofuel crop and grassland soils in multiple geographies

    Science.gov (United States)

    As crop and non-crop lands are increasingly converted to biofuel feedstock production, it is of interest to identify potential impacts of annual and perennial feedstocks on soil ecosystem services. Soil samples were obtained from diverse regionally distributed biofuel cropping si...

  18. Vegetation pattern variation, soil degradation and their relationship along a grassland desertification gradient in Horqin Sandy Land, northern China

    Science.gov (United States)

    Zuo, Xiaoan; Zhao, Halin; Zhao, Xueyong; Guo, Yirui; Yun, Jianying; Wang, Shaokun; Miyasaka, Takafumi

    2009-09-01

    The Horqin Sandy Land is one of the most severely desertified regions in northern China. Plant communities and soil conditions at five stages of grassland desertification (potential, light, moderate, severe and very severe) were selected for the study of vegetation pattern variation relating to soil degradation. The results showed that vegetation cover, species richness and diversity, aboveground biomass (AGB), underground biomass, litter, soil organic carbon (C), total nitrogen (N), total phosphorus (P), electrical conductivity, very fine sand (0.1-0.05 mm) content and silt (0.05-0.002 mm) content decreased with the desertification development. Plant community succession presented that the palatable herbaceous plants gave place to the shrub species with asexual reproduction and sand pioneer plants. The decline of vegetation cover and AGB was positively related to the loss of soil organic C and total N with progressive desertification ( P < 0.01). The multivariate statistical analysis showed that plant community distribution, species diversity and ecological dominance had the close relationship with the gradient of soil nutrients in the processes of grassland desertification. These results suggest that grassland desertification results in the variation of vegetation pattern which presents the different composition and structure of plant community highly influenced by the soil properties.

  19. Contrasting Hydraulic Strategies during Dry Soil Conditions in Quercus rubra and Acer rubrum in a Sandy Site in Michigan

    Directory of Open Access Journals (Sweden)

    Julia E. Thomsen

    2013-12-01

    Full Text Available Correlation analyses were carried out for the dynamics of leaf water potential in two broad-leaf deciduous tree species in a sandy site under a range of air vapor pressure deficits and a relatively dry range of soil conditions. During nights when the soil is dry, the diffuse-porous, isohydric and shallow-rooted Acer rubrum does not recharge its xylem and leaf water storage to the same capacity that is observed during nights when the soil is moist. The ring-porous, deep-rooted Quercus rubra displays a more anisohydric behavior and appears to be capable of recharging to capacity at night-time even when soil moisture at the top 1 m is near wilting point, probably by accessing deeper soil layers than A. rubrum. Compared to A. rubrum, Q. rubra displays only a minimal level of down-regulation of stomatal conductance, which leads to a reduction of leaf water potential during times when vapor pressure deficit is high and soil moisture is limiting. We determine that the two species, despite typically being categorized by ecosystem models under the same plant functional type—mid-successional, temperate broadleaf—display different hydraulic strategies. These differences may lead to large differences between the species in water relations, transpiration and productivity under different precipitation and humidity regimes.

  20. No-tillage lessens soil CO2 emissions the most under arid and sandy soil conditions: results from a meta-analysis

    Science.gov (United States)

    Abdalla, Khatab; Chivenge, Pauline; Ciais, Philippe; Chaplot, Vincent

    2016-06-01

    The management of agroecosystems plays a crucial role in the global carbon cycle with soil tillage leading to known organic carbon redistributions within soils and changes in soil CO2 emissions. Yet, discrepancies exist on the impact of tillage on soil CO2 emissions and on the main soil and environmental controls. A meta-analysis was conducted using 46 peer-reviewed publications totaling 174 paired observations comparing CO2 emissions over entire seasons or years from tilled and untilled soils across different climates, crop types and soil conditions with the objective of quantifying tillage impact on CO2 emissions and assessing the main controls. On average, tilled soils emitted 21 % more CO2 than untilled soils, which corresponded to a significant difference at Ptillage had no impact on CO2 fluxes in clayey soils with high background SOCC (> 3 %). Finally, nitrogen fertilization and crop residue management had little effect on the CO2 responses of soils to no-tillage. These results suggest no-tillage is an effective mitigation measure of carbon dioxide losses from dry land soils. They emphasize the importance of including information on soil factors such as texture, aggregate stability and organic carbon content in global models of the carbon cycle.

  1. Biological soil crust formation under artificial vegetation effect and its properties in the Mugetan sandy land, northeastern Qinghai-Tibet Plateau

    Science.gov (United States)

    Li, Y. F.; Li, Z. W.; Jia, Y. H.; Zhang, K.

    2016-08-01

    Mugetan sandy land is an inland desertification area of about 2,065 km2 in the northeastern Qinghai-Tibet Plateau. In the ecological restoration region of the Mugetan sandy land, different crusts have formed under the action of vegetation in three types of sandy soil (i.e. semi-fixed sand dune, fixed sand dune and ancient fixed aeolian sandy soil). The surface sand particle distribution, mineral component and vegetation composition of moving sand dunes and three types of sandy soil were studied in 2010-2014 to analyze the biological crust formation properties in the Mugetan sandy land and the effects of artificial vegetation. Results from this study revealed that artificial vegetation increases the clay content and encourages the development of biological curst. The fine particles (i.e. clay and humus) of the surface layer of the sand dunes increased more than 15% ten years after the artificial vegetation planting, and further increased up to 20% after one hundred years. The interaction of clay, humus, and other fine particles formed the soil aggregate structure. Meanwhile, under the vegetation effect from the microbes, algae, and moss, the sand particles stuck together and a biological crust formed. The interconnection of the partial crusts caused the sand dunes to gradually be fixed as a whole. Maintaining the integrity of the biological crust plays a vital role in fixing the sand under the crust. The precipitation and temperature conditions in the Mugetan sandy land could satisfy the demand of biological crust formation and development. If rational vegetation measures are adopted in the region with moving sand dunes, the lichen-moss-algae biological curst will form after ten years, but it still takes more time for the sand dunes to reach the nutrient enrichment state. If the biological curst is partly broken due to human activities, reasonable closure and restoration measures can shorten the restoration time of the biological crust.

  2. Cover crops to improve soil health and pollinator habitat in nut orchards

    Science.gov (United States)

    Jerry. Van Sambeek

    2017-01-01

    Recently several national programs have been initiated calling for improving soil health and creating pollinator habitat using cover crops. Opportunities exist for nut growers to do both with the use of cover crops in our nut orchards. Because we can include perennial ground covers as cover crops, we have even more choices than landowners managing cover crops during...

  3. Validation of the PESTLA model: Field test using data from a sandy soil in Schaijk (the Netherlands)

    NARCIS (Netherlands)

    Boekhold AE; Swartjes FA; Hoogenboom FGG; van der Linden AMA

    1993-01-01

    Within the framework of the project "Validation of PESTLA" the Schaijk data set was used to analyse PESTLA model performance. The Schaijk data set contains field data on bentazon behaviour in a coarse textured humic gley soil cropped with maize. PESTLA model input parameters were derived

  4. Crop residues as soil amendments and feedstock for bioethanol production.

    Science.gov (United States)

    Lal, R

    2008-01-01

    Traditional solid fuels account for more than 90% of the energy supply for 3 billion people in developing countries. However, liquid biofuels (e.g., ethanol) are perceived as an important alternative to fossil fuel. Global crop residue production is estimated at about 4 billion Mg for all crops and 3 billion Mg per annum for lignocellulosic residues of cereals. One Mg of corn stover can produce 280L of ethanol, compared with 400L from 1Mg of corn grains; 1Mg of biomass is also equivalent to 18.5GJ of energy. Thus, 3 billion Mg of residues are equivalent to 840 billion L of ethanol or 56x10(9)GJ of energy. However, removal of crop residues exacerbates soil degradation, increases net emission of CO2, and aggravates food insecurity. Increasing the SOC pool by 1 Mg C ha(-1)yr(-1) through residue retention on soil can increase world food grain production by 24-40 million Mg yr(-1), and root/tuber production by 6-11 million Mg yr(-1). Thus, identifying alternate sources of biofuel feedstock (e.g., biofuel plantations, animal waste, municipal sold waste) is a high priority. Establishing biofuel plantations on agriculturally marginal or degraded lands can off-set 3.5-4 Pg Cyr(-1).

  5. Soil Tillage Conservation and its Effect on Soil Properties Bioremediation and Sustained Production of Crops

    Science.gov (United States)

    Rusu, Teodor; Ioana Moraru, Paula; Muresan, Liliana; Andriuca, Valentina; Cojocaru, Olesea

    2017-04-01

    soil features resulted in a positive impact on the water permeability of the soil. Availability of soil moisture during the crop growth resulted in better plant water status. Subsequent release of conserved soil water regulated proper plant water status, soil structure, and lowered soil penetrometer resistance. Productions obtained at STC did not have significant differences for the wheat and maize crop but were higher for soybean. The advantages of minimum soil tillage systems for Romanian pedo-climatic conditions can be used to improve methods in low producing soils with reduced structural stability on sloped fields, as well as measures of water and soil conservation on the whole agroecosystem. Presently, it is necessary to make a change concerning the concept of conservation practices and to consider a new approach regarding the good agricultural practice. We need to focus on an upper level concerning conservation by focusing on soil quality. Carbon management is necessary for a complexity of matters including soil, water management, field productivity, biological fuel and climatic change. In conclusion a Sustainable Agriculture includes a range of complementary agricultural practices: (i) minimum soil tillage (through a system of reduced tillage or no-tillage) to preserve the structure, fauna and soil organic matter; (ii) permanent soil cover (cover crops, residues and mulches) to protect the soil and help to remove and control weeds; (iii) various combinations and rotations of the crops which stimulate the micro-organisms in the soil and controls pests, weeds and plant diseases. Acknowledgements: This paper was performed under the frame of the Partnership in priority domains - PNII, developed with the support of MEN-UEFISCDI, project no. PN-II-PT-PCCA-2013-4-0015: Expert System for Risk Monitoring in Agriculture and Adaptation of Conservative Agricultural Technologies to Climate Change, and International Cooperation Program - Sub-3.1. Bilateral AGROCEO c. no. 21BM

  6. Soil suitability evaluation for crop selection using fuzzy sets methodology

    Directory of Open Access Journals (Sweden)

    Amin SHARIFIFAR

    2016-04-01

    Full Text Available In this study appraisal of four different agricultural land evaluation methods including the so-called Storie method, square root method, maximum limitation method and fuzzy sets method, was done. The study was performed in Bastam region, located in Semnan province at the north east of Iran. Three crops including tomato, wheat and potato were assessed for the purpose of this research. Soil characteristics assessed were rooting depth, CaCo3, organic carboncontent, clay content, pH and slope gradient. Statistical analyses were done at significance levels of α = 0.1 and α = 0.05. Results of regression between land indices, calculated through the four methods, with observed yields of the crops, showed that the regression were significant in fuzzy sets method for all of the assessed crops at p = 0.05 but not significant in maximum limitation method for any of the crops. The Storie and square root methods also showed a significant correlation with wheat yield at p = 0.1. This study was a demonstrative test of fuzzy sets theory in land suitability evaluation for agricultural uses, which revealed that this methodology is the most correct method in given circumstances.

  7. Crop diversification, tillage, and management system influences on spring wheat yield and soil water use

    Science.gov (United States)

    Depleted soil quality, decreased water availability, and increased weed competition constrain spring wheat production in the northern Great Plains. Integrated crop management systems are necessary for improved crop productivity. We conducted a field experiment from 2004-2010 comparing productivity...

  8. Effects of irrigation on crops and soils with Raft River geothermal water

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, N.E.; Schmitt, R.C.

    1980-01-01

    The Raft River Irrigation Experiment investigated the suitability of using energy-expended geothermal water for irrigation of selected field-grown crops. Crop and soil behavior on plots sprinkled or surface irrigated with geothermal water was compared to crop and soil behavior on plots receiving water from shallow irrigation wells and the Raft River. In addition, selected crops were produced, using both geothermal irrigation water and special management techniques. Crops irrigated with geothermal water exhibited growth rates, yields, and nutritional values similar to comparison crops. Cereal grains and surface-irrigated forage crops did not exhibit elevated fluoride levels or accumulations of heavy metals. However, forage crops sprinkled with geothermal water did accumulate fluorides, and leaching experiments indicate that new soils receiving geothermal water may experience increased salinity, exchangeable sodium, and decreased permeability. Soil productivity may be maintained by leaching irrigations.

  9. Converging strategies by farmers and scientists to improve soil fertility and enhance crop production in Benin

    NARCIS (Netherlands)

    Saidou, A.

    2006-01-01

    Keywords: Farmer perception, indigenous knowledge, extensive cassava, earthworm casts, arbuscular mycorrhiza, crop rotation, nutrient uptake, soil fertility, co-research, land tenure.Farmers in the transitional zone of Benin claim that extensive cassava cropping and prior cotton fertiliser enhance

  10. COVER CROPS ENHANCE SOIL ORGANIC MATTER, CARBON DYNAMICS AND MICROBIOLOGICAL FUNCTION IN A MEDITERRANEAN VINEYARD AGROECOSYSTEM

    Science.gov (United States)

    Impacts of soil tillage and cover crops on soil carbon (C) dynamics and microbiological function were investigated in a vineyard grown in California’s Mediterranean climate. We 1) compared soil organic matter (SOM), C dynamics and microbiological activity of two cover crops [Trios 102 (Triticale x T...

  11. Understanding cropping systems in the semi-arid environments of Zimbabwe: options for soil fertility management

    NARCIS (Netherlands)

    Ncube, B.

    2007-01-01

    African smallholder farmers face perennial food shortages due to low crop yields. The major cause of poor crop yields is soil fertility decline. The diversity of sites and soils between African farming systems isgreat,therefore strategies to solve soil fertility problems

  12. Understanding cropping systems in the semi-arid environments of Zimbabwe: options for soil fertility management

    NARCIS (Netherlands)

    Ncube, B.

    2007-01-01

    African smallholder farmers face perennial food shortages due to low crop yields. The major cause of poor crop yields is soil fertility decline. The diversity of sites and soils between African farming systems isgreat,therefore strategies to solve soil fertility problems sho

  13. Effects of different mechanized soil fertilization methods on corn soil fertility under continuous cropping

    Science.gov (United States)

    Shi, Qingwen; Wang, Huixin; Bai, Chunming; Wu, Di; Song, Qiaobo; Gao, Depeng; Dong, Zengqi; Cheng, Xin; Dong, Qiping; Zhang, Yahao; Mu, Jiahui; Chen, Qinghong; Liao, Wenqing; Qu, Tianru; Zhang, Chunling; Zhang, Xinyu; Liu, Yifei; Han, Xiaori

    2017-05-01

    Experiments for mechanized soil fertilization for corns were conducted in Faku demonstration zone. On this basis, we studied effects on corn soil fertility under continuous cropping due to different mechanized soil fertilization methods. Our study would serve as a theoretical basis further for mechanized soil fertilization improvement and soil quality improvement in brown soil area. Based on the survey of soil physical characteristics during different corn growth periods, we collected soil samples from different corn growth periods to determine and make statistical analysis accordingly. Stalk returning to field with deep tillage proved to be the most effective on available nutrient improvement for arable soil in the demonstration zone. Different mechanized soil fertilization methods were remarkably effective on total phosphorus improvement for arable soil in the demonstration zone, while less effective on total nitrogen or total potassium, and not so effective on C/N ratio in soil. Stalk returning with deep tillage was more favorable to improve content of organic matter in soil, when compared with surface application, and organic granular fertilizer more favorable when compared with decomposed cow dung for such a purpose, too.

  14. Effects of Irrigating with Treated Oil and Gas Product Water on Crop Biomass and Soil Permeability

    Energy Technology Data Exchange (ETDEWEB)

    Terry Brown; Jeffrey Morris; Patrick Richards; Joel Mason

    2010-09-30

    Demonstrating effective treatment technologies and beneficial uses for oil and gas produced water is essential for producers who must meet environmental standards and deal with high costs associated with produced water management. Proven, effective produced-water treatment technologies coupled with comprehensive data regarding blending ratios for productive long-term irrigation will improve the state-of-knowledge surrounding produced-water management. Effective produced-water management scenarios such as cost-effective treatment and irrigation will discourage discharge practices that result in legal battles between stakeholder entities. The goal of this work is to determine the optimal blending ratio required for irrigating crops with CBNG and conventional oil and gas produced water treated by ion exchange (IX), reverse osmosis (RO), or electro-dialysis reversal (EDR) in order to maintain the long term physical integrity of soils and to achieve normal crop production. The soils treated with CBNG produced water were characterized with significantly lower SAR values compared to those impacted with conventional oil and gas produced water. The CBNG produced water treated with RO at the 100% treatment level was significantly different from the untreated produced water, while the 25%, 50% and 75% water treatment levels were not significantly different from the untreated water. Conventional oil and gas produced water treated with EDR and RO showed comparable SAR results for the water treatment technologies. There was no significant difference between the 100% treated produced water and the control (river water). The EDR water treatment resulted with differences at each level of treatment, which were similar to RO treated conventional oil and gas water. The 100% treated water had SAR values significantly lower than the 75% and 50% treatments, which were similar (not significantly different). The results of the greenhouse irrigation study found the differences in biomass

  15. Use of Crop Models in Assessment of Soil Drought

    Directory of Open Access Journals (Sweden)

    Milada Stastna

    2007-03-01

    Full Text Available The aims of the study were to apply, test and to present the ability of the deterministic simulation models SIMWASER and CERES-Wheat computing soil-water balance components, percolation losses, ground water recharge and capillary rise. Two case studies for the assessment of percolation losses from irrigated carrots to deep groundwater at Obersiebenbrunn in the Marchfeld (Austria and ground water recharge and capillary rise from shallow groundwater in grass lysimeters at Berlin-Dahlem (Germany together with two test sites with similar climatic conditions and soil water storage potential but with (Grossenzesdorf, Austria and without (Zabcice, Czech Republic groundwater impact in a semi-arid agricultural area in central Europe were chosen. At Obersiebenbrunn, simulated percolation and evapotranspiration were 183 and 629 mm, while the respective measured values amounted to 198 and 635 mm. Up to 42% (194 mm of evapotranspiration was provided by groundwater at s Grossenzesdorf and only 126 mm was used for the worst case comparing to observed data. Th ese results showed both models as proper applicable tools to demonstrate cropsoil – water relations. However, the availability and management of soil water reserves will remain important, especially when extreme events such as droughts occur more frequently and annual soil and groundwater recharge decrease.

  16. Soil carbon sequestration via cover crops- A meta-analysis

    Science.gov (United States)

    Poeplau, Christopher; Don, Axel

    2014-05-01

    Agricultural soils are depleted in soil organic carbon (SOC) and have thus a huge potential to sequester SOC. This can primarily be achieved by increasing carbon inputs into the soil. Replacing winter fallows by cover crop cultivation for green manure has many benefits for the soil and forms an additional carbon input. An increase in carbon concentration has been reported in several studies worldwide. However, the effect on SOC stocks, as well as the influence of environmental parameters and management on SOC dynamics is not known. We therefore conducted a meta-analysis to investigate those issues. A total of 33 studies, comprising 47 sites and 147 plots were compiled. A pedotransfer function was used to estimate bulk densities and calculate SOC stocks. SOC stock change was found to be a linear function of time since introduction, with an annual sequestration rate of 0.32 Mg C ha-1 yr-1. Since no saturation was visible in the observations, we used the model RothC to estimate a new steady state level and the resulting total SOC stock change for an artificial "average cropland". The total average SOC stock change with an annual input of 1.87 Mg C ha-1 yr-1 was 16.76 Mg C ha-1 for the average soil depth of 22 cm. We estimated a potential global SOC sequestration of 0.12±0.03 Pg C yr-1, which would compensate for 8 % of the direct annual greenhouse gas emissions from agriculture.

  17. Summer cover crops and soil amendments to improve growth and nutrient uptake of okra

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.R.; Li, Y.C.; Klassen, W. [University of Florida, Homestead, FL (United States). Center for Tropical Research & Education

    2006-04-15

    A pot experiment with summer cover crops and soil amendments was conducted in two consecutive years to elucidate the effects of these cover crops and soil amendments on 'Clemson Spineless 80' okra (Abelmoschus esculentus) yields and biomass production, and the uptake and distribution of soil nutrients and trace elements. The cover crops were sunn hemp (Crotalaria juncea), cowpea (Vigna unguiculata), velvetbean (Mucuna deeringiana), and sorghum sudan-grass (Sorghum bicolor x S. bicolor var. sudanense) with fallow as the control. The organic soil amendments were biosolids (sediment from wastewater plants), N-Viro Soil (a mixture of biosolids and coal ash), coal ash (a combustion by-product from power plants), co-compost (a mixture of 3 biosolids: 7 yard waste), and yard waste compost (mainly from leaves and branches of trees and shrubs, and grass clippings) with a soil-incorporated cover crop as the control. As a subsequent vegetable crop, okra was grown after the cover crops, alone or together with the organic soil amendments, had been incorporated. All of the cover crops, except sorghum sudangrass in 2002-03, significantly improved okra fruit yields and the total biomass production. Both cover crops and soil amendments can substantially improve nutrient uptake and distribution. The results suggest that cover crops and appropriate amounts of soil amendments can be used to improve soil fertility and okra yield without adverse environmental effects or risk of contamination of the fruit. Further field studies will be required to confirm these findings.

  18. Improvement in the water retention characteristics of sandy loam soil using a newly synthesized poly(acrylamide-co-acrylic acid)/AlZnFe2O4 superabsorbent hydrogel nanocomposite material.

    Science.gov (United States)

    Shahid, Shaukat Ali; Qidwai, Ansar Ahmad; Anwar, Farooq; Ullah, Inam; Rashid, Umer

    2012-08-03

    The use of some novel and efficient crop nutrient-based superabsorbent hydrogel nanocomposites (SHNCs), is currently becoming increasingly important to improve the crop yield and productivity, due to their water retention properties. In the present study a poly(Acrylamide-co-acrylic acid)/AlZnFe2O4 superabsorbent hydrogel nanocomposite was synthesized and its physical properties characterized using Energy Dispersive X-ray (EDX), FE-SEM and FTIR spectroscopic techniques. The effects of different levels of SHNC were studied to evaluate the moisture retention properties of sandy loam soil (sand 59%, silt 21%, clay 19%, pH 7.4, EC 1.92 dS/m). The soil amendment with 0.1, 0.2, 0.3 and 0.4 w/w% of SHNC enhanced the moisture retention significantly at field capacity compared to the untreated soil. Besides, in a separate experiment, seed germination and seedling growth of wheat was found to be notably improved with the application of SHNC. A delay in wilting of seedlings by 5-8 days was observed for SHNC-amended soil, thereby improving wheat plant growth and establishment.

  19. Experimental studies on the physico-mechanical properties of jet-grout columns in sandy and silty soils

    Science.gov (United States)

    Akin, Muge K.

    2016-04-01

    The term of ground improvement states to the modification of the engineering properties of soils. Jet-grouting is one of the grouting methods among various ground improvement techniques. During jet-grouting, different textures of columns can be obtained depending on the characteristics of surrounding subsoil as well as the adopted jet-grouting system for each site is variable. In addition to textural properties, strength and index parameters of jet-grout columns are highly affected by the adjacent soil. In this study, the physical and mechanical properties of jet-grout columns constructed at two different sites in silty and sandy soil conditions were determined by laboratory tests. A number of statistical relationships between physical and mechanical properties of soilcrete were established in this study in order to investigate the dependency of numerous variables. The relationship between qu and γd is more reliable for sandy soilcrete than that of silty columns considering the determination coefficients. Positive linear relationships between Vp and γd with significantly high determination coefficients were obtained for the jet-grout columns in silt and sand. The regression analyses indicate that the P-wave velocity is a very dominant parameter for the estimation of physical and mechanical properties of jet-grout columns and should be involved during the quality control of soilcrete material despite the intensive use of uniaxial compressive strength test. Besides, it is concluded that the dry unit weight of jet-grout column is a good indicator of the efficiency of employed operational parameters during jet-grouting.

  20. Magnesium content in soil and roughages depending on soil type and forage crops

    Directory of Open Access Journals (Sweden)

    Jakšić Snežana P.

    2017-01-01

    Full Text Available The aim of this study is to examine the effects of soil type and forage crops on the content of magnesium in soil and roughages, as well as forage quality regarding Mg content for the prevention of animal disease ‘tetany’. The trial was carried out on chernozem and humogley under alfalfa and red clover. Samples for determination of Mg content in plant and total Mg content in soil were digested using the apparatus Milestone Ethos 1. The content of Mg was determined using the apparatus ICP-OES Vista Pro-Axial Varian. The average total Mg content in soil of the tested sites was 0.64%. Total Mg content in chernozem was higher than in humogley. A higher total Mg content was in the deeper horizon. A significant positive correlation was found between total Mg content in soil and soil pH as well as the content of CaCO3. The average Mg content in forage crops was 0.28%. A higher Mg content in the dry matter was observed in crops grown on humogley. Mg content was significantly higher in red clover. There was no risk for the occurrence of animal disease ‘tetany’ regarding Mg content in crops, because the ratio K/(Ca+Mg was below 2.2, and K and Mg content in the dry matter of crops was below the critical value. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR31072: Stanje, tendencije i mogućnosti povećanja plodnosti poljoprivrednog zemljišta u Vojvodini

  1. Crop rotations with annual and perennial forages under no-till soil management: soil attributes, soybean mineral nutrition, and yield

    Science.gov (United States)

    Extensive use of sustainable and intensive agricultural systems would result in profitable farms producing greater yields while maintaining or enhancing natural resources. Development of sustainable crop and soil management systems depends on understanding complex relationships between soil managem...

  2. The influence of clay-to-carbon ratio on soil physical properties in a humid sandy loam soil with contrasting tillage and residue management

    DEFF Research Database (Denmark)

    Getahun, Gizachew Tarekegn; Munkholm, Lars Juhl; Schjønning, Per

    2016-01-01

    was sampled at the 0–10, 10–20 and 25–30 cm depths of a sandy loam soil at Flakkebjerg, Denmark in 2013. We used the experimental plots of a long-term field experiment with mouldboard ploughing (MP) and direct drilling (DD) treatments. The residue management included straw removal (−S) and straw retention (+S...... decreased clay dispersibility (p = 0.09) and increased soil friability (p b 0.05) compared with the MP soil. Direct drilling with straw removal (DD − S) resulted in higher workability compared with mouldboard ploughing with straw removal (MP − S) (p b 0.05). We defined non-complexed clay as NCC = clay −10...

  3. ECOGEN - Soil ecological and economic evaluation of genetically modified crops

    DEFF Research Database (Denmark)

    Krogh, P. H

    2007-01-01

    ECOGEN is a project funded by the EU under the 6th Framework Programme. Based on results obtained from soil biodiversity studies and economic evaluations, ECOGEN assessed the impact on soil organisms of different agricultural management practices, including those involving genetically modified (GM...... Policy were then evaluated. These two major factors - ecological and economic - were then integrated into decision support models for predicting the overall consequences of introducing GM crops into an agricultural system. Bt-maize line MON 810, resistant to a widespread insect pest called the European...... indicate that the EU corn growing farmers would forego direct economic benefits in the area of 150 million Euro per year by postponing the full introduction of MON 810. The direct economic benefits are high enough to compensate for possible but highly unlikely irreversible costs of full introduction...

  4. Catch crops impact on soil water infiltration in vineyards

    Science.gov (United States)

    Cerdà, Artemi; Bagarello, Vincenzo; Iovino, Massimo; Ferro, Vito; Keesstra, Saskia; Rodrigo-Comino, Jesús; García Diaz, Andrés; di Prima, Simone

    2017-04-01

    Infiltration is the key component of the hydrological cycle (Cerdà, 1999; Bagarello et al.,, 2014; Zema et al., 2016). Infiltration determines the partitioning of rainfall into runoff and subsurface flow (Cerdà, 1996; Bagarello et al., 2006; Wang et al., 2016). In the Mediterranean, agriculture resulted in the degradation of the soil structure, reduction of the organic matter and increase in the soil losses (Cerdà et al., 2009; Laudicina et al., 2015; Iovino et al., 2016; Willaarts et al., 2016). There is an urgent need to restore the agriculture soils to avoid floods, reduce the carbon emissions and avoid reservoir siltation (Aksakal et al., 2016; Ben Slimane et al., 2016; Yagüe et al., 2016). Catch Crops are widespread used due to their impact on the soil fertility (Mwango et al., 2016; Nishigaki et al., 2016 ; Nawaz et al., 2016). Catch crops also increase the amount of organic matter but little is known about the effect on soil infiltration. Two paired plots were selected in Les Alcusses (Moixent municipality) in Eastern Iberian Peninsula to compare the infiltration rates between a 8-years catch crop (Vicia sp) with a control (plough) soil. The measurements were carried out by means of ring infiltrometer in August 2014 and December 2014 under dry and wet conditions (Cerdà, 2001; Di Prima et al., 2016). The results show that the steady-state infiltration rates were 1.8 higher during the summer period, and that the catch crops did not increase the infiltration rates. Acknowledgements The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n 603498 (RECARE project) and the CGL2013- 47862-C2-1-R and CGL2016-75178-C2-2-R national research projects. References Aksakal, E. L., Sari, S., & Angin, I. (2016). Effects of vermicompost application on soil aggregation and certain physical properties. Land Degradation and Development, 27(4), 983-995. doi:10.1002/ldr.2350

  5. Initial soil formation and humus accumulation on the spoil heaps of sandy quarry, Russian-North-West

    Science.gov (United States)

    Abakumov, E.

    2009-04-01

    The accumulation and transformation of organic matter were studied in chronoseries of different aged (3-, 10-, 20-, 30-, 43-, and 60-year-old) soils and a reference (mature) plot. The ecogenetic succession of plants on sand quarry dumps was started from grass plant community and finished on the Scotch Pine forest on the 60-years old plot. The pedogenesis rate was closely related to the rate of phytocenosis development, and the thicknesses of organic and mineral horizons increased synchronously. The profile distribution of organic matter in young soils was estimated as an ectomorphic distribution, and the humus stocks in the mineral horizons of the same soils were comparable with the reserves of organic matter in the litters. The illuvial (Bs) horizons of the soils under study played a significant role in the accumulation of organic carbon; the resistance of organic matter to mineralization increased with age. In the soil chronoseries, the caloricity of litter organic matter increased, as well as the content of energy accumulated in the litters. The composition of humus differed strongly between the eluvial and illuvial horizons; in the chronosequence, the relative content of humic acids increased in the E horizon, and that of fulvic acids increased in the B horizon. On the base of C-13 NMR study of humic substances the humic and fulvic acid are different in organic, eluvial and illuvial horizons in terms of different structural components content. The effect of the phytocenosis on the soil was increasingly mediated with time. The accumulation and transformation of organic matter were the leading pedogenic processes at all stages. The main conclusion of investigation is that the 60 years is enough for formation of embrio-profile of podzol soil on the dumps of quaternary sands of former sandy quarry in the south taiga, North-West of Russia.

  6. Soil Water Improvements with the Long Term Use of a Winter Rye Cover Crop

    Science.gov (United States)

    Basche, A.; Kaspar, T.; Archontoulis, S.; Jaynes, D. B.; Sauer, T. J.; Parkin, T.; Miguez, F.

    2015-12-01

    The Midwestern United States, a region that produces one-third of maize and one-quarter of soybeans globally, is projected to experience increasing rainfall variability with future climate change. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance soil water storage, reducing the risks of flooding and runoff as well as drought-induced crop water stress. While some research indicates that a winter cover crop in a maize-soybean rotation increases soil water, producers continue to be concerned that water use by cover crops will reduce water for a following cash crop. We analyzed continuous in-field soil moisture measurements over from 2008-2014 at a Central Iowa research site that has included a winter rye cover crop in a maize-soybean rotation for thirteen years. This period of study included years in the top third of wettest years on record (2008, 2010, 2014) as well as years in the bottom third of driest years (2012, 2013). We found the cover crop treatment to have significantly higher soil water storage from 2012-2014 when compared to the no cover crop treatment and in most years greater soil water content later in the growing season when a cover crop was present. We further found that the winter rye cover crop significantly increased the field capacity water content and plant available water compared to the no cover crop treatment. Finally, in 2012 and 2013, we measured maize and soybean biomass every 2-3 weeks and did not see treatment differences in crop growth, leaf area or nitrogen uptake. Final crop yields were not statistically different between the cover and no cover crop treatment in any of the years of this analysis. This research indicates that the long-term use of a winter rye cover crop can improve soil water dynamics without sacrificing cash crop growth.

  7. Effect of pineapple cropping on soil chemical and physical changes in Tha-yang soil series, Petchaburi province

    OpenAIRE

    Isuwan, A.

    2007-01-01

    The experiment was conducted to investigate the effect of pineapple cropping on chemical and physical property changes of Tha-yang soil series, located on Tumbon Nong-ya-plong, Amphor Nong-yaplong,Petchaburi province. The experimental treatments were the different pineapple cropping soil ages arranged in a completely randomized design, consisting of undisturbed soil (year 0) and pineapple croppingsoil ages of 1, 4 and 8 years with 4 replications each. Soil samples were separated according to ...

  8. Effects of Straw-Based Soil Conditioners on Available Phosphorus Contents in Sandy Yellow Soil%秸秆改良材料对冷沙黄泥中速效磷含量的影响

    Institute of Scientific and Technical Information of China (English)

    赵蕾; 杨巍; 王定勇

    2011-01-01

    Crop straws (rice straw, wheat straw, maize straw and rape straw) were mixed with bentonite and polyacrylamide (PAM) to make straw-based soil conditioners, which were used in a pot experiment tc investigate their effects on available phosphorus (P) content in a sandy yellow soil widely distributed in Chongqing. The results indicated that all the 4 materials significantly increased the content of available P in the soil, the order of increment being rape straw (39. 4%~55. 7%) > maize straw (38. 9%~54. 8 2%) > wheat straw (34. 5%~46. 1%) > rice straw (28. 1% ~42. 5%). With the same straw, Treatment 3 (straw : bentonite : PAM = 900 : 100 : 30) showed the greatest soil amelioration effect by increasing available phosphorus (P) in the sandy yellow soil.%以重庆分布面积较大的沙质土壤--冷沙黄泥为研究对象,将秸秆进行生物顸处理后与膨润土、聚丙烯酰胺(PAM)按比例配制成土壤改良材料,采用盆栽土培试验方法,研究了水稻、小麦、玉米和油菜4种秸秆改良材料对冷沙黄泥速效磷含量的影响.结果表明:(1)4种秸秆改良材料均能明显提高冷沙黄泥的速效磷含量,其顺序由高到低为油菜、玉米、水稻和小麦,它们施入土壤后速效磷的平均含量分别增长了约39.4%~55.7%,38.9%~54.8%,34.5%~46.1%和28.1%~42.5%.(2)相同秸秆条件下不同分处理对土壤速效磷的增磷效果有所差异,其中秸秆:膨润土:PAM=900:100:30的T3处理对提高土壤有效磷含量的效果最好.

  9. Bio-chemical properties of sandy calcareous soil treated with rice straw-based hydrogels

    Directory of Open Access Journals (Sweden)

    Houssni El-Saied

    2016-06-01

    The results obtained show that, application of the investigated hydrogels positively affects bio-chemical properties of the soil. These effects are assembled in the following: (a slightly decreasing soil pH, (b increasing cation exchange capacity (CEC of the soil indicating improvement in activating chemical reactions in the soil, (c increasing organic matter (OM, organic carbon, total nitrogen percent in the soil. Because the increase in organic nitrogen surpassed that in organic carbon, a narrower CN ratio of treated soils was obtained. This indicated the mineralization of nitrogen compounds and hence the possibility to save and provide available forms of N to growing plants, (d increasing available N, P and K in treated soil, and (e improving biological activity of the soil expressed as total count of bacteria and counts of Azotobacter sp., phosphate dissolving bacteria (PDB, fungi and actinomycetes/g soil as well as the activity of both dehydrogenase and phosphatase.

  10. Separating soil evaporation and crop transpiration to improve crop water use efficiency

    Science.gov (United States)

    Heng, Lee; Nguyen, Long; Gong, Daozhi; Mei, Xurong; Amenzou, Noureddine

    2014-05-01

    A network of a FAO/IAEA Coordinated Research Project (CRP) on "Managing Irrigation Water to Enhance Crop Productivity under Water-Limiting Conditions: A Role for Isotopic Techniques", involving seven countries was implemented from 2007 to 2012, to identify approaches to improve crop water productivity (production per unit of water input) under water-limiting conditions using isotopic and related techniques. This paper presents findings from the two of the studied sites, one in China and another in Morocco, in using both isotopic and conventional techniques to separate soil evaporation (E) and crop transpiration (T) from total water losses in evapotranspiration (ET) for winter wheat grown under different climatic conditions and methods of irrigation management practices. In the North China Plain (NCP), the estimated E/ET of winter wheat by the isotopic method (Keeling plot using delta oxygen-18 (δ18O)) was in agreement with that obtained by conventional methods (eddy covariance and micro-lysimeter). The high correlation between these methods (R2=0.85, n=27) showed that the E from wheat-growing field contributes an average of 30% of water losses for the whole growing season (Nov-June), with higher E percentage (68%) can be expected before elongation stage due to incomplete canopy cover. The results also showed that through deficit irrigation and improved irrigation scheduling, soil E losses could be reduced by 10-30% of the total water loss compared with full irrigation. In Morocco, field Keeling plot isotopic E and T separation study was carried out for two days in spring of 2012 at Sidi Rahal. The percentage contribution of T to total ET was approximately 73%. The experimental results obtained from both China and Moroccan sites were used to validate FAO's AquaCrop model for E and T, and for improving irrigation scheduling and agronomic practices. Good correlation (R2=0.83) was obtained between measured (isotopic) and AquaCrop simulated ET from NCP. The measured

  11. Winter pasture and cover crops and their effects on soil and summer grain crops

    Directory of Open Access Journals (Sweden)

    Alvadi Antonio Balbinot Junior

    2011-10-01

    Full Text Available The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N fertilization (intercropping cover; the same intercropping, with grazing and 100 kg ha-1 of N per year topdressing (pasture with N; the same intercropping, with grazing and without nitrogen fertilization (pasture without N; oilseed radish, without grazing and nitrogen fertilization (oilseed radish; and natural vegetation, without grazing and nitrogen fertilization (fallow. Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.

  12. Effect of pineapple cropping on soil chemical and physical changes in Tha-yang soil series, Petchaburi province

    Directory of Open Access Journals (Sweden)

    Isuwan, A.

    2007-03-01

    Full Text Available The experiment was conducted to investigate the effect of pineapple cropping on chemical and physical property changes of Tha-yang soil series, located on Tumbon Nong-ya-plong, Amphor Nong-yaplong,Petchaburi province. The experimental treatments were the different pineapple cropping soil ages arranged in a completely randomized design, consisting of undisturbed soil (year 0 and pineapple croppingsoil ages of 1, 4 and 8 years with 4 replications each. Soil samples were separated according to the soil level, namely Top-soil (0-15 cm. and Sub-soil (15-30 cm. for chemical and physical evaluation. The results showedthat soil chemical properties such as pH, OM, CEC, exchangeable Ca and Mg were decreased significantly (in both Top- and Sub-soil level, whereas available P and S were increased significantly in the 4-year soilsamples when compared with undisturbed soil. However, soil physical properties were not significantly different among cropping age treatments, except for clay particle in Top-soil which increased in the 4-year soil samples when compared with the 1-year soil samples and undisturbed soil. The results revealed thatpineapple cropping notably reduced soil fertility. As a result, soil resource management and plant nutrient management strategies must be carefully planned and implemented for sustainable pineapple production.

  13. Threshold Dynamics in Soil Carbon Storage for Bioenergy Crops

    Science.gov (United States)

    Woo, D.; Quijano, J.; Kumar, P.; Chaoka, S.; Bernacchi, C.

    2014-12-01

    Due to increasing demands for bioenergy, a considerable amount of land in the Midwestern United States could be devoted to the cultivation of second-generation bioenergy crops, such as switchgrass and miscanthus. In this study, we attempt to explore and analyze how different amounts of above-ground biomass returned to the soil at harvest affect the below-ground dynamics of carbon and nitrogen as a comparative study between miscanthus, swichgrass, and corn-corn-soybean rotation. The simulation results show that there is a threshold effect in the amount of above-ground litter input in the soil after harvest that will reach a critical organic matter C:N ratio in the soil, triggering a reduction of the soil microbial population, with significant consequences in other microbe-related processes such as decomposition and mineralization. These thresholds are approximately 25% and 15% of above-ground biomass for switchgrass and miscanthus, respectively. However, we do not observe such threshold effects for corn-corn-soybean rotation. These results suggest that values above these thresholds could result in a significant reduction of decomposition and mineralization, which in turn would enhance the sequestration of atmospheric carbon dioxide in the topsoil and reduce inorganic nitrogen losses when compared with a corn-corn-soybean rotation.

  14. The Amazonian Formative: Crop Domestication and Anthropogenic Soils

    Directory of Open Access Journals (Sweden)

    Manuel Arroyo-Kalin

    2010-03-01

    Full Text Available The emergence of sedentism and agriculture in Amazonia continues to sit uncomfortably within accounts of South American pre-Columbian history. This is partially because deep-seated models were formulated when only ceramic evidence was known, partly because newer data continue to defy simple explanations, and partially because many discussions continue to ignore evidence of pre-Columbian anthropogenic landscape transformations. This paper presents the results of recent geoarchaeological research on Amazonian anthropogenic soils. It advances the argument that properties of two different types of soils, terras pretas and terras mulatas, support their interpretation as correlates of, respectively, past settlement areas and fields where spatially-intensive, organic amendment-reliant cultivation took place. This assessment identifies anthropogenic soil formation as a hallmark of the Amazonian Formative and prompts questions about when similar forms of enrichment first appear in the Amazon basin. The paper reviews evidence for embryonic anthrosol formation to highlight its significance for understanding the domestication of a key Amazonian crop: manioc (Manihot esculenta ssp. esculenta. A model for manioc domestication that incorporates anthropogenic soils outlines some scenarios which link the distribution of its two broader varieties—sweet and bitter manioc—with the widespread appearance of Amazonian anthropogenic dark earths during the first millennium AD.

  15. Nonlinear Allometric Equation for Crop Response to Soil Salinity

    Directory of Open Access Journals (Sweden)

    E. Misle

    2015-06-01

    Full Text Available Crop response to soil salinity has been extensively studied, from empirical works to modelling approach, being described by different equations, first as a piecewise linear model. The equation employed can differ with actual response, causing miscalculation in practical situations, particularly at the higher extremes of the curve. The aim of this work is to propose a new equation, which allows determining the full response to salinity of plant species and to provide a verification using different experimental data sets. A new nonlinear equation is exposed supported by the allometric approach, in which the allometric exponent is salinity-dependent and decreases with the increase in relative salinity. A conversion procedure of parameters of the threshold-slope model is presented; also, a simple procedure for estimating the maximum salinity (zero-yield point when data sets are incomplete is exposed. The equation was tested in a wide range of experimental situations, using data sets from published works, as well as new measurements on seed germination. The statistical indicators of quality (R2, absolute sum of squares and standard deviation of residuals showed that the equation accurately fits the tested empirical results. The new equation for determining crop response to soil salinity is able to follow the response curve of any crop with remarkable accuracy and flexibility. Remarkable characteristics are: a maximum at minimum salinity, a maximum salinity point can be found (zero-yield depending on the data sets, and a meaningful inflection point, as well as the two points at which the slope of the curve equals unity, can be found.

  16. Impacts of grass removal on wetting and actual water repellency in a sandy soil

    National Research Council Canada - National Science Library

    Klaas Oostindie; Louis W. Dekker; Jan G. Wesseling; Violette Geissen; Coen J. Ritsema

    2017-01-01

    Soil water content and actual water repellency were assessed for soil profiles at two sites in a bare and grasscovered plot of a sand pasture, to investigate the impact of the grass removal on both properties...

  17. Effects of dune stabilization on vegetation characteristics and soil properties at multiple scales in Horqin Sandy Land, Northern China

    Institute of Scientific and Technical Information of China (English)

    XiaoAn Zuo; XueYong Zhao; ShaoKun Wang; Xin Zhou; Peng Lv; Jing Zhang

    2015-01-01

    Ecological patterns and processes in dune ecosystems have been a research focus in recent years, however information on how dune stabilization influences vegetation and soil at different spatial scales is still lacking. In this study, we measured vegetation characteristics and soil properties across three spatial scales (10, 100 and 1,000 m2) along gradient dune stabi-lization stages (mobile dune, semi-fixed dune and fixed dune) in Horqin Sandy Land, Northern China. Vegetation cover over all scales significantly increased with degree of dune stabilization, as well as species richness and C/N ratio at 10 m2 scale. Species richness significantly increased with the increase in measured scales at each stage of dune stabilization and was higher in fixed dune than that in mobile dune and semi-fixed dune at 100 and 1,000 m2 scales. Over all scales, aboveground biomass was lower in mobile dune than that in semi-fixed dune and fixed dune, and soil organic C, total N, EC, very fine sand and silt+clay contents were higher in fixed dune than those in mobile dune and semi-fixed dune. These results suggest that along the gradient dune stabilization, species richness has strong spatial scale-dependence, but vege-tation cover, aboveground biomass and soil properties is generally scale independent (i.e., the pattern of response is con-sistent across all scales). Effect of dune stabilization on vegetation and soil over all spatial scales results in the positive correlation among vegetation cover, species richness, biomass, soil organic C, total N, C/N, EC, very fine sand and silt+clay along the gradient dune stabilization. In addition, species richness at the smallest scale (10 m2) has more sensitive response to dune stabilization. Thus, the monitoring strategies at small scales are essential to detect changes of species diversity in semiarid dune ecosystems.

  18. Straw gasification biochar increases plant available water capacity and plant growth in coarse sandy soil

    DEFF Research Database (Denmark)

    Hansen, Veronika; Hauggaard-Nielsen, Henrik; Petersen, Carsten Tilbæk

    Gasification biochar (GB) contains recalcitrant carbon that can contribute to soil carbon sequestration and soil quality improvement. However, the impact of GB on plant available water capacity (AWC) and plant growth in diverse soil types needs further reserach. A pot experiment with spring barley...

  19. Chemical speciation of heavy metals in sandy soils in relation to availability and mobility

    NARCIS (Netherlands)

    Temminghoff, E.J.M.

    1998-01-01

    The environmental risk of heavy metals which are present in soil at a certain total content is highly dependent on soil properties. Chemical speciation is a comprehensive term for the distribution of heavy metals over all possible chemical forms (species) in soil solution and in the solid

  20. Chemical speciation of heavy metals in sandy soils in relation to availability and mobility.

    NARCIS (Netherlands)

    Temminghoff, E.J.M.

    1998-01-01

    The environmental risk of heavy metals which are present in soil at a certain total content is highly dependent on soil properties. Chemical speciation is a comprehensive term for the distribution of heavy metals over all possible chemical forms (species) in soil solution and in the solid phase. The

  1. A review of soils and crops in the Bukidnon Highlands of Northern Mindanao, the Philippines

    Directory of Open Access Journals (Sweden)

    Dejarme-Calalang, GM.

    2014-01-01

    Full Text Available Introduction. This article reviews soil and crop production information from Bukidnon, Northern Mindanao, the Philippines. It focuses on the parent materials involved in forming Bukidnon soils, clay forming minerals, soil classification, types and location distribution, physico-chemical characteristics, soil potentialities and constraints, and the yields of the major crops. Literature. The information discussed was gathered from on-line journals, a compilation of agricultural research reports published in Northern Mindanao, published theses, government data and reports, and books. Bukidnon has existing soil information that could be useful for assessing and monitoring soil fertility and in establishing a regional Land Information System (LandIS. Soils in the Province are classified according to Soil Order, Great Group and soil type under the USDA Soil Taxonomic Classification. Data on crop production yields are also available. Soil information is intended more for crop fertilization planning at the broader scale. Studies on geomorphopedology and the interactions of elements within the soil are scarce. The relationship between soil formation and its characteristics and plant responses is not discussed here. Conclusion. The recommendations arising from this study are: (1 to conduct in-depth geomorphopedological studies in marginal areas of undifferentiated soils, (2 to study the relationship between soil characteristics and crop responses including nutrient assimilation by plants, focusing on phosphorus (P, and (3 to develop a generic protocol and establish a LandIS for mountain areas that can be replicated in other areas in Mindanao, the Philippines.

  2. Soil hydrology of agroforestry systems: Competition for water or positive tree-crops interactions?

    Science.gov (United States)

    Gerjets, Rowena; Richter, Falk; Jansen, Martin; Carminati, Andrea

    2017-04-01

    In dry periods during the growing season crops may suffer from severe water stress. The question arises whether the alternation of crop and tree strips might enhance and sustain soil water resources available for crops during drought events. Trees reduce wind exposure, decreasing the potential evapotranspiration of crops and soils; additionally hydraulic lift from the deep roots of trees to the drier top soil might provide additional water for shallow-rooted crops. To understand the above and belowground water relations of agroforestry systems, we measured soil moisture and soil water potential in crop strips as a function of distance to the trees at varying depth as well as meteorological parameters. At the agroforestry site Reiffenhausen, Lower Saxony, Germany, two different tree species are planted, each in one separated tree strip: willow breed Tordis ((Salix viminalis x Salix Schwerinii) x Salix viminalis) and poplar clone Max 1 (Populus nigra x Populus maximowiczii). In between the tree strips a crop strip of 24 m width was established with annual crop rotation, managed the same way as the reference site. During a drought period in May 2016 with less than 2 mm rain in four weeks, an overall positive effect on hydrological conditions of the agroforestry system was observed. The results show that trees shaded the soil surface, lowering the air temperature and further increasing the soil moisture in the crop strips compared to the reference site, which was located far from the trees. At the reference site the crops took up water in the upper soil (crop strips of the agroforestry system, crops took up water in the upper soil. However, the lower soil layers remained wet for an extended period of time. The tree strips reduced the wind speed, hence lowering evapotranspiration in the crop strip. The plot was not aligned directly to North and we observed steeper soil water potential gradients in the part of the crop strip more exposed to sunlight. The two tree species

  3. Rice production in relation to soil quality under different rice-based cropping systems

    Science.gov (United States)

    Tran Ba, Linh; Sleutel, Steven; Nguyen Van, Qui; Thi, Guong Vo; Le Van, Khoa; Cornelis, Wim

    2016-04-01

    Soil quality of shallow paddy soils may be improved by introducing upland crops and thus a more diverse crop cultivation pattern. Yet, the causal relationship between crop performance and enhanced soil traits in rice-upland crop rotations remains elusive. The objectives of this study were to (i) find correlations among soil properties under different rice-upland crop systems and link selected soil properties to rice growth and yield, (ii) present appropriate values of soil parameters for sustainable rice productivity in heavy clay soil, (iii) evaluate the effect of rotating rice with upland crops on rice yield and economic benefit in a long-term experiment. A rice-upland crop rotational field experiment in the Vietnamese Mekong delta was conducted for 10 years using a randomized complete block design with four treatments and four replications. Treatments were: (i) rice-rice-rice (control - conventional system as farmers' practice), (ii) rice-maize-rice, (iii) rice-mung bean-rice, and (iv) rice-mung bean-maize. Soil and plant sampling were performed after harvest of the rice crop at the end of the final winter-spring cropping season (i.e. year 10). Results show differences in rice growth and yield, and economic benefit as an effect of the crop rotation system. These differences were linked with changes in bulk density, soil porosity, soil aggregate stability index, soil penetration resistance, soil macro-porosity, soil organic carbon, acid hydrolysable soil C and soil nutrient elements, especially at soil depth of 20-30 cm. This is evidenced by the strong correlation (P soil properties such as bulk density, porosity, penetration resistance, soil organic carbon and Chydrolysable. It turned out that good rice root growth and rice yield corresponded to bulk density values lower than 1.3 Mg m-3, soil porosity higher than 50%, penetration resistance below 1.0 MPa, and soil organic carbon above 25 g kg-1. The optimal soil depth without restriction for rice root elongation

  4. Fate of the insecticidal Cry1Ab protein of GM crops in two agricultural soils as revealed by ¹⁴C-tracer studies.

    Science.gov (United States)

    Valldor, Petra; Miethling-Graff, Rona; Martens, Rainer; Tebbe, Christoph C

    2015-09-01

    Insecticidal delta-endotoxins of Bacillus thuringiensis are among the most abundant recombinant proteins released by genetically modified (GM) crops into agricultural soils worldwide. However, there is still controversy about their degradation and accumulation in soils. In this study, (14)C-labelled Cry1Ab protein was applied to soil microcosms at two concentrations (14 and 50 μg g(-1) soil) to quantify the mineralization of Cry1Ab, its incorporation into the soil microbial biomass, and its persistence in two soils which strongly differed in their texture but not in silt or pH. Furthermore, ELISA was used to quantify Cry1Ab and its potential immunoreactive breakdown products in aqueous soil extracts. In both soils, (14)CO2-production was initially very high and then declined during a total monitoring period of up to 135 days. A total of 16 to 23 % of the (14)C activity was incorporated after 29 to 37 days into the soil microbial biomass, indicating that Cry1Ab protein was utilized by microorganisms as a growth substrate. Adsorption in the clay-rich soil was the most important factor limiting microbial degradation; as indicated by higher degradation rates in the more sandy soil, extremely low concentrations of immunoreactive Cry1Ab molecules in the soils' aqueous extracts and a higher amount of (14)C activity bound to the soil with more clay. Ecological risk assessments of Bt-crops should therefore consider that the very low concentrations of extractable Cry1Ab do not reflect the actual elimination of the protein from soils but that, on the other hand, desorbed proteins mineralize quickly due to efficient microbial degradation.

  5. Influence of Soil Tillage Systems on Soil Respiration and Production on Wheat, Maize and Soybean Crop

    Science.gov (United States)

    Moraru, P. I.; Rusu, T.

    2012-04-01

    Soil respiration leads to CO2 emissions from soil to the atmosphere, in significant amounts for the global carbon cycle. Soil capacity to produce CO2 varies depending on soil, season, intensity and quality of agrotechnical tillage, soil water, cultivated plant, fertilizer etc. The data presented in this paper were obtained on argic-stagnic Faeoziom (SRTS, 2003). These areas were was our research, presents a medium multiannual temperature of 8.20C, medium of multiannual rain drowns: 613 mm. The experimental variants chosen were: A. Conventional system (CS): V1-reversible plough (22-25 cm)+rotary grape (8-10 cm); B. Minimum tillage system (MT): V2 - paraplow (18-22 cm) + rotary grape (8-10 cm); V3 - chisel (18-22 cm) + rotary grape (8-10 cm);V4 - rotary grape (10-12 cm); C. No-Tillage systems (NT): V5 - direct sowing. The experimental design was a split-plot design with three replications. In one variant the area of a plot was 300 m2. The experimental variants were studied in the 3 years crop rotation: maize - soy-bean - autumn wheat. To soil respiration under different tillage practices, determinations were made for each crop in four vegetative stages (spring, 5-6 leaves, bean forming, harvest) using ACE Automated Soil CO2 Exchange System. Soil respiration varies throughout the year for all three crops of rotation, with a maximum in late spring (1383 to 2480 mmoli m-2s-1) and another in fall (2141 to 2350 mmoli m-2s-1). The determinations confirm the effect of soil tillage system on soil respiration, the daily average is lower at NT (315-1914 mmoli m-2s-1), followed by MT (318-2395 mmoli m-2s-1) and is higher in the CS (321-2480 mmol m-2s-1). Productions obtained at MT and NT don't have significant differences at wheat and are higher at soybean. The differences in crop yields are recorded at maize and can be a direct consequence of loosening, mineralization and intensive mobilization of soil fertility. Acknowledgments: This work was supported by CNCSIS

  6. Interaction between soil mineralogy and the application of crop residues on aggregate stability and hydraulic conductivity of the soil

    Science.gov (United States)

    Lado, M.; Kiptoon, R.; Bar-Tal, A.; Wakindiki, I. I. C.; Ben-Hur, M.

    2012-04-01

    One of the main goals of modern agriculture is to achieve sustainability by maintaining crop productivity while avoiding soil degradation. Intensive cultivation could lead to a reduction in soil organic matter that could affect the structure stability and hydraulic conductivity of the soil. Moreover, crops extract nutrients from the soil that are taken away from the field when harvested, and as a consequence, the addition of fertilizers to the soil is necessary to maintain crop productivity. One way to deal with these problems is to incorporate crop residues into the soil after harvest. Crop residues are a source of organic matter that could improve soil physical properties, such as aggregate stability and soil hydraulic conductivity. However, this effect could vary according to other soil properties, such as clay content, clay mineralogy, and the presence of other cementing materials in the soil (mainly carbonates and aluminum and iron oxides). In the present work, the interaction between the addition of chickpea crop residues to the soil and clay mineralogy on aggregate stability and saturated hydraulic conductivity were studied. Chickpea plant residues were added at a rate of 0.5% (w/w) to smectitic, kaolinitic, illitic and non-phyllosilicate soils from different regions. The soils without (control) and with chickpea residues were incubated for 0, 3, 7 and 30 days, and the saturated hydraulic conductivity of the soils was measured in columns after each incubation time. The response of hydraulic conductivity to the addition of residues and incubation time was different in the soils with various mineralogies, although in general, the addition of chickpea residues increased the saturated hydraulic conductivity as compared with the control soils. This positive effect of crop residues on hydraulic conductivity was mainly a result of improved aggregate stability and resistance to slaking during wetting.

  7. A review of soils and crops in the Bukidnon Highlands of Northern Mindanao, The Philippines

    OpenAIRE

    Dejarme-Calalang, GM.; Colinet, G.

    2014-01-01

    Introduction. This article reviews soil and crop production information from Bukidnon, Northern Mindanao, the Philippines. It focuses on the parent materials involved in forming Bukidnon soils, clay forming minerals, soil classification, types and location distribution, physico-chemical characteristics, soil potentialities and constraints, and the yields of the major crops. Literature. The information discussed was gathered from on-line journals, a compilation of agricultural research reports...

  8. Impacts of projected climate change on productivity and nitrogen leaching of crop rotations in arable and pig farming systems in Denmark

    DEFF Research Database (Denmark)

    Doltra, Jordi; Lægdsmand, Mette; Olesen, Jørgen E

    2014-01-01

    in Denmark, differing in soil and climate, and representative of the selected production systems. The CO2 effects were modelled using projected CO2 concentrations for the A1B emission scenario. Crop rotations were irrigated (sandy soil) and unirrigated (sandy loam soil), and all included systems...... rather than single crops for impact assessments. Potato and sugar beet in arable farming and grain maize in pig farming contributed most to the productivity increase in the future scenarios. The highest productivity was obtained in the arable system on the sandy loam soil, with an increase of 20...

  9. Changes in soil and vegetation on moving sand dunes after exclosure in Horqin Sandy Land, Northern China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In the semiarid Horqin Sandy Land of northern China, land desertification is the main causation in vegetation degradation and formation of moving dunes. A study was conducted from 1996 to 2005 to monitor the changes of vegetation characteristics and soil properties after moving dunes were fenced. The changes were compared between moving sand dunes with exclosure and without exclosure to evaluate the effectiveness of vegetation and soil restoration after exclosure establishment. The results show that exlosure establishment facilitated the colonization and development of plant species by ameliorating stressful environmental conditions. Species diversity, average coverage, and plant density significantly increased after exclosure of moving sand dunes along sequence compared with sand dunes without exclosure. Vegetation recovery on moving sand dunes accelerated by exclosure resulted in significant changes in soil properties including increased silt and clay contents, organic C and total N and decreased sand content, especially at the 0-5 cm depth. The results implied that moving sand dunes can be rapidly fixed by construction of exclosure.

  10. Extraction of bitumen, crude oil and its products from tar sand and contaminated sandy soil under effect of ultrasound.

    Science.gov (United States)

    Abramov, O V; Abramov, V O; Myasnikov, S K; Mullakaev, M S

    2009-03-01

    In the present paper, the kinetics of the water extraction of bitumen from tar sand and crude oil or residual fuel oil from model contaminated soils under the effect of ultrasound is studied. The influence of process temperature, ultrasound power, the nature, and properties of the components of heterogeneous mixtures being separated, and the concentration of added alkaline reagents on the rate and degree of oil recovery is investigated. A functional form of the dependencies of separation efficiency on the mean size of solid particles and the temperature of a working medium is found. Optimum concentrations of reagents in the process solution are determined. It is shown that the spent solution of sodium silicate can be multiply used for separation, its reuse even speeding up the yield of oil in the initial period. Taking into account obtained results, a multipurpose pilot plant with a flow-type reactor for ultrasonic extraction of petroleum and its products from contaminated soils was manufactured and tested. During tests, the purification of sandy soil contaminated with residual fuel oil was carried out which verified the results of laboratory studies.

  11. Effect of crop rotation on soil nutrient balance and weediness in soddy podzolic organic farming fields

    Science.gov (United States)

    Zarina, Livija; Zarina, Liga

    2017-04-01

    The nutrient balance in different crop rotations under organic cropping system has been investigated in Latvia at the Institute of Agricultural Resources and Economics since 2006. Latvia is located in a humid and moderate climatic region where the rainfall exceeds evaporation (soil moisture coefficient > 1) and the soil moisture regime is characteristic with percolation. The average annual precipitation is 670-850 mm. The average temperature varies from -6.7° C in January to 16.5 °C in July. The growing season is 175 - 185 days. The most widespread are podzolic soils and mainly they are present in agricultural fields in all regions of Latvia. In a wider sense the goal of the soil management in organic farming is a creation of the biologically active flora and fauna in the soil by maintaining a high level of soil organic matter which is good for crops nutrient balance. Crop rotation is a central component of organic farming systems and has many benefits, including growth of soil microbial activity, which may increase nutrient availability. The aim of the present study was to calculate nutrient balance for each crop in the rotations and average in each rotation. Taking into account that crop rotations can limit build-up of weeds, additionally within the ERA-net CORE Organic Plus transnational programs supported project PRODIVA the information required for a better utilization of crop diversification for weed management in North European organic arable cropping systems was summarized. It was found that the nutrient balance was influenced by nutrients uptake by biomass of growing crops in crop rotation. The number of weeds in the organic farming fields with crop rotation is dependent on the cultivated crops and the succession of crops in the crop rotation.

  12. Impacts of grass removal on wetting and actual water repellency in a sandy soil

    Directory of Open Access Journals (Sweden)

    Oostindie Klaas

    2017-03-01

    Full Text Available Soil water content and actual water repellency were assessed for soil profiles at two sites in a bare and grasscovered plot of a sand pasture, to investigate the impact of the grass removal on both properties. The soil of the plots was sampled six times in vertical transects to a depth of 33 cm between 23 May and 7 October 2002. On each sampling date the soil water contents were measured and the persistence of actual water repellency was determined of field-moist samples. Considerably higher soil water contents were found in the bare versus the grass-covered plots. These alterations are caused by differences between evaporation and transpiration rates across the plots. Noteworthy are the often excessive differences in soil water content at depths of 10 to 30 cm between the bare and grass-covered plots. These differences are a consequence of water uptake by the roots in the grass-covered plots. The water storage in the upper 19 cm of the bare soil was at least two times greater than in the grass-covered soil during dry periods. A major part of the soil profile in the grass-covered plots exhibited extreme water repellency to a depth of 19 cm on all sampling dates, while the soil profile of the bare plots was completely wettable on eight of the twelve sampling dates. Significant differences in persistence of actual water repellency were found between the grass-covered and bare plots.

  13. Seed Burial Depth and Soil Water Content Affect Seedling Emergence and Growth of Ulmus pumila var. sabulosa in the Horqin Sandy Land

    Directory of Open Access Journals (Sweden)

    Jiao Tang

    2016-01-01

    Full Text Available We investigated the effects of seed burial depth and soil water content on seedling emergence and growth of Ulmus pumila var. sabulosa (sandy elm, an important native tree species distributed over the European-Asian steppe. Experimental sand burial depths in the soil were 0.5, 1.0, 1.5, 2.0 and 2.5 cm, and soil water contents were 4%, 8%, 12% and 16% of field capacity. All two-way ANOVA (five sand burial depths and four soil water contents results showed that seed burial depths, soil water content and their interactions significantly affected all the studied plant variables. Most of the times, seedling emergence conditions were greater at the lower sand burial depths (less than 1.0 cm than at the higher (more than 1.0 cm seed burial depths, and at the lower water content (less than 12% than at the higher soil water content. However, high seed burial depths (more than 1.5 cm or low soil water content (less than 12% reduced seedling growth or change in the root/shoot biomass ratios. In conclusion, the most suitable range of sand burial was from 0.5 to 1.0 cm soil depth and soil water content was about 12%, respectively, for the processes of seedling emergence and growth. These findings indicate that seeds of the sandy elm should be kept at rather shallow soil depths, and water should be added up to 12% of soil capacity when conducting elm planting and management. Our findings could help to create a more appropriate sandy elm cultivation and understand sparse elm woodland recruitment failures in arid and semi-arid regions.

  14. Metagenome-wide association study and machine learning prediction of bulk soil microbiome and crop productivity

    Science.gov (United States)

    Areas within an agricultural field in the same season often differ in crop productivity despite having the same cropping history, crop genotype, and management practices. One hypothesis is that abiotic or biotic factors in the soils differ between areas resulting in these productivity differences. I...

  15. Cover crops for enriching soil carbon and nitrogen under bioenergy sorghum

    Science.gov (United States)

    Soil carbon (C) and nitrogen (N) can be enriched with cover crops under agronomic crops, but little is known about their enrichment under bioenergy crops. Legume (hairy vetch [Vicia villosa Roth]), nonlegume (rye [Secaele cereale L.]), a mixture of legume and nonlegume (hairy vetch and rye) and a co...

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

    DEFF Research Database (Denmark)

    Chirinda, N.; Carter, Mette Sustmann; Albert, Kristian Rost

    2010-01-01

    . 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...

  17. Restoring Eroded Lands in Southern Iceland: Efficacy of Domestic, Organic Fertilizers in Sandy Gravel Soils

    OpenAIRE

    Brenner, Julia Miriam, 1989-

    2016-01-01

    Since settlement Iceland has faced severe soil degradation due to a combination of natural stressors – glacial flooding, volcanic eruption, and heavy wind – and anthropogenic stressors – grazing livestock, wood harvesting, and land use change. Declining soil stability under these conditions resulted in extensive soil erosion: 40% of Iceland now has considerable, severe, or extremely severe erosion. Fertilizers have been utilized for land reclamation in Iceland for many years, but they have mo...

  18. Soil quality parameters for row-crop and grazed pasture systems with agroforestry buffers

    Science.gov (United States)

    Incorporation of trees and establishment of buffers are practices that can improve soil quality. Soil enzyme activities and water stable aggregates are sensitive indices for assessing soil quality by detecting early changes in soil management. However, studies comparing grazed pasture and row crop...

  19. Ruminant Grazing of Cover Crops: Effects on Soil Properties and Agricultural Production

    Science.gov (United States)

    Poffenbarger, Hanna

    2010-01-01

    Integrating livestock into a cropping system by allowing ruminant animals to graze cover crops may yield economic and environmental benefits. The effects of grazing on soil physical properties, soil organic matter, nitrogen cycling and agricultural production are presented in this literature review. The review found that grazing cover crops…

  20. Effect of mixed and single crops on disease suppressiveness of soils

    NARCIS (Netherlands)

    Hiddink, G.A.; Termorshuizen, A.J.; Raaijmakers, J.M.; Bruggen, van A.H.C.

    2005-01-01

    The effect of mixed cropping on disease suppressiveness of soils was tested for two cropping systems, Brussels sprouts¿barley and triticale¿white clover. Disease suppressiveness of field soils was evaluated in bioassays for the soilborne pathogens Rhizoctonia solani, Fusarium oxysporum f. sp. lini,

  1. Soil pH and exchangeable cation responses to tillage and fertilizer in dryland cropping systems

    Science.gov (United States)

    Long-term use of nitrogen (N) fertilizers can lead to soil acidification and other chemical changes that can lower fertility. Here, we present near-surface (0-7.6 cm) soil chemistry data from 16 years of two different crop rotations in the US northern Great Plains: (1) continuous crop (CC; spring w...

  2. Impacts of organic conservation tillage systems on crops, weeds, and soil quality

    Science.gov (United States)

    Organic farming has been identified as promoting soil quality even though tillage is used for weed suppression. Adopting conservation tillage practices can enhance soil quality in cropping systems where synthetic agrichemicals are used for crop nutrition and weed control. Attempts have been made t...

  3. Chemistry and microbial functional diversity differences in biofuel crop and grassland soils in multiple geographies

    Science.gov (United States)

    As crop and non-crop lands are increasingly becoming converted to biofuel feedstock production, it is of interest to identify potential impacts of annual and perennial feedstocks on soil ecosystem services. Soil samples obtained from 6 regional sets of switchgrass (Panicum virgatum L.) and 3 regiona...

  4. Crop rotations with annual and perennial forages under no-till soil management

    Science.gov (United States)

    Development of crop rotations that support sustainable agriculture depends on understanding complex relationships between soils, crops, and yield. Objectives were to measure how soil chemical and physical attributes as well as maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] stover dry weig...

  5. Developing a Foundation for Constructing New Curricula in Soil, Crop, and Turfgrass Sciences

    Science.gov (United States)

    Jarvis, Holly D.; Collett, Ryan; Wingenbach, Gary; Heilman, James L.; Fowler, Debra

    2012-01-01

    Some soil and crop science university programs undergo curricula revision to maintain relevancy with their profession and/or to attract the best students to such programs. The Department of Soil and Crop Sciences at Texas A&M University completed a thorough data gathering process as part of its revision of the undergraduate curriculum and…

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

    Science.gov (United States)

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

  7. Effects of Grazing Sorghum Stubble on Soil Physical Properties and Subsequent Crop Performance

    Directory of Open Access Journals (Sweden)

    B. J. Radford

    2008-01-01

    Full Text Available Two grazing trials were conducted on a Vertosol in central Queensland to assess the effects of stubble grazing by cattle on soil properties and subsequent crop performance. Two adjacent contour bays were selected for two treatments (grazed and ungrazed in each trial. Both trials were conducted following a grain sorghum crop. In trial 1 (during 1996 the surface soil was dry throughout grazing. In trial 2 (during 1998 the surface soil became saturated during grazing after 125 mm of rain. Soil physical properties including bulk density, shear strength, cone index and hydraulic conductivity were measured pre-and post-grazing in both trials and the response of wheat crops sown after grazing was assessed. The area was then double-cropped to sorghum to measure any further residual impacts. After grazing on dry soil, hoof marks were barely evident and no significant change was found in any soil physical property or the establishment or yield of a subsequent wheat crop. After grazing on saturated soil, there were visible hoof marks 49 mm deep and increases in soil shear strength, cone index and drawbar power requirement. The following wheat crop had reduced dry matter at 32 days and reduced grain yield. There was no immediate change in ground cover and no effect on wheat establishment following direct-drilling 37 days after the cattle were removed. In a sorghum crop following the wheat crop, there were no carryover effects on any soil physical property or on crop yield. We conclude that under a similar regime to that of trial 1 (dry soil and no rainfall during grazing, adverse effects of stubble grazing are unlikely. It follows that if grazing can be restricted to times when the surface soil is dry enough to minimise compaction by animals, there is little risk of adverse effects on subsequent crop performance.

  8. The evolution of sandy soils under the influence of vegetation succession and anthropogenic activities - case study from Błędów Desert

    Science.gov (United States)

    Gus, Magdalena; Drewnik, Marek

    2016-04-01

    Sandy areas are an important source of research about early stages of the soils formation process and their further development. The rate of succession is reflecting the influence of vegetation on chemical and physical properties of soils which as the time goes undergo the evolution process caused by other environmental factors. The Błędów Desert (Poland, Central Europe) is an example of this kind of area, where sandy soils evolved into Podzols, but as a result of human activities conducted since Middle Ages soil cover has been destroyed to bedrock. Currently progressing vegetation succession occurred in two ways: primary, which took place in areas covered by loose sand and secondary, in the areas with fossil soils. Presently the Błędów Desert is a suitable example to study soil changes in both cases mentioned above. The main aim of the study was to present diversity and characteristics of soils in The Błędów Desert in relation to their development stages and vegetation succession. During field studies soil profiles were described and selected for the detailed studies and soils samples were taken for laboratory analysis, including a determination of basic physical and chemical analysis as well as for micromorphological analysis (selected profiles). Podzols located near the boundary of the study area was selected as a reference soils. The results proved the complexity of the soil process formation, which strongly depends on the vegetation succession and human activities including human-induced aeolian processes. Results confirmed the presence of buried soils, which together with the contemporary soils formed a soil sequence. Moreover, research shows that the dominant soil-forming processes at the Błędów Desert are humus accumulation and podzolization. To summarize, The Błędów Desert is a dynamic environment undergoing rapid changes of soil cover under the influence of the interaction of vegetation, anthropopression and aeolian processes.

  9. The Effect of Crop Rotation on Soil Nematode Community Composition in a Greenhouse

    Institute of Scientific and Technical Information of China (English)

    Jingwen LU; Wei SHENG; Qian YU; Zijing CHEN; Qiang XU; Qian WANG; Linlin DONG

    2015-01-01

    Objective] The aim was to identify changes in a nematode community in response to crop rotation and to determine the appropriate catch crop for a green-house. [Method] The experiment was carried out in a typical 6-year-old greenhouse, in which cucumber crops were cultivated twice each year (in spring and autumn), and catch crops were planted in summer. The total number of nematodes was counted and nematode community indices were calculated after col ecting soil sam-ples in different stages. [Result] Total nematode abundance was decreased in the soils of catch crop in contrast with former crops (cucumber crops). The abundance of the nematode community was reduced in the treatment of crop rotation compared to the soils of catch crop. ln addition, the number of nematode taxa was significant-ly reduced by the treatment of crown daisy compared to the treatments of fol owing crops. Crop rotation regulated the functional composition of the nematode community by increasing the omnivores-predators functional group and decreasing the relative abundance of root herbivores. [Conclusion] These results indicate that crop rotation affects the nematode community in abundance, diversity and functional composition of the nematode community and crown daisy can be served as the most appropri-ate catch crop in the greenhouse.

  10. An integrated soil-crop system model for water and nitrogen management in North China

    Science.gov (United States)

    Liang, Hao; Hu, Kelin; Batchelor, William D.; Qi, Zhiming; Li, Baoguo

    2016-05-01

    An integrated model WHCNS (soil Water Heat Carbon Nitrogen Simulator) was developed to assess water and nitrogen (N) management in North China. It included five main modules: soil water, soil temperature, soil carbon (C), soil N, and crop growth. The model integrated some features of several widely used crop and soil models, and some modifications were made in order to apply the WHCNS model under the complex conditions of intensive cropping systems in North China. The WHCNS model was evaluated using an open access dataset from the European International Conference on Modeling Soil Water and N Dynamics. WHCNS gave better estimations of soil water and N dynamics, dry matter accumulation and N uptake than 14 other models. The model was tested against data from four experimental sites in North China under various soil, crop, climate, and management practices. Simulated soil water content, soil nitrate concentrations, crop dry matter, leaf area index and grain yields all agreed well with measured values. This study indicates that the WHCNS model can be used to analyze and evaluate the effects of various field management practices on crop yield, fate of N, and water and N use efficiencies in North China.

  11. [Advances in effects of insecticidal crystal proteins released from transgenic Bt crops on soil ecology].

    Science.gov (United States)

    Zhou, Xue-Yong; Liu, Ning; Zhao, Man; Li, He; Zhou, Lang; Tang, Zong-Wen; Cao, Fei; Li, Wei

    2011-05-01

    With the large scale cultivation of transgenic crops expressing Bacillus thuringiensis (Bt) insecticidal crystal proteins in the world, the problem of environmental safety caused by these Bt crops has received extensive attention. These insecticidal crystal proteins can be released into the soil continuously in the growing period of Bt plants. If their accumulation of the insecticidal crystal proteins exceeds consumption by insect larvae and degradation by the environmental factors, these insecticidal crystal proteins could constitute a hazard to non-target insects and soil microbiota. There are three main ways to release insecticidal crystal proteins into soil for Bt plants: root exudates, pollen falling, and crop reside returning. The Bt insecticidal crystal proteins released into soil can be adsorbed rapidly by active soil particles and the absorption equilibrium attained within 1-3 h. The adsorption protects Bt insecticidal crystal proteins against soil microbial degradation or enzyme degradation, which leads to remarkable prolong of the persistence of insecticidal activity. The change of soil microorganism species is an important index for evaluating the effect of Bt plants on soil ecology. The research showed that these insecticidal crystal proteins released by the Bt plant root exudates or Bt organism had no toxicity to the soil earthworms, nematodes, protozoa, bacteria and fungi; however, it could reduce the mycelium length of the arbuscular mycorrhizal fungi (AMF) and restrain AMF to form invasion unit. The influencing degree of Bt protein on soil enzyme activity varied with the releasing modes or growth period of Bt crops. Bt Cry1Ab protein can be taken up from soil by parts of following crops; however, different results were obtained with different commercial kits. To better understand the soil ecological evaluation about the insecticidal crystal proteins released from transgenic Bt crops, this review provides a comprehensive overview about the release

  12. Assessing soil water repellency of a sandy field with visible near infrared spectroscopy

    DEFF Research Database (Denmark)

    Knadel, Maria; Masis Melendez, Federico; de Jonge, Lis Wollesen

    2016-01-01

    Soil water repellency (WR) is a widespread phenomenon caused by aggregated organic matter (OM) and layers of hydrophobic organic substances coating the surface of soil particles. These substances have a very low surface free energy, reducing a soil’s water attraction. There is focus on WR due...

  13. Phytoremediation of soil polluted by nickel using agricultural crops.

    Science.gov (United States)

    Giordani, Cesare; Cecchi, Stefano; Zanchi, Camillo

    2005-11-01

    Soil pollution due to heavy metals is widespread; on the world scale, it involves about 235 million hectares. The objectives of this research were to establish the uptake efficiency of nickel by some agricultural crops. In addition, we wanted to establish also in which part of plants the metal is stored for an eventual use of biomass or for recycling the metal. The experiments included seven herbaceous crops such as: barley (Hordeum vulgaris), cabbage (Brassica juncea), spinach (Spinacea oleracea), sorghum (Sorgum vulgare), bean (Phaseolus vulgaris), tomato (Solanum lycopersicum), and ricinus (Ricinus communis). We used three levels of treatment (150, 300, and 600 ppm) and one control. At the end of the biological cycle of the crops, the different parts of plants, i.e., roots, stems, leaves, fruits, or seeds, were separately collected, oven dried, weighed, milled, and separately analysed. The leaves and stems of spinach showed a very good nickel storage capacity. The ricinus too proved to be a very good nickel storer. The ability of spinach and ricinus to store nickel was observed also in the leaves of cabbage, even if with a lower storage capacity. The bean, barley, and tomato, in decreasing order of uptake and storage capacity, showed a high concentration of nickel in leaves and stems, whereas the sorghum evidenced a lesser capacity to uptake and store nickel in leaves and stems. The bean was the most efficient in storing nickel in fruits or grains. Tomato, sorghum, and barley have shown a storage capacity notably less than bean. The bean appeared to be the most efficient in accumulating nickel in the roots, followed in decreasing order by sorghum, ricinus, and tomato. With regard to the removal of nickel, spinach was the most efficient as it contains the highest level of this metal per gram of dry matter. The ricinus, cabbage, bean, sorghum, barley, and tomato evidenced a progressively decreasing efficiency in the removal of nickel.

  14. Vertical distribution of phosphorus in a sandy soil fertilized with recovered manure phosphates

    Science.gov (United States)

    Purpose: To evaluate the environmental fate of recovered manure phosphates to provide application recommendations for their use as crop fertilizers. Materials and methods: A greenhouse study was conducted to evaluate the leaching potential and vertical distribution of total and plant available phos...

  15. Does agricultural crop diversity enhance soil microbial biomass and organic matter dynamics? A meta-analysis.

    Science.gov (United States)

    McDaniel, M D; Tiemann, L K; Grandy, A S

    2014-04-01

    Our increasing dependence on a small number of agricultural crops, such as corn, is leading to reductions in agricultural biodiversity. Reductions in the number of crops in rotation or the replacement of rotations by monocultures are responsible for this loss of biodiversity. The belowground implications of simplifying agricultural plant communities remain unresolved; however, agroecosystem sustainability will be severely compromised if reductions in biodiversity reduce soil C and N concentrations, alter microbial communities, and degrade soil ecosystem functions as reported in natural communities. We conducted a meta-analysis of 122 studies to examine crop rotation effects on total soil C and N concentrations, and the faster cycling microbial biomass C and N pools that play key roles in soil nutrient cycling and physical processes such as aggregate formation. We specifically examined how rotation crop type and management practices influence C and N dynamics in different climates and soil types. We found that adding one or more crops in rotation to a monoculture increased total soil C by 3.6% and total N by 5.3%, but when rotations included a cover crop (i.e., crops that are not harvested but produced to enrich the soil and capture inorganic N), total C increased by 8.5% and total N 12.8%. Rotations substantially increased the soil microbial biomass C (20.7%) and N (26.1%) pools, and these overwhelming effects on microbial biomass were not moderated by crop type or management practices. Crop rotations, especially those that include cover crops, sustain soil quality and productivity by enhancing soil C, N, and microbial biomass, making them a cornerstone for sustainable agroecosystems.

  16. Root growth of Lotus corniculatus interacts with P distribution in young sandy soil

    Directory of Open Access Journals (Sweden)

    R. Schulin

    2012-07-01

    Full Text Available Large areas of land are restored with un-weathered soil substrates following mining activities in eastern Germany and elsewhere. In the initial stages of colonization of such land by vegetation, plant roots may become key agents in generating soil formation patterns by introducing gradients in chemical and physical soil properties. On the other hand, such patterns may be influenced by root growth responses to pre-existing substrate heterogeneities. In particular, the roots of many plants were found to preferentially proliferate into nutrient-rich patches. Phosphorus (P is of primary interest in this respect because its availability is often low in unweathered soils, limiting especially the growth of leguminous plants. However, leguminous plants occur frequently among the pioneer plant species on such soils as they only depend on atmospheric nitrogen (N fixation as N source. In this study we investigated the relationship between root growth allocation of the legume Lotus corniculatus and soil P distribution on recently restored land. As test sites the experimental Chicken Creek Catchment (CCC in eastern Germany and a nearby experimental site (ES with the same soil substrate were used. We established two experiments with constructed heterogeneity, one in the field on the experimental site and the other in a climate chamber. In addition we conducted high-density samplings on undisturbed soil plots colonized by L. corniculatus on the ES and on the CCC. In the field experiment, we installed cylindrical ingrowth soil cores (4.5×10 cm with and without P fertilization around single two-month-old L. corniculatus plants. Roots showed preferential growth into the P-fertilized ingrowth-cores. Preferential root allocation was also found in the climate chamber experiment, where single L. corniculatus plants were grown in containers filled with ES soil and where a lateral portion of the containers was additionally supplied with a range of different P

  17. Root growth of Lotus corniculatus interacts with P distribution in young sandy soil

    Directory of Open Access Journals (Sweden)

    B. Felderer

    2013-03-01

    Full Text Available Large areas of land are restored with unweathered soil substrates following mining activities in eastern Germany and elsewhere. In the initial stages of colonization of such land by vegetation, plant roots may become key agents in generating soil formation patterns by introducing gradients in chemical and physical soil properties. On the other hand, such patterns may be influenced by root growth responses to pre-existing substrate heterogeneities. In particular, the roots of many plants were found to preferentially proliferate into nutrient-rich patches. Phosphorus (P is of primary interest in this respect because its availability is often low in unweathered soils, limiting especially the growth of leguminous plants. However, leguminous plants occur frequently among the pioneer plant species on such soils, as they only depend on atmospheric nitrogen (N fixation as N source. In this study we investigated the relationship between root growth allocation of the legume Lotus corniculatus and soil P distribution on recently restored land. As test sites, the experimental Chicken Creek Catchment (CCC in eastern Germany and a nearby experimental site (ES with the same soil substrate were used. We established two experiments with constructed heterogeneity, one in the field on the experimental site and the other in a climate chamber. In addition, we conducted high-density samplings on undisturbed soil plots colonized by L. corniculatus on the ES and on the CCC. In the field experiment, we installed cylindrical ingrowth soil cores (4.5 × 10 cm with and without P fertilization around single two-month-old L. corniculatus plants. Roots showed preferential growth into the P-fertilized ingrowth-cores. Preferential root allocation was also found in the climate chamber experiment, where single L. corniculatus plants were grown in containers filled with ES soil and where a lateral portion of the containers was additionally supplied with a range of different P

  18. Root growth of Lotus corniculatus interacts with P distribution in young sandy soil

    Science.gov (United States)

    Felderer, B.; Boldt-Burisch, K. M.; Schneider, B. U.; Hüttl, R. F. J.; Schulin, R.

    2013-03-01

    Large areas of land are restored with unweathered soil substrates following mining activities in eastern Germany and elsewhere. In the initial stages of colonization of such land by vegetation, plant roots may become key agents in generating soil formation patterns by introducing gradients in chemical and physical soil properties. On the other hand, such patterns may be influenced by root growth responses to pre-existing substrate heterogeneities. In particular, the roots of many plants were found to preferentially proliferate into nutrient-rich patches. Phosphorus (P) is of primary interest in this respect because its availability is often low in unweathered soils, limiting especially the growth of leguminous plants. However, leguminous plants occur frequently among the pioneer plant species on such soils, as they only depend on atmospheric nitrogen (N) fixation as N source. In this study we investigated the relationship between root growth allocation of the legume Lotus corniculatus and soil P distribution on recently restored land. As test sites, the experimental Chicken Creek Catchment (CCC) in eastern Germany and a nearby experimental site (ES) with the same soil substrate were used. We established two experiments with constructed heterogeneity, one in the field on the experimental site and the other in a climate chamber. In addition, we conducted high-density samplings on undisturbed soil plots colonized by L. corniculatus on the ES and on the CCC. In the field experiment, we installed cylindrical ingrowth soil cores (4.5 × 10 cm) with and without P fertilization around single two-month-old L. corniculatus plants. Roots showed preferential growth into the P-fertilized ingrowth-cores. Preferential root allocation was also found in the climate chamber experiment, where single L. corniculatus plants were grown in containers filled with ES soil and where a lateral portion of the containers was additionally supplied with a range of different P concentrations. In

  19. Mobility of Arsenic and Heavy Metals in a Sandy-Loam Textured and Carbonated Soil

    Institute of Scientific and Technical Information of China (English)

    GARCIA; M.DIEZ; F.MARTIN; M.SIMóN; C.DORRONSORO

    2009-01-01

    The continued effect of the pyrite-tailing oxidation on the mobility of arsenic,lead,zinc,cadmium,and copper was studied in a carbonated soil under natural conditions,with the experimcntal plot preserved with a layer of tailing covering the soil during three years.The experimental area is located in Southern Spain and was affected by a pyrite-mine spill.The climate in the area is typically Mediterranean,which determines the rate of soil alteration and element mobility.The intense alteration processes that occurred in the soil during three years caused important changes in its morphology and a strong degradation of the main soil properties.In this period,lead concentrated in the first 5 mm of the soil,with concentrations higher than 1500 mg kg-1,mainly associated to the neoformation of plumbojarosite.Arsenic was partially leached from the first 5 mm and mainly concentrated between 5-10 mm in the soil,with maximum values of 1 239 mg kg-1;the retention of arsenates was related to the neoformation of iron hydroxysulfates (jarosite,schwertmannite) and oxyhydroxides (goethite,ferrihydrite),both with a variable degree of crystallinity.The mobility of Zn,Cd,and Cu was highly affected by pH,producing a stronger leaching in depth;their retention was related to the forms of precipitated aluminium and,in the case of Cu,also to the neoformation of hydroxysulfate.

  20. Phosphate reactivity in long-term poultry litter-amended southern Delaware sandy soils

    Science.gov (United States)

    Arai, Y.; Livi, K.J.T.; Sparks, D.L.

    2005-01-01

    Eutrophication caused by dissolved P from poultry litter (PL)-amended agricultural soils has been a serious environmental concern in the Delaware-Maryland-Virginia Peninsula (Delmarva), USA. To evaluate state and federal nutrient management strategies for reducing the environmental impact of soluble P from long-term PL-amended Delaware (DE) soils, we investigated (i) inorganic P speciation; (ii) P adsorption capacity; and (iii) the extent of P desorption. Although the electron microprobe (EMP) analyses showed a strong correlation between P and Al/Fe, crystalline Al/Fe-P precipitates were not detected by x-ray diffraction (XRD). Instead, the inorganic P fractionation analyses showed high levels of oxalate extractable P, Al, and Fe fractions (615-858, 1215-1478, and 337-752 mg kg-1, respectively), which were susceptible to slow release during the long-term (30-d) P desorption experiments at a moderately acidic soil pHwater. The labile P in the short-term (24-h) desorption studies was significantly associated with oxalate and F extractable Fe and Al, respectively. This was evident in an 80% reduction maximum in total desorbable P from NH4 oxalate/F pretreated soils. In the adsorption experiments, P was strongly retained in soils at near targeted pH of lime (???6.0), but P adsorption gradually decreased with decreasing pH near the soil pHwater (???5.0). The overall findings suggest that P losses from the can be suppressed by an increase in the P retention capacity of soils via (i) an increase in the number of lime applications to maintain soil pHwater at near targeted pH values, and/or (ii) alum/iron sulfate amendments to provide additional Al- and Fe-based adsorbents. ?? Soil Science Society of America.

  1. Grain legume-cereal intercropping: The practical application of diversity, competition and facilitation in arable and organic cropping systems

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Jørnsgaard, B.; Kinane, J.

    2008-01-01

    Intercropping is the simultaneous cultivation of more than one crop species on the same piece of land and is regarded as the practical application of basic ecological principles such as diversity, competition and facilitation. Field experiments were carried out on a sandy loam soil and a sandy so...

  2. Agronomic performance and chemical response of sunflower ( Helianthus annuus L.) to some organic nitrogen sources and conventional nitrogen fertilizers under sandy soil conditions

    Energy Technology Data Exchange (ETDEWEB)

    Helmy, A. M.; Fawzy Ramadan, M. F.

    2009-07-01

    Sunflower ( Helianthus annuus L.) is an option for oilseed production, particularly in dry land areas due to good root system development. In this study, two field experiments were performed in the El-Khattara region (Sharkia Governorate, Egypt) during the 2005 season. The objective of this research was to determine the effect of organic nitrogen (ON) sources and their combinations as well as to compare the effect of ON and ammonium sulfate (AS) as a conventional fertilizer added individually or in combination on growth, yield components, oil percentage and the uptake of some macro nutrients by sunflowers grown on sandy soil.The treatments of chicken manure (CM) and a mixture of farmyard manure (FYM) with CM were superior to the other treatments and gave the highest yield, dry matter yield, NPK uptake by plants at all growth stages along with seed yield at the mature stage. The effect of the different ON on crop yield and its components may follow the order; CM> palma residues (PR)> FYM. This was more emphasized when the materials were mixed with AS at a ratio of 3:1 and 1:1. The uptake of nitrogen (N), phosphorus (P) and potassium (K) by plants was affected by the addition of different N sources and treatments. The highest nutrient content and uptake by straw were obtained when treated with CM followed by PR at all growth stages, while it was PR followed by CM for seeds. Oil recovery was shown to respond to the N supply and the changes in individual fatty acids were not statistically different. However, it seems that the application of organic fertilizers resulted in an increase in total unsaturated fatty acids compared to the control. (Author) 58 refs.

  3. The effect of straw or straw-derived gasification biochar on soil quality and crop production

    DEFF Research Database (Denmark)

    Hansen, Veronika; Müller-Stöver, Dorette Sophie; Imparato, Valentina;

    2016-01-01

    Thermal gasification of straw is a highly efficient technology that produces bioenergy and gasification biochar that can be used as a soil amendment, thereby returning non-renewable nutrients and stable carbon, and securing soil quality and crop productivity. A Danish on-farm field study investig......Thermal gasification of straw is a highly efficient technology that produces bioenergy and gasification biochar that can be used as a soil amendment, thereby returning non-renewable nutrients and stable carbon, and securing soil quality and crop productivity. A Danish on-farm field study...... with winter wheat (Triticum aestivum L.), winter oilseed rape (Brassica napus L.) and winter wheat, respectively, to assess the potential effects on the soil carbon pool, soil microorganisms, earthworms, soil chemical properties and crop yields. The application of GB did not increase the soil organic carbon...

  4. Developing High-resolution Soil Database for Regional Crop Modeling in East Africa

    Science.gov (United States)

    Han, E.; Ines, A. V. M.

    2014-12-01

    The most readily available soil data for regional crop modeling in Africa is the World Inventory of Soil Emission potentials (WISE) dataset, which has 1125 soil profiles for the world, but does not extensively cover countries Ethiopia, Kenya, Uganda and Tanzania in East Africa. Another dataset available is the HC27 (Harvest Choice by IFPRI) in a gridded format (10km) but composed of generic soil profiles based on only three criteria (texture, rooting depth, and organic carbon content). In this paper, we present a development and application of a high-resolution (1km), gridded soil database for regional crop modeling in East Africa. Basic soil information is extracted from Africa Soil Information Service (AfSIS), which provides essential soil properties (bulk density, soil organic carbon, soil PH and percentages of sand, silt and clay) for 6 different standardized soil layers (5, 15, 30, 60, 100 and 200 cm) in 1km resolution. Soil hydraulic properties (e.g., field capacity and wilting point) are derived from the AfSIS soil dataset using well-proven pedo-transfer functions and are customized for DSSAT-CSM soil data requirements. The crop model is used to evaluate crop yield forecasts using the new high resolution soil database and compared with WISE and HC27. In this paper we will present also the results of DSSAT loosely coupled with a hydrologic model (VIC) to assimilate root-zone soil moisture. Creating a grid-based soil database, which provides a consistent soil input for two different models (DSSAT and VIC) is a critical part of this work. The created soil database is expected to contribute to future applications of DSSAT crop simulation in East Africa where food security is highly vulnerable.

  5. Soil Organic Carbon Response to Cover Crop and Nitrogen Fertilization under Bioenergy Sorghum

    Science.gov (United States)

    Sainju, U. M.; Singh, H. P.; Singh, B. P.

    2015-12-01

    Removal of aboveground biomass for bioenergy/feedstock in bioenergy cropping systems may reduce soil C storage. Cover crop and N fertilization may provide additional crop residue C and sustain soil C storage compared with no cover crop and N fertilization. We evaluated the effect of four winter cover crops (control or no cover crop, cereal rye, hairy vetch, and hairy vetch/cereal rye mixture) and two N fertilization rates (0 and 90 kg N ha-1) on soil organic C (SOC) at 0-5, 5-15, and 15-30 cm depths under forage and sweet sorghums from 2010 to 2013 in Fort Valley, GA. Cover crop biomass yield and C content were greater with vetch/rye mixture than vetch or rye alone and the control, regardless of sorghum species. Soil organic C was greater with vetch/rye than rye at 0-5 and 15-30 cm in 2011 and 2013 and greater with vetch than rye at 5-15 cm in 2011 under forage sorghum. Under sweet sorghum, SOC was greater with cover crops than the control at 0-5 cm, but greater with vetch and the control than vetch/rye at 15-30 cm. The SOC increased at the rates of 0.30 Mg C ha-1 yr-1 at 0-5 cm for rye and the control to 1.44 Mg C ha-1 yr-1 at 15-30 cm for vetch/rye and the control from 2010 to 2013 under forage sorghum. Under sweet sorghum, SOC also increased linearly at all depths from 2010 to 2013, regardless of cover crops. Nitrogen fertilization had little effect on SOC. Cover crops increased soil C storage compared with no cover crop due to greater crop residue C returned to the soil under forage and sweet sorghum and hairy vetch/cereal rye mixture had greater C storage than other cover crops under forage sorghum.

  6. Soil Salinity: Effect on Vegetable Crop Growth. Management Practices to Prevent and Mitigate Soil Salinization

    Directory of Open Access Journals (Sweden)

    Rui Manuel Almeida Machado

    2017-05-01

    Full Text Available Salinity is a major problem affecting crop production all over the world: 20% of cultivated land in the world, and 33% of irrigated land, are salt-affected and degraded. This process can be accentuated by climate change, excessive use of groundwater (mainly if close to the sea, increasing use of low-quality water in irrigation, and massive introduction of irrigation associated with intensive farming. Excessive soil salinity reduces the productivity of many agricultural crops, including most vegetables, which are particularly sensitive throughout the ontogeny of the plant. The salinity threshold (ECt of the majority of vegetable crops is low (ranging from 1 to 2.5 dS m−1 in saturated soil extracts and vegetable salt tolerance decreases when saline water is used for irrigation. The objective of this review is to discuss the effects of salinity on vegetable growth and how management practices (irrigation, drainage, and fertilization can prevent soil and water salinization and mitigate the adverse effects of salinity.

  7. Soil quality index as affected by different cropping systems in northwestern Himalayas.

    Science.gov (United States)

    Sofi, J A; Bhat, A G; Kirmai, N A; Wani, J A; Lone, Aabid H; Ganie, Mumtaz A; Dar, G I H

    2016-03-01

    Soil quality assessment provides a tool for evaluating the sustainability of soils under different crop cafeterias. Our objective was to develop the soil quality index for evaluating the soil quality indicators under different cropping systems in northwest Himalaya-India. Composite soil samples were taken from the study area from different cropping systems which include T1 (forest soil control), T2 (rice-oilseed, lower belts), T3 (rice-oilseed, higher belts), T4 (rice-oats), T5 (rice-fallow), T6 (maize-oats), T7 (maize-peas), T8 (apple), T9 (apple-beans), and T10 (apple-maize). Physical, chemical, and biological soil indicators were determined, and it was found that soil enzyme activities involved in nutrient cycling were significantly higher in forest soils, which were reflected in higher levels of available pool of nutrients. Carbon stocks were found significantly higher in forest soil which was translated in improved soil physical condition. Principal component analysis (PCA) was performed to reduce multidimensionality of data followed by scoring by homothetic transformation of the selected indicators. Pearson's interclass correlation was performed to avoid redundancy, and highly correlated variables were not retained. Inclusion of legumes in the apple orchard floor recorded highest soil quality rating across the treatments. Cereal-based cropping systems were found in lower soil quality rating; however, the incorporation of peas in the system improved soil health.

  8. Cations extraction of sandy-clay soils from cavado valley, portugal, using sodium salts solutions

    OpenAIRE

    Silva João Eudes da; Castro Fernando

    2002-01-01

    Cases of contamination by metals in the water wells of the Cavado Valley in north-west Portugal can be attributed to the heavy leaching of clay soils due to an excess of nitrogen resulting from the intensive use of fertilisers in agricultural areas. This work focuses on the natural weathering characteristics of soils, particularly the clay material, through the study of samples collected near the River Cavado. Samples taken from various sites, after physico-chemical characterisation, were sub...

  9. Soil Seed Bank and Plant Community Development in Passive Restoration of Degraded Sandy Grasslands

    Directory of Open Access Journals (Sweden)

    Renhui Miao

    2016-06-01

    Full Text Available To evaluate the efficacy of passive restoration on soil seed bank and vegetation recovery, we measured the species composition and density of the soil seed bank, as well as the species composition, density, coverage, and height of the extant vegetation in sites passively restored for 0, 4, 7, and 12 years (S0, S4, S7, and S12 in a degraded grassland in desert land. Compared with S0, three more species in the soil seed bank at depths of 0–30 cm and one more plant species in the community was detected in S12. Seed density within the topsoil (0–5 cm was five times higher in S12 than that in S0. Plant densities in S7 and S12 were triple and quadruple than that in S0. Plant coverage was increased by 1.5 times (S4, double (S7, and triple (S12 compared with S0. Sørensen’s index of similarity in species composition between the soil seed bank and the plant community were high (0.43–0.63, but it was lower in short-term restoration sites (S4 and S7 than that in no and long-term restoration sites (S0 and S12. The soil seed bank recovered more slowly than the plant community under passive restoration. Passive restoration is a useful method to recover the soil seed bank and vegetation in degraded grasslands.

  10. Effects of charcoal-enriched goat manure on soil fertility parameters and growth of pearl millet (Pennisetum glaucum L. in a sandy soil from northern Oman

    Directory of Open Access Journals (Sweden)

    Melanie Willich

    2016-12-01

    Full Text Available The effect of charcoal feeding on manure quality and its subsequent application to enhance soil productivity has received little attention. The objectives of the present study therefore were to investigate the effects of (i charcoal feeding on manure composition, and (ii charcoal-enriched manure application on soil fertility parameters and growth of millet (Pennisetum glaucum L.. To this end, two experiments were conducted: First, a goat feeding trial where goats were fed increasing levels of activated charcoal (AC; 0, 3, 5, 7, and 9% of total ration; second, a greenhouse pot experiment using the manure from the feeding trial as an amendment for a sandy soil from northern Oman. We measured manure C, N, P, and K concentrations, soil fertility parameters and microbial biomass indices, as well as plant yield and nutrient concentrations. Manure C concentration increased significantly (P<0.001 from 45.2% (0% AC to 60.2% (9% AC with increasing dietary AC, whereas manure N, P, and K concentrations decreased (P<0.001 from 0% AC (N: 2.5%, P: 1.5%, K: 0.8% to 9% AC (N: 1.7%, P: 0.8%, K: 0.4%. Soil organic carbon, pH, and microbial biomass N showed a response to AC-enriched manure. Yield of millet decreased slightly with AC enrichment, whereas K uptake was improved with increasing AC. We conclude that AC effects on manure quality and soil productivity depend on dosage of manure and AC, properties of AC, trial duration, and soil type.

  11. Understanding cropping systems in the semi-arid environments of Zimbabwe: options for soil fertility management

    OpenAIRE

    Ncube, B.

    2007-01-01

    African smallholder farmers face perennial food shortages due to low crop yields. The major cause of poor crop yields is soil fertility decline. The diversity of sites and soils between African farming systems isgreat,therefore strategies to solve soil fertility problems should suit the opportunities and problems encountered in the different climatic regions. This thesis characterizes the semi-arid regions of south-western Zimbabwe and explores some of the strategies that can be used to provi...

  12. Effects of Cropping System Change for Paddy Field with Double Harvest Rice on the Crops Growth and Soil Nutrient

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of the cropping system change for paddy field with double harvest rice on crops growth and soil nutrient in red soil were studied. The results indicated that the economic benefit and the ratio of the output to input were all increased in terms of the market price for the crops under various treatments. The greatest economic benefit was obtained in the treatment of paddy-upland rotation, and the corresponding economic benefit was increased by 34.7, 21.4, and 2.2% in comparison with that of control (rice-rice-astragali), pasture, and upland cropping treatments. The economic benefits in pasture and upland cultivation treatments were increased by 11.0 and 31.8%, respectively, when compared with that of the control treatment (CK). The ratio of output to input in pasture, paddy-upland rotation, and upland cropping treatments was enhanced by 0.9, 0.6, and 0.3, respectively, in comparison with that of control. To grow pasture is beneficial for improving soil fertility since the contents of soil organic matter, total nitrogen, total phosphorus, and available phosphorus are all enhanced significantly. However, the concentrations of the soil available nitrogen, the total potassium, the available potassium were somewhat reduced in all the treatments, suggesting that increasing the input of nitrogen,particularly potassium, was necessary under the present fertilization level. Based on the conditions of fertility, climate,cultivation, and management of paddy field with double harvest rice in red soil regions, it is feasible to alter the cultivation system of paddy field with bad irrigation condition. In particular, cultivation systems such as pasture and paddy-upland rotation can be selected to extend because better economic benefit and improvement of soil fertility in the purpose region were obtained.

  13. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    Science.gov (United States)

    Hai-Ming, Tang; Xiao-Ping, Xiao; Wen-Guang, Tang; Ye-Chun, Lin; Ke, Wang; Guang-Li, Yang

    2014-01-01

    Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L.) system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice-rice-ryegrass (Lolium multiflorum L.) (R-R-Ry), rice-rice-Chinese milk vetch (Astragalus sinicus L.) (R-R-Mv), rice-rice-rape (Brassica napus L.) (R-R-Ra) and rice-rice with winter fallow (R-R-Fa). The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (Pwinter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality.

  14. Drainage and leaching dynamics in a cropped hummocky soil landscape with erosion-affected pedogenesis

    Science.gov (United States)

    Gerke, Horst H.; Rieckh, Helene; Sommer, Michael

    2016-04-01

    Hummocky soil landscapes are characterized by 3D spatial patterns of soil types that result from erosion-affected pedogenesis. Due to tillage and water erosion, truncated profiles have been formed at steep and mid slopes and colluvial soils at hollows. Pedogenetic variations in soil horizons at the different hillslope positions suggested feedback effects between erosion affected soil properties, the water balances, and the crop growth and leaching rates. Water balance simulations compared uniform with hillslope position-specific crop and root growths for soils at plateau, flat mid slope, steep slope, and hollow using the Hydrus-1D program. The boundary condition data were monitored at the CarboZALF-D experimental field site, which was cropped with perennial lucerne (Medicago sativa L.) in 2013 and 2014. Crop and root growth was assumed proportional to observed leaf area index (LAI). Fluxes of dissolved organic and inorganic carbon (DOC, DIC) were obtained from simulated water fluxes and measured DOC and DIC concentrations. For the colluvic soil, the predominately upward flow led to a net input in DIC and DOC. For the truncated soils at steep slopes, a reduced crop growth caused an relative increase in drainage, suggesting an accelerated leaching, which in the long term could accelerate the soil development and more soil variations along eroding hillslopes in arable soil landscapes.

  15. Soil carbon fractions in response to long-term crop rotations in the Loess Plateau of China

    Science.gov (United States)

    Diversified crop rotations may enhance C fractions and soil quality by affecting the quality and quantity of crop residue returned to the soil compared with monocropping and fallow. We evaluated the effect of 30-yr-old diversified crop rotations on soil C fractions at 0- to 15- and 15- to 30-cm dept...

  16. Influence of crop rotation and tillage intensity on soil physical properties and functions

    Science.gov (United States)

    Krümmelbein, Julia

    2013-04-01

    Soil tillage intensity can vary concerning tillage depth, frequency, power input into the soil and degree of soil turn-over. Conventional tillage systems where a plough is regularly used to turn over the soil can be differentiated from reduced tillage systems without ploughing but with loosening the upper soil and no tillage systems. Between conventional tillage and no tillage is a wide range of more or less reduced tillage systems. In our case the different tillage intensities are not induced by different agricultural machinery or techniques, but result from varying crop rotations with more or less perennial crops and therefore lower or higher tillage frequency. Our experimental area constitutes of quite unstructured substrates, partly heavily compacted. The development of a functioning soil structure and accumulation of nutrients and organic matter are of high importance. Three different crop rotations induce varying tillage intensities and frequencies. The first crop rotation (Alfalfa monoculture) has only experienced seed bed preparation once and subsequently is wheeled once a year to cut and chaff the biomass. The second crop rotation contains perennial and annual crops and has therefore been tilled more often, while the third crop rotation consists only of annual crops with annual seedbed preparation. Our results show that reduced tillage intensity/frequency combined with the intense root growth of Alfalfa creates the most favourable soil physical state of the substrate compared to increased tillage and lower root growth intensity of the other crop rotations. Soil tillage disturbs soil structure development, especially when the substrate is mechanically unstable as in our case. For such problematic locations it is recommendable to reduce tillage intensity and/or frequency to allow the development of soil structure enhanced by root growth and thereby the accumulation of organic matter and nutrients within the rooting zone.

  17. Soil microbial biomass and function are altered by 12 years of crop rotation

    Science.gov (United States)

    McDaniel, Marshall D.; Grandy, A. Stuart

    2016-11-01

    Declines in plant diversity will likely reduce soil microbial biomass, alter microbial functions, and threaten the provisioning of soil ecosystem services. We examined whether increasing temporal plant biodiversity in agroecosystems (by rotating crops) can partially reverse these trends and enhance soil microbial biomass and function. We quantified seasonal patterns in soil microbial biomass, respiration rates, extracellular enzyme activity, and catabolic potential three times over one growing season in a 12-year crop rotation study at the W. K. Kellogg Biological Station LTER. Rotation treatments varied from one to five crops in a 3-year rotation cycle, but all soils were sampled under a corn year. We hypothesized that crop diversity would increase microbial biomass, activity, and catabolic evenness (a measure of functional diversity). Inorganic N, the stoichiometry of microbial biomass and dissolved organic C and N varied seasonally, likely reflecting fluctuations in soil resources during the growing season. Soils from biodiverse cropping systems increased microbial biomass C by 28-112 % and N by 18-58 % compared to low-diversity systems. Rotations increased potential C mineralization by as much as 53 %, and potential N mineralization by 72 %, and both were related to substantially higher hydrolase and lower oxidase enzyme activities. The catabolic potential of the soil microbial community showed no, or slightly lower, catabolic evenness in more diverse rotations. However, the catabolic potential indicated that soil microbial communities were functionally distinct, and microbes from monoculture corn preferentially used simple substrates like carboxylic acids, relative to more diverse cropping systems. By isolating plant biodiversity from differences in fertilization and tillage, our study illustrates that crop biodiversity has overarching effects on soil microbial biomass and function that last throughout the growing season. In simplified agricultural systems

  18. Soil respiration in cucumber field under crop rotation in solar greenhouse

    Directory of Open Access Journals (Sweden)

    Yinli Liang

    2014-08-01

    Full Text Available Crop residues are the primary source of carbon input in the soil carbon pool. Crop rotation can impact the plant biomass returned to the soil, and influence soil respiration. To study the effect of previous crops on soil respiration in cucumber (Cucumis statirus L. fields in solar greenhouses, soil respiration, plant height, leaf area and yield were measured during the growing season (from the end of Sept to the beginning of Jun the following year from 2007 to 2010. The cucumber was grown following fallow (CK, kidney bean (KB, cowpea (CP, maize for green manure (MGM, black bean for green manure (BGM, tomato (TM, bok choy (BC. As compared with CK, KB, CP, MGM and BGM may increase soil respiration, while TM and BC may decrease soil respiration at full fruit stage in cucumber fields. Thus attention to the previous crop arrangement is a possible way of mitigating soil respiration in vegetable fields. Plant height, leaf area and yield had similar variation trends under seven previous crop treatments. The ratio of yield to soil respiration revealed that MGM is the crop of choice previous to cucumber when compared with CK, KB, CP, BGM, TM and BC.

  19. Agronomic assessment of pyrolysed food waste digestate for sandy soil management.

    Science.gov (United States)

    Opatokun, Suraj Adebayo; Yousef, Lina F; Strezov, Vladimir

    2017-02-01

    The digestate (DFW) of an industrial food waste treatment plant was pyrolysed for production of biochar for its direct application as bio-fertilizer or soil enhancer. Nutrient dynamics and agronomic viability of the pyrolysed food waste digestate (PyD) produced at different temperatures were evaluated using germination index (GI), water retention/availability and mineral sorption as indicators when applied on arid soil. The pyrolysis was found to enrich P, K and other micronutrients in the biochar at an average enrichment factor of 0.87. All PyD produced at different temperatures indicated significantly low phytotoxicity with GI range of 106-168% and an average water retention capacity of 40.2%. Differential thermogravimetric (DTG) thermographs delineated the stability of the food waste digestate pyrolysed at 500 °C (PyD500) against the degradation of the digestate food waste despite the latter poor nutrient sorption potential. Plant available water in soil is 40% when treated with 100 g of digestate per kg soil, whereas PyD500 treated soil indicated minimal effect on plant available water, even with high application rates. However, the positive effects of PyD on GI and the observed enrichment in plant macro and micronutrients suggest potential agronomic benefits for PyD use, in addition to the benefits from energy production from DFW during the pyrolysis process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Soil testing for P and K has value in nutrient management for annual crops

    Directory of Open Access Journals (Sweden)

    Daniel Geisseler

    2016-08-01

    Full Text Available Adequate nutrients in forms available to plant roots are essential for sustainable crop production. Soil testing for phosphorus and potassium availability allows growers and crop advisers to determine whether a soil is likely to respond to fertilization. As yields have risen with improved management and production systems, crop nutrient demand and the removal of nutrients with harvested crops have increased. An in-depth discussion of soil tests for phosphorus and potassium and their use in California cropping systems is clearly needed. We review how these nutrients become available to plant roots, how samples are taken and test results interpreted, complementary ways to assess the adequacy of supplies and what research is needed to improve soil testing for phosphorus and potassium.

  1. Spatial pattern of soil and soybean crop: an assessment using digital mapping techniques

    Science.gov (United States)

    Castro Franco, Mauricio; Cordoba, Mariano; Costa, Jose Luis; Aparicio, Virginia; Domenech, Marisa

    2017-04-01

    The aim of this study was to analyze the relationships among spatial patterns of soil properties and soybean crop. The study was carried out in three provinces of Argentina: (i) Buenos Aires (BA), (ii) Entre Rios (ER) and (iii) Cordoba (COR). In each province, 2 agricultural fields were selected. Ancillary information related to soil forming factors in each field was gathered, for example apparent electrical conductivity (ECa), NDVI and yield maps. We used principal component spatial analysis (MULTISPATI-PCA) to delimit zones for soil type by field. To zonal validation, 4 sampling sites were located in which we collected soil samples, grain yield and soybean crop quality. Random Forest (RF) was used to determine the importance of soil properties over soybean crop properties. For comparing soil properties in each zone between fields, a mix lineal model and ANOVA were adjusted. Our results suggest that MULTISPATI-PCA was efficient to delimit zones for soil type. Relationships between soil properties and crop yield were examined and understood. However, it did not occur with crop quality patterns. Topography did not prove to be an accurate indicator of spatial pattern relations of soil properties and crop, whereas ECa, yield maps and NDVI proved to be effective indicators. Grains m-2 and NDVI were affected homogeneously and were showed spatial correspondence according to soil limitations. Percentage of protein did not show spatial correspondence with delimitated zones in saline soils, particularly in ER. In such fields, Om and pH were important for percentage of protein. It was evidenced that a direct relation exists between complex relationship of soil and crop properties and soil degradation.

  2. Testing the validity of a Cd soil quality standard in representative Mediterranean agricultural soils under an accumulator crop

    Energy Technology Data Exchange (ETDEWEB)

    Recatala, L., E-mail: luis.recatala@uv.es [Departamento de Planificacion Territorial, Centro de Investigaciones sobre Desertificacion-CIDE (CSIC-Universitat de Valencia-Generalitat Valenciana), Cami de la Marjal S/N, 46470 Albal (Valencia) (Spain); Sanchez, J. [Departamento de Planificacion Territorial, Centro de Investigaciones sobre Desertificacion-CIDE (CSIC-Universitat de Valencia-Generalitat Valenciana), Cami de la Marjal S/N, 46470 Albal (Valencia) (Spain); Arbelo, C. [Departamento de Edafologia y Geologia, Facultad de Biologia, Universidad de La Laguna, 38206 La Laguna (Tenerife), Islas Canarias (Spain); Sacristan, D. [Departamento de Planificacion Territorial, Centro de Investigaciones sobre Desertificacion-CIDE (CSIC-Universitat de Valencia-Generalitat Valenciana), Cami de la Marjal S/N, 46470 Albal (Valencia) (Spain)

    2010-12-01

    The validity of a quality standard for cadmium (Cd) in representative agricultural Mediterranean soils under an accumulator crop (Lactuca sativa L.) is evaluated in this work considering both its effect on the crop growth (biomass production) and the metal accumulation in the edible part of the plant. Four soils with different properties relevant to regulate the behaviour of heavy metals were selected from the Valencian Region, a representative area of the European Mediterranean Region. For all soils, the effective concentration of added Cd causing 50% inhibition (EC{sub 50}) on the biomass production was much higher than the minimum legal concentration used to declare soils as contaminated by cadmium, i.e. 100 times the baseline value for Cd, in Spain (Spanish Royal Decree 9/2005). As expected, Cd toxicity in the crop was higher in the soils having less carbonate content. On the other hand, for all soils, from the second dose on, which represents 10-times the baseline value for Cd, the metal content in crops exceeded the maximum level established for leaf crops by the European legislation (Regulation EC no. 466/2001). Soil salinity and coarse textures make the accumulation of Cd in the edible part of the plant easier. Therefore, the legal baseline soil cadmium content established by the Spanish legislation seems not valid neither from the point of view of the effect on the crop growth nor from the point of view of the metal accumulation in the edible part of the plant. In order to realistically declare contaminated soils by heavy metals, soil quality standards should be proposed taking into account the soil properties. Further research in other agricultural areas of the region would improve the basis for proposing adequate soil quality standards for heavy metals as highlighted by the European Thematic Strategy for Soil Protection.

  3. [Effects of crop rotation and bio-organic manure on soil microbial characteristics of Chrysanthemum cropping system].

    Science.gov (United States)

    Xiao, Xin; Zhu, Wei; Du, Chao; Shi, Ya-dong; Wang, Jian-fei

    2015-06-01

    We conducted a field experiment to evaluate the effects of rotation system and bio-organic manure on soil microbial characteristics of Chrysanthemum cropping system. Taking Chrysanthemum morifolium Ramat and wheat as experimental plants, treatments under Chrysanthemum continuous cropping system (M1), conventional Chrysanthemum-wheat rotation system (M2), and Chrysanthemum-wheat rotation system receiving bio-organic manure application of 200 kg · 667 m(-2) (M3) were designed. Soil chemical properties, soil microbial biomass carbon (MBC) and nitrogen (MBN), and the amounts of different types of soil microorganisms were determined. Results showed that compared with M1, treatments of M2 and M3 significantly increased soil pH, organic matter, available N, P, and K, MBC, MBN, and the amounts of bacteria, fungi and actinomycetes, but decreased the ratio of MBC/MBN, and the relative percentage of fungi in the total amount of microorganisms. Treatment of M3 had the highest contents of soil organic matter, available N, available P, available K, MBC, MBN, and the amounts of bacteria, fungi and actinomycetes, with the values being 15.62 g · kg(-1), 64.75 mg · kg(-1), 83.26 mg · kg(-1), 96.72 mg · kg(-1), 217.40 mg · kg(-1), 38.41 mg · kg(-1), 22.31 x 10(6) cfu · g(-1), 56.36 x 10(3) cfu · g(-1), 15.90 x 10(5) cfu · g(-1), respectively. We concluded that rational crop rotation and bio-organic manure application could weaken soil acidification, improve soil fertility and microbial community structure, increase the efficiency of nutrition supply, and have a positive effect on reducing the obstacles of continuous cropping.

  4. SOIL CHEMICAL ATTRIBUTES AND LEAF NUTRIENTS OF ‘PACOVAN’ BANANA UNDER TWO COVER CROPS

    Directory of Open Access Journals (Sweden)

    JOSÉ EGÍDIO FLORI

    2016-01-01

    Full Text Available Banana is one of the most consumed fruits in the world, which is grown in most tropical countries. The objective of this work was to evaluate the main attributes of soil fertility in a banana crop under two cover crops and two root development locations. The work was conducted in Curaçá, BA, Brazil, between October 2011 and May 2013, using a randomized block design in split plot with five repetitions. Two cover crops were assessed in the plots, the cover 1 consisting of Pueraria phaseoloides, and the cover 2 consisting of a crop mix with Sorghum bicolor, Ricinus communis L., Canavalia ensiformis, Mucuna aterrima and Zea mays, and two soil sampling locations in the subplots, between plants in the banana rows (location 1 and between the banana rows (location 2. There were significant and independent effects for the cover crop and sampling location factors for the variables organic matter, Ca and P, and significant effects for the interaction between cover crops and sampling locations for the variables potassium, magnesium and total exchangeable bases. The cover crop mix and the between-row location presented the highest organic matter content. Potassium was the nutrient with the highest negative variation from the initial content and its leaf content was below the reference value, however not reducing the crop yield. The banana crop associated with crop cover using the crop mix provided greater availability of nutrients in the soil compared to the coverage with tropical kudzu.

  5. [Dynamic changes of surface soil organic carbon and light-fraction organic carbon after mobile dune afforestation with Mongolian pine in Horqin Sandy Land].

    Science.gov (United States)

    Shang, Wen; Li, Yu-qiang; Wang, Shao-kun; Feng, Jing; Su, Na

    2011-08-01

    This paper studied the dynamic changes of surface (0-15 cm) soil organic carbon (SOC) and light-fraction organic carbon (LFOC) in 25- and 35-year-old sand-fixing Mongolian pine (Pinus sylvestris var. mongolica) plantations in Horqin Sandy Land, with a mobile dune as a comparison site. After the afforestation on mobile dune, the content of coarse sand in soil decreased, while that of fine sand and clay-silt increased significantly. The SOC and LFOC contents also increased significantly, but tended to decrease with increasing soil depth. Afforestation increased the storages of SOC and LFOC in surface soil, and the increment increased with plantation age. In the two plantations, the increment of surface soil LFOC storage was much higher than that of SOC storage, suggesting that mobile dune afforestation had a larger effect on surface soil LFOC than on SOC.

  6. Seasonal differences in tillage draught on a sandy loam soil with long-term additions of animal manure and mineral fertilizers

    DEFF Research Database (Denmark)

    Peltre, Clément; Nyord, T.; Christensen, B.T.;

    2016-01-01

    Energy requirements for soil tillage are closely linked to soil properties, such as clay, water and soil organic carbon (SOC) contents. Long-term application of inorganic fertilizer and organic amendments affects SOC content but little is known about seasonal differences in tillage draught...... requirements of soils subject to contrasting nutrient management regimes. We assessed autumn and spring tillage draught following harvest of early-sown and timely sown winter wheat grown on a sandy loam in the Askov Long-Term Experiment on Animal Manure and Mineral Fertilizers. Draught force was related...... to soil texture, soil water and SOC content, shear strength and bulk density, nutrient management, and yield of the preceding winter wheat. Contents of clay and SOC ranged from 8.9 to 10.6% and from 0.98 to 1.36%, respectively. In the autumn and spring, SOC normalized by clay content explained 38 and 5...

  7. Crabgrass (Digitaria sanguinalis) allelochemicals that interfere with crop growth and the soil microbial community.

    Science.gov (United States)

    Zhou, Bin; Kong, Chui-Hua; Li, Yong-Hua; Wang, Peng; Xu, Xiao-Hua

    2013-06-05

    Three chemicals, veratric acid, maltol, and (−)-loliolide, were isolated from crabgrass and their structures were identified by spectroscopic analysis. The chemicals were detected in crabgrass root exudates and rhizosphere soils, and their concentrations ranged from 0.16 to 8.10 μg/g. At an approximate concentration determined in crabgrass root exudates, all chemicals significantly inhibited the growth of wheat, maize, and soybean and reduced soil microbial biomass carbon. Phospholipid fatty acid profiling showed that veratric acid, maltol, and (−)-loliolide affected the signature lipid biomarkers of soil bacteria, actinobacteria, and fungi, resulting in changes in soil microbial community structures. There were significant relationships between crop growth and soil microbes under the chemicals' application. Chemical-specific changes in the soil microbial community generated negative feedback on crop growth. The results suggest that veratric acid, maltol, and (−)-loliolide released from crabgrass may act as allelochemicals interfering with crop growth and the soil microbial community.

  8. [Advances in safety studies of soil Bt toxin proteins released from transgenic Bt crops].

    Science.gov (United States)

    Bai, Yaoyu; Jiang, Mingxing; Cheng, Jia; Jiang, Yonghou

    2003-11-01

    Commercialized transgenic Bt (Bacillus thuringiensis) crops are permitted for field growth in a large scale, which leads to significant issues of ecological risk assessment in soil ecosystem. In this paper, some general safety problems involving in the soil Bt active toxins released from insect-resistant transgenic Bt crops in the forms of plant residues, root exudates and pollens were reviewed, including their adsorption by soil active-particles, their insecticidal activity, persistence, and biodegradation by soil microbes, and their effects on soil organisms.

  9. Clinoptilolite zeolite influence on inorganic nitrogen in silt loam and sandy agricultural soils

    Science.gov (United States)

    Development of best management practices can help improve inorganic nitrogen (N) availability to plants and reduce nitrate-nitrogen (NO3-N) leaching in soils. This study was conducted to determine the influence of the zeolite mineral Clinoptilolite (CL) additions on NO3-N and ammonium-nitrogen (NH4...

  10. Clinoptilolite zeolite influence on nitrogen in a manure-amended sandy agricultural soil

    Science.gov (United States)

    Development of best management practices can help improve inorganic nitrogen (N) availability to plants and reduce nitrate-nitrogen (NO3-N) leaching in soils. This study was conducted to determine the influence of the zeolite mineral clinoptilolite (CL) additions on NO3-N and ammonium-nitrogen (NH4-...

  11. Origin and fate of organic matter in sandy soils along a primary vegetation succession

    NARCIS (Netherlands)

    Nierop, K.

    1999-01-01

    Until now little is known about the role vegetation plays in the organic matter formation, particularly at the molecular level. Most ecosystems have a long history, which is unknown or too complex to find distinct relations between vegetation and the chemical composition of soil organic matter. To g

  12. Water quality and surfactant effects on the water repellency of a sandy soil

    Science.gov (United States)

    Differences in irrigation water quality may affect the water repellency of soils treated or untreated with surfactants. Using simulated irrigations, we evaluated water quality and surfactant application rate effects upon the water repellency of a Quincy sand (Xeric Torripsamment). We used a split ...

  13. Nitrogen and Carbon Leaching in Repacked Sandy Soil with Added Fine Particulate Biochar

    DEFF Research Database (Denmark)

    Bruun, Esben W.; Petersen, Carsten; Strobel, Bjarne W.

    2012-01-01

    Biochar amendment to soil may affect N turnover and retention, and may cause translocation of dissolved and particulate C. We investigated effects of three fine particulate biochars made of wheat (Triticum aestivum L.) straw (one by slow pyrolysis and two by fast pyrolysis) on N and C leaching fr...

  14. Complexation with dissolved organic matter and solubility control of heavy metals in sandy soil

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Lofts, S.; Tipping, E.; Riemsdijk, van W.H.

    2002-01-01

    The complexation of heavy metals with dissolved organic matter (DOM) in the environment influences the solubility and mobility of these metals. In this paper, we measured the complexation of Cu, Cd, Zn, Ni, and Pb with DOM in the soil solution at pH 3.7-6.1 using a Donnan membrane technique. The res

  15. Altered humin compositions under organic and inorganic fertilization on an intensively cultivated sandy loam soil

    Science.gov (United States)

    Humin is the largest and also the least understood fraction of soil organic matter. The humin structure and its correlation with microbiological properties are particularly uncertain. We applied advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy to investigate the structural chan...

  16. Effect of Soil Surface Evaporation with Fly Ash as Sandy Soil Amendment%施用粉煤灰对沙土土面蒸发的影响

    Institute of Scientific and Technical Information of China (English)

    成钢; 赵亮; 孙鹏程; 唐泽军

    2011-01-01

    Based on evaporation experiment in natural condition, research were carried out to study the effect of water retention capacity of sandy soil under four fly ash application rate (10%, 20%, 30%, 40%). Results showed that, the usage of fly ash reduced evaporation capability and enhance water reten- tion capacity of sandy soil. The evaporation capability always reduced by the effort of fly ash application throughout the experiment, and showed that less evaporation effect with increasing fly ash application rate. As total evaporation, compared with controlled experiment, the total evaporation of three treatments of 20%, 30%, 40% reduced 8.3%, 13.0%, 27.2% except 10% treatment has similar evaporation.%通过自然条件下蒸发试验,研究了4种粉煤灰施用率对沙土土面蒸发的影响。结果表明,粉煤灰的施用减弱了沙土土面蒸发水平,增强了沙土的保水性能。通过对蒸发过程的日观察,粉煤灰的施用始终表现出减弱沙土蒸发的能力,且呈现出随粉煤灰施用率增多而蒸发能力愈弱的特点。施用率10%处理土壤总蒸发量与对照试验大致相同,施用率20%、30%、40%三种处理总蒸发量分别较对照试验减少8.3%、13.0%、27.2%。

  17. Soil disturbance alters plant community composition and decreases mycorrhizal carbon allocation in a sandy grassland.

    Science.gov (United States)

    Schnoor, Tim Krone; Mårtensson, Linda-Maria; Olsson, Pål Axel

    2011-11-01

    We have studied how disturbance by ploughing and rotavation affects the carbon (C) flow to arbuscular mycorrhizal (AM) fungi in a dry, semi-natural grassland. AM fungal biomass was estimated using the indicator neutral lipid fatty acid (NLFA) 16:1ω5, and saprotrophic fungal biomass using NLFA 18:2ω6,9. We labeled vegetation plots with (13)CO(2) and studied the C flow to the signature fatty acids as well as uptake and allocation in plants. We found that AM fungal biomass in roots and soil decreased with disturbance, while saprotrophic fungal biomass in soil was not influenced by disturbance. Rotavation decreased the (13)C enrichment in NLFA 16:1ω5 in soil, but (13)C enrichment in the AM fungal indicator NLFA 16:1ω5 in roots or soil was not influenced by any other disturbance. In roots, (13)C enrichment was consistently higher in NLFA 16:1ω5 than in crude root material. Grasses (mainly Festuca brevipila) decreased as a result of disturbance, while non-mycorrhizal annual forbs increased. This decreases the potential for mycorrhizal C sequestration and may have been the main reason for the reduced mycorrhizal C allocation found in disturbed plots. Disturbance decreased the soil ammonium content but did not change the pH, nitrate or phosphate availability. The overall effect of disturbance on C allocation was that more of the C in AM fungal mycelium was directed to the external phase. Furthermore, the functional identity of the plants seemed to play a minor role in the C cycle as no differences were seen between different groups, although annuals contained less AM fungi than the other groups.

  18. Soil quality indicators of a mature alley-cropping agroforestry system in temperate North America

    Science.gov (United States)

    Although agroforestry practices are believed to improve soil quality, reports on long-term effects of alley cropping on soils within agroforestry in the temperate zone are limited. The objective of this study was to examine effects of management, landscape, and soil depth of an established agrofores...

  19. Influence of crop residues on trifluralin mineralization in a silty clay loam soil.

    Science.gov (United States)

    Farenhorst, Annemieke

    2007-01-01

    Trifluralin is typically applied onto crop residues (trash, stubble) at the soil surface, or onto the bare soil surface after the incorporation of crop residues into the soil. The objective of this study was to quantify the effect of the type and amount of crop residues in soil on trifluralin mineralization in a Wellwood silty clay loam soil. Leaves and stubble of Potato (Solanum tuberosum) (P); Canola (Brassica napus) (C), Wheat (Triticum aestivum) (W), Oats (Avena sativa), (O), and Alfalfa (Medicago sativa) (A) were added to soil microcosms at rates of 2%, 4%, 8% and 16% of the total soil weight (25 g). The type and amount of crop residues in soil had little influence on the trifluralin first-order mineralization rate constant, which ranged from 3.57E-03 day(-1) in soil with 16% A to 2.89E-02 day(-1) in soil with 8% W. The cumulative trifluralin mineralization at 113 days ranged from 1.15% in soil with 16% P to 3.21% in soil with 4% C, again demonstrating that the observed differences across the treatments are not of agronomic or environmental importance.

  20. Plant adaptation to acid soils: the molecular basis for crop aluminum resistance

    Science.gov (United States)

    Aluminum (Al) toxicity on acid soils is a significant limitation to crop production worldwide, as approximately 50% of the world’s potentially arable soils are acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring resistance to ...

  1. Modelling soil properties in a crop field located in Croatia

    Science.gov (United States)

    Bogunovic, Igor; Pereira, Paulo; Millan, Mesic; Percin, Aleksandra; Zgorelec, Zeljka

    2016-04-01

    Development of tillage activities had negative effects on soil quality as destruction of soil horizons, compacting and aggregates destruction, increasing soil erosion and loss of organic matter. For a better management in order to mitigate the effects of intensive soil management in land degradation it is fundamental to map the spatial distribution of soil properties (Brevik et al., 2016). The understanding the distribution of the variables in space is very important for a sustainable management, in order to identify areas that need a potential intervention and decrease the economic losses (Galiati et al., 2016). The objective of this work is study the spatial distribution of some topsoil properties as clay, fine silt, coarse silt, fine sand, coarse sand, penetration resistance, moisture and organic matter in a crop field located in Croatia. A grid with 275x25 (625 m2) was designed and a total of 48 samples were collected. Previous to data modelling, data normality was checked using the Shapiro wilk-test. As in previous cases (Pereira et al., 2015), data did not followed the normal distribution, even after a logarithmic (Log), square-root, and box cox transformation. Thus, for modeling proposes, we used the log transformed data, since was the closest to the normality. In order to identify groups among the variables we applied a principal component analysis (PCA), based on the correlation matrix. On average clay content was 15.47% (±3.23), fine silt 24.24% (±4.08), coarse silt 35.34% (±3.12), fine sand 20.93% (±4.68), coarse sand 4.02% (±1.69), penetration resistance 0.66 MPa (±0.28), organic matter 1.51% (±0.25) and soil moisture 32.04% (±3.27). The results showed that the PCA identified three factors explained at least one of the variables. The first factor had high positive loadings in soil clay, fine silt and organic matter and a high negative loading in fine sand. The second factor had high positive loadings in coarse sand and moisture and a high

  2. Gypsum effects on crop yield and chemistry of soil, crop tissue, and vadose zone water: A meta-analysis.

    Science.gov (United States)

    Gypsum has various potential benefits as a soil amendment, but data are lacking on gypsum effects on crop yields and on environmental impacts across diverse field sites. Gypsum studies were conducted in six states using a common design with three rates each of mined and flue gas desulfurization (FGD...

  3. Dryland crop yields and soil organic matter as influenced by long-term tillage and cropping sequence

    Science.gov (United States)

    Long-term management practices are needed to sustain dryland crop yields and maintain soil organic matter in the northern Great Plains. We evaluated the 21-yr effects of no-till continuous spring wheat (NTCW), spring till continuous spring wheat (STCW), fall and spring till continuous spring wheat (...

  4. Effect of maize canopy and water repellency on moisture patterns in a Dutch black plaggen soil

    NARCIS (Netherlands)

    Dekker, L.W.; Ritsema, C.J.

    1997-01-01

    Man-made raised sandy soils in the Netherlands are classified as `brown' or `black' plaggen soils. When dry, the brown soils are wettable, but the black soils are water repellent. For one growing season, transects were sampled in a maize cropped black plaggen soil at the Heino experimental farm. Due

  5. Fate of carbosulfan and monocrotophos in sandy loam soils of Pakistan under field conditions at different watertable depths.

    Science.gov (United States)

    Tariq, Muhammad Ilyas; Afzal, Shahzad; Shahzad, Farina

    2010-05-01

    Information regarding pesticide mobility is critical for the evaluation of pesticide management practices. For this purpose, lysimetric studies were conducted to develop assessment schemes to protect groundwater from unacceptable effects caused by pesticide use. By using these studies, specific monitoring actions and prevention measures for the protection of waters can be studied, and the results thus obtained can provide the local authorities and the decision makers with an identification tool for demarcating risk areas. Pesticide residues were found at the bottom of lysimeters in the following pattern i.e., 1.52 > 2.1 > 2.74 m which could represent an "index of risk" for groundwater pollution. Regressions built for carbofuran and monocrotophos against watertable depths showed a decreasing trend of pesticide in higher watertable treatments. These findings support the existence of a significant role for chromatographic flow in sandy texture soil. Moreover, the higher values of pesticide residue at the bottom of lysimeters reflect that chromatographic flow as well as preferential flow pattern prevails during higher precipitation events. The precipitation received during the study was higher than the 10 year average and can be considered relatively as a worst case scenario. Finally, the authors have recommended a standardized pesticide monitoring scheme for groundwater in accordance with the already validated generic schemes in developed countries.

  6. Indicators of soil quality in the implantation of no-till system with winter crops

    Directory of Open Access Journals (Sweden)

    Marco Antonio Nogueira

    Full Text Available We assessed the effect of different winter crops on indicators of soil quality related to C and N cycling and C fractions in a Rhodic Kandiudult under no-till system at implantation, during two growing seasons, in Londrina PR Brazil. The experimental design was randomized blocks with split-plot in time arrangement, with four replications. The parcels were the winter crops: multicropping of cover crops with black oat (Avena strigosa, hairy vetch (Vicia villosa and fodder radish (Raphanus sativus; sunflower (Heliantus annuus intercropped with Urochloa ruziziensis; corn (Zea mays intercropped with Urochloa; and corn; fodder radish; or wheat (Triticum aestivum as sole crops. The subplots were the years: 2008 and 2009. Determinations consisted of total organic C, labile and resistant C, total N, microbial biomass C and N, the C/N ratio of soil organic matter, and the microbial quotient (qMic, besides microbiological and biochemical attributes, assessed only in 2009. The attributes significantly changed with the winter crops, especially the multicropping of cover crops and fodder radish, as well as effect of years. Despite stimulating the microbiological/biochemical activity, fodder radish cropping decreased the soil C in the second year, likewise the wheat cropping. The multicropping of cover crops in winter is an option for management in the establishment of no-till system, which contributes to increase the concentrations of C and stimulate the soil microbiological/biochemical activity.

  7. Cropping systems and control of soil erosion in a Mediterranean environment

    Science.gov (United States)

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

    2013-04-01

    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.

  8. Measurement of the fluorescence of crop residues: A tool for controlling soil erosion

    Science.gov (United States)

    Daughtry, C. S. T.; Mcmurtrey, J. E., III; Chappelle, E. W.; Hunter, W. J.

    1994-01-01

    Management of crop residues, the portion of a crop left in the field after harvest, is an important conservation practice for minimizing soil erosion and for improving water quality. Quantification of crop residue cover is required to evaluate the effectiveness of conservation tillage practices. Methods are needed to quantify residue cover that are rapid, accurate, and objective. The fluorescence of crop residue was found to be a broadband phenomenon with emission maxima at 420 to 495 nm for excitations of 350 to 420 nm. Soils had low intensity broadband emissions over the 400 to 690 nm region for excitations of 300 to 600 nm. The range of relative fluorescence intensities for the crop residues was much greater than the fluorescence observed of the soils. As the crop residues decompose their blue fluorescence values approach the fluorescence of the soil. Fluorescence techniques are concluded to be less ambiguous and better suited for discriminating crop residues and soils than reflectance methods. If properly implemented, fluorescence techniques can be used to quantify, not only crop residue cover, but also photosynthetic efficiency in the field.

  9. Olive Mill Effluent Spreading Effects on Water Retention of Tunisian Sandy Loam Soil

    Directory of Open Access Journals (Sweden)

    Hamdi SAHRAOUI

    2014-01-01

    Full Text Available Olive mill effluents (OME are characterized by their nutrients content and their adhesive and hydrophobic properties. An experiment was carried out at an olive growing area in Tunisia, “Sidi Bou Ali”, to identify the impact of spreading over OME on physical soil characteristics. Three treatments were in situ monitored, namely T0 (Control, T1 (25 m3/ha and T2 (50 m3/ha, over a period of 4 months. Measurements were conducted monthly corresponding respectively to D1, D2, D3 and D4. Water retention curves were established by a physical capillary model in porous medium. Results showed that the two applied OME doses induced a decrease in water retention, especially for potential matrixes above pF 2 corresponding to the water available range. No significant differences were found between the treated soil plots T1 and T2.doi:10.14456/WJST.2014.27

  10. Complexation with dissolved organic matter and solubility control of heavy metals in a sandy soil.

    Science.gov (United States)

    Weng, Liping; Temminghoff, Erwin J M; Lofts, Stephen; Tipping, Edward; Van Riemsdijk, Willem H

    2002-11-15

    The complexation of heavy metals with dissolved organic matter (DOM) in the environment influences the solubility and mobility of these metals. In this paper, we measured the complexation of Cu, Cd, Zn, Ni, and Pb with DOM in the soil solution at pH 3.7-6.1 using a Donnan membrane technique. The results show that the DOM-complexed species is generally more significant for Cu and Pb than for Cd, Zn, and Ni. The ability of two advanced models for ion binding to humic substances, e.g., model VI and NICA-Donnan, in the simulation of metal binding to natural DOM was assessed by comparing the model predictions with the measurements. Using the default parameters of fulvic and humic acid, the predicted concentrations of free metal ions from the solution speciation calculation using the two models are mostly within 1 order of magnitude difference from the measured concentrations, except for Ni and Pb in a few samples. Furthermore, the solid-solution partitioning of the metals was simulated using a multisurface model, in which metal binding to soil organic matter, dissolved organic matter, clay, and iron hydroxides was accounted for using adsorption and cation exchange models (NICA-Donnan, Donnan, DDL, CD-MUSIC). The model estimation of the dissolved concentration of the metals is mostly within 1 order of magnitude difference from those measured except for Ni in some samples and Pb. The solubility of the metals depends mainly on the metal loading over soil sorbents, pH, and the concentration of inorganic ligands and DOM in the soil solution.

  11. Modeling Tractive Force Requirements of Wheel tractors For Disc Ploughing in Sandy Loam Soil

    Directory of Open Access Journals (Sweden)

    S O Nkakini

    2012-10-01

    Full Text Available Tractive force models at different tillage speeds were developed using dimensional analysis, describing the tractor tyre - soil interaction. In this research study, disc ploughing on an experimental plot at twenty different soil moisture levels in loamy sand soil was carried out using trace tractor techniques. The independent variables: drawbar pull force, rolling (motion resistance, wheel slip, moisture content, cone index, wheel numeric, contact pressure, speed, width of plough, depth of plough, and dependent variable (Tractive force were measured and compared to computed values. High coefficients of determination R2 = 0.9492, 0.9555 and 0.9447 for ploughing at tillage speeds of 1.94m/s, 2.22m/s and 2.5m/s were obtained respectively. Standard errors of 0.3672552, 0.8628 and 0.8047 and the percentage (% errors of -2.272608059 and 2.45655144,-2.304946155 and 2.523126085,-1.424947801 and 2.020155232 at minimum and maximum values, were obtained. These results are clear evidence of the test of goodness of fit of the models between predictive and measured parameters for ploughing at different tillage speeds. The models were verified and validated by comparing the predicted with the measured tractive forces, and shown to closely followed the experimental results.

  12. Improvement of red pepper yield and soil environment by summer catch aquatic crops in greenhouses

    Science.gov (United States)

    Du, X. F.; Wang, L. Z.; Peng, J.; Wang, G. L.; Guo, X. S.; Wen, T. G.; Gu, D. L.; Wang, W. Z.; Wu, C. W.

    2016-08-01

    To investigate effects of the rotation of summer catch crops on remediation retrogressed soils in continuous cropping, a field experiment was conducted. Rice, water spinach, or cress were selected as summer catch crops; bare fallow during summer fallow was used as the control group. Results showed that aquatic crops grown in summer fallow period could effectively reduce soil bulk density and pH, facilitate soil nutrient release, and improve soil physical and chemical properties compared with those grown in fallow period. Paddy-upland rotation could improve soil microbial members and increase bacterial and actinomycete populations; by contrast, paddy-upland rotation could reduce fungal populations and enhance bacterium-to-fungus ratio. Paddy-upland rotation could also actively promote activities of soil enzymes, such as urease, phosphatase, invertase, and catalase. The proposed paddy-upland rotation significantly affected the growth of red pepper; the yield and quality of the grown red pepper were enhanced. Summer catch crops, such as rice, water spinach, and cress significantly increased pepper yield in the following growing season by 15.4%, 10.2% and 14.0%, respectively, compared with those grown in fallow treatment. Therefore, the proposed paddy-upland crop rotation could be a useful method to alleviate continuous cropping problems involved in cultivating red pepper in greenhouses.

  13. Soil CO2 Emissions as Affected by 20-Year Continuous Cropping in Mollisols

    Institute of Scientific and Technical Information of China (English)

    YOU Meng-yang; YUAN Ya-ru; LI Lu-jun; XU Yan-li; HAN Xiao-zeng

    2014-01-01

    Long-term continuous cropping of soybean (Glycine max), spring wheat (Triticum aesativum) and maize (Zea mays) is widely practiced by local farmers in northeast China. A ifeld experiment (started in 1991) was used to investigate the differences in soil carbon dioxide (CO2) emissions under continuous cropping of the three major crops and to evaluate the relationships between CO2 lfuxes and soil temperature and moisture for Mollisols in northeast China. Soil CO2 emissions were measured using a closed-chamber method during the growing season in 2011. No remarkable differences in soil organic carbon were found among the cropping systems (P>0.05). However, signiifcant differences in CO2 emissions from soils were observed among the three cropping systems (Pcontinuous wheat ((629±22) g CO2 m-2)>continuous soybean ((474±30) g CO2 m-2). Soil temperature explained 42-65% of the seasonal variations in soil CO2 flux, with a Q10 between 1.63 and 2.31; water-filled pore space explained 25-47% of the seasonal variations in soil CO2 lfux. A multiple regression model including both soil temperature (T, °C) and water-iflled pore space (W,%), log(f)=a+bT log(W), was established, accounting for 51-66%of the seasonal variations in soil CO2 lfux. The results suggest that soil CO2 emissions and their Q10 values under a continuous cropping system largely depend on crop types in Mollisols of Northeast China.

  14. Response of corn silage (Zea mays L. to zinc fertilization on a sandy soil under field and

    Directory of Open Access Journals (Sweden)

    Saad Drissi

    2017-04-01

    Full Text Available The purpose of the experiments was to evaluate zinc (Zn fertilization effect on growth, yield and yield components of corn silage grown on a sandy soil under field and outdoor container conditions. Six rates of Zn supply (0 or control; 1.5; 3; 5; 10 and 50 mg kg−1 were tested. They were split at three different times during the growing season: (i 50% immediately after sowing, (ii 25% at 4–5 leaf stage and (iii 25% at 8–9 leaf stage. These Zn rates were applied to the soil surface as a solution of Zn sulfate (ZnSO4·7H2O. Zn deficiency symptoms appeared at an earlier stage (4–5 leaf stage as white stripes between the midrib and the margin of leaves for a Zn rate below or equal to 5 mg kg−1. Severity of these symptoms manifested more in container than in field. For both experiments, Zn supply induced a significant increase in stem height and leaf area. Furthermore, in both experiments, control plants showed a notable delay in achieving anthesis, silking, pollination and kernels maturity. The maximum shoot dry weight at harvest was recorded with Zn supply of 5 mg kg−1 in field experiment and 10 mg kg−1 in containers experiment. The shoot dry weight was especially linked to kernels dry weight. This latter was mainly enhanced through two compounds: 1000 kernels dry weight and pollination rate. On the other hand, outdoor container results can be used to help predict field plant responses to Zn except for control treatment.

  15. Effect of rainfall and tillage direction on the evolution of surface crusts, soil hydraulic properties and runoff generation for a sandy loam soil

    Science.gov (United States)

    Ndiaye, Babacar; Esteves, Michel; Vandervaere, Jean-Pierre; Lapetite, Jean-Marc; Vauclin, Michel

    2005-06-01

    The study was aimed at evaluating the effect of rainfall and tillage-induced soil surface characteristics on infiltration and runoff on a 2.8 ha catchment located in the central region of Senegal. This was done by simulating 30 min rain storms applied at a constant rate of about 70 mm h -1, on 10 runoff micro-plots of 1 m 2, five being freshly harrowed perpendicularly to the slope and five along the slope (1%) of the catchment. Runoff was automatically recorded at the outlet of each plot. Hydraulic properties such as capillary sorptivity and hydraulic conductivity of the sandy loam soil close to saturation were determined by running 48 infiltration tests with a tension disc infiltrometer. That allowed the calculation of a mean characteristic pore size hydraulically active and a time to ponding. Superficial water storage capacity was estimated using data collected with an electronic relief meter. Because the soil was subject to surface crusting, crust-types as well as their spatial distribution within micro-plots and their evolution with time were identified and monitored by taking photographs at different times after tillage. The results showed that the surface crust-types as well as their tillage dependent dynamics greatly explain the decrease of hydraulic conductivity and sorptivity as the cumulative rainfall since tillage increases. The exponential decaying rates were found to be significantly greater for the soil harrowed along the slope (where the runoff crust-type covers more than 60% of the surface after 140 mm of rain) than across to the slope (where crusts are mainly of structural (60%) and erosion (40%) types). That makes ponding time smaller and runoff more important. Also it was shown that soil hydraulic properties after about 160 mm of rain were close to those of untilled plot not submitted to any rain. That indicates that the effects of tillage are short lived.

  16. [Phytoavailability and chemical speciation of cadmium in different Cd-contaminated soils with crop root return].

    Science.gov (United States)

    Zhang, Jing; Yu, Ling-Ling; Xin, Shu-Zhen; Su, De-Chun

    2013-02-01

    Pot experiments were conducted under greenhouse condition to investigate the effects of crop root return on succeeding crops growth, Cd uptake and soil Cd speciation in Cd-contaminated soil and artificial Cd-contaminated soil. The results showed that the amount of root residue returned to soil by corn and kidney bean growth successive for 3 times was 0.4%-1.1%. The Cd returned to soil by root residue was 1.3%-3.5% to the total soil Cd. There was no significant difference in the shoot dry weights of winter wheat and Chinese cabbage grown on the 2 Cd-contaminated soils with and without root return. While Cd concentration of Chinese cabbage increased significantly in the Cd-contaminated soil with corn or kidney bean root return. Light fraction of soil organic matter increased with root return in both of the Cd-contaminated soils. The percentage of Cd in the light fraction of soil organic matter increased with root return in the artificial Cd-contaminated soil. Soil carbonates-bound Cd concentration decreased significantly with corn root return in the Cd-contaminated soil. Soil exchangeable Cd concentration decreased and soil Fe-Mn oxide-bound Cd concentration increased significantly with kidney bean root return in the artificial Cd-contaminated soil.

  17. Microbial metabolic profiles in Australian soils with varying crop management strategies

    Science.gov (United States)

    Aldorri, Sind; McMillan, Mary; Pereg, Lily

    2015-04-01

    Cotton production belt in Australia is covering vast areas from subtropical to temperate and grassland. Soil types are mostly different variations of clay with mainly black, grey and red clay soil containing variable proportions of sand in it. Growers often grow cotton in rotation with other crops, such as wheat, beans and corn, and soil fertilization vary with a number of growers using organic amendments as a main or supplementary source of nutrients. We have collected soil samples from farms in different regions and with different crop management strategies and studied the metabolic signature of microbial communities using the Biolog Ecoplate system. The metabolic patterns, supplemented with molecular analysis of the community will further the understanding of the influence of crop and soil management on soil functions carried out by microbes.

  18. The use of crop rotation for mapping soil organic content in farmland

    Science.gov (United States)

    Yang, Lin; Song, Min; Zhu, A.-Xing; Qin, Chengzhi

    2017-04-01

    Most of the current digital soil mapping uses natural environmental covariates. However, human activities have significantly impacted the development of soil properties since half a century, and therefore become an important factor affecting soil spatial variability. Many researches have done field experiments to show how soil properties are impacted and changed by human activities, however, spatial variation data of human activities as environmental covariates have been rarely used in digital soil mapping. In this paper, we took crop rotation as an example of agricultural activities, and explored its effectiveness in characterizing and mapping the spatial variability of soil. The cultivated area of Xuanzhou city and Langxi County in Anhui Province was chosen as the study area. Three main crop rotations,including double-rice, wheat-rice,and oilseed rape-cotton were observed through field investigation in 2010. The spatial distribution of the three crop rotations in the study area was obtained by multi-phase remote sensing image interpretation using a supervised classification method. One-way analysis of variance (ANOVA) for topsoil organic content in the three crop rotation groups was performed. Factor importance of seven natural environmental covariates, crop rotation, Land use and NDVI were generated by variable importance criterion of Random Forest. Different combinations of environmental covariates were selected according to the importance rankings of environmental covariates for predicting SOC using Random Forest and Soil Landscape Inference Model (SOLIM). A cross validation was generated to evaluated the mapping accuracies. The results showed that there were siginificant differences of topsoil organic content among the three crop rotation groups. The crop rotation is more important than parent material, land use or NDVI according to the importance ranking calculated by Random Forest. In addition, crop rotation improved the mapping accuracy, especially for the

  19. Effects of crop management, soil type, and climate on N2O emissions from Austrian Soils

    Science.gov (United States)

    Zechmeister-Boltenstern, Sophie; Sigmund, Elisabeth; Kasper, Martina; Kitzler, Barbara; Haas, Edwin; Wandl, Michael; Strauss, Peter; Poetzelsberger, Elisabeth; Dersch, Georg; Winiwarter, Wilfried; Amon, Barbara

    2015-04-01

    Within the project FarmClim ("Farming for a better climate") we assessed recent N2O emissions from two selected regions in Austria. Our aim was to deepen the understanding of Austrian N2O fluxes regarding region specific properties. Currently, N2O emissions are estimated with the IPCC default emission factor which only considers the amount of N-input as an influencing factor for N2O emissions. We evaluated the IPCC default emission factor for its validity under spatially distinct environmental conditions. For this two regions for modeling with LandscapeDNDC have been identified in this project. The benefit of using LandscapeDNDC is the detailed illustration of microbial processes in the soil. Required input data to run the model included daily climate data, vegetation properties, soil characteristics and land management. The analysis of present agricultural practices was basis for assessing the hot spots and hot moments of nitrogen emissions on a regional scale. During our work with LandscapeDNDC we were able to adapt specific model algorithms to Austrian agricultural conditions. The model revealed a strong dependency of N2O emissions on soil type. We could estimate how strongly soil texture affects N2O emissions. Based on detailed soil maps with high spatial resolution we calculated region specific contribution to N2O emissions. Accordingly we differentiated regions with deviating gas fluxes compared to the predictions by the IPCC inventory methodology. Taking region specific management practices into account (tillage, irrigation, residuals) calculation of crop rotation (fallow, catch crop, winter wheat, barley, winter barley, sugar beet, corn, potato, onion and rapeseed) resulted in N2O emissions differing by a factor of 30 depending on preceding crop and climate. A maximum of 2% of N fertilizer input was emitted as N2O. Residual N in the soil was a major factor stimulating N2O emissions. Interannual variability was affected by varying N-deposition even in case

  20. [Mechanisms of grass in slope erosion control in Loess sandy soil region of Northwest China].

    Science.gov (United States)

    Zhao, Chun-Hong; Gao, Jian-En; Xu, Zhen

    2013-01-01

    By adopting the method of simulated precipitation and from the viewpoint of slope hydrodynamics, in combining with the analysis of soil resistance to erosion, a quantitative study was made on the mechanisms of grass in controlling the slope erosion in the cross area of wind-water erosion in Loess Plateau of Northwest China under different combinations of rainfall intensity and slope gradient, aimed to provide basis to reveal the mechanisms of vegetation in controlling soil erosion and to select appropriate vegetation for the soil and water conservation in Loess Plateau. The grass Astragalus adsurgens with the coverage about 40% could effectively control the slope erosion. This grass had an efficiency of more than 70% in reducing sediment, and the grass root had a greater effect than grass canopy. On bare slope and on the slopes with the grass plant or only the grass root playing effect, there existed a functional relation between the flow velocity on the slopes and the rainfall intensity and slope gradient (V = DJ(0.33 i 0.5), where V is flow velocity, D is the comprehensive coefficient which varies with different underlying surfaces, i is rainfall intensity, and J is slope gradient). Both the grass root and the grass canopy could markedly decrease the flow velocity on the slopes, and increase the slope resistance, but the effect of grass root in decreasing flow velocity was greater while the effect in increasing resistance was smaller than that of grass canopy. The effect of grass root in increasing slope resistance was mainly achieved by increasing the sediment grain resistance, while the effect of canopy was mainly achieved by increasing the slope form resistance and wave resistance. The evaluation of the soil resistance to erosion by using a conceptual model of sediment generation by overland flow indicated that the critical shear stress value of bare slope and of the slopes with the grass plant or only the grass root playing effect was 0.533, 1.672 and 0

  1. Determination of Selenium Toxicity for Survival and Reproduction of Enchytraeid Worms in a Sandy Loam Soil

    Science.gov (United States)

    2016-07-01

    active radiation (PAR) light intensity of 12.8  0.7 µM m2/s (985  52 lux ), and mean temperature of 21.6  0.1 C. The soil moisture level was...PAR light intensity of 12.8  0.7 µM m2/s (985  52 lux ), and a mean temperature of 21.6  0.1 °C, for the duration of the 28 d test. The containers

  2. Regional crop productivity and greenhouse gas emissions from Swiss soils under organic farming

    Science.gov (United States)

    Lee, Juhwan; Necpalova, Magdalena; Six, Johan

    2016-04-01

    There is worldwide concern about the increase in atmospheric greenhouse gases (GHG) and their impact on climate change and food security. As a sustainable alternative, organic cropping in various forms has been promoted to minimize the environmental impacts of conventional practices. However, relatively little is known about the potential to reduce GHG emissions while maintaining crop productivity through the large-scale adoption of organic practices. Therefore, we simulated and compared regional crop production, soil organic carbon status, and net soil GHG emissions under organic and conventional practices. Grid-level (2.2 km by 2.2 km) simulation was performed using previously validated DailyDayCent by considering typical crop rotations. Regional model estimates are presented and discussed specifically with the focus on Swiss organic and conventional cropping systems, which differ by type and intensity of manuring, tillage, and cover crop.

  3. Field scale spatio-temporal soil moisture variability for trafficability and crop water availability

    Science.gov (United States)

    Carranza, Coleen; van der Ploeg, Martine; Ritsema, Coen

    2016-04-01

    Spatio-temporal patterns of soil moisture have been studied mostly for inputs in land surface models for weather and climate predictions. Remote sensing techniques for estimation of soil moisture have been explored because of the good spatial coverage at different scales. Current available satellite data provide surface soil moisture as microwave systems only measure soil moisture content up to 5cm soil depth. The OWAS1S project will focus on estimation of soil moisture from freely available Sentinel-1 datasets for operational water management in agricultural areas. As part of the project, it is essential to develop spatio-temporal methods to estimate root zone soil moisture from surface soil moisture. This will be used for crop water availability and trafficability in selected agricultural fields in the Netherlands. A network of single capacitance sensors installed per field will provide continuous measurements of soil moisture in the study area. Ground penetrating radar will be used to measure soil moisture variability within a single field for different time periods. During wetter months, optimal conditions for traffic will be assessed using simultaneous soil strength and soil moisture measurements. Towards water deficit periods, focus is on the relation (or the lack thereof) between surface soil moisture and root zone soil moisture to determine the amount of water for crops. Spatio-temporal distribution will determine important physical controls for surface and root zone soil moisture and provide insights for root-zone soil moisture. Existing models for field scale soil-water balance and data assimilation methods (e.g. Kalman filter) will be combined to estimate root zone soil moisture. Furthermore, effects of root development on soil structure and soil hydraulic properties and subsequent effects on trafficability and crop water availability will be investigated. This research project has recently started, therefore we want to present methods and framework of

  4. Nitrogen dynamics following grain legumes and subsequent catch crops and the effects on succeeding cereal crops

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Mundus, Simon; Jensen, Erik Steen

    2009-01-01

    balances. A 2½-year lysimeter experiment was carried out on a temperate sandy loam soil. Crops were not fertilized in the experimental period and the natural 15N abundance technique was used to determine grain legume N2 fixation. Faba bean total aboveground DM production was significantly higher (1,300 g m...

  5. Occurrence and distribution of polycyclic aromatic hydrocarbons in organo-mineral particles of alluvial sandy soil profiles at a petroleum-contaminated site.

    Science.gov (United States)

    Lu, Zhe; Zeng, Fangang; Xue, Nandong; Li, Fasheng

    2012-09-01

    The occurrence and the distribution of 16 USEPA priority pollutants polycyclic aromatic hydrocarbons (PAHs) were investigated in two alluvial sandy soil profiles and in their four sizes of organo-mineral particles (200 μm coarse sand) beside a typical oil sludge storage site in eastern China. PAHs were mainly enriched in the surface soil (0-20 cm) and the concentrations declined in deeper soils, from 3.68 to 0.128 μg/g in profile 1 and 10.8 to 0.143 μg/g in profile 2 (dry wt.). The PAHs in the upper soil layers of this study site mainly came from combustion pollution, whereas in the lower soil layers petroleum contamination became the major source of PAHs. The content of different sized organo-mineral particles of this alluvial sandy soil decreased in the following order: fine sand>coarse sand>silt>clay. X-ray diffraction (XRD) results showed that all the different sized soil fractions of this study site were dominated by quartz, calcite and feldspar. The particle surface became smoother with size increasing as shown by scanning electron microscope (SEM) images. PAH concentrations varied largely in different sized soil fractions. The highest PAH concentration was associated with clay and decreased in the order: clay>silt>coarse sand>fine sand. Soil organic matter (SOM) content, mineral composition and particle surface characteristics were suggested as three main factors affecting the distribution of PAHs in different sized organo-mineral particles. This study will help to understand the distribution and transport characteristics of PAHs in soil profiles at petroleum-contaminated sites.

  6. Influence of Cultivation and Cropping Systems on Production of Soil Sediment on Agricultural Land

    Science.gov (United States)

    Poposka, Hristina; Mukaetov, Dusko

    2017-04-01

    Soil conservation practices and in particular soil tillage and crop cultivation patterns are becoming an important issue in agricultural production. Combating soil erosion and diminishing its negative impact on agricultural soil imposes as a matter of vital interest which gained even greater significance, in a pronounced negative impact of climate change. Main objective of the three-year research and monitoring program was to evaluate the effects of the easy-to-use adaptive measures on intensity of soil erosion, and soil properties considering to be of crucial importance on run-off velocity and sediment loss, like: soil structure stability, soil infiltration rate, soil organic matter and soil moisture conservation. The influence of soil tillage practices and different cropping systems on soil intensity and sediment loss, has been monitored on specially designed soil erosion fields with standard dimensions (20m length x 4m. width), on a sloppy terrain (12% slope). The experimental field is located on heavily textured Chromic cambisol on saprolite. This is the predominant soil type on the sloppy terrains in the country, usually under intensive agricultural activities Soil texture and physical characteristics were thoroughly investigated in order to determine the base soil conditions. The influence of downslope and contour ploughing on quantity of eroded sediment has been monitored in three consecutive years. The eroded sediment has been collected periodically on a weekly base and after intensive rainfalls. The intensity of soil erosion under most widespread cropping systems in the country, like: a) cereals as a monoculture, b) crop rotation, and c) perennial grass, was monitored as well. The collected sediment was examined in order to determine the quantity of soil organic matter and nutrient loss (nitrogen, phosphorus and potassium). Soil chemical properties are examined after each vegetative season in order to quantify the effect of tillage and cropping systems on

  7. Influence of zeolite and cement additions on mechanical behavior of sandy soil

    Institute of Scientific and Technical Information of China (English)

    Hossein Mola-Abasi; Issa Shooshpasha

    2016-01-01

    It is well known that the cemented sand is one of economic and environmental topics in soil stabili-zation. In this instance, a blend of sand, cement and other materials such as fiber, glass, nanoparticle and zeolite can be commercially available and effectively used in soil stabilization in road construction. However, the influence and effectiveness of zeolite on the properties of cemented sand systems have not been completely explored. In this study, based on an experimental program, the effects of zeolite on the characteristics of cemented sands are investigated. Stabilizing agent includes Portland cement of type II and zeolite. Results show the improvements of unconfined compressive strength (UCS) and failure properties of cemented sand when the cement is replaced by zeolite at an optimum proportion of 30%after 28 days. The rate of strength improvement is approximately between 20%and 78%. The efficiency of using zeolite increases with the increases in cement amount and porosity. Finally, a power function of void-cement ratio and zeolite content is demonstrated to be an appropriate method to assess UCS of zeolite-cemented mixtures.

  8. Influence of zeolite and cement additions on mechanical behavior of sandy soil

    Directory of Open Access Journals (Sweden)

    Hossein Mola-Abasi

    2016-10-01

    Full Text Available It is well known that the cemented sand is one of economic and environmental topics in soil stabilization. In this instance, a blend of sand, cement and other materials such as fiber, glass, nanoparticle and zeolite can be commercially available and effectively used in soil stabilization in road construction. However, the influence and effectiveness of zeolite on the properties of cemented sand systems have not been completely explored. In this study, based on an experimental program, the effects of zeolite on the characteristics of cemented sands are investigated. Stabilizing agent includes Portland cement of type II and zeolite. Results show the improvements of unconfined compressive strength (UCS and failure properties of cemented sand when the cement is replaced by zeolite at an optimum proportion of 30% after 28 days. The rate of strength improvement is approximately between 20% and 78%. The efficiency of using zeolite increases with the increases in cement amount and porosity. Finally, a power function of void-cement ratio and zeolite content is demonstrated to be an appropriate method to assess UCS of zeolite-cemented mixtures.

  9. Evapotranspiration simulated by CRITERIA and AquaCrop models in stony soils

    National Research Council Canada - National Science Library

    Pasquale Campi; Francesca Modugno; Alejandra Navarro; Fausto Tomei; Giulia Villani; Marcello Mastrorilli

    2015-01-01

    .... The objective of this paper is to test CRITERIA and AquaCrop models in order to evaluate their suitability in estimating evapotranspiration at the field scale in two types of soil in the Mediterranean region...

  10. CHAMOMILE PRODUCTION USING SUPPLEMENTARY IRRIGATION AND ORGANIC FERTILIZATION IN SANDY SOILS

    Directory of Open Access Journals (Sweden)

    CATARINY CABRAL ALEMAN

    2016-01-01

    Full Text Available The use of medicinal plants in the herbal medicine of Brazilian Health System has intensified production and the need for developing efficient agricultural techniques that promote greater productivity of these species. The objective of this work was to evaluate the chamomile production at field conditions as a function of irrigation depths and organic fertilizer rates. The experiment was conducted in the Universidade do Oeste Paulista (Campus II experimental area, in Presidente Prudente, São Paulo State, Brazil. A triple factorial experimental design was used, consisting of irrigation rates (150, 100, 75, 50, 25 and 0% of the reference evapotranspiration - ETo, organic manure types (poultry and cattle manure and manure rates (0, 3 and 5 kg m-2, with four replications. The capitula production per plant, capitula dry weight and yield per water input (water use efficiency were evaluated. The supplementary irrigation combined with organic manure fertilization provided the highest capitula yield for chamomile crop in the Presidente Prudente region. The combination of poultry manure at rate of 5 kg m-2 with water depth equal to 150% of the ETo resulted in higher average values of capitula fresh and dry weight and water use efficiency.

  11. Field controlled experiments of mercury accumulation in crops from air and soil

    Energy Technology Data Exchange (ETDEWEB)

    Niu Zhenchuan [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Zhang Xiaoshan, E-mail: zhangxsh@rcees.ac.cn [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Wang Zhangwei, E-mail: wangzhw@rcees.ac.cn [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Ci Zhijia [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)

    2011-10-15

    Field open top chambers (OTCs) and soil mercury (Hg) enriched experiments were employed to study the influence of Hg concentrations in air and soil on the Hg accumulation in the organs of maize (Zea mays L.) and wheat (Triticum aestivum L.). Results showed that Hg concentrations in foliages were correlated significantly (p < 0.05) with air Hg concentrations but insignificantly correlated with soil Hg concentrations, indicating that Hg in crop foliages was mainly from air. Hg concentrations in roots were generally correlated with soil Hg concentrations (p < 0.05) but insignificantly correlated with air Hg concentrations, indicating that Hg in crop roots was mainly from soil. No significant correlations were found between Hg concentrations in stems and those in air and soil. However, Hg concentrations in upper stems were usually higher than those in bottom stems, implying air Hg might have stronger influence than soil Hg on stem Hg accumulation. - Highlights: > Hg accumulation in crop organs was studied by OTCs and soil Hg enriched experiments. > Hg accumulation in foliages and roots was mainly from air and soil, respectively. > Air Hg had stronger influence than soil Hg on stem Hg accumulation. > Foliar Hg concentrations showed the trend of increase over growth stages. - Capsule Mercury accumulated in the aboveground organs of crop was mainly from the air.

  12. Morphostructural characterization of soil conventionally tilled with mechanized and animal traction with and without cover crop

    Directory of Open Access Journals (Sweden)

    Ricardo Ralisch

    2010-12-01

    Full Text Available The structural stability and restructuring ability of a soil are related to the methods of crop management and soil preparation. A recommended strategy to reduce the effects of soil preparation is to use crop rotation and cover crops that help conserve and restore the soil structure. The aim of this study was to evaluate and quantify the homogeneous morphological units in soil under conventional mechanized tillage and animal traction, as well as to assess the effect on the soil structure of intercropping with jack bean (Canavalia ensiformis L.. Profiles were analyzed in April of 2006, in five counties in the Southern-Central region of Paraná State (Brazil, on family farms producing maize (Zea mays L., sometimes intercropped with jack bean. The current structures in the crop profile were analyzed using Geographic Information Systems (GIS and subsequently principal component analysis (PCA to generate statistics. Morphostructural soil analysis showed a predominance of compact units in areas of high-intensity cultivation under mechanized traction. The cover crop did not improve the structure of the soil with low porosity and compact units that hamper the root system growth. In areas exposed to animal traction, a predominance of cracked units was observed, where roots grew around the clods and along the gaps between them.

  13. Hydrodispersive characterization of a sandy porous medium by tracer tests carried out in laboratory on undisturbed soil samples

    Science.gov (United States)

    Ferrante, Aldo Pedro; Fallico, Carmine; Rios, Ana C.; Fernanda Rivera, Maria; Santillan, Patricio; Salazar, Mario

    2013-04-01

    The contamination of large areas and correspondent aquifers often imposes to implement some recovery operations which are generally complex and very expensive. Anyway, these interventions necessarily require the preventive characterization of the aquifers to be reclaimed and in particular the knowledge of the relevant hydrodispersive parameters. The determination of these parameters requires the implementation tracer tests for the specific site (Sauty JP, 1978). To reduce cost and time that such test requires tracer tests on undisturbed soil samples, representative of the whole aquifer, can be performed. These laboratory tests are much less expensive and require less time, but the results are certainly less reliable than those obtained by field tests for several reasons, including the particular scale of investigation. In any case the hydrodispersive parameters values, obtained by tests carried out in laboratory, can provide useful information on the considered aquifer, allowing to carry out initial verifications on the transmission and propagation of the pollutants in the aquifer considered. For this purpose, tracer tests with inlet of short time were carried out in the Soil Physics Laboratory of the Department of Soil Protection (University of Calabria), on a series of sandy soil samples with six different lengths, repeating each test with three different water flow velocities (5 m/d; 10 m/s and 15 m/d) (J. Feyen et al., 1998). The lengths of the samples taken into account are respectively 15 cm, 24 cm, 30 cm, 45 cm, 60 cm and 75 cm, while the solution used for each test was made of 100 ml of water and NaCl with a concentration of this substance corresponding to 10 g/L. For the porous medium taken into consideration a particle size analysis was carried out, resulting primarily made of sand, with total porosity equal to 0.33. Each soil sample was placed in a flow cell in which was inlet the tracer from the bottom upwards, measuring by a conductivimeter the

  14. Cover Crop and Liquid Manure Effects on Soil Quality Indicators in a Corn Silage System.

    Science.gov (United States)

    Due to a lack of surface residue and organic matter inputs, continuous corn (Zea mays L.) silage production is one of the most demanding cropping systems imposed on our soil resources. In this study, our objective was to determine if using cover/companion crops and/or applying low-solids liquid dair...

  15. Converging strategies by farmers and scientists to improve soil fertility and enhance crop production in Benin

    NARCIS (Netherlands)

    Saidou, A.

    2006-01-01

    Keywords: Farmer perception, indigenous knowledge, extensive cassava, earthworm casts, arbuscular mycorrhiza, crop rotation, nutrient uptake, soil fertility, co-research, land tenure.Farmers in the transitional zone of Benin claim that extensive cassava cropping and prior cotton fertiliser enhance y

  16. Resource flows, crops and soil fertility management in smallholder farming systems in semi-arid Zimbabwe

    NARCIS (Netherlands)

    Ncube, B.; Twomlow, S.J.; Dimes, J.P.; Wijk, van M.T.; Giller, K.E.

    2009-01-01

    Poor soil fertility and erratic rains are major constraints to crop production in semi-arid environments. In the smallholder farming systems of sub-Saharan Africa, these constraints are manifested in frequent crop failures and endemic food insecurity. We characterized a semi-arid smallholder farming

  17. Soil quality improvement for crop production in semi-arid West Africa

    NARCIS (Netherlands)

    Ouédraogo, E.

    2004-01-01

    Soil quality maintenance and crop production improvement in semi-arid West Africa require appropriate cropping technologies, which are ecologically sound and economically viable. Thus, on-farm and on-station experiments have been carried out on the central plateau and in the south of Burkina Faso Th

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

    Science.gov (United States)

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

  19. A GPS Backpack System for Mapping Soil and Crop Parameters in Agricultural Fields

    Science.gov (United States)

    Stafford, J. V.; Lebars, J. M.

    Farmers are having to gather increasing amounts of data on their soils and crops. Precision agriculture metre-by-metre is based on a knowledge of the spatial variation of soil and crop parameters across a field. The data has to be spatially located and GPS is an effective way of doing this. A backpack data logging system with GPS position tagging is described which has been designed to aid a fanner in the manual collection of data.

  20. Organic matter and soil moisture content and double cropping with organic matter sourceplants

    OpenAIRE

    John Bako Baon; Aris Wibawa

    2005-01-01

    Double cropping of coffee with organic matter source plants is thought to increase organic matter content of soil. This study examined the effect of double cropping of coffee and organic matter source plants on soil organic matter content and yield of coffee plants. Arabica coffee trees in Andungsari Experimental Station (Bondowoso district), 1400 m asl. and climate type C; and Robusta coffee trees in Sumberasin Experimental Station (Malang district), 550 m asl. and climate type C, were used ...

  1. Persistence, distribution, and emission of Telone C35 injected into a Florida sandy soil as affected by moisture, organic matter, and plastic film cover.

    Science.gov (United States)

    Thomas, J E; Ou, L T; Allen, L H; McCormack, L A; Vu, J C; Dickson, D W

    2004-05-01

    With the phase-out of methyl bromide scheduled for 2005, alternative fumigants are being sought. This study of Telone C35, a mixture of (Z)- and (E)-1,3-dichloropropene (1,3-D) with chloropicirin (CP), focuses on its emissions, distribution, and persistence in Florida sandy soil in microplots with different soil-water and organic matter carbon (C) content with and without two different plastic film mulches. The addition of CP did not affect the physical behavior of the isomers of 1,3-D. Slower subsurface dispersion and longer residence time of the mixed fumigant occurred at higher water content. An increase in the percent organic carbon in the soil led to a more rapid decrease for chloropicirin than for 1,3-dichloropene isomers. The use of a virtually impermeable film (VIF) for soil cover provided a more even distribution and longer persistence under all the conditions studied in comparison to polyethylene (PE) film cover or no cover. The conditions of near field capacity water content, low organic matter, and a virtually impermeable film cover yielded optimum conditions for the distribution, emission control, and persistence of Telone C35 in a Florida sandy soil.

  2. Heat-Activated Persulfate Oxidation of Chlorinated Solvents in Sandy Soil

    Directory of Open Access Journals (Sweden)

    Jialu Liu

    2014-01-01

    Full Text Available Heat-activated persulfate oxidative treatment of chlorinated organic solvents containing chlorinated ethenes and ethanes in soil was investigated with different persulfate dosages (20 g/L, 40 g/L, and 60 g/L and different temperatures (30°C, 40°C, and 50°C. Chlorinated organic solvents removal was increased as persulfate concentration increase. The persulfate dosage of 20 g/L with the highest OE (oxidant efficiency value was economically suitable for chlorinated organic solvents removal. The increasing temperature contributed to the increasing depletion of chlorinated organic solvents. Chlorinated ethenes were more easily removed than chlorinated ethanes. Moreover, the persulfate depletion followed the pseudo-first-order reaction kinetics (kps=0.0292 [PS]0+0.0008, R2=0.9771. Heat-activated persulfate appeared to be an effective oxidant for treatment of chlorinated hydrocarbons.

  3. Changes in Soil Organic Carbon Fractions in Response to Cover Crops in an Orange Orchard

    Directory of Open Access Journals (Sweden)

    Francisco Éder Rodrigues de Oliveira

    2016-01-01

    Full Text Available ABSTRACT The cultivation of cover crops intercropped with fruit trees is an alternative to maintain mulch cover between plant rows and increase soil organic carbon (C stocks. The objective of this study was to evaluate changes in soil total organic C content and labile organic matter fractions in response to cover crop cultivation in an orange orchard. The experiment was performed in the state of Bahia, in a citrus orchard with cultivar ‘Pera’ orange (Citrus sinensis at a spacing of 6 × 4 m. A randomized complete block design with three replications was used. The following species were used as cover crops: Brachiaria (Brachiaria decumbes – BRAQ, pearl millet (Pennisetum glaucum – MIL, jack bean (Canavalia ensiformis – JB, blend (50 % each of jack bean + millet (JB/MIL, and spontaneous vegetation (SPV. The cover crops were broadcast-seeded between the rows of orange trees and mechanically mowed after flowering. Soil sampling at depths of 0.00-0.10, 0.10-0.20, and 0.20-0.40 m was performed in small soil trenches. The total soil organic C (SOC content, light fraction (LF, and the particulate organic C (POC, and oxidizable organic C fractions were estimated. Total soil organic C content was not significantly changed by the cover crops, indicating low sensitivity in reacting to recent changes in soil organic matter due to management practices. Grasses enabled a greater accumulation of SOC stocks in 0.00-0.40 m compared to all other treatments. Jack bean cultivation increased LF and the most labile oxidizable organic C fraction (F1 in the soil surface and the deepest layer tested. Cover crop cultivation increased labile C in the 0.00-0.10 m layer, which can enhance soil microbial activity and nutrient absorption by the citrus trees. The fractions LF and F1 may be suitable indicators for monitoring changes in soil organic matter content due to changes in soil management practices.

  4. Evapotranspiration simulated by CRITERIA and AquaCrop models in stony soils

    Directory of Open Access Journals (Sweden)

    Pasquale Campi

    2015-06-01

    Full Text Available The performance of a water balance model is also based on the ability to correctly perform simulations in heterogeneous soils. The objective of this paper is to test CRITERIA and AquaCrop models in order to evaluate their suitability in estimating evapotranspiration at the field scale in two types of soil in the Mediterranean region: non-stony and stony soil. The first step of the work was to calibrate both models under the non-stony conditions. The models were calibrated by using observations on wheat crop (leaf area index or canopy cover, and phenological stages as a function of degree days and pedo-climatic measurements. The second step consisted in the analysing the impact of the soil type on the models performances by comparing simulated and measured values. The outputs retained in the analysis were soil water content (at the daily scale and crop evapotranspiration (at two time scales: daily and crop season. The model performances were evaluated through four statistical tests: normalised difference (D% at the seasonal time scale; and relative root mean square error (RRMSE, efficiency index (EF, coefficient of determination (r2 at the daily scale. At the seasonal scale, values of D% were less than 15% in stony and on-stony soils, indicating a good performance attained by both models. At the daily scale, the RRMSE values (<30% indicate that the evapotranspiration simulated by CRITERIA is acceptable in both soil types. In the stony soil conditions, 3 out 4 statistical tests (RRMSE, EF, r2 indicate the inadequacy of AquaCrop to simulate correctly daily evapotranspiration. The higher performance of CRITERIA model to simulate daily evapotranspiration in stony soils, is due to the soil submodel, which requires the percentage skeleton as an input, while AquaCrop model takes into account the presence of skeleton by reducing the soil volume.

  5. Impact of slurry management strategies on potential leaching of nutrients and pathogens in a sandy soil amended with cattle slurry.

    Science.gov (United States)

    Fangueiro, D; Surgy, S; Napier, V; Menaia, J; Vasconcelos, E; Coutinho, J

    2014-12-15

    For farmers, management of cattle slurry (CS) is now a priority, in order to improve the fertilizer value of the slurry and simultaneously minimize its environmental impact. Several slurry pre-treatments and soil application methods to minimize ammonia emissions are now available to farmers, but the impact of such management strategies on groundwater is still unclear. A laboratory experiment was performed over 24 days in controlled conditions, with undisturbed soil columns (sandy soil) in PVC pipes (30 cm high and 5.7 cm in diameter). The treatments considered (4 replicates) were: a control with no amendment (CTR), injection of whole CS (WSI), and surface application of: whole CS (WSS), acidified (pH 5.5) whole CS (AWSS), the liquid fraction obtained by centrifugation of CS (LFS), and acidified (pH 5.5) liquid fraction (ALFS). An amount of CS equivalent to 240 kg N ha(-1) was applied in all treatments. The first leaching event was performed 72 h after application of the treatments and then leaching events were performed weekly to give a total of four irrigation events (IEs). All the leachates obtained w