• Authors:
    • Dong, G.
    • Chen, Z.
    • Wu, Z.
    • Sun, C.
    • Chen, L.
    • Zhang, Y.
  • Source: Plant Soil and Environment
  • Volume: 56
  • Issue: 11
  • Year: 2010
  • Summary: Agricultural practices that reduce soil degradation and improve agriculture sustainability are important particularly for dry hilly land of Chaoyang County in the Liaoning Province, North-east China, where cinnamon soils are widely distributed and mainly for wheat production. The impacts of 10-year cropping systems (wheat-cabbage sequential cropping, wheat-corn intercrop, wheat-sunflower rotation, wheat-soybean rotation) on soil enzyme properties of surface-soil (0-20 cm) were studied. Total carbon, nitrogen, phosphorus and sulfur, and nine soil hydrolases related to nutrient availabilities (beta-galactosidase, alpha-galactosidase, beta-glucosidase, alpha-glucosidase, urease, protease, phosphomonoesterase, phosphodiesterase, arylsulphatase) and five enzymes kinetic characters were examined. Wheat-corn intercrop systems had higher total C, total N, total P and total S concentrations than wheat-soybean and wheat-sunflower rotation systems. Most test enzyme activities (alpha-galactosidase, beta-galactosidase, alpha-glucosidase, beta-glucosidase, urease, protease, phosphomonoesterase and arylsulphatase) showed the highest activities under wheat-corn intercropping system. Urease, protease and phosphodiesterase activities of wheat-cabbage sequential cropping system were significantly higher than two rotation systems. The maximum reaction rates of enzymes ( Vmax) were higher than apparent enzyme activity, which suggests larger potential activity of enzymes, while not all kinetic parameters were adaptive as soil quality indicators in dry hilly cinnamon soil.
  • Authors:
    • Al-Tawaha, A.
    • Al-Ghzawi, A.
    • Al-Ajlouni, M.
  • Source: Journal of Food Agriculture & Environment
  • Volume: 8
  • Issue: 3/4 part 2
  • Year: 2010
  • Summary: Field experiments were conducted in North Part of Jordan to determine the best combination of crop rotations and fertilization levels that would improve the productivity of land and increase barley production under dryland conditions. Six-year field trials were conducted from 1996/1997 to 2001/2002 growing seasons at Ramtha Agricultural Research Station in north Jordan. Treatments effect was independent from each other and it is possible to select the best combination of treatments that give the highest yield. Rotation effect varied across growing seasons. Barley/vetch rotation showed the highest productive rotation. Additionally, barley yield was the same after vetch as after fallow. The application of 30 and 80 kg ha -1 of nitrogen and phosphorus, respectively, resulted in the highest values of fertilizer utilization efficiency.
  • Authors:
    • Evansf, R.
    • Lartey, R.
    • Caesar, T.
    • Sainju, U.
    • Lenssen ,A.
    • Allen, B.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Division Symposium 3.2 Nutrient best management practices
  • Year: 2010
  • Summary: Available water and N fertility are primary constraints to crop production in the northern Great Plains of the USA. A field trial was initiated in 2004 to compare four crop rotations in a complete factorial of two tillage and two management systems. Rotations were continuous spring wheat (SW), pea-SW, barley hay-pea-SW, and barley hay-corn-pea-SW. Tillage systems were no till and field cultivator tillage, while management systems were conventional and ecological. Conventional management included broadcast nitrogen fertilizer, standard seeding rates, and short stubble height. Ecological management practices varied by crop, and included banded nitrogen fertilizer for cereals, increased seeding rate, delayed planting date for SW, and taller stubble height. Continuous SW grain yield was 26% lower than SW in more diverse rotations. Pea grain yield was 18% lower in 2-yr rotations than in more diverse rotations. Ecologically managed SW yielded 29% less than conventionally managed SW, presumably due to the delayed planting date. Ecological management of pea resulted in 12% greater yield compared to conventional management. Tillage system rarely impacted crop yield. Yield increases in SW were related to increased N use efficiency.
  • Authors:
    • Nahas, E.
    • Cora, J.
    • Borges, C.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Symposium 2.2.1 Biogeochemical interfaces in soils
  • Year: 2010
  • Summary: Crop rotations have agronomic advantage. Type of crop rotations in combination with no-tillage system has not been evaluated systematically in Brazil. The objective of this work was to evaluate the effect of the crop rotation on the soil microbiological properties (MP) and the effect of winter crops on summer crops in no-tillage systems in a tropical region. This ecosystem management has been carried out annually since 2002. The summer crops are continuous soybean, continuous corn and soybean/corn rotation (SM). The winter crops are: corn, sunflower, radish, millet, pigeon pea, sorghum and sunn hemp. Samples were collected in April 2008 at 0-0,15 m depth after summer crops were harvested. Microbial respiratory activity, the activity of the enzymes dehydrogenase, urease and phosphatase, the biomass C, N and P, qMIC, organic matter and organic carbon contents were determined. Data was analyzed by principal components analysis (PCA). Soybean/corn sequence influenced the MP more than continuous corn and continuous soybean. For soybean/corn sequence soil, the main variables selected by PCA were biomass C, N and P, respiratory and phosphatase activities, and qMIC. Pigeon pea, sorghum and sunn hemp strongly affected the soil properties when compared with the other winter crops.
  • Authors:
    • Stone, L.
    • Kelley, K.
    • Sweeney, D.
    • Kluitenberg, G.
    • Buckley ,M.
  • Source: Soil Science Society of America Journal
  • Volume: 74
  • Issue: 6
  • Year: 2010
  • Summary: The midwestern United States has >4 million ha of claypan soils. These soils often require special management because of poor infiltration, drainage, and available water supply. This study was conducted to quantify the hydrologic balance of a claypan soil and determine the effect of tillage on water balance components. It was part of an ongoing project in Labette County, Kansas, in which no-till and chisel tillage plots had been maintained since 1995. A sorghum [ Sorghum bicolor (L.) Moench]-soybean [ Glycine max (L.) Merr.] rotation was initiated in 2003, with both crops grown each year in a randomized complete block design. The plots in sorghum were instrumented to measure water content throughout the profile. Precipitation and evapotranspiration (ET) were determined at the field scale. Soil hydraulic properties and water content data were used to estimate drainage. Runoff was determined as the residual in this water balance. Evaporation from chisel tillage was up to 1 mm d -1 greater than that from no-till during the early season. This resulted in differences in surface water content and runoff. These effects were limited to the early season, however, so that the water balance for the full growing season was not significantly affected by tillage. Drainage from the claypan soil was negligible. The 2006 crop year had 23.5 cm of ET, a value greater than the in-season precipitation. The 2007 crop year had 33.5 cm of ET, a value less than the in-season precipitation. With limited drainage and storage in the claypan, 37.5 cm of runoff occurred in 2007.
  • Authors:
    • Wruck, F.
    • Feigl, B.
    • Bernoux, M.
    • Cerri, C.
    • Raucci, G.
    • Carvalho, J.
    • Cerri, C.
  • Source: Soil & Tillage Research
  • Volume: 110
  • Issue: 1
  • Year: 2010
  • Summary: Changes in land use can result in either sources or sinks of atmospheric carbon (C), depending on management practices. In Brazil, significant changes in land use result from the conversion of native vegetation to pasture and agriculture, conversion of pasture to agriculture and, more recently, the conversion of pasture and agriculture to integrated crop-livestock systems (ICL). The ICL system proposes a diversity of activities that include the strategic incorporation of pastures to agriculture so as to benefit both. In agricultural areas, for example, the implementation of ICL requires the production of quality forage for animals between crops as well as the production of straw to facilitate the sustainability of the no-tillage (NT) management system. The objective of this study was to evaluate the modifications in soil C stocks resulting from the main processes involved in the changes of land use in Amazonia and Cerrado biomes. For comparison purposes, areas under native vegetation, pastures, crop succession and ICL under different edapho-climatic conditions in Amazonia and Cerrado biomes were evaluated. This study demonstrated that the conversion of native vegetation to pasture can cause the soil to function either as a source or a sink of atmospheric CO 2, depending on the land management applied. Non-degraded pasture under fertile soil showed a mean accumulation rate of 0.46 g ha -1 year -1. Carbon losses from pastures implemented in naturally low fertile soil ranged from 0.15 to 1.53 Mg ha -1 year -1, respectively, for non-degraded and degraded pasture. The conversion of native vegetation to agriculture in areas under the ICL system, even when cultivated under NT, resulted in C losses of 1.31 in six years and of 0.69 Mg ha -1 in 21 years. The conversion of a non-degraded pasture to cropland (soybean/sorghum) released, in average, 1.44 Mg of C ha -1 year -1to the atmosphere. The ICL system in agricultural areas has shown evidences that it always functions as a sink of C with accumulation rates ranging from 0.82 to 2.58 Mg ha -1 year -1. The ICL produces soil C accumulation and, as a consequence, reduces atmospheric CO 2 in areas formerly cultivated under crop succession. However, the magnitude of C accumulation in soil depends on factors such as the types of crops, the edapho-climatic conditions and the amount of time the area is under ICL.
  • Authors:
    • Martins, M.
    • Marcelo, A.
    • Fernandes, C.
    • Seben, G.
    • Cora, J.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Symposium 3.2.1 Highland agriculture and conservation of soil and water
  • Year: 2010
  • Summary: The no-tillage system is utilized in approximately 100 million hectares in the world. However, this system still needs to be better adapted to tropical regions, with warm and dry winters. The adaptation of no-tillage system in tropical regions depends on the suitable choice of summer and winter crops which should contribute to improvement of soil properties and soil productive capacity. The aim of the present study was to determine the effect of crop sequences on soil physical attributes of a Rhodic Eutrudox under no-tillage system. The treatments consisted of the combination of tree summer crop sequences and seven winter crop sequences. The summer crop sequences were: maize monocrop ( Zea mays L.), soybean monocrop ( Glycine max (L.) Merrill), and soybean/maize rotation. The winter crops were: maize, sunflower ( Helianthus annuus L.), radish ( Raphanus sativus L.), pearl millet ( Pennisetum americanum (L.) Leeke), pigeon pea ( Cajanus cajan (L.) Millsp), grain sorghum ( Sorghum bicolor (L.) Moench) and sunn hemp ( Crotalaria juncea L.). The experiment began in September 2002. Lower bulk density and high soil tensile strength were found in the soybean/maize rotation after sorghum and sunn hemp. Sorghum and sunn hemp provided the highest waterstability of soil aggregates. Millet, sorghum, maize and sunn hemp provided the highest mean aggregate diameter. The water-stability of soil aggregates and mean aggregate diameter showed positive correlation with soil tensile strength. There were no differences among effects of the summer and winter crops on the soil organic matter. In general, better soil physical conditions were found in the soybean/maize crop rotation and after sunn hemp, sorghum and millet.
  • Authors:
    • Chianu, J.
    • Kimetu, J.
    • Waswa, B.
    • Vanlauwe, B.
    • Kihara, J.
    • Bationo, A.
  • Source: Experimental Agriculture
  • Volume: 46
  • Issue: 1
  • Year: 2010
  • Summary: Many food production systems in sub-Saharan Africa are constrained by phosphorus (P).We hypothesized that within legume-cereal rotation systems: targeting P to the legume phase leads to higher system productivity, and that use of grain legumes leads to better economic returns than use of herbaceous legumes. Four P application regimes: (i) no P, (ii) P applied every season, (iii) P applied in season 1 only and (iv) P applied in season 2 only were tested for four seasons in three cropping systems (continuous maize, mucuna-maize rotation and soybean-maize rotation) in a split plot experiment set up in Nyabeda, western Kenya. Treatments where P was applied were better than no P treatments.While continuous cereal systems showed the need for application of P every second season, rotation systems involvingmucuna and soyabean indicated that application in one out of three seasons could be sufficient. Nitrogen fertilizer equivalence was 52 to >90 kg N ha -1 for soyabean and 37 to >90 kg N ha -1 for mucuna, depending on P fertilization and season. Analysis of marginal rates of return (MRR) showed that soybean-maize rotation with one application of P was the most economically viable option, with an MRR of at least 147% compared to other non-dominated options.
  • Authors:
    • Tittonell, P.
    • Leveque, J.
    • Sogbedji, J.
    • Guibert, H.
    • Kintche, K.
  • Source: Plant and Soil
  • Volume: 336
  • Issue: 1/2
  • Year: 2010
  • Summary: Soil degradation in the savannah-derived agroecosystems of West Africa is often associated with rapid depletion of organic carbon stocks in soils of coarse texture. Field experiments were conducted over a period of more than 30 years at two sites in semiarid Togo to test the impact of agricultural management practices on soil C stocks and crop productivity. The resulting datasets were analysed using dynamic simulation models of varying complexity, to study the impact of crop rotation, fertiliser use and crop residue management on soil C dynamics. The models were then used to calculate the size of the annual C inputs necessary to restore C stocks to thresholds that would allow positive crop responses to fertilisers under continuous cultivation. Yields of all crops declined over the 30 years irrespective of crop rotation, fertiliser use or crop residue management. Both seed-cotton and cereal grain yields with fertiliser fluctuated around 1 t ha -1 after 20 years. Rotations that included early maturing sorghum varieties provided larger C inputs to the soil through residue biomass; around 2.5 t C ha -1year -1. Soil C stocks, originally of 15 t ha -1 after woodland clearance, decreased by around 3 t ha -1 at both sites and for virtually all treatments, reaching lower equilibrium levels after 5-10 years of cultivation. Soil C dynamics were well described with a two-pool SOM model running on an annual time step, with parameter values of 0.25 for the fraction of resistant plant material (K 1), 0.15-0.20 for the decomposition rate of labile soil C (K 2) and 8-10 t C ha -1 for the fraction of stable C in the soil. Simulated addition of organic matter to the soil 30 years after woodland clearance indicated that additions of 3 t C ha -1year -1 for 15-20 years would be necessary to build 'threshold' soil C stocks of around 13 t ha -1, compatible with positive crop response to fertiliser. The simulated soil C increases of 0.5 to 1.6% per year are comparable with results from long-term experiments in the region. However, the amounts of organic matter necessary to build these soil C stocks are not readily available to resource-poor farmers. These experimental results question the assumption that crop residue removal and lack of fertiliser input are responsible for soil C decline in these soils. Even when residues were incorporated and fertilisers used at high rates, crop C inputs were insufficient to compensate for C losses from these sandy soils under continuous cultivation.
  • Authors:
    • Zombre, P.
    • Dakuo, D.
    • Traore, O.
    • Koulibaly, B.
    • Bonde, D.
  • Source: Tropicultura
  • Volume: 28
  • Issue: 3
  • Year: 2010
  • Summary: The effect of crop residues management on crops yields and nutrients balances in a cotton-cereals cropping system was studied in a long-term experiment carried out from 1982 to 2006. The experimental design was a simple nonrandomized blocks comparing extensive management of crops residues (T1), semiintensive management of crops residues (T2) and intensive management of crops residues (T3). Crops yields, soil chemical properties and mineral balances were measured. Results showed that after 25 years, soil carbon contents decrease was respectively 44%, 15% and 13%, with an extensive, semi-intensive and intensive management of crops residues. Total phosphorus decrease was 25% in all the treatments. Exchangeable Ca and Mg declined from 2.43 to 1.37 cmol+ kg -1 and 0.9 to 0.29 cmol+ kg -1 respectively while the Sum of Exchangeable Bases declined from 3.79 to 1.79 cmol+ kg -1. Recycling crops residues to compost and manure increased cotton yields from 13 to 22%, maize yields from 45 to 60%, and sorghum yields from 19 to 44%. Mineral balance in N, P, K and S was improved after 25 years of continuous cultivation while using compost or manure. At the same time, the decline of soil properties was due to nutrients losses which need to be evaluated. This study recommends integrated crops residues management and the use of rock phosphate to improve sustainability in cottoncereals cropping systems.