• 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:
    • Iyapo, O.
    • Solomon, M.
    • Bello, O.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Symposium 3.1.2 Farm system and environment impacts
  • Year: 2010
  • Summary: Most of the arable land in Nigeria is characterized by fragile soils, having undergone intensive weathering, leaching and they are dominated by low activity clay, are infertile, have low nutrient response and are either acid or posses tendencies to become acid due to continuous or over cultivation. Soils especially around the cities in Nigeria are used for growing vegetables, cereals like maize, legumes like melon, soybean and cowpea which have been cultivated continuously for a period upward of 20 years due to the lack of arable land and the good market for the crops. Studies were conducted on the soil properties, soil reaction (pH); total nitrogen, organic carbon, base saturation, microbial populations (fungi and bacteria) and the determination of crop response to nutrient applications. The results obtained showed that the pH is acidic ranging from 4.1 to 5.1 and values of total nitrogen, organic carbon, base saturation, microbial populations and the identified nitrogen fixers are low. There is about a 60% yield reduction for the cultivated crops. The uptake of the applied nutrients by the crops is low consequently the soil is generally of low productivity.
  • Authors:
    • Pire, E.
    • Boccanelli, S.
    • Lewis, J.
  • Source: CIENCIA E INVESTIGACION AGRARIA
  • Volume: 37
  • Issue: 2
  • Year: 2010
  • Summary: Agriculture has been practised in the Argentine Pampa Region for more than a century. This long history of disturbance has strongly modified the native vegetation of the region. Some original species have disappeared or its area has been remarkably reduced. The objective was to evaluate vegetation changes over time after the abandonment of agriculture practice. Our hypothesis was that over time vegetation in this region will evolve towards a "flechillar" ( Stipa spp. community) similar to the original vegetation. The experiment was conducted at Zavalla (Santa Fe) Argentina (33degrees01′S, 60degrees53′W and 50 m.a.s.l.). Vegetation evolution was studied during 15 years (1982-1997) after abandonment, considering four initial crop situations (i.e. wheat, soybean, pasture and tillage). Periodically, we measured species cover and abundance in 60 subplots. Data was analyzed using multivariate methods. We identified several groups corresponding to two very well defined successional stages. The first group was very small, and showed predominance of annual species; the second group showed a reduction or almost disappearance of annuals and an increase in perennials such as Baccharis salicifolia (Ruiz & Pav.) Pers. and Sorghum halepense (L.) Pers. accompanied by Carduus acanthoides L. Therefore, a secondary succession was developed, with a first stage of annual species dominance followed by long life cycle species. However, even after 15 years there was no reversion of the vegetation to the original community.
  • 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:
    • Bosede, A.
  • Source: African Journal of Agricultural Research
  • Volume: 5
  • Issue: 5
  • Year: 2010
  • Summary: An assessment of fertilizer use and other integrated practices was carried out with two hundred farmers selected by stratified random sampling from twenty villages in Kano and Katsina States of Nigeria. The farming system was mixed farming (legume-cereal-livestock mixture), as a strategy both to address nutrient management as well as their livelihoods (both food and income security). The major crops comprised maize, sorghum, millet, rice, soybean, groundnut and cowpea. The average farm size was 7.4 ha and livestock comprised an average of 14 goats, 15 poultry birds, 7 sheep and 9 cattle. An average of 63 kg fertilizer was applied per ha of land relative to about 649 kg of fertilizer requirement per hectare of the crops grown, very low relative to Asia and some other African countries such as South Africa, Malawi, Benin and Ethiopia. The livestock mix provided substantial farmyard manure for fertilizing the soils and supplemented farm drought animals/animal traction while the crop residues (legumes and cereals) provided feeds for the livestock. It was found that fertilizer use multiplies the returns on farmers' output by a factor of 2.1-14.6, which was relatively higher than previous findings (IFDC, 2002) for the same crops in Nigeria, but crop yields were comparatively less for other Sub-Saharan and Asian countries. The observed higher response coefficient could be explained by the use of organic/farmyard manures and other soil conservation practices. Farmers exploit land and the natural fertility of the soil through continuous cropping and poor fertilization (organic and inorganic). Critical environmental issues emanating from these are soil nutrient depletion, soil degradation by erosion, weed and pest invasion, all culminating in sustained low productivity. It was therefore concluded that sustained growth in agricultural productivity without environmental exploitation and degradation cannot be achieved unless efforts to enhance farmers' fertilizer use and organic fertilization are taken seriously. Efforts should be put in place to correct fertilizer market inadequacies, particularly to monitor the quality standard and guarantee farmers' access to fertilizers, as well as encourage National research and extension programs to emphasize economic use of basic local materials for effective fertilization of farmers' fields, reduced vulnerability to nutrient loss and drought, and increased agricultural productivity.
  • 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:
    • Pierzynski, G.
    • Tuppad, P.
    • Janssen, K.
    • Maski, D.
    • Douglas-Mankin, K.
  • Source: Transactions of the ASABE
  • Volume: 53
  • Issue: 5
  • Year: 2010
  • Summary: Cropland best management practice recommendations often combine tillage and nutrient application improvements to reduce nutrient losses with surface runoff. This study used the Soil and Water Assessment Tool (SWAT) model to evaluate nutrient runoff yields from conventional-till and no-till management practices with surface and deep-banded fertilizer application in a sorghum-soybean rotation. The model was calibrated for three field plots (0.39 to 1.46 ha) with different combinations of practices and validated for three field plots (0.40 to 0.56 ha) during 2001 to 2004. Daily performance of the calibrated SWAT model in simulating total N for all treatments was satisfactory for median-based Nash-Sutcliffe model efficiency (E f* of 0.54 to 0.64), good to very good for percent bias (PBIAS of 31% to 7%), and satisfactory to good for median-based root mean square error to observations standard deviation ratio (RSR* of 0.72 to 0.62). Performance was slightly lower and more variable for total P calibration (E f* of 0.42 to 0.62, PBIAS of -48% to 2%, and RSR* of 0.76 to 0.62). Monthly statistics improved for total P runoff yield compared to daily performance, but changed little for total N runoff yields, probably due to the stronger influence of outliers in the N data. Based on validation results, SWAT was more robust in simulating total N runoff yields from the treatment with less soil disturbance (NT/SB) and total P for the two treatments with more soil disturbance (NT/DB and TILL). A major concern was that SWAT predicted greater annual average total N runoff yields for no-till treatments than for tilled treatments, which was contrary to measured values at the study site. This reinforces a fundamental research issue that tillage system effects on nutrient losses are still very much uncertain and thus may not be properly modeled. The SWAT model generally underpredicted monthly total N yields for all treatments in the higher-precipitation months of May and June and overpredicted total N and total P yields from September through November. Calibration for N and P resulted in identical calibration parameters for NPERCO (1.0), RSDCO (0.05), BIOMIX (0.2), PPERCO (10), PHOSKD (175), and UBP (50) regardless of tillage practice or fertilizer application method. Together with results that calibrated parameters for runoff (CN, K sat, AWC) and erosion (C min) differed among the treatments, this study found that differences in nutrient yields among tillage and fertilizer management may be adequately modeled with SWAT by calibrating runoff and sediment yields only, and that further calibration of nutrient parameters may not improve model results.
  • Authors:
    • Sweeney, D.
    • Kelley, K.
  • Source: Crop Management
  • Issue: July
  • Year: 2010
  • Summary: Field studies were conducted from 1996 through 2006 in southeastern Kansas to evaluate the influence of previous crop [corn, Zea mays L.; grain sorghum, Sorghum bicolor (L.); and soybean, Glycine max (L.) Merr.] and tillage system (conventional versus no-till) on grain yield of hard red winter wheat ( Triticum aestivum L.) and double-crop soybean in a 2-year rotation. On average, wheat yield was greater following corn or soybean than following grain sorghum. Yield of double-crop soybean averaged 20% greater when wheat followed corn or grain sorghum than when wheat followed full-season soybean. Tillage system influenced grain yield of double-crop soybean more than it influenced wheat yield. Double-crop soybean yield often was greater for continuous no-till than for conventional or one-time no-till per cropping cycle. Soil analyses at the end of the study showed that total C and total N were greater for no-till than for conventional in the 0- to 3-inch depth, but total C and total N were greater for conventional than no-till in the 3- to 6-inch depth. In the multi-cropping systems of the eastern Great Plains, both crop rotation and tillage system can significantly influence grain yield and selected soil properties.