• Authors:
    • Stahlman,P. W.
    • Vigil,M. F.
    • Benjamin,J. G.
    • Schlegel,A. J.
    • Stone,L. R.
    • Blanco-Canqui,H.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 4
  • Year: 2010
  • Summary: Because of increased concerns over compaction in no-till (NT) soils, it is important to assess how continuous cropping systems influence risks of soil compaction across a range of soils and NT management systems. We quantified differences in maximum bulk density (BD max) and critical water content (CWC) by the Proctor test, field bulk density (rho b), and their relationships with soil organic carbon (SOC) concentration across three (>11 yr) cropping systems on a silty clay loam, silt loam, and loam in the central Great Plains. On the silty clay loam, BD max in sorghum [ Sorghum bicolor (L.) Moench]-fallow (SF) and winter wheat [ Triticum aestivum (L.)]-fallow (WF) was greater than in continuous wheat (WW) and continuous sorghum (SS) by 0.1 Mg m -3 in the 0- to 5-cm soil depth. On the loam, BD max in WF was greater than in W-corn ( Zea mays L.)-millet ( Panicum liliaceum L.) (WCM) by 0.24 Mg m -3 and perennial grass (GRASS) by 0.11 Mg m -3. On the silt loam, soil properties were unaffected by cropping systems. Elimination of fallowing increased the CWC by 10 to 25%. The rho b was greater in WF (1.52 Mg m -3) than in WW (1.16 Mg m -3) in the silty clay loam, while rho b under WF and WCF was greater than under WCM and GRASS in the loam for the 0- to 5-cm depth. The BD max and rho b decreased whereas CWC increased with an increase in SOC concentration in the 0- to 15-cm depth. Overall, continuous cropping systems in NT reduced near-surface maximum soil compaction primarily by increasing SOC concentration.
  • Authors:
    • DeHaan,L. R.
    • Cox,C. M.
    • Tassel,D. L. van
    • Cox,T. S.
  • Source: Crop & Pasture Science
  • Volume: 61
  • Issue: 7
  • Year: 2010
  • Summary: Annual cereal, legume and oilseed crops remain staples of the global food supply. Because most annual crops have less extensive, shorter-lived root systems than do perennial species, with a correspondingly lower capacity to manage nutrients and water, annual cropping systems tend to suffer higher levels of soil erosion and generate greater water contamination than do perennial systems. In an effort to reduce soil degradation and water contamination simultaneously - something that neither no-till nor organic cropping alone can accomplish - researchers in the United States, Australia and other countries have begun breeding perennial counterparts of annual grain and legume crops. Initial cycles of hybridization, propagation and selection in wheat, wheatgrasses, sorghum, sunflower and Illinois bundleflower have produced perennial progenies with phenotypes intermediate between wild and cultivated species, along with improved grain production. Further breeding cycles will be required to develop agronomically adapted perennial crops with high grain yields.
  • Authors:
    • Schlegel, A. J.
    • Stone, L. R.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 2
  • Year: 2010
  • Summary: Efficient water use is the primary determinant of profitability in dryland crop production of the western Great Plains. For a sustainable increase in precipitation use efficiency (PUE) from that typical of the traditional winter wheat (Triticum aestivum L.)-fallow rotation with conventional stubble-mulch (sweep) tillage (CT) to occur, decreased use of fallow and tillage is required. Our objective was to quantify the effect of tillage intensity (no-till [NT], reduced tillage [RT], and CT) and phase of the winter wheat-grain sorghum [Sorghum bicolor (L.) Moench]-fallow rotation on selected sod properties that influence PUE, with emphasis on infiltration and the association between water-stable aggregates (WSA) and infiltration rate. Soil water content at -1.5 MPa matric potential, concentration of WSA >= 0.5 mm, mean weight diameter of WSA, and ponded steady-state infiltration rate were significantly greater with NT than RT or CT (infiltration rates: NT, 30.6; RT, 15.3; and CT, 11.4 mm h(-1)). Infiltration rate was significantly greater in the wheat phase (25.8 mm h(-1)) than in the sorghum (15.4 mm h(-1)) or fallow (16.2 mm h(-1)) phases. The significantly better conditions of aggregate stability and water infiltration with NT management and the lack of development of poor infiltration properties during the wheat season that would need to be alleviated by tillage after harvest reinforce the appropriateness of NT management in crop production systems of the region.
  • Authors:
    • Kohei, U.
    • Ebel, R.
    • Horowitz, J.
  • Source: Economic Information Bulletin
  • Volume: 70
  • Year: 2010
  • Summary: Most U.S. farmers prepare their soil for seeding and weed and pest control through tillage-plowing operations that disturb the soil. Tillage practices affect soil carbon, water pollution, and farmers' energy and pesticide use, and therefore data on tillage can be valuable for understanding the practice's role in reaching climate and other environmental goals. In order to help policymakers and other interested parties better understand U.S. tillage practices and, especially, those practices' potential contribution to climate-change efforts, ERS researchers compiled data from the Agricultural Resource Management Survey and the National Resources Inventory-Conservation Effects Assessment Project's Cropland Survey. The data show that approximately 35.5 percent of U.S. cropland planted to eight major crops, or 88 million acres, had no tillage operations in 2009.
  • Authors:
    • Wrigley, C. W.
    • Batey, I. L.
  • Source: Cereal grains: assessing and managing quality
  • Year: 2010
  • Summary: This book provides a convenient and comprehensive overview of academic research and industry best practice in the assessment and management of cereal grain quality. It includes 18 chapters and 2 appendices organized into 5 parts. Part I (3 chapters) introduces the themes of the book, reviews cereal grain morphology and composition, and discusses the diversity of uses of cereal grains. Part II (7 chapters) describes the characteristics and quality requirements of particular cereals, including wheat, rye, triticale, barley, oats, maize, rice, sorghum and millets. Part III (3 chapters) covers the use of analytical methods at different stages of the value-addition chain. It discusses the analysis of grain quality at receival, identification of grain variety and quality type, and food safety aspects of grain and cereal product quality. Part IV (5 chapters) reviews the factors affecting grain quality, such as breeding, storage and grain processing, and discusses possible future developments. Part V includes appendices on the composition of grains and grain products and the equivalence between metric and US units for the grain industry. This book will be a valuable reference for all those involved in the production and processing of cereal grains worldwide.
  • Authors:
    • Asnakech, T.
    • Adamu, M.
  • Source: World Journal of Agricultural Sciences
  • Volume: 6
  • Issue: 5
  • Year: 2010
  • Summary: It is becoming a necessity to intensify crop production in the face of the ever shrinking per capita agricultural land Experiences elsewhere suggest that intercropping potato with sorghum could be a feasible alternative so as to intensify production and give cash and food source alternatives for subsistence farmers. Three intercrop proportions (intercropping full density of potato with 75, 50 and 25% of sole crop density of sorghum) were compared with sole crops of potato and sorghum in a RCB of four replications for two years on sites representing sandy clay loam and clay black soil so as to determine compatible proportions of sorghum for intercropping with full density of potato. Marketable tuber yield of potato on sandy clay loam soil was not significantly affected by intercropping but it was significantly (P
  • 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.