• Authors:
    • Halvorson, A. D.
    • Archer, D. W.
  • Source: Soil Science Society of America Journal
  • Volume: 74
  • Issue: 2
  • Year: 2010
  • Summary: Recent soil and crop management technologies have potential for mitigating greenhouse gas emissions; however, these management strategies must be profitable if they are to be adopted by producers. The economic feasibility of reducing net greenhouse gas emissions in irrigated cropping systems was evaluated for 5 yr on a Fort Collins clay loam soil (a fine-loamy, mixed, superactive, mesic Aridic Haplustalf). Cropping systems included conventional tillage continuous corn ( Zea mays L.) (CT-CC), no-till continuous corn (NT-CC), and no-till corn-bean (NT-CB) including 1 yr soybean [ Glycine max (L.) Merr.] and 1 yr dry bean ( Phaseolus vulgaris L.). The study included six N fertilization rates ranging from 0 to 246 kg ha -1. Results showed highest average net returns for NT-CB, exceeding net returns for NT-CC and CT-CC by US$182 and US$228 ha -1, respectively, at economically optimum N fertilizer rates. Net global warming potential (GWP) generally increased with increasing N fertilizer rate with the exception of NT-CC, where net GWP initially declined and then increased at higher N rates. Combining economic and net GWP measurements showed that producers have an economic incentive to switch from CT-CC to NT-CB, increasing annual average net returns by US$228 ha -1 while reducing annual net GWP by 929 kg CO 2 equivalents ha -1. The greatest GWP reductions (1463 kg CO 2 equivalents ha -1) could be achieved by switching from CT-CC to NT-CC while also increasing net returns, but the presence of a more profitable NT-CB alternative means NT-CC is unlikely to be chosen without additional economic incentives.
  • Authors:
    • Frederick, J. R.
    • Fortnum, B. A.
    • Bauer, P. J.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 4
  • Year: 2010
  • Summary: Longer rain-free periods are predicted to occur more often in the southeastern United States as a result of global climate change. This nonirrigated field study was conducted from 1997 through 2002, which coincided with the 1998-2002 drought that affected most of the United States. The objective was to determine the effect of rotation and tillage on cotton (Gossypium hirsutum L.) productivity. Treatments in the study were rotation [cotton rotated with corn (Zea mays L.), cotton planted after a rye (Secale cereale L.) winter cover crop, and continuous cotton with no cover crop] and tillage system (conventional tillage and conservation tillage). Two levels of aldicarb [2-methyl-2-(methylthio)propanal O-{(methylamino)carbonyl}oxime] (0 and 1.18 kg a.i. ha(-1)) were also included because of known soil management effects on thrips (Frankliniella sp.) and root-knot nematodes (Meloidigyne incognita). The predominant soil types were Bonneau loamy sand (loamy, siliceous, subactive, thermic Arenic Paleudult) and Norfolk loamy sand (fine-loamy, kaolinitic, thermic Typic Kandiudult). Rotation did not affect cotton yield in any year. Tillage did not affect cotton yield in 1997. Conservation tillage resulted in an average 25% yield increase in cotton lint yield over conventional tillage during the 5-yr drought. Tillage and aldicarb affected both thrips and root-knot nematodes, but lack of interaction among these factors for lint yield suggested that management of these pests was not the predominant cause for the cotton yield increase with conservation tillage. Conservation tillage for cotton production could be an important method to help mitigate the effects of climate change in the region if change occurs as predicted.
  • Authors:
    • Schindler, U.
    • Muller, L.
  • Source: Proceedings of the 10th International Agricultural Engineering Conference
  • Year: 2009
  • Summary: Land management practice is a decisive factor for the quantities of seepage flow and solute leaching, which constitute two fundamental aspects of land use characterised by potentially conflictive ecologic implications. Efficient water use and intelligent water management are essential for Northeast Germany as a sub-humid region marked by an annual water balance deficit between 80 and 250 mm. Throughout that region, measures are in demand to support groundwater recharge. To meet this claim, knowledge is required about suitable land management systems providing drainage flow sustainable in quantity and quality. Long-term soil hydrological measurements were used to quantify deep drainage and nitrate leaching insitu under undisturbed soil conditions. Deep drainage rates and nitrate losses from arable land managed under various farming regimes (integrated, integrated with irrigation, ecologic and low input) and tillage systems (plough and no till) were quantified in the Pleistocene region of Northeast Germany from 1994 to 2007. Soil water content and tension measurements down to 3 m depth and soil water sampling were used to determine deep drainage dynamics and loss of nitrogen by leaching. As dependent on the management system, the nitrate concentration varied between 40 and 150 mg l -1. In connection with annual deep drainage rates between 100 mm and 200 mm during the study period, the annual nitrogen loss varied between 14 and 41 kg ha -1. Differences in nitrogen loss observed between the farming systems were low, but yields increased and nitrogen losses decreased as a result of irrigation throughout the variants. No-till treatment resulted in reduced nitrate leaching (18 kg ha -1) as compared with the tillage system with plough and tooth cultivator (27 kg ha -1). The suitability of long-term soil hydrological in-situ measurements for quantifying arable management effects on ecological processes - deep drainage dynamics and solute leaching - was confirmed. The trend of decreasing deep drainage was low and not significant. However, due to no significance and quite short investigation period it is not allowed to suggest on climate change effects.
  • Authors:
    • Abrol, V.
    • Singh, J. P.
    • Hussain, S. Z.
  • Source: AMA-Agricultural Mechanization in Asia, Africa and Latin America
  • Volume: 40
  • Issue: 1
  • Year: 2009
  • Summary: Tillage is a major farm operation that consumes time, energy and expense. Dryland cultivation practices need to minimize cost of production in all crops. An experiment has been conducted on two tillage systems: (1) conventional and (2) reduced tillage, to save energy in production of maize and wheat in Jammu, India. Three tillage treatments in combination with three fertilizer treatments were used. The highest yield of maize was 20.50 q/ha with conventional tillage + interculture. The next highest yield for maize was 20.16 q/ha with 50% conventional tillage + weedicide + interculture. The highest yield of wheat was 29.33 q/ha with 50% conventional tillage + weedicide + interculture. The next highest yield of wheat was 27.87 q/ha with conventional tillage + interculture. The fertilizer treatment showed the highest average grain yield of maize of 21.90 q/ha with 100% N with inorganic fertilizer. The next highest fertilized treatment with maize was with 50% N through organic + 50% N through inorganic fertilizers for a yield of 19.85 q/ha. A similar trend was found for wheat with the highest average grain yield of 29.00 q/ha with 100% N through inorganic fertilizer. The next highest fertilized treatment with wheat was with 50% N through organic + 50% N through inorganic fertilizers with a grain yield of 28.25 q/ha. The operational energy and cost of operation were higher in the conventional tillage system (5013.8 MJ, Rs. 10 574 and 2907.53 MJ, Rs.11 347.33) than in reduce tillage (3625.39 MJ, Rs.9750 and 2227.20 MJ, Rs.10 335.30) and the benefit cost ratio ranged from 1.52: 1 to 0.36: 1 and 1.08: 1 to 1.41: 1 in production of maize and wheat, respectively.
  • Authors:
    • Sousa, D. M. G. de
    • Rein, T. A.
  • Source: Informações Agronômicas
  • Issue: 126
  • Year: 2009
  • Summary: Soyabean monoculture with inadequate agricultural practices has resulted in losses of soil organic matter in the Brazilian cerrado, especially in sandy soils. This has led to erosion, reduced cation exchange capacity and water storage, and diminished fertilizer use efficiency. One of the ways of avoiding the loss of soil organic matter is to reduce tillage, as in the system of direct (as opposed to conventional) planting, and the use of this system is growing in the cerrado region. This paper reviews work that has been done on the correction of soil acidity and fertilizing with macronutrients in the direct planting system, both before and after crop establishment. The section on soil acidity discusses both surface (0-20 cm) and subsurface (20-60 cm) acidity, and the effects of correction with limestone or gypsum under conventional and no tillage systems, and on cotton and soyabean yields under a direct planting system. The section on fertilizers looks at the effects of liming, conventional and no tillage systems and dry farming on soil macronutrient content (with particular reference to nitrogen, phosphorus and potassium) and crop yield (with data for maize). Soil organic matter content is also compared under conventional and no tillage systems.
  • Authors:
    • Gomes, A. da S.
    • Vernetti Junior, F. de J.
    • Schuch, L. O. B.
  • Source: Revista Brasileira de Agrociencia
  • Volume: 15
  • Issue: 1/4
  • Year: 2009
  • Summary: In the state of Rio Grande do Sul, Brazil, there are 5,5 million ha of tilled plain soils that have been partly cropped with irrigated rice ( Oryza sativa L.), the remainder area lodging extensive beef cattle raising. This research was undertaken aiming chiefly to identify one or more technical solutions to the agribusiness associated with the agro-ecosystem of the "Temperate Climate region". The work was carried out at experimental area of Lowland Agricultural Research Station of Embrapa Temperate Climate (31degrees 52′S; 52degrees 21′24W), Brazil. The experiment was planned in a split-plot randomized blocks design with three replications and performed along ten years. The treatments were successive winter and spring-summer crops growing during five years, followed by two years of no-cropping and then three years of irrigated rice crop growing. The spring-summer crops were corn and soybean, besides rice; the winter crops were poaceae (Ps), fabaceae (Fs), species mixtures (Ms), turnip (T) and native grass species (NG). Seeding was performed either by no-ploughing (PD) or conventional (SC). Grain and dry-matter yields were estimated and evaluated. The evaluations were performed by analysis of variance (F and Duncan tests). The results allowed the following conclusions: (1) Ps and Fs had the highest yields; (2) corn yields were higher when its crop followed Fs species and/or Ms; (3) corn crop in tiled plains shows better performance when planted in no-plow; (4) soybean crop following Ps performed better than following Fs; (5) no-plough favors the soybean crop in tilled plains; (6) irrigated rice yields are higher succeeding the corn crop.
  • Authors:
    • Wuest, S. B.
    • Siemens, M. C.
    • Gollany, H. T.
    • Williams, J. D.
    • Long, D. S.
  • Source: Journal of Soil and Water Conservation
  • Volume: 64
  • Issue: 1
  • Year: 2009
  • Summary: Conservation tillage systems that reduce Soil erosion and maintain or increase soil carbon offer long-term benefits for producers in the inland Pacific Northwestern United States but Could result in reduced grain yields due to increased pressure from weeds, disease, and insect pests. Our objective was to compare runoff, soil erosion, and crop yields from a conventional tillage, wheat-fallow two-year rotation and a no-till four-year rotation. The experiment was undertaken within a small,watershed to provide results that would be representative of conservation effectiveness at the field scale. Two neighboring drainages, 5.8 and 10.7 ha (14 and 26 ac), in the 340 mm y(-1) (13.4 in yr(-1)) precipitation zone of northeastern Oregon, were instrumented to record rainfall, runoff, and erosion over a four-year period (2001 through 2004). One drainage was cropped to a winter wheat-fallow rotation and received inversion tillage (tillage fallow). The second drainage was cropped in a four-year no-till rotation: winter wheat-chemical fallow-winter wheat-chickpea (no-till Fallow). We recorded 13 runoff events from the inversion tillage system and 3 from the no-till system. Total runoff and erosion values from inversion tillage drainage were 5.1 mm (0.20 in) and 0.42 Mg ha(-1) (0.19 tn ac(-1)) versus 0.7 mm (0.03 in) and 0.01 Mg ha(-1) (<0.005 in ac(-1)) from no-till drainage. The no-till rotation was substantially more effective in conserving soil and water in this field-scale comparison. Soil erosion observed in this research is a fraction of that reported for similar tillage practices outside of the Pacific Northwestern. Mean wheat yields did not significantly differ between inversion tillage and no-till treatment despite intensifying the rotation by replacing one year of fallow with a chickpea crop in the four-year rotation. Because of high year-to-year variability in yield and limited sample size, more study is needed to compare winter wheat yields in no-till production systems with inversion tillage. The no-till cropping system was more e effective in reducing runoff and soil erosion and provides producers with an ability to protect soil and water resources in the dryland Pacific Northwest.
  • Authors:
    • Gonzalez, A.
    • Luciano, R.
    • Bertol, I.
    • Barbosa, F.
    • Vazquez, E.
  • Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
  • Volume: 33
  • Issue: 2
  • Year: 2009
  • Summary: Where nutrients are lost by water erosion, the eroded soil is impoverished and crop productivity is reduced, apart from the water contamination. Soluble N in the runoff is biologically available and contributes to eutrophication of the water and, depending on the form and content in the water, may be toxic to aquatic organisms. In order to evaluate the N content in the form of ammonium and nitrate in the runoff water, an experiment was conducted with simulated rainfall from April to November 2006, on an Inceptisol under conventional tillage. A combination of three factors was studied: crop type, sowing form and simulated rainfall test. The crops black oat ( Avena strigosa) [ Avena nuda] and common vetch ( Vicia sativa) were studied, as well as the sowing forms: mechanical, along rows in slope direction; broadcast by hand; and mechanized along contour lines; and five simulated rainfall tests, at a constant and planned intensity of 64 mm/h and rainfall duration of 1 h. The first four rainfall tests were applied during the crop cycles and the fifth on the crop residues maintained on the soil surface. Nitrogen application to oat as urea cover dressing, immediately before rainfall test 1, resulted in a higher N-NH 4+ content in the runoff water from oat than from vetch, exceeding the acceptable level for the aquatic community. The residues decomposition on the soil surface under rainfall, the content of soluble N-NO 3- in the runoff water was higher in the crops of contour sowing than of slope sowing. The contents of soluble N-NH 4+ and N-NO 3- in the runoff water decreased from the beginning to the end of the crop cycles, but increased in the rainfall test on vetch mulch, to higher values than in the treatment with oat residue.
  • Authors:
    • Vanderlinden, K.
    • Murillo, J. M.
    • Madejon, E.
    • Lopez-Garrido, R.
    • Melero, S.
    • Ordonez, R.
    • Moreno, F.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 133
  • Issue: 1-2
  • Year: 2009
  • Summary: Long-term field experiments can provide relevant information regarding soil organic carbon sequestration under different soil tillage systems. Especially, conservation tillage (CT) has been proved to be a practice that highly contributes to improve soil quality. For that reason, the study of soil quality indicators, such as organic fractions, are useful tools to assess changes caused by different soil tillage systems in long-term field experiments. We evaluated long-term effects of conservation tillage on soil carbon fractions and biological properties in a sandy clay loam Entisol (soil A) and in a clay Vertisol (soil B) located in semi-arid SW Spain. Cereal-sunflower-legume rotations under rainfed conditions were used in both soils in which conservation tillage (CT) was compared to traditional tillage (TT). Soil samples were collected at three depths (0-5, 5-10 and 10-20 cm) four months after sowing a pea crop ( Pisum arvense L.) in the Entisol and a wheat crop ( Triticum aestivum L.) in the Vertisol. Labile fractions of the total organic carbon (TOC) were determined as active carbon (AC) and water soluble carbon (WSC). Biological status was evaluated using soil microbial biomass carbon (MBC) and enzymatic activities [dehydrogenase activity (DHA), o-diphenol oxidase activity (Dphox), and beta-glucosidase activity (beta-glu)]. As a rule, the contents of AC, WSC, MBC, beta-glu and Dphox in soil A and contents of TOC, AC and DHA in soil B were higher in CT than in TT, at the 0-5 cm depth. In both soils, the studied parameters decreased with depth under both tillage treatments (TT and CT). Values of AC, TOC, MBC and beta-glu were positively correlated with each other ( p
  • Authors:
    • Ruiz, J. C.
    • Vanderlinden, K.
    • Melero, S.
    • Madejon, E.
  • Source: The Journal of Agricultural Science
  • Volume: 147
  • Issue: 1
  • Year: 2009
  • Summary: Soil enzyme activities are widely utilized as rapid and sensitive indicators in discriminating among soil management effects. The objective of the present study was to compare the influence of conservation tillage, i.e. direct drilling (DD) (residue cover is left on the soil surface) v. conventional tillage (CT), on soil chemical and biochemical properties in a crop rotation (cereals-sunflower-legumes) under dryland production in a semi-arid Mediterranean Vertisol after 23 years. A randomized experimental design was established. Soil biological status was evaluated by measuring of enzymatic activities (dehydrogenase, beta-glucosidase, alkaline phosphatase and protease). Total organic carbon (TOC) contents were greater in soils managed by DD than those found by CT. Except for protease activity, enzymatic activity values were approximately 2-fold higher in soils under DD than in soils under CT. The beta-glucosidase, alkaline phosphatase and dehydrogenase values showed a high correlation (from r=0.481 to r=0.886, P≤0.01) with TOC contents and they were correlated with each other (from r=0.664 to r=0.923, P≤0.01). The coefficient of variation of biochemical properties was higher than those of chemical properties in both treatments. Principal component analysis (PCA) showed that two principal components explained 58% and 20% of the total variability. The first principal component was influenced mostly by beta-glucosidase, dehydrogenase and TOC, whereas the second was influenced by pH. The first component effectively differentiated managed soil under both agriculture practices. In general, long-term soil conservation management by DD in a dryland farming system improved the quality of this Vertisol by enhancing its organic matter content and biochemical activity.