• Authors:
    • Westfall, D.
    • Davis, J.
    • Reich, R.
    • Moshia, M.
    • Khosla, R.
  • Source: Proceedings of the 9th International Conference on Precision Agriculture
  • Year: 2008
  • Summary: Animal manure is a useful resource that could be recycled beneficially for crop production. When applied to the agricultural land, manure can increase grain yield and improve soil fertility. The objective of this study was to assess the influence of variable rate manure applications on grain yield under continuous maize ( Zea mays L.) fields across low, medium and high Management Zones (MZs) in dryland cropping systems. The study was conducted over two consecutive years in northeastern Colorado on a fine-loamy, mixed, mesic Aridic Haplustalfs soil. Treatments included (i) Variable and Constant yield goal manure treatments ranging from 22 to 67 Mg ha -1 and (ii) uniform application of synthetic N fertilizer based on soil testing. Experimental strips were 4.5 m wide and 540 m long spanned across MZs with treatments nested within MZs. Manure applications exhibited positive relationship with grain yield in site-year I (R 2=0.53) and site-year III (R 2=0.98), which were dryland fields in succeeding years. After two years of the on-going study, VYG and CYG manure treatments produced higher grain yield on low MZs as opposed to high MZs. The increased grain yield on low MZ in SY III was due to the increased level of organic matter, mineralized N and increase precipitation. Uniform application of synthetic N fertilizer has shown no improvement in the second year, producing lesser grain yield as opposed to VYG and CYG manure treatments on low producing MZ. Variable rate applications of manure have the potential to significantly enhance maize grain yield of low producing areas of the field. The study suggests that variable rate application of manure has potential to be used as an alternative to or in conjunction with synthetic N fertilizer for improving soil fertility and maintaining or improving grain yield. The key to precision manure management is to find a balance between agronomically and environmentally sound manure application rates across spatially variable soils. The good thing about manure application in dryland farming is that, there is little environmental pollution concern, more especially in semi-arid environment of northeastern Colorado.
  • Authors:
    • Nayyar, A.
    • Bijay, S.
    • Humphreys, E.
    • Brar, N.
    • Yadvinder, S.
    • Timsina, J.
  • Source: ACIAR Proceedings Series
  • Issue: 127
  • Year: 2008
  • Summary: Rice-wheat (RW) is the dominant cropping system in north-western India and is of immense importance for national food security. However, the sustainability of the RW system is threatened by water shortage and nutrient mining. Permanent bed RW systems with crop residue retention have been proposed as a means of reducing irrigation water use, improving soil properties and reducing the cost of crop establishment. A field experiment was conducted over 4 years in Punjab, India, to compare conventional and permanent bed RW cropping systems, with and without retention of crop residues, in terms of crop performance and nitrogen use efficiency (NUE). Two methods of rice establishment (transplanting and dry seeding) were included on both beds and flats with four N application rates (0, 80, 120, 160 kg N/ha). Rice grain yield increased significantly as N rate increased up to 160 kg N/ha irrespective of method of rice establishment. Puddled transplanted rice (PTR) was always superior to all other establishment methods in terms of biomass, yield and NUE. At 120 kg N/ha, yield of transplanted rice on permanent beds (TRB) was 29% lower than yield of PTR, while yield of direct-seeded rice on permanent beds (DSRB) was even lower (44% lower than yield of TRB). Wheat straw mulch further reduced yield of DSRB by 26% on average, but there was no effect of mulching on yield of TRB. Dry-seeded rice on flats and beds was prone to severe iron deficiency and root nematode infestation. Yield of DSRB relative to yield of PTR declined as the beds aged but there was no trend in relative yield of TRB. Recovery of fertiliser 15N in the straw plus grain was 30% in PTR compared with 14% for TRB and 17% for DSRB. The majority (65-83%) of the crop N uptake was derived from the soil in all treatments despite the application of urea at 120 kg N/ha. Total N losses from the urea N applied to rice ranged from 52% to 60% in TRB and DSRB compared with 38% in PTR. Wheat yield increased with N rate up to 120 kg N/ha, with further significant response to 160 kg N/ha in 2 of the 4 years. Wheat grain yield on permanent beds after TRB and DSRB was 75-96% of that of conventionally tilled wheat (CTW), with no trend in relative yield over time as the beds aged. Grain yield of wheat was similar in CTW and direct-drilled ('zero-till') wheat (DDW) on the flat. The 15N recovery in the wheat plants in all flat and bed treatments was similar. Straw mulch had no effect on yield or NUE of wheat. Recoveries of applied N in the wheat plants (27-38%) and soil (45-59%) were much higher than in rice. Total fertiliser N losses were much lower in wheat (mean 14-21%) compared with rice (mean 38-60%). After eight crops, soil organic C, total N and available K were significantly higher with straw mulch compared with no mulch. Permanent beds for RW seem to have limited potential under the soil and climatic conditions of Punjab, India, with current technology, even with full residue retention for both crops. Further research on permanent raised beds should focus on selection of rice and wheat cultivars that are better suited to beds; soil health issues such as nematodes and iron deficiency; weed control; N, water and residue management; and machinery development and practices.
  • Authors:
    • Bellinder, R. R.
    • Brainard, D. C.
    • Hahn, R. R.
    • Shah, D. A.
  • Source: WEED SCIENCE
  • Volume: 56
  • Issue: 3
  • Year: 2008
  • Summary: Three major hypotheses were examined in this study: (1) the density of summer annual weeds is reduced in crop rotation systems that include winter wheat compared to those with strictly summer annual crops, (2) the integration of a red clover in cropping systems reduces weed seedbank densities, and (3) changes in weed seedbanks due to crop rotation system have greater impact on future crops that are managed with cultivation alone, compared to those managed with herbicides. To test these hypotheses, five 3-year rotation sequences were examined in central New York state, USA: continuous field maize (FC); field maize with red clover (FC+CL); field maize-oats-wheat (FC/O/W); sweetcorn-peas-wheat (SC/P/W), and SC/P/W with red clover (SC/P/W+CL). In the fourth year, sweetcorn, snap beans, and cabbage were planted in subplots with three levels of weed management as sub-subplots: cultivation alone, reduced-rate herbicides (1/2*), and full-rate herbicides (1*). The trial was carried out in two separate cycles, from 1997 to 2000 (cycle 1) and from 1998 to 2001 (cycle 2). Crop rotations with strictly summer annual crops (FC) did not result in consistently higher weed seedbank densities of summer annual weeds compared to rotations involving winter wheat (FC/O/W; SC/P/W; SC/P/W+CL). Integration of red clover in continuous field maize resulted in higher weed seedbanks (cycle 1) or emergence (cycle 2) of several summer annual weeds compared to field maize alone. In contrast, integration of red clover in the SC/P/W rotation led to a 96% reduction in seedbank density of winter annuals in cycle 1, although this effect was not detected in cycle 2. Observed changes in weed seedbank density and emergence due to crop rotation resulted in increased weed biomass in the final year in only one case (sweetcorn, cycle 2), and did not result in detectable differences in crop yields. In contrast, final year weed management had a strong effect on weed biomass and yield; cultivation alone resulted in yield losses for sweetcorn (32 to 34%) and cabbage (0 to 7%), but not snap beans compared to either 1/2* or 1* herbicides.
  • Authors:
    • Castoldi, G.
    • Gobbi, F.
    • Pivetta, L.
    • Costa, L.
    • Steiner, F.
    • Costa, M.
    • Tremea, A.
  • Source: Central theme, technology for all: sharing the knowledge for development. Proceedings of the International Conference of Agricultural Engineering, XXXVII Brazilian Congress of Agricultural Engineering, International Livestock Environment Symposium - ILES V
  • Year: 2008
  • Summary: The objective of this work was to evaluate the effect of two soil tillage systems (rotation and succession crops) and three fertilizations (mineral, organic and organomineral) in the wheat yield, under no-tillage system. The assay was conducted in the Experimental Station Prof. Dr. Antonio Carlos dos Santos Pessoa, located at the Nucleo of Experimental Station belonging to West Parana State University - Marechal Candido Rondon. In the winter of the 2006 was cropping the wheat in the plots in succession crops and black oat+radish+hairy vetch in the plots in rotation crops. The wheat received the mineral, organic and organomineral fertilization, while the cover crops weren't fertilized. In the summer was cropping corn in all the plots, receiving the three kind of fertilization. In the winter of the 2007 was cropping wheat in all the plots, receiving again the three kind of fertilization. The plant high and the weight of 100 grains weren't affected by the management systems and fertilizations. The succession system (wheat/corn/wheat) showed superior yield than the rotation system (green manure/corn/wheat). The organic manure showed superior hectoliter weight than mineral fertilization.
  • Authors:
    • Lopez, M. V.
    • Cantero-Martinez, C.
    • Arrue, J. L.
    • Alvaro-Fuentes, J.
  • Source: Soil Science Society of America Journal
  • Volume: 72
  • Issue: 2
  • Year: 2008
  • Summary: Under semiarid conditions, soil quality and productivity can be improved by enhancing soil organic matter content by means of alternative management practices. In this study, we evaluated the feasibility of no-till (NT) and cropping intensification as alternative soil practices to increase soil organic C (SOC). At the same time, we studied the influence of these management practices on two SOC fractions (particulate organic matter C, POM-C, and the mineral-associated C, Min-C), in semiarid agroecosystems of the Ebro River valley. Soil samples were collected from five soil layers (0–5-, 5–10-, 10–20-, 20–30-, 30–40-cm depth) during July 2005 at three long-term tillage experiments located at different sites in the Ebro River valley (northeast Spain). Soil bulk density, SOC concentration and content, SOC stratification ratio, POM-C, and Min-C were measured. Higher soil bulk density was observed under NT than under reduced tillage (RT), subsoil tillage (ST), or conventional tillage (CT). At the soil surface (0–5-cm depth), the highest total SOC concentration, POM-C, and Min-C were measured under NT, followed by RT, ST, and CT, respectively. In the whole soil profile (0–40 cm), similarly, slightly greater SOC content was measured under NT than under CT with the exception of the Selvanera site, where deep subsoil tillage combined with moldboard plowing accumulated more SOC than NT. In semiarid Mediterranean agroecosystems where CT consists in moldboard plowing, NT is a viable management practice to increase SOC.
  • Authors:
    • Reule, C. A.
    • Del Grosso, S. J.
    • Halvorson, A. D.
  • Source: Journal of Environmental Quality
  • Volume: 37
  • Issue: 4
  • Year: 2008
  • Summary: We evaluated the effects of irrigated crop management practices on nitrous oxide (N2O) emissions from soil. Emissions were monitored from several irrigated cropping systems receiving N fertilizer rates ranging from 0 to 246 kg N ha-1 during the 2005 and 2006 growing seasons. Cropping systems included conventional-till (CT) continuous corn (Zea mays L.), no-till (NT) continuous corn, NT corn-dry bean (Phaseolus vulgaris L.) (NT-CDb), and NT corn-barley (Hordeum distichon L.) (NT-CB). In 2005, half the N was subsurface band applied as urea-ammonium nitrate (UAN) at planting to all corn plots, with the rest of the N applied surface broadcast as a polymer-coated urea (PCU) in mid-June. The entire N rate was applied as UAN at barley and dry bean planting in the NT-CB and NT-CDb plots in 2005. All plots were in corn in 2006, with PCU being applied at half the N rate at corn emergence and a second N application as dry urea in mid-June followed by irrigation, both banded on the soil surface in the corn row. Nitrous oxide fluxes were measured during the growing season using static, vented chambers (1-3 times wk-1) and a gas chromatograph analyzer. Linear increases in N2O emissions were observed with increasing N-fertilizer rate, but emission amounts varied with growing season. Growing season N2O emissions were greater from the NT-CDb system during the corn phase of the rotation than from the other cropping systems. Crop rotation and N rate had more effect than tillage system on N2O emissions. Nitrous oxide emissions from N application ranged from 0.30 to 0.75% of N applied. Spikes in N2O emissions after N fertilizer application were greater with UAN and urea than with PCU fertilizer. The PCU showed potential for reducing N2O emissions from irrigated cropping systems.
  • Authors:
    • Hons, F.
    • Wright, A.
    • Dou, F.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 39
  • Issue: 5/6
  • Year: 2008
  • Summary: Distribution of dissolved (DOC) and soil organic carbon (SOC) with depth may indicate soil and crop-management effects on subsurface soil C sequestration. The objectives of this study were to investigate impacts of conventional tillage (CT), no tillage (NT), and cropping sequence on the depth distribution of DOC, SOC, and total nitrogen (N) for a silty clay loam soil after 20 years of continuous sorghum cropping. Conventional tillage consisted of disking, chiseling, ridging, and residue incorporation into soil, while residues remained on the soil surface for NT. Soil was sampled from six depth intervals ranging from 0 to 105 cm. Tillage effects on DOC and total N were primarily observed at 0-5 cm, whereas cropping sequence effects were observed to 55 cm. Soil organic carbon (C) was higher under NT than CT at 0-5 cm but higher under CT for subsurface soils. Dissolved organic C, SOC, and total N were 37, 36, and 66%, respectively, greater under NT than CT at 0-5 cm, and 171, 659, and 837% greater at 0-5 than 80-105 cm. The DOC decreased with each depth increment and averaged 18% higher under a sorghum-wheat-soybean rotation than a continuous sorghum monoculture. Both SOC and total N were higher for sorghum-wheat-soybean than continuous sorghum from 0-55 cm. Conventional tillage increased SOC and DOC in subsurface soils for intensive crop rotations, indicating that assessment of C in subsurface soils may be important for determining effects of tillage practices and crop rotations on soil C sequestration.
  • Authors:
    • Roel, A.
    • Terra, J.
    • Pravia, M.
  • Source: Proceedings of the 9th International Conference on Precision Agriculture, Denver, Colorado, USA, 20-23 July, 2008
  • Year: 2008
  • Summary: Soil management practices impacts on sorghum ( Sorghum bicolor) productivity have rarely been evaluated at field-scale. Field-scale soil management practices effects on sorghum grain yield were evaluated in three no-till crop-pasture rotation systems during two years in Uruguay (Oxyaquic Argiudoll). Treatments were established in a randomized complete block design in strips traversing the landscape in a sorghum-soyabean ( Glycine max) sequence integrated in three rotation systems: (1) continuous cropping (CC) with a winter cover crop of Lolium multiflorum; (2) short rotation (SR): two years pasture of T. pratense and L. multiflorum and two years of CC and; (3) long rotation (LR) four years pasture of Dactylis glomerata, Trifolium repens and Lotus corniculatus and two years of CC. Strips treatments included a factorial arrangement of two levels of cover crop residues (generated by winter grazing) with and without paraplough subsoiling. Strips were harvested with a combine equipped with a yield monitor. Data were analysed with mixed models accounting for spatial correlation. Yield was affected by year and rotation system but was not affected by management practices; either residue or subsoiling. Although its lower soil quality, CC had greater yield than SR and LR in 2006 (8.61 vs. 8.1 and 7.75 tonnes ha -1, respectively); however, no differences existed in 2007 (4.58 tonnes ha -1). Yield variations between field topographic zones were only found in 2007 SR (35%). Weak evidence of spatial correlation was found for soil properties at the site. No correlations were found between soil chemical properties and yield. Accounting for spatial correlation of 2006-2007 yields improved the statistical analysis. Animal treading and grazing did not appear to affect yield. For undegraded soils in temperate climates, cropping systems including no-tillage and perennial pastures preserved soil C, but did not guaranteed the same levels of grain productivity than more intensive cropping systems.
  • Authors:
    • Kremer, R. J.
    • Sudduth, K. A.
    • Kitchen, N. R.
    • Jung, W. K.
  • Source: Soil Science and Plant Nutrition
  • Volume: 54
  • Issue: 6
  • Year: 2008
  • Summary: Crop management has the potential to either enhance or degrade soil quality, which in turn impacts on crop production and the environment. Few studies have investigated how crop management affects soil quality over different landscape positions. The objective of the present study was to investigate how 12 years of annual cropping system (ACS) and conservation reserve program (CRP) practices impacted soil quality indicators at summit, backslope and footslope landscape positions of a claypan soil in north-central Missouri. Claypan soils are particularly poorly drained because of a restrictive high-clay subsoil layer and are vulnerable to high water erosion. Three replicates of four management systems were established in 1991 in a randomized complete block design, with landscape position as a split-block treatment. The management systems were investigated: (1) annual cropping system 1 (ACS1) was a mulch tillage (typically >= 30% of soil covered with residue after tillage operations) corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotation system, (2) annual cropping system 2 (ACS2) was a no-till corn-soybean rotation system, (3) annual cropping system 3 (ACS3) was a no-till corn-soybean-wheat (Triticum aestivum L.) rotation system, with a cover crop following wheat, (4) CRP was a continuous cool-season grass and legume system. In 2002, soil cores (at depths of 0-7.5, 7.5-15 and 15-30 cm) were collected by landscape position and analyzed for physical, chemical and biological soil quality properties. No interactions were observed between landscape and crop management. Relative to management effects, soil organic carbon (SOC) significantly increased with 12 years of CRP management, but not with the other management systems. At the 0-7.5-cm soil depth in the CRP system, SOC increased over this period by 33% and soil total nitrogen storage increased by 34%. Soil aggregate stability was approximately 40% higher in the no-till management systems (ACS2 and ACS3) than in the tilled system (ACS1). Soil aggregation under CRP management was more than double that of the three grain-cropping systems. Soil bulk density at the shallow sampling depth was greater in ACS3 than in ACS1 and ACS2. In contrast to studies on other soil types, these results indicate only minor changes to claypan soil quality after 12 years of no-till management. The landscape had minor effects on the soil properties. Of note, SOC was significantly lower in the 7.5-15-cm soil depth at the footslope compared with the other landscape positions. We attribute this to wetter and more humid conditions at this position and extended periods of high microbial activity and SOC mineralization. We conclude that claypan soils degraded by historical cropping practices will benefit most from the adoption of CRP or CRP-like management.
  • Authors:
    • Ushakova, E. Yu
    • Markova, V. E.
  • Source: Kormoproizvodstvo
  • Issue: 7
  • Year: 2008
  • Summary: Investigations were conducted during 1990-2007 on dark grey forest heavy loamy soils with intermediate content of nutrients using the standard technology of haylage mixture production, i.e. without the use of mineral fertilizers. The results showed that 12 variants of fodder crop mixtures were suitable for haylage production. Data are tabulated on energy indicators of mixtures of annual crops, i.e. oat + spring rape and spring vetch, oat + barley + pea, oat + field pea, barley + field pea, Sudan grass + oilseed radish, Sudan grass + spring vetch, Sudan grass + oat + pea, Sudan grass + field pea, Sudan grass + oat + soyabean, Sudan grass + barley + soyabean, Sudan grass + soyabean and Sudan grass + fodder bean. Data are included on energy value, energy consumption, green fodder yield and digestible protein content in crop mixtures. The results confirmed the possibility of development of continuous haylage production and high keeping quality of haylage made from the crop mixtures.