19,014 research outputs found
Residue and Compaction Management
No-till is becoming more popular because it reduces soil erosion, improves water conservation, and decreases labor requirements. Unfortunately, the crop residues that protect the soil surface from erosion in no-till systems may reduce com yields by slowing soil warming in the spring. One way to solve this problem may be to clear residues from the seed row, while leaving the rest of the soil surface residue covered
Importance of Soil Quality in Environment Protection
Soil quality can be characterised by the harmony between it’s physical and biological state and the fertility. From the practical crop production viewpoint, some important contrasting factors of soil quality are: (1) soil looseness – compaction; (2) aggregation – clod and dust formation; friable structure – smeared or cracked structure; (3) organic material: conservation – decrease; (4) soil moisture: conservation – loss; water transmission – water-logging; (5) at least soil condition as a result of the long term ef ect of land use moderates or strengthens climatic harm. In our long-term research project practical soil
quality factors were examined in arable i eld and experimental conditions.
We state that prevention of the soil quality deterioration can be done by the developing and maintaining harmony between land use and environment. Elements of the soil quality conditions such as looseness, aggregation,
workability, organic matter, water transport are examined and the improving methods are suggested. Tillage and production factors which can be adopted to alleviate the harmful climatic impacts are also summarised
The effects of compaction and residue management on soil properties and growth of Eucalyptus grandis at two sites in KwaZulu-Natal, South Africa.
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.Concerns have been raised over the long-term site productivity (LTSP) of short rotation plantation forests, such as those of Eucalyptus, in South Africa. This is because diminished productivity of long rotation plantations overseas has been found to be generally due to decreases in soil porosity and organic matter. Since soil porosity and organic matter in plantations are mainly affected by soil compaction by harvesting machinery and residue management, the more frequent harvesting of short rotation plantations are of particular concern. Therefore the effects of soil compaction and residue management on soil properties at two sites, one a low organic carbon, sandy soil (Rattray), the other a high organic carbon, clay soil (Shafton) were investigated. The potential of early E. grandis productivity as an indicator of changes in soil properties at these sites was also evaluated. Three different levels of compaction (low, moderate and high) were applied to the sites by three methods of timber extraction, i.e. manual, logger and forwarder loaded by a logger, respectively. Three types of residue management, i.e. broadcast, windrow and residue removal were also applied. A factorial treatment design was used to ensure a resource-efficient study that allowed separation of main and interaction effects. Various soil physical and chemical properties were measured at intervals from before treatment implementation, until approximately 44, and 38 months after treatment implementation at Rattray and Shafton, respectively. Trees were planted at a commercial espacement at both trials, and their growth monitored over the same time period. In addition, to accelerate early growth, negate silvicultural variation, and determine changes in stand productivity with treatments, a portion of the treatment plots were planted at a very high density and harvested when these trees reached canopy closure at about six months of age. Moderate and high compaction treatments at both sites resulted in significant increases in penetrometer soil strength, and often in bulk density. Increasing residue retention decreased the compaction effects of machinery and, generally, increased the total quantity of nutrients contained in residues and soil. Changes in soil bulk density and organic matter as a result of the treatments in turn affected soil water characteristics, generally decreasing plant available water capacity with increasing compaction intensity and residue removal. Tree growth measurements showed that at both sites, tree productivity was negatively affected at some point by increasing compaction. In contrast, residue management only significantly affected tree growth at Shafton, initially increasing and later decreasing growth with residue removal. These variations in tree growth over time in response to treatments are most likely a result of changes in tree characteristics that occurred with age. In addition, trees did not always reflect changes in soil properties that may affect LTSP, most likely because these soil properties had not yet reached levels that would affect tree growth. It was therefore concluded that early tree growth is not always a good indicator of changes in LTSP, and that soil properties are a more reliable indicator. Plantation management practices that lead to soil compaction and residue removals will negatively impact LTSP in South Africa. However, variable responses of the two soils indicate that soils vary in their sensitivity to compaction and residue management. This therefore needs to be quantified across a range of major soil types in the South African forestry industry
Development of a framework for the evaluation of the environmental benefits of controlled traffic farming
Although controlled traffic farming (CTF) is an environmentally friendly soil management system, no quantitative evaluation of environmental benefits is available. This paper aims at establishing a framework for quantitative evaluation of the environmental benefits of CTF, considering a list of environmental benefits, namely, reducing soil compaction, runoff/erosion, energy requirement and greenhouse gas emission (GHG), conserving organic matter, enhancing soil biodiversity and fertiliser use efficiency. Based on a comprehensive literature review and the European Commission Soil Framework Directive, the choice of and the weighting of the impact of each of the environmental benefits were made. The framework was validated using data from three selected farms. For Colworth farm (Unilever, UK), the framework predicted the largest overall environmental benefit of 59.3% of the theoretically maximum achievable benefits (100%), as compared to the other two farms in Scotland (52%) and Australia (47.3%). This overall benefit could be broken down into: reducing soil compaction (24%), tillage energy requirement (10%) and GHG emissions (3%), enhancing soil biodiversity (7%) and erosion control (6%), conserving organic matter (6%), and improving fertiliser use efficiency (3%). Similar evaluation can be performed for any farm worldwide, providing that data on soil properties, topography, machinery, and weather are available
Effects of no-tillage and subsoil loosening on soil physical properties and crop performance : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science in Soil Science at Massey University
Much of New Zealand's lowland agriculture integrates animal and crop production on poorly drained, easily compacted soils. Over the years, conventional cultivation has given rise to degraded soil structure on many farms. No-tillage has been shown to avoid many of these problems but the question remains: "Where soils are compact, what combination of deep tillage and/or drainage systems and no-tillage allow for the most efficient transition from conventional cultivation to no-tillage crop establishment?" The objective of this study was to ascertain if soil properties, and crop (Brassica campestis x Brassica napus cv "Pasja" followed by wheat Triticum aestivum cv "Kohika") establishment and yield on land converted from a conventionally tilled system to a no-tillage system could be improved by various subsoiling and mole plough operations. Plots on a Milson silt loam (Argillic Perch-Gley Pallic Soil) (Typic Ochraqualf) were paraplowed (PP), straight-legged subsoiled (SL), mole ploughed (M) or were left as non-subsoiled controls (C) in the autumn of 1997. Forage brassica was then sown with a Cross-Slot™ no-tillage drill. Wheat was established on the same plots with the same no-tillage drill in the spring of 1997. Subsoiling initially reduced soil strength by a significant amount. Shortly after subsoiling cone indices showed disruption to 300 mm with PP, 350 mm with SL and 100 mm with M. At the same time, approximately 20% of profile cone indices from subsoiled treatments were greater than 2 MPa, compared to approximately 52% for C and M. At 267 days after subsoiling, PP continued to have lower cone index values than C and M. Subsoiling initially reduced bulk density. When measured in May, the bulk density of PP plots was significantly lower than SL, M and C although reconsolidation in all plots was observed in February 1998 after the wheat was harvested. Air permeability in PP, SL and M was significantly greater than in C. Despite the differences in soil strength and bulk density (but not air permeability), subsoiling and mole ploughing did not produce differences in plant populations or yield for either the winter brassica or spring-sown wheat crops. The lack of any differences for brassica crop performance criteria were in spite of the vertical rooting depth being greater in the PP treatment. The lack of differences in plant establishment and yield was thought to be due to the relatively dry autumn and winter soil conditions and the use of the Cross-Slot™ no-tillage opener which is reported to be tolerant of variable soil conditions
The economic sustainability of second crops implementation in organic maize production
Although organic crop production has numerous advantages, concerns about economic sustainability, both environmental and financial, make farmers reluctant to convert their conventional production into the organic production. Certain agricultural methods, such as second crop use, can alleviate some problems regarding soil tilth, erosion prevention, nutrients availability and weed control, thus contributing toward more sustainable crop production. Also, the added value crop growth, such as maize (Zea mais L.) hybrid's parental line production, with lower yields but higher prices, can contribute to sustainability of organic production. In order to test the hypothesis that the use of second crops can contribute toward the sustainability of organically grown maize after soybean (Glycine max L.) as a previous crop in the crop rotation, the experimental site was established in Valpovo, Croatia, in the eutric brown soil type, during the years 2005 and 2006. The experimental design was set up as a CRBD in four repetitions, with six second crop treatments: CT – Control, without second crop; WW – winter wheat (Triticum aestivum L.) second crop; RY – rye (Secale cereale L.) second crop; FP – fodder pea (Pisum arvense L.) second crop; WP – mixture of WW and FP; and RP – mixture of RY and FP. In order to assess the soil surface protection and evaluate the weed suppression, the second crop coverage had been recorded. Regarding the economic sustainability, the second crop use depending costs were analysed in relation to the extra produced maize yield. The RY treatment had the highest profitability, followed by WW, RP and O. The WP and FP revealed lower relative profitability than O, thus presenting the evidence of sustainability risk of these treatments
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