Wall Street Journal - USA
... of gallons of fuel, perhaps one billion tons of soil each year from running into waterways, and significantly improving moisture conservation as well. ...
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Thursday, January 31, 2008
WATER CONSERVATION AND EFFICIENCY: A Prairie Perspective
... uncertainty of changing weather patterns producing adequate moisture, loss of ... Other
benefits of conservation include: • Deferral and/or elimination of ...
benefits of conservation include: • Deferral and/or elimination of ...
principles and practices of crop rotation
... Moisture conservation In a moisture-limited environment such as Saskatchewan,
crops generally use all the available water in the root zone. ...
crops generally use all the available water in the root zone. ...
Organic Crop Production: Soil Conservation Practices - Agriculture ...
... Moisture conservation is important to soil conservation because the additional moisture
will improve crop growth, thus residue production, the following year. ...
will improve crop growth, thus residue production, the following year. ...
Effects of Soil Management Practices and Tillage Systems on Soil Moisture Conservation and Maize Yield on a Sandy Loam in Semiarid Kenya
| Page Range: 77 - 92 DOI: 10.1300/J064v27n03_06 Copyright Year: 2005 | |||
| Contributors: | P T Gicheru, Kenya Agricultural Research Institute, Nairobi, Africa, kss@iconnect.co.ke C. K.K. Gachene, Department of Soil Science, University of Nairobi, Nairobi, Africa, ckkgachene@africaonline.co.ke J. P. Mbuvi, Department of Soil Science, University of Nairobi, Nairobi, Africa | ||
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| Abstract: | |||
| Maize is an important crop in the high and medium rainfall areas of Kenya and thus, there is a need for additional information on the effect of tillage and soil management practices on water conservation and yield of maize. The objective of this study was to determine the effects of seven soil management practices: bare with conventional tillage (BC), bare with minimum tillage (BM), incorporated mulch with conventional tillage (IMuC), manure with conventional tillage (MaC), manure with minimum tillage (MaM), surface mulch with conventional tillage (SMuC), and surface mulch with minimum tillage (SMuM) on water conservation and yield of maize. Soil water content was greater in minimum tilled plots than in the conventionally tilled (hand hoeing) plots during the study period. This was demonstrated by the manure with minimum tilled treatment, which had the highest soil moisture (7.6% and 8.3%) both at 0-7 cm and 7-23 cm depth. However, when organic matter additions were analyzed separately, it was observed that manure irrespective of tillage had the highest soil moisture in both depths (7.6% and 8.1%). The differences within the treatments occurred when soil water contents were highest shortly after the rains. When the amount of soil water for each management practice was averaged for all the seasons, a significant difference was found at P = 0.0001. Manure (Ma) and surface mulched (Smu) treatments had significantly higher soil moisture content than the other treatments. The higher moisture content found under these treatments was attributed to higher infiltration rates, better cover that reduced the rainfall kinetic energy, and to better structural stability contributed to by higher organic carbon. Compared with the traditional form of hand hoeing, minimum tillage increased available soil water content drastically and crop performance was improved. Grain yields were greatest in manure and lowest in bare treatments. There were significant differences in grain yield in all treatments. | |||
| Journal Title: | |||
| Journal of Sustainable Agriculture: . . . innovations for long-term and lasting maintenance and enhancement of agricultural resources, production and environmental quality Volume: 27 Issue: 3 ISSN: 1044-0046 Pub Date: 3/9/2006 Table of Contents for this Issue Recommend This Journal | |||
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Reprints and Permissions Sunday, January 6, 2008
Soil Quality and Moisture Conservation Benefits of Direct Seeding
Direct seeding of crops into standing stubble can enhance soil quality and moisture conservation by reducing the detrimental effects of tillage on soil. In comparison to conventional tillage systems, direct seeding can result in:
* better water infiltration
* increased seedbed moisture
* increased soil organic matter
* reduced soil erosion potential.
The extent to which these benefits are realized depends on local soil type and weather conditions.
Water Infiltration Increases
Tillage can reduce infiltration of rain and snowmelt by changing the natural soil structure. Cultivator shovels, discs or plows create a compacted layer (or shear plane) beneath the bottom of the implement. Tillage also destroys natural pores, root channels and cracks, and fills them with loose soil particles. This problem is more pronounced in clay soils.
Direct seeding leaves more of the soil s natural channels and cracks intact, allowing water to infiltrate more easily. This is very important for deep storage of soil moisture, for reducing water ponding on the soil surface, and for reducing runoff and water erosion.
Tillage can also reduce infiltration by leaving the soil surface bare of crop residue. Raindrop impact and running water can loosen soil particles and carry them into soil pores, sealing off the soil surface. On direct-seeded fields, crop residue cushions the impact of rainfall and reduces runoff, so soil particles are not as easily dislodged and moved.
Seedbed Moisture Increases
Standing stubble in the spring preserves seedbed moisture for planting. Soil moisture is greater in direct-seeded fields because of increased snow trapping and reduced evaporation at the soil surface. Higher moisture levels can improve crop germination in drier, warmer springs. However, in wetter and cooler springs, higher soil moisture may reduce soil temperature and delay crop development.
Wetter soils are slower to warm. As a result, direct-seeded fields are usually about 0o to 3o C cooler than tilled fields in the spring, depending on soil texture and amount of crop residue cover. Clay soils hold more moisture and tend to be cooler than loamy or sandy soils. See Soil Temperature and Direct Seeding (Agdex 590-2) for more information.
Soil Organic Matter Increases
Soil organic matter is a storehouse of plant nutrients and a binding agent that influences soil erodibility, aeration, and water storage. Increasing organic matter increases the soil s nutrient- and moisture-holding capacity, and reduces soil crusting.
Direct seeding can increase organic matter content in the upper soil layer if crop yields are maintained. Reduced soil disturbance helps to preserve organic materials that naturally accumulate from crop root growth and decomposition. Research has shown that the increase in organic matter is more pronounced for continuous crop rotations where straw is not removed.
The limited soil disturbance and increased crop residue cover under direct seeding also tend to increase earthworm populations. Earthworms are beneficial because they speed up recycling of crop nutrients from surface residue and may create large soil pores that help to improve water infiltration rates.
Long-term studies have found that direct seeding s most dramatic effect on soil organic matter is to increase its active fraction. The active fraction is made up of living organisms and readily decomposable organic materials. It is only a small proportion of the total organic matter pool; the rest is composed of compounds called humus which are more complex and more resistant to decomposition. Increasing the active fraction helps soil to more quickly convert plant materials into crop nutrients and may help to decompose contaminants.
Soil Erosion Risk Is Less
Water and wind erosion can reduce crop yields and physically destroy emerging crops. Direct-seeded fields are much less susceptible to erosion because of the protection provided by standing stubble. Soil texture, slope, and the amount and type of crop residue also affect erosion risk.
Summary
Direct seeding systems can improve several factors affecting crop productivity. These include increased water infiltration, increased seedbed moisture, enhanced soil organic matter and reduced risk of soil erosion.
* better water infiltration
* increased seedbed moisture
* increased soil organic matter
* reduced soil erosion potential.
The extent to which these benefits are realized depends on local soil type and weather conditions.
Water Infiltration Increases
Tillage can reduce infiltration of rain and snowmelt by changing the natural soil structure. Cultivator shovels, discs or plows create a compacted layer (or shear plane) beneath the bottom of the implement. Tillage also destroys natural pores, root channels and cracks, and fills them with loose soil particles. This problem is more pronounced in clay soils.
Direct seeding leaves more of the soil s natural channels and cracks intact, allowing water to infiltrate more easily. This is very important for deep storage of soil moisture, for reducing water ponding on the soil surface, and for reducing runoff and water erosion.
Tillage can also reduce infiltration by leaving the soil surface bare of crop residue. Raindrop impact and running water can loosen soil particles and carry them into soil pores, sealing off the soil surface. On direct-seeded fields, crop residue cushions the impact of rainfall and reduces runoff, so soil particles are not as easily dislodged and moved.
Seedbed Moisture Increases
Standing stubble in the spring preserves seedbed moisture for planting. Soil moisture is greater in direct-seeded fields because of increased snow trapping and reduced evaporation at the soil surface. Higher moisture levels can improve crop germination in drier, warmer springs. However, in wetter and cooler springs, higher soil moisture may reduce soil temperature and delay crop development.
Wetter soils are slower to warm. As a result, direct-seeded fields are usually about 0o to 3o C cooler than tilled fields in the spring, depending on soil texture and amount of crop residue cover. Clay soils hold more moisture and tend to be cooler than loamy or sandy soils. See Soil Temperature and Direct Seeding (Agdex 590-2) for more information.
Soil Organic Matter Increases
Soil organic matter is a storehouse of plant nutrients and a binding agent that influences soil erodibility, aeration, and water storage. Increasing organic matter increases the soil s nutrient- and moisture-holding capacity, and reduces soil crusting.
Direct seeding can increase organic matter content in the upper soil layer if crop yields are maintained. Reduced soil disturbance helps to preserve organic materials that naturally accumulate from crop root growth and decomposition. Research has shown that the increase in organic matter is more pronounced for continuous crop rotations where straw is not removed.
The limited soil disturbance and increased crop residue cover under direct seeding also tend to increase earthworm populations. Earthworms are beneficial because they speed up recycling of crop nutrients from surface residue and may create large soil pores that help to improve water infiltration rates.
Long-term studies have found that direct seeding s most dramatic effect on soil organic matter is to increase its active fraction. The active fraction is made up of living organisms and readily decomposable organic materials. It is only a small proportion of the total organic matter pool; the rest is composed of compounds called humus which are more complex and more resistant to decomposition. Increasing the active fraction helps soil to more quickly convert plant materials into crop nutrients and may help to decompose contaminants.
Soil Erosion Risk Is Less
Water and wind erosion can reduce crop yields and physically destroy emerging crops. Direct-seeded fields are much less susceptible to erosion because of the protection provided by standing stubble. Soil texture, slope, and the amount and type of crop residue also affect erosion risk.
Summary
Direct seeding systems can improve several factors affecting crop productivity. These include increased water infiltration, increased seedbed moisture, enhanced soil organic matter and reduced risk of soil erosion.
Monday, October 22, 2007
Land preparation and moisture conservation with rice cultivation in the Northern region of Ghana (2007)
AA Mahama and JK Boamah
Journal of the Ghana Science Association Vol. 1 (1) 1999: pp.41-45
Journal of the Ghana Science Association Vol. 1 (1) 1999: pp.41-45
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