Author
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UNGER, P - 6209-05-15 |
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Submitted to: Journal of Soil and Water Conservation Society
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/14/1994 Publication Date: N/A Citation: N/A Interpretive Summary: Crop residues retained on the soil surface are widely recognized and, hence, are being widely promoted for their soil conservation benefits. Surface residues also provide for increased water conservation. The 1985 and 1990 farm bills mandated that erosion be controlled on highly erodible lands. As a result, crop residue management was chosen as a key practice to help control erosion on nearly 75 percent of the highly erodible land covered by conservation plans. However, in some regions, dryland crops do not produce enough residues to provide satisfactory erosion control and full irrigation may not be practical because of limited water supplies. In addition, full irrigation may produce excessive residues, thus causing problems for producing the next crop. This study determined the effects of retaining all residues (NT+Res), removing residues at harvest (NT-ResH) or planting (NT-ResP), and conventional tillage (ConvT) treatments on soil water storage and use, and yields of continuous winter wheat (Triticum aestivum L.) produced with limited irrigation. Water storage between crops was greater with NT+Res and NT-ResH than with ConvT, but soil water depletion was not affected by treatments. Wheat grain yields were 4560, 4180, 4450, and 4260 kg/ha with the NT+Res, NT-ResH, NT-ResP, and ConvT treatments, respectively. Straw yields were not affected by the treatments. Grain and straw yield differences among cropping seasons were significant. Continuous wheat production with limited irrigation can help producers meet the surface residue requirements established for their conservation plans for highly erodible lands in the southern Great Plains. Technical Abstract: Crop residue management was chosen as a key practice to help control erosion on nearly 75 percent of the highly erodible land covered by conservation plans. However, in some regions, dryland crops do not produce enough residues to provide satisfactory erosion control and full irrigation may not be practical because of limited water supplies. In addition, full irrigation may produce excessive residues, thus causing problems for producing the next crop. This study determined the effects of retaining all residues (NT+Res), removing residues at harvest (NT-ResH) or planting (NT-ResP), and conventional tillage (ConvT) treatments on soil water storage and use, and yields of continuous winter wheat (Triticum aestivum L.) produced with limited irrigation. Water storage between crops was greater with NT+Res and NT-ResH than with ConvT, but soil water depletion was not affected by treatments. Mean grain yields were 4.56, 4.18, 4.45, and 4.26 Mg/ha with the NT+Res, NT-ResH, NT-ResP, and ConvT treatments, respectively. Mean straw yields were not affected by the treatments. Grain and straw yields differed among cropping seasons. Continuous wheat production with limited irrigation can help producers meet the surface residue requirements established for their conservation plans for highly erodible lands in the southern Great Plains |
