Runoff and soil loss from ultra-narrow row cotton plots with and without stiff-grass hedges.

摘要

Grass hedges and no-till cropping systems reduced soil losses on standard erosion plots in ultra-narrow row (20 cm) cotton during a 4-year study (1999-2002). No-till cotton with grass hedges, no-till cotton without grass hedges, conventional-till cotton with grass hedges, and conventional-till cotton without grass hedges produced 4-year average annual soil losses of 1.8, 2.9, 4.0, and 30.8 t ha-1, respectively, and produced 4-year average runoff amounts of 267, 245, 353, and 585 mm, respectively. The annual ratio of soil loss for no-till ultra-narrow row cotton plots with grass hedges to those without hedges averaged 0.62. The annual ratio of soil loss for conventional-till plots with grass hedges to without hedges was 0.13. Averaged over all plots (with and without grass hedges), no-till plots had 86% less soil loss than conventional-till plots. No-till plots without grass hedges had 90% less soil loss than conventional-till plots without grass hedges. Grass hedges effectively reduced soil loss on erosion plots with similar cropping practices as compared to plots without hedges. Along with the reduced soil losses from no-till system as compared to conventional-till system, the no-till ultra-narrow row cotton system resulted in an average 0.2 t ha-1 yield increase as compared to the conventional-till system. Reduced soil loss and increased crop yield are both positive factors that the user should consider when adopting this cotton system. Other studies of contoured grass hedges on field-sized areas are being conducted to determine their applicability on larger areas with greater concentrations of runoff..