PCARRD Highlights '98: Summary of the Proceedings of the 1998 Regional Research and Development Symposia.
1999
Results of the study showed that as the number of vegetative strips or hedgerows increased, the spacing between rows of the main crop became wider, resulting in reduced number of rows and consequently reduced total yield of the main crop. Soil loss declined as the number of hedgerows increased. However, the rate of reduction in soil loss decreased with the increase in the number of hedgerows. One hedgerow in the middle of a 50-meter slope length reduced soil loss by 67 percent on the first year and 59 percent on the second year. Three hedgerows spaced 12 m apart at 4-m vertical drop reduced soil loss by 74 percent on the first year and 66 percent on the second year. Seven hedgerows spaced 6 m apart at 2-m vertical drop reduced soil loss by 77 percent on the first year and 84 percent on the second year. Dense hedgerows, i.e. 15 hedgerows spaced 3 m apart at 1-m vertical drop, reduced soil loss by 86 percent on the first year and 96 percent on the second year. Although, the higher number of hedgerows prevented a higher amount of soil loss and gave a higher amount of biomass and nutrients to the system, those increases were not significant to offset the increase in labor cost and compensate forthe loss in yield of the main crop. The study recommended the planting of hedgerows at a vertical elevation of 2-4 m between strips, spaced at 6-12 m apart to effectively reduce soil erosion and maximize crop production area. The pattern with 2-m vertical drop gave seven vegetative strips in a 50-m slope length, and the other pattern with 4-m vertical drop gave three vegetative strips. Corn yield and soil loss reduction in these two pattern did not vary significantly.
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