Effect of rainwater harvesting with ridge and furrow on yield of potato in semiarid areas

A new planting pattern for potato production in semiarid areas was designed and tested for enhanced tuber yield and for the benefit of collecting rainwater. This pattern comprised two elements: the ridge mulched by plastic film that acts as the runoff area and the furrow as the infiltration basin or planting area. The conventional planting pattern for potato production in semiarid regions of northwestern China is the opposite with mulched ridges for planting and the furrow as an infiltration zone. The purpose of this study was to examine the effect of the ridge with or without mulching on rainwater harvesting and the response in potato yield and to determine the optimal cross-sectional area of the ridge and furrow. A ratio defined as the width of the ridge to the width of the furrow or the planting area was used to evaluate the cross-sectional area. Three ratios of 0.5, 0.75, and 1.0 were tested under the conditions of mulched ridge, bare earth ridge, and no ridge or flat planting, respectively. No matter what ratio used, the width of the planting belt was the same at 0.6 m. The results showed that for tuber yield, the ridge with the plastic mulching was more effective than the bare earth ridge and that the bare earth ridge was better than flat planting. In the mulched ridges, a ridge width of 0.45 m or a ratio of ridge to furrow of 0.75 led to higher yield than that of ridges with a width of 0.3 and 0.6 m. For the bare earth ridges, the yield in the 0.6 m ridge width was higher than that of the other two ridges. Besides improving potato yield, the mulched ridge and furrow planting had the added advantage of collecting considerable rainwater for soil moisture. In addition, the percentage of small-sized potatoes was low. Therefore, we recommend that the mulched ridge with a ridge width of 0.45 m and a furrow width of 0.6 m as a successful method to increase potato yield in semiarid areas where potato production relies totally on rainwater. (C) 2003 Elsevier B.V. All rights reserved.