坡耕地垄作区田最佳挡距数学模型及其检验

Mathematic Model and Its Examination of the Optimum Block Space on Ridge Plotted Sloping Field

根据黑龙江省垄体的几何图形，推导出各种坡度垄作区田单个浅穴容积Ｖ的计算公式。建立了最佳挡距数学模型Ｌ＝１６８θ－０．５０。在利用人工模拟降雨检验此模型时，选择了２°，４°和６°坡的玉米和大豆坡耕地，比较最佳挡距、最大挡距和不设土挡的开放垄的拦蓄降雨量。最佳挡距拦蓄降雨量分别是５４．８ｍｍ，５０．４ｍｍ和４２．０６ｍｍ，比最大挡距分别多拦蓄１８．４ｍｍ，１９．９ｍｍ和１９．７ｍｍ降雨。比不设土挡的分别多拦蓄４９．４ｍｍ，４４．６ｍｍ和３９．９ｍｍ。在自然降雨条件下，６°大豆坡耕地最佳挡距的产量比最大挡距和不设挡的对照区分别增产２２．３％和３６．８％。

According to the geometrics of ridge furrow,a formula for calculating the volume of individual shallow basin in various slopes was derived,and an optimum block space model was developed.This model suited various sloping fields. Through the examination on 2°,4° and 6° sloping fields with 3.6mm/min rainstorm by rainfall simulater in the ridge plots of optimum block space,they intercepted the rainfall of 54.8,50.4,and 42.0mm respectively,and were 18.4,19.9,19.7 and 49.4,44.6,39.9mm higher than that on the maximum block space and the open ridge respectively.Under the natural rainfall,the yield of soybean on 6° sloping field according to this model was 2 200 kg/ha,and was 22.3% and 36.8% higher than the check plots of the maximum block space and the open ridge.Therefore,the model is verified to be feasible and reliable.