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利用 SWAP模拟程序模拟沙漠地区小麦土壤水势变化、水分利用的结果 ,无论是灌淤土 ,还是流动沙丘沙土 ,即使是在最低灌溉标准 (土壤水分含量保持田间持水量的 40 % ) ,小麦作物仍不受干旱威胁。由于每次灌溉水量偏大 ,以及土壤的高渗水特性 ,流动沙丘风沙土深层渗漏损失率高达 60 %～ 90 % ,而灌淤土也达 3 0 %～ 70 % ,这种损失随灌溉量增加而增加 ,这表明在这一地区将灌溉量降到目前的最低标准 ( 64 90 m3·hm- 2 )以下是值得考虑的。实验区土壤养分含量较低 ,且施肥改良土壤水肥保持能力的效果不能立即表现 ,在目前的施肥标准下 ,施肥量对土壤水势、以及水分利用率没有显著影响。流动沙丘沙土的灌溉量远高于灌淤土 ,但根系区土壤水势平均值、最低值均相对较高 ,特别是最低值是灌淤土的 2～ 3倍。相比两种土壤 ,除在表土层、根系层土壤水势有明显差异之外 ,临界层以下土层并无显著差异。
Using SWAP simulator to simulate the change of wheat soil water potential in desert area, the results of water use, whether irrigated silt or mobile sand dune, even in the minimum irrigation standard (soil water content keep 40% of field capacity) Not threatened by drought. Due to the large amount of irrigation water and the high permeability of soil, the seepage loss rate of deep sand flow in flowing sand dunes reaches as high as 60% -90%, while the amount of irrigation silt reaches 30% -70%. The loss increases with the amount of irrigation This indicates that it is worth considering the reduction of irrigation to the current minimum level (64 90 m3 · hm-2) in this area. In the experimental area, the soil nutrient content is low, and the effect of fertilization on soil water and fertilizer retention can not be immediately demonstrated. Under the current fertilization standards, the amount of fertilizer has no significant effect on soil water potential and water use efficiency. The amount of irrigation in mobile dune sand is much higher than that of irrigation silt, but the average and minimum values of soil water potential in root zone are relatively high, especially the lowest value is 2 ~ 3 times of irrigated soil. Compared with the two soils, there was no significant difference except for the soil water potential in the topsoil and the root layer.