水保所知识产出(1956---)知识库

土壤水库是旱作农业区粮食稳产和可持续发展的基础.本文结合长期田间定位试验，通过对黄土高原南部长武旱塬2012—2015年冬小麦土壤水分变化的研究，分析了土壤水库的年际与年内变化特征和动态规律.结果表明：研究区冬小麦田间平均土壤含水量垂直分布曲线均呈“双峰双谷”形，第一处峰点在10～20 cm土层，第一处谷点在50 cm左右，第二处峰点在100 cm左右，第二处谷点在280 cm左右.无论何种降水年型下，土壤水库对降水的响应滞后且滞后的程度一致.降水年型对土壤水库的年际与年内动态变化影响较大.与丰水年相比，枯水年、平水年土壤水库对大气干旱的调节能力降低，表现为主要供水层上移；枯水年、平水年降水量虽少，但对土壤水分的补充作用较丰水年明显；丰水年土壤水库有较大盈余（84.2 mm），水分平衡出现正补偿，枯水年土壤水库稍有亏缺（1.5 mm），水分平衡出现负补偿，平水年土壤水库稍有盈余（9.5 mm），水分平衡出现正补偿.长武旱塬冬小麦田间土壤水分动态可分为4个时期：苗期耗水期、缓慢消耗期、大量消耗期、收获期，整体蒸散耗水大小顺序为：大量消耗期>苗期耗水期>收获期>缓慢消耗期.

Soil reservoir is the basis of stable grain production and sustainable development in dry farming area. Based on the long-term field experiment, we investigated the changes of soil moisture in wheat field located in the rain-fed Changwu Tableland, and analyzed the interannual and annual variation characteristics and dynamics trends of soil reservoir from 2012 to 2015. The results showed that the vertical distribution curves of average soil water content were "double peaks and double valleys": first peak and valley occurred in the 10-20 and 50 cm soil layer, respectively, while for the second peak and valley, the corresponding soil layer was  the 100 and 280 cm soil layer. Soil reservoir did not coincide with precipitation for all yearly precipitations patterns but lagged behind. Yearly precipitation patterns had a great influence on the interannual and annual dynamic changes of soil reservoir. Compared with rainy year, the depth of soil moisture consumption decreased and supplementary effect of Precipitation on soil moisture became obviously under effects of drought year and normal year. In rainy year, soil reservoir had a large surplus (84.2 mm); in normal year, it had a slight surplus (9.5 mm); while in drought year, it was slightly deficient (1.5 mm). We can infer that in rainy year and normal year water balance was compensated, while in drought year water balance was negatively compensated. The dynamics of soil water in winter wheat field in the rain-fed Changwu Tableland can be divided into four periods: seedling period, slow consumption period, large consumption period, and harvest period and the order of evapotranspiration were large consumption period> seedling period> harvest period> slow consumption period.