黄土台塬旱地小麦土壤水分特征及水分利用效率研究

Study on characteristics of soil moisture and its use efficiency in dryland wheat in the loess tableland.

对黄土台塬乾县试区旱地小麦不同降水年型的土壤水分特征及水分利用效率长期研究结果表明,该区按降水量多少分为丰水、平水和干旱3种降水年型,干旱少雨是这一研究时段的主要特点;夏闲期是该区旱地小麦土壤水分的恢复阶段,降水多少与下渗深浅密切相关;小麦生育期是旱地小麦土壤水分的损耗阶段,时至收获2m土层内土壤水分降到全年最低值;小麦产量与耗水系数呈负相关,与田间耗水量和水分利用效率呈正相关。

Annual precipitation in the tableland of the northern Qian County during the years of 1987 - 2000 can be divided into three types: plenty of rainfall, normal and dry. However, drought and rainfall deficiency are the main characters during this period of time. The restoring period of soil moisture is in summer fallow time, while its consumption and losing period is during the growth of wheat and the soil moisture in 0 - 2m soil layer declines to the minimum of the whole year in harvest time. Wheat yield has a direct correlation with moisture consumption in the field and water use efficiency, while it has a negative correlation with water use coefficient.