陇东黄土高原塬区冬小麦越冬期土壤水分损耗规律浅析

Simple Analysis of Consuming Law of Soil Moisture in Winter Wheat Field at Overwintering Stage on Plateau Form of Longdong Loess Plateau

通过分析陇东塬区冬小麦越冬期土壤水分损耗,以及决定越冬土壤水分损耗的关键气象要素,指出在秋季降水充沛、土壤收墒充足、冬季气温偏高、降水明显偏少的年型,越冬期土壤水分损耗是不可忽视的,其中有一半年份,越冬期土壤水分损耗占冬小麦生长季节自然降水的10%～22%。尤其是入冬前土壤含水量充沛,而返青以后生长期降水相对较少的年份,越冬期麦田土壤水分损耗相当于返青到成熟期降水量的44%。

Through the analysis of soil moistwre wastes of winter wheat at ov erw in tering stages on plateau forms of longdong loess plateau and the key mete orologic factors affecting soil moisture wastes at overwintering stages, the pap er pointed out the following:In the years in which the precipitations in autumns were abun dant,the gained moistures of soils were plentiful,the temperatures in winters were on the high side and the precipitations were remarkably on the low side,the soil moisture wastes at overwintering stages couldn't be neglected.Am ong all the years,the soil moisture wastes at overwintering stages of half of th e total years accountedl for 10%-22% of natural precipitations in the growth sea sons of winter wheat. Especially in the years in which the soil moisture content s were abundant before winter,but after wheat seedlings turned green,the precipi tations were relatively less during growth periods,the soil moisture wastes in w heat fields at overwintering stages were equivalent to 44% of the precipitations from the turned green period to mature period.