西藏左贡农区土壤水分动态与青稞需水平衡

Soil moisture dynamics and supply demand balance in farming area in Zuogong,Tibet

观测了西藏左贡农区的土壤水分动态特征， 分析了农田水分供需平衡状况，结果表明， 在青稞生育期内， 农区土壤水分变化可分为三个时期， 缓慢失墒期， 强烈失墒期和墒情恢复期。其中， 强烈失墒期水分亏缺最严重， 易出现旱情。农田水分供需平衡状况结果亦表明， 青稞播种－ 出苗， 出苗－ 分蘖两生育期水分供需严重失衡， 土壤水分含量过低， 水分满足率分别仅为２０３％ 、１６４％ 。其余时期均能满足作物水分需求。乳熟期后还有较多水分盈余。

This paper dealt with the variation characteristics of soil moisture and analysed the farm water balance in Zuogong,Tibet.The results indicated that during the highland barley growth periods,the changing dynamics of soil moisture in farmlands can be apparently divided into three stages.Also,the analysis from the water supply demand balance showed that there were two growing stages:emergence and tillering stage,in which water was in great need and badly out of balance,due to quite low rates of water supply.In the rest stages water supply was sufficient to the crop,even had a large suplus after maturation.