塔里木灌区膜下滴灌棉田土壤水分动态与耗水特性

土壤水分条件是棉花生长和发育的重要因素。为了研究塔里木灌区膜下滴灌棉田土壤水分特征,于2014年4月18日至10月31日采用中子仪对膜下滴灌棉田0~120cm土壤水分进行观测,分析了不同生育期土壤含水率的时空变化,采用水量平衡原理计算了膜下滴灌棉田耗水量。结果表明:4月中旬到7月中旬为土壤水分稳定期,7月中旬到8月底为土壤水分剧烈变化期,8月底到10月底为缓慢消耗期;0~20cm为土壤水分活跃层,20~60cm为土壤水分次活跃层,60~120cm为土壤水分稳定层;灌溉入渗水主要分布在0~40cm;膜下滴灌棉田苗期、蕾期、花铃期、吐絮期的耗水强度分别为0.63、2.62、7.01、0.71mm/d。

Dynamic Change of Soil Moisture and Water Consumption of Cotton Under Drip Irrigation Patterns in Tarim Irrigation Area

Soil moisture condition is an important factor for the grow th and development of cotton .Based on the observation of soil moisture in 0~120 cm soil layers from December April 2014 to October 2014 ,the spatiotemporal characteristics of soil moisture con-tent of cotton field in different growth period are studied ,the water consumption of drip irrigation under film is calculated by water balance principle .The results showed that :the growth period of cotton can be divided into three periods ,including stable soil mois-ture (from mid-April to mid-July ) ,soil moisture dramatic changes state (from mid-July to the end of August) ,and slow consump-tion period (from the end of August to the end of October );the 0~20 cm depth layer is soil water active layer ,the 20~60 cm depth layer is soil moisture active layer ,and the 60~120 cm depth layer is stable soil moisture layer ;irrigation water infiltration is mainly distributed in the 0~40 cm depth layer ;the water consumption intensity of the cotton field under film drip irrigation at seedling stage ,bud stage ,flowering stage ,boll opening stage is 0 .63 ,2 .62 ,7 .01 and 0 .71 mm/d ,respectively .