干播湿出棉田土壤温度及水分对出苗率的影响

Impacts of Drip Irrigation under Mulch with Dry Sowing and Wet Seedling on Soil Temperature,Water Content and Seedling Emergence Rate of Cotton

在新疆南疆灌区棉花干播湿出种植方式下,通过田间试验研究土壤温度、水分变化及其对出苗率的影响.研究表明：各处理不同深度土壤温度在一天中表现为低-高-低的变化规律;表层5cm内土壤温度变幅最大,平均增幅63.5％～70％;随着深度增加土壤温度变化逐渐趋于平缓.各处理不同深度处下层土壤温度达到峰值的时间滞后于上层土壤,上层土壤降温速度高于下层土壤;土壤含水率越大地温变幅越小;600 m3/hm2的干播湿出灌水定额可为棉花种子发育创造较好的湿热环境,利于棉花出苗.

Under the plant mode of drip irrigation under mulch with dry sowing and wet seedling in South Xinjiang, the impacts of this plant mode on soil temperature, water content and seedling emergence of cotton is analyzed through field trial. The results show that the soil temperature presents the rule of low-high-low at different depth in different treatment; the maximum change of temperature is in surface layer 5 cm and the average value was 63.5% to 70% with the soil depth increases, the soil temperature variation is gentle. The time of sublayer peak temperature is lagged behind upper soil layer, the rate of temperature reduction in upper soil layer is higher than that in sublayer; the variation of soil temperature is small with the higher soil water content. Thus,the appropriate hot and humid condition under the irrigation water quota of 600 m^3/hm^2 can meet cotton seed development and emergence.