新疆棉花膜下滴灌条件下盐分变化及最优洗盐模式的确定

通过对棉花生育期的监测实验数据进行分析,研究了滴灌条件下不同灌溉定额土壤盐分的变化.结果表明,灌水量对棉花地土壤盐分的影响十分显著,灌后土壤含盐量明显低于初始土壤含盐量,随着灌水量的增加洗盐效果趋于明显.灌水周期为7 d的处理抑盐效果优于灌水周期为3.5 d的处理.土壤盐分含量呈现随距滴头距离的增加而增加的趋势.在滴头下方土壤含盐量减少幅度最明显,在水平方向距滴头50 cm以内基本无明显的盐分累积发生.通过对棉花主根区范围内土壤盐分的量化分析,得出最优的洗盐模式为灌水周期7 d,灌溉定额为3 900～4 500 m3/hm2的方案.

Changes of Soil Salinity and Determination of Optimal Salt Washing Mode in the Condition of Drip Irrigation under Plastic Film of Cotton in Xinjiang

Through the analysis of monitoring data in cotton growing period,change in soil salinity with different irrigation norms in the different conditions of drip irrigation are studied.Results show that the quantity of irrigated water has significant influences on soil salinity.The soil salinity after irrigation is significantly lower than the initial soil salinity and the more water,the more obvious effect of washing salt is.The suppression salt treatment of seven-day irrigating cycle is better than 3.5-day irrigating cycle.Soil salinity is increased with emitter distance.The decreased trend of soil salinity is significant under emitter and the salt accumulation has no change within 50cm from emitter in horizontal direction.Through the quantitative analysis of soil salinity around the main root of cotton,the optimal mode of salt washing is the seven-day irrigation cycle with the 3900-4500m³/hm² of irrigation norm.