内蒙古河套灌区不同灌溉模式对土壤温度及盐分的影响

Effects of Different Irrigation Modes on Soil Temperature and Salinity in Hetao Irrigation District of Inner Mongolia

针对内蒙古河套灌区井渠结合膜下滴灌这一灌排发展趋势,分别选取了黄灌（H）、井灌（J）、滴灌（D）3种灌溉模式,研究了土壤温度时空变化规律和生育期盐分平衡状况。结果表明：玉米生育期内不同灌溉模式膜内膜外土壤温度月季下降明显,且膜内外土壤温度差异随着时间的推移越来越小;玉米需水旺季（6、7月）膜内5cm土壤日温度受灌水影响程度依次是滴灌〉井灌〉黄灌,平均温度黄灌较井灌高0.47℃,较滴灌高1.18℃;自6月下旬开始膜内5cm 10日平均土壤温度黄灌始终高于井灌0.35-1.53℃,滴灌基本小于井灌;30日平均温度黄灌较井灌温度始终高0.34-1.02℃,较滴灌高1.12-1.98℃。生育期黄灌、井灌、滴灌0-100、0-60cm土壤均积盐,膜外积盐率0-60cm远大于0-100cm。若地面灌溉一年一洗盐,滴灌0-100cm盐分累积至井灌土壤盐分水平需2年一次秋浇洗盐。

According to the irrigation and drainage development trend of combining well,canal and drip irrigation under mulch in Hetao District of Inner Mongolia,three irrigation modes,including surface irrigation with yellow river water（H）,surface irrigation with well water（J）and drip irrigation with well water（D）,are selected to study the variation of soil temperature and salinity balance in maize growth period.The results show that monthly soil temperature of H,J and D modes declines significantly,and the soil temperature inside mulch is much closer to that outside mulch as time goes by;in the water demand season（June and July）,the influence degree of irrigating water on soil temperature at 5cm depth inside mulch is D〉J〉H,and the mean temperature of H mode is 0.4 ℃ higher than that of J mode,and 1.18 ℃ higher than that of D mode;the ten days mean soil temperature at 5cm depth inside mulch of H mode is always 0.35-1.53℃ higher than that of J mode,and that of D mode is less than that of J mode;the thirty days mean soil temperature of H mode is always higher than that of W mode and D mode by 0.34-1.02℃ and 1.12-1.98℃,respectively;the soil salinity of H,J and D modes accumulates during maize growth period in the range of 0-100cm depth or 0-60cm depth,and the soil salinity accumulation rate of 0-60cm depth outside mulch is far greater than that of 0-100cm;so,salt leaching is necessary in Hetao District after corn growth periods for all the H,J or D modes;if leaching irrigation is needed every year for surface irrigation,when 0-100cm salt accumulation of D mode reaches to that of J mode level,then the leaching cycle of D mode is 2years.