间歇灌溉技术参数对南疆盐渍土水盐运移的影响

Effects of intermittent irrigation technical parameters on saline soil water-salt transport in Southern Xinjiang

为明确间歇灌溉条件下南疆盐渍土盐分淋洗适宜灌水技术参数,采用室内土柱试验研究了总灌水量为30 cm的条件下不同初始灌水量(7.5 cm、15 cm)与灌水间隔(1 d、3 d、5 d)对土壤水、盐分布与排水、排盐特性的影响。结果表明灌水间隔是影响土壤水、盐分布的重要因素,随着灌水间隔延长,0~100 cm土层土壤含水率总体呈增大趋势;土壤盐分则以40 cm深度为分界线,40 cm以上土层土壤盐分含量随灌水间隔延长呈降低趋势,40 cm以下土层土壤盐分含量则逐渐增大。不同初始灌水量与灌水间隔对土柱排水、排盐影响显著,随初始灌水量增加、灌水间隔延长,土柱排水量逐渐降低,排水矿化度逐渐增大,土柱排盐量、排盐效率变化规律则与排水量一致,均以初始灌水量7.5 cm、灌水间隔1 d处理最高。综合考虑灌后土壤水、盐分布以及排盐量,在总灌水量30 cm的条件下,分2次灌溉,初始灌水量7.5 cm、灌水间隔1 d是本试验条件下适宜的间歇灌溉淋盐技术参数。

To elucidate the optimal irrigation parameters for salt leaching of saline soil of Southern Xinjiang under intermittent irrigation,a laboratory soil column experiment was conducted under conditions of a 30 cm total irrigation volume.This study investigated the impacts of varying initial irrigation volumes(7.5 cm,15 cm)and irrigation intervals(1 d,3 d,5 d)on soil water and salt distribution,as well as the patterns of water drainage and salt discharge.The results showed that irrigation interval significantly influenced the distribution of both soil water and salt.As the extension of irrigation lengthened,an increasing trend was observed in the soil moisture content of 0-100 cm soil layer.The salt content in the soil layer above 40 cm decreased with the extension of irrigation interval,while the salt content below 40 cm gradually increased.The initial irrigation amount and irrigation interval had a marked impact on water drainage and salt discharge from soil column.With the increase of initial irrigation volume and the extension of irrigation interval,the volume of water drainage from soil column gradually decreased,while the mineralization degree of water discharged gradually increased.The changes in the volume and efficiency of salt discharge from the soil column paralleled that of the water drainage volume.The maximum values were observed under the treatment involving an initial irrigation volume of 7.5 cm and irrigation interval of 1 d.Given the soil water and salt distribution,and salt discharged post-irrigation,the experimental condition suggest that the optimal parameters for intermittent irrigation salt leaching are an initial irrigation volume of 7.5 cm and irrigation interval of 1 d,with a total irrigation volume of 30 cm applied twice.