咸水非充分灌溉下土壤水盐动态及对制种玉米生长的影响

为了探究石羊河流域地下水资源的利用方式,在甘肃省石羊河流域开展了为期2年的制种玉米咸水非充分灌溉田间试验,试验设置3种灌水水平即w1(1ETc)、w2(2/3ETc)、w3(1/2ETc),3种盐分水平即s1(矿化度0.71 g·L~(-1),淡水)、s2(矿化度3 g·L~(-1))、s3(矿化度6 g·L~(-1)),共9个试验处理,研究咸水非充分灌溉对土壤水盐动态及制种玉米生长的影响。研究结果表明:咸水非充分灌溉条件下,由于灌溉水量和灌水矿化度不同,土壤水盐动态表现出不同的特征,非充分灌溉处理土壤含水量低于充分灌溉处理,咸水灌溉处理土壤含水量高于淡水灌溉处理;充分灌溉处理盐分累积较深,非充分灌溉处理盐分主要累积在表层土壤和根系吸水层土壤。灌溉水量采用2/3 ETc的非充分灌溉方式进行灌溉,土壤盐分随着水分运移,盐分主要累积在表层土壤和根系吸水层土壤,短时期采用灌水矿化度为3 g·L~(-1)的微咸水灌溉,盐分不会在土壤产生大量累积。因此,在研究区灌溉水量控制在2/3 ETc左右,灌水矿化度不超过3 g·L~(-1),对制种玉米生长的影响较小,减产幅度在11%以下,能够达到合理利用地下咸水资源和节水灌溉的目的。

Effect of deficit irrigation with saline water on soil water salt dynamic and seed maize growth

In order to explore the use mode for groundwater resources and research the effects on soil water salt dy namics and maize growth,the field experiments of deficit irrigation with saline water for seed maize were conducted during 2012 and 2013 in the Shiyang River Basin.Set up total nine treatments included three water levels w1,w2 and w3 as 1ETc,2/3ETc and 1/2ETc and three salinity levels s1,s2 and s3 as 0.71,3 g·L-1 and 6 g·L-1 respectively.The re search results were indicated that under the conditions of deficit irrigation with saline water,due to different irrigation water quantity and salinity level,the soil water salt dynamics have showed different characteristics.lThe soil water content under deficit irrigation was lower than sufficient irrigation and higher than fresh water irrigation.The salt was accumulated in deeper soil under sufficient irrigation and major accumulated in the surface soil and root zone layer under deficit irriga tion.The soil salinity was moved with water under deficit irrigation with water quantity as 2/3 ETc,and when using the salinity level 3 g· L-1 for irrigation in short term,the soil salinity would not be largely accumulated in the soil.Therefore,if irrigation amount was controlled about 2/3ETc and the water salinity level was not more than 3 g· L-1,the effect on seed maize growth was small and yield decrease was less than 11％.So the purpose of reasonable use saline water and water-saving irrigation could be achieved.