莫索湾垦区不同滴灌年限及不同水质灌溉棉田盐分运移规律研究

Research on Law of Salt Transfer in Cotton Field at the Condition of Different Irrigation Times and Different Water Quality in Mosuowan Reclamation Area

为分析莫索湾垦区不同滴灌年限及不同水质灌溉棉田膜下滴灌盐分的运移规律,从不同土壤质地、不同生育时期、水平方向不同土层、垂直方向不同土层、总盐含量与产量间关系等5个方面对膜下滴灌盐分的运移进行了分析比对,初步得出:黏土中的盐分积累最重,壤土中次之,砂土积累最少;随着生育时期的推后,各土层含盐量都有不同程度的加大;水平方向露地行中央土层盐分积累最多,滴头处盐分积累最少;垂直方向盐分的积累在0—60cm土层逐渐增加,60—100cm土层盐分积累受膜下滴灌影响较小;总盐含量越高产量下降越严重;总体来说,井水灌处理要比河水灌各处理积盐多。分析认为,井水与河水轮灌,定期大水漫灌洗盐,恢复排碱渠功能以及合理的轮作是土壤脱盐的必要手段。

This paper was mainly compared five aspects of salt transfer law for cotton field with drip irrigation under the plastic mulch,i.e. different soil texture,different postemergences,from horizontal direction,from vertical direction and the relationship between the total salt content and cotton yield to analyse the salt transfer law for cotton field in Mosuowan reclamation area at the condition of different length of irrigation and different water quality. The results showed that the accumulation of salt in clay is more than in doras and sandy clay,and the accumulation of salt in sandy clay is the least. With the retardation of postemergences,the cummulation of salt in different soil layers was increased in certain degree. The accumulation of salt in horizontal direction at the center of open ground is more than any other position and the one under the drop point is least. The largest accumulation of salt in vertical direction is in the soil layers from 40 to 60 cm,but the one in the soil layers from 60 to 100 cm change a little. The more the salt content in soil,the less the cotton yield. In general,the salt accumulation of well water irrigation is more than the one in river water irrigation. It can be summed up that there are four ways for desalination,viz,rotation irrigation of well water and river water,using flood irrigation to flush salt periodically,resuming alkali-drainage-channel and go on with reasonable crop rotation.