灌水矿化度及土壤含盐量对南疆棉花出苗率的影响

Effects of mineralization of irrigation water and soil salinity on cotton emergence rate in Southern Xinjiang Uygur Autonomous Region of China

为获知新疆棉花苗期耐盐度阀值及其影响因素,该文进行了不同灌水矿化度单因素及不同灌水矿化度和土壤含盐量2种组合因素对棉花出苗的耐盐性试验研究,结果表明,灌水矿化度及土壤含盐量均与棉花相对出苗率呈线性负相关;而灌水矿化度则随土壤盐碱程度的不同而改变,当土壤盐质量分数在0.33%以下,灌水矿化度不超过5g/L,土壤盐质量分数在0.33%～0.5%之间灌水矿化度不超过3g/L,土壤盐质量分数大于0.5%时,则应采用淡水灌溉;从对比这2种因素对出苗率的影响来看,在中度及以下盐渍土壤中,灌水矿化度的影响较土壤含盐量的大;同时结合大田出苗率调查,则表明在轻度盐碱土中灌水矿化度的临界值为4.28g/L,而对土壤而言棉花苗期的耐盐阀值则为0.58%。该研究为进一步研究棉花耐盐性提供参考,对指导新疆棉花生产具有重要意义。

For investigating salt tolerance of cotton and its effect factors in Xinjiang Uygur Autonomous Region,the experiment were carried on salt tolerance of cotton under the condition of different mineralization of irrigation water and the soil salinity.Results indicated that the relationship between soil salinity or mineralization of irrigation water and the cotton relative emergence rate was linear.The mineralization of irrigation water was changed with the soil saline and alkaline degree.The mineralization of irrigation water was less 5 g/L when the soil salinity was hereinafter 0.33%,the mineralization of irrigation water was less than 3 g/L when the soil salinity was between 0.33% and 0.5%,and the irrigation water was fresh water when soil salinity exceeded 0.5%.Contrasting the two factors affected on emergence rate of the cotton,the results indicated in the medium grade and hereinafter saline-alkaline soil,the effect was bigger in the mineralization of irrigation water than soil salinity.Combining investigation of cotton emergence rate in field,the results indicated that the critical mineralization of irrigation water was 4.28 g/L,and the cotton salt tolerance was 0.58% in soil.The study provides reference for further research of salt tolerance of cotton,and possesses great significance in directing local cotton production.