膜下滴灌棉花耐盐预警值的研究

Research on early warning value of salt tolerance of cotton with drip irrigation under mulch

以不同次生盐渍化膜下滴灌棉田为对象,研究次生盐渍化对棉花生长发育的影响,并以此为基础探讨其状态预警问题。结果表明:在各生育期,土壤盐度与株高、干物质重、叶面积指数均呈极显著的负相关关系。低土壤盐度对棉花生物量和产量不会产生影响,说明棉花具有一定的耐盐性。籽棉产量的降低主要是由于土壤盐度的升高使棉花单株结铃数明显减少造成的。不同生育期棉花耐盐程度不同,各棉田的警度随着生育期的进行有逐渐减轻的趋势;0.6 dS/m以下的土壤盐度在各生育期都不会对棉花生长造成较大危害,2.8 dS/m以上的土壤盐度在前期更易对棉花生长造成严重影响,到吐絮期2.8 dS/m左右的盐度已不能对棉田造成较大危害。

Effect of secondary salinization on the growth of cotton was studied by choosing different cotton fields with drip irrigation under mulch with the salinity gradient in Xinjiang, then the condition for early warning on its basis was investigated. The results showed that plant height, dry matter weight and leaf area index showed a significant negative correlation with soil salinity respectively in different growth period. Cotton is resistant to salinity, because the aboveground growth and yield of cotton were not influenced by the low soil salinity. The yield reduction was due to a reduction in the number of available bells. The salt tolerance level of cotton varied in different growth period. The warning degree of each cotton field tended to reduce gradually with the growth period process. The soil salinity below 0.6 dS/m would not harm the growth of cotton in every growth period, while the soil salinity above 2.8 dS/m would result in a serious impact to the growth of cotton in early growth periods, and in boll opening period the soil salinity around 2.8 dS/m did not cause harm to the growth of cotton.