咸水灌溉对覆膜棉花生长与水分利用的影响

为了揭示棉花生长发育对咸水灌溉的响应特征,采用小区对比试验,研究了不同矿化度咸水灌溉对棉花出苗、株高、叶面积、果枝数、地上部干质量等形态指标以及产量构成、耗水量和水分利用率的影响.结果表明,棉花出苗率和成苗率随着灌溉水矿化度的增大而减小,但3 g/L灌水处理与对照间的差异不具有统计学意义,而5,7 g/L处理与对照间差异极具统计学意义.在移栽补全苗情况下,咸水灌溉对棉花形态生长指标产生了一定的抑制效应,灌溉水矿化度愈大,抑制作用愈大;对株高、叶面积和地上部干质量的影响在蕾期最明显,花铃期之后开始逐渐减弱;对果枝数和棉铃生长的影响程度随着棉花生育进程的推进而降低.处理间棉花的耗水量差异不具有统计学意义,籽棉产量和水分利用率的大小顺序,按灌水处理依次为3,1,5,7 g/L,其中7 g/L处理与对照间的差异具有统计学意义.与灌水前初始值相比,试验结束后1,3 g/L灌水处理的0~40 cm土层盐分未增加,5,7 g/L灌水处理则形成了积盐.研究结果可为咸水安全利用提供重要参考.

Effects of irrigation with saline water on growth and water use efficiency of film-mulched cotton plant

In order to reveal the characteristics in growth and development of a cotton plant for response to irrigation with saline water, effects of water salinity on germination, plant height, leaf area, number of fruit branches, aboveground biomass, yield, water consumption and water use efficiency etc were studied for cotton plants by means of small-scale field trial. The results showed that germination rate and qualified seedling rate decreased with increasing salinity of water, and there is statistical significance between the 5 and 7 g/L total dissolved solid(TDS)salinity treatments and the control group, but not for 3 g/L TDS treatment. In the case of whole gap filling through transplanting plants, the saline water exhibited an inhibitory effect on the morphological indices of growth and development of cotton plants, and the higher the water salinity, the stronger the effect. Particularly, the plant height, leaf area and aboveground biomass were affected most significantly by the salinity in bud stage, but gradually less influenced after boll stage. Additionally, the number of fruit branches and boll growth were decreasingly affected with growth of cotton plants. There was no statistical significance in the water consumption among various treatments. The cotton seed yield and water use efficiency were decreased gradually in 3, 1, 5, 7 g/L treatments, among which there is statistical significance between the 7 g/L treatment and the control group. Compared with the initial salt content in 0-40 cm soil la-yer, after the irrigation trails the salt content in the soil layer remained unchanged in 1 g/L and 3 g/L treatments, but was increased in 5 and 7 g/L treatments. These results can provide an important reference for productive use of saline water.