微咸水滴灌对绿洲棉田水盐运移特征及棉花产量的影响

Effect of Saline Water Drip Irrigation on Water and Salt Transport Features and Cotton Yield of Oasis Cotton Field

在南疆绿洲棉田,以河水为对照(CK),利用咸水与河水混合方式,设置矿化度为3,5g/L的微咸水,研究微咸水滴灌对棉田水盐运移特征及棉花产量的影响。结果表明:矿化度为3,5g/L处理的土壤含水量、含盐量在整个生育期呈上升趋势,且随矿化度增加而增大,盛花期(7月21日)前土壤含水量差异不显著,CK的土壤含盐量最高,盛花期后土壤含盐量5g/L>3g/L>CK,差异显著(p<0.05)。垂直方向,土壤深度增加土壤含水量增大,且随着微咸水矿化度增加土壤含水量呈增大趋势,不同处理在盛花期以后差异显著;随土壤深度的增加土壤含盐量呈下降趋势,滴灌次数越多处理间差异越大,至盛铃期(8月4日)达显著水平。水平方向,距离滴头越远土壤含水量越小,且随着矿化度增加土壤含水量逐渐增大;3,5g/L土壤含盐量在盛花期前低于CK,盛花期后距离滴头越远土壤含盐量下降越小,且与矿化度呈正相关。与CK相比,3g/L皮棉产量下降2.1%,差异不显著,5g/L则下降9.6%,差异显著,产量下降主要原因是单株结铃数和单铃重显著下降,而对衣分影响不显著。因此,棉花盛花期前可利用微咸水进行滴灌,且微咸水矿化度不宜超过3g/L。

In southern Xinjiang oasis cotton fields, the river water was taken as control （CK）, using salt water mixed with water, settings for 3 g/L and 5 g/L saline water, researched on the effect of saline water drip irrigation on water and salt transport features and cotton yield. The results showed that： Soil moisture content and soil salt content of 3 g/L and 5 g/L salinity in the whole growth period increased with the increase of salinity, before full-bloom stage （July 21） there was no significant difference of soil moisture content, but the highest soil salinity was CK, the soil salt content after full-bloom stage was 5 g/L〉3 g/L〉CK and its difference was significant （p〈0.05）. Vertical direction, soil moisture content increased with increasing soil depth, and with the increase of brackish water salinity, soil moisture content showed a trend of increase, which had a significant differences between treatment after full-bloom stage. With the increase of soil depth, the soil salt content showed the downtrend, the more times of drip irrigation, the more difference of different treatments, at full-boll stage （August 4） it reached significant level. Horizontal direction, the farther distance of water dropper head, the smaller soil moisture content, and the soil moisture content increased gradually with the increase of salinity. The soil salt content of 3 g/L and 5 g/L was lower than that of CK before full-bloom stage, after full-bloom stage the soil salt content declined along with the distance of water drops head, and was positive correlation with salinity. Lint yield of 3 g/L decreased by 2.1%, no obvious difference, but that of 5 g/L decreased by 9.6%, and there was significant difference. The main reason of declining lint yield was a significant reduction in the boll number per plant and single boll weight, but no significant effect on lint percentage. Therefore, before full-bloom stage cotton could use saline water for irrigation, and saline water salinity should not be more than 3 g/L.