石膏和腐植酸配施对干旱盐碱区土壤改良及棉花生长影响

针对试验区盐碱土特点，选择石膏和腐殖酸为盐碱土壤改良剂，通过石膏、腐殖酸单施与石膏和腐殖酸不同用量配施试验，分析了改良剂施用后土壤盐分含量和pH值变化、及对棉花株高、茎粗和产量的影响，优选出适宜于该试验区的最佳改良剂。试验结果表明，石膏和腐殖酸9:1组合在200和300 kg/667 m2施用量情况下，0-20 cm土壤降盐效果好于单独施用石膏或腐殖酸处理；而单施腐殖酸处理对棉花增产效果最好，较控制处理棉花产量增加29.8%。综合分析，亩施石膏和腐殖酸9:1组合改良剂200 kg为该地区较优的改良剂用量，可使0-20 cm土壤含盐量较控制处理下降24.3%，棉花增产24%。

Effects of Combined Application of Gypsum and Humic Acid on Improvement of Saline-alkali Soil and Cotton Growth in Arid Areas

According to the characteristics of saline-alkali soil in experimental area, the gypsum and humic acid was used alone and combined to mitigate negative effects of soil salinity on cotton. Soil salt content, pH, plant height, stem diameter and yield were measured during the cotton growth period. The purpose of this study was to choose the optimal soil amendments suitable to the test area. The results showed that the gypsum and humic acid 9:1 were combined under the application amount of 200 and 300 kg/667 m2 had the better desalting effect than that of using gypsum and humic acid alone at the soil depth of 0-20 cm. The humic acid treatment had the best effect on cotton yield, which increased by 29.8% compared with that of control treatment. In addition, the optimal soil amendment was 9:1 combination of gypsum and humic acid with application amount 200 kg/667 m2, which could maintain the soil salinity of 0-20 cm decreased by 24.3% and the cotton yield increased by 24%.