ABSTRACT

Cotton is an important cash crop with an indeterminate growth characteristic. The labor costs of multiple management practices, including repeated foliar applications of mepiquat chloride (MC) and topdressing with potassium (K) fertilizers, restrict its planting area and benefits. To help address this problem, a field experiment was performed to evaluate the effects of controlled-release potassium chloride containing mepiquat chloride (CRKMC) on soil K forms and cotton yield. CRKMC, 70%CRKMC (30% reduced K dosage), CRK (coated potassium chloride), KCl and no K fertilizer used treatments were carried out. Results showed that MC and K from CRKMC exhibited a trend of slow release, followed by fast release and eventually stabilization. Soils maintained more non-exchangeable K than available K. The contents of all soil K forms for the CRKMC treatment were significantly higher than these for KCl. Plant heights, SPAD values and stem diameters in CRKMC and 70%CRKMC were larger than those in KCl. Cotton yield, K use efficiency and net profit in the CRKMC treatment were increased than KCl. The successive release pattern of MC and K from CRKMC corresponded well to the demands of cotton, sufficiently manipulated the plant canopy and provided adequate K nutrition.

摘要

棉花是一种重要的经济作物，具有不确定的生长特性。多种管理措施的劳动力成本，包括重复叶面喷施氯化肥快 (MC) 和追施钾肥 (K)，限制了其种植面积和效益。为帮助解决这个问题，进行了一项田间试验，以评估含氯壮素的控释氯化钾 (CRKMC) 对土壤钾形态和棉花产量的影响。进行了CRKMC、70%CRKMC（减少30%的钾用量）、CRK（包膜氯化钾）、KCl和不施钾肥的处理。结果表明，来自 CRKMC 的 MC 和 K 表现出缓慢释放的趋势，然后是快速释放并最终稳定。土壤保持的不可交换钾多于可用钾。CRKMC 处理的所有土壤形式 K 的含量显着高于 KCl。CRKMC和70%CRKMC的株高、SPAD值和茎粗均大于KCl。CRKMC 处理的棉花产量、钾肥利用率和净利润均高于 KCl。CRKMC 连续释放 MC 和 K 的模式很好地符合棉花的需求，充分操纵植物冠层并提供足够的 K 营养。