Abstract:
Objective Potassium (K) application is a necessary means to ensure soil K supply and high yield of cotton. Chemical capping with mepiquat chloride (MC) is an important measure to regulate the distribution of cotton biomass. Reasonable coordination of the relationship between the two is the premise of cotton quality improvement and yield increase. Therefore, the effects of MC containing K chloride in the envelope on soil K morphology and cotton growth characteristics were explored, so as to provide basis for maintaining soil K balance and achieving weight loss and high yield of cotton.
Method A pot experiment was conducted to study the effects of coated K chloride containing MC on soil K morphology and cotton growth characteristics. There were seven treatments, including basal application of coated K chloride containing mepiquat chloride (CRKMC, 0.15 g kg−1 soil fertilizer), reduced 30% K dosage of CRKMC (CRKMC70%), basal application of controlled release K chloride (CRK), reduced 30% K dosage of CRK (CRK70%), and split applications of ordinary K chloride (KCl), reduced 30% K dosage of KCl (KCl70%) and no K fertilizer used (CK). Soil K content, cotton plant height, stem diameter, photosynthetic characteristics and yield were measured during cotton growth period.
Result The results showed that the seed cotton yield of CRKMC treatment was the highest, which was significantly increased by 13.80% and 22.58% compared with that of CRK and KCl treatment, respectively. The cotton yield of CRKMC70% treatment did not decrease compared with that of CRK treatment. In addition, CRKMC treatment significantly increased cotton plant stem diameter, net photosynthetic rate, SPAD value and agronomic utilization. The soil available K, slowly available K and water-soluble K content of CRKMC was higher than that of KCl after bud stage. From bud stage to blooming stage, the available K was partially converted to slow K storage, which increased the content of slow K, and the effect of each controlled release treatment was better than that of ordinary K fertilizer.
Conclusion One-time application of coating K chloride containing MC could effectively ensure soil K supply, improve soil K fixation potential, optimize cotton growth characteristics, and provide technical support to achieve high yield of cotton and optimize labor.
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