控释含缩节胺氯化钾对棉花叶片生理及土壤钾素形态的影响

Effects of controlled-release potassium chloride containing mepiquat chloride on leaf physiology and soil potassium fraction of cotton

钾素是棉花必需的元素,缩节胺是控制棉株旺盛生长的重要调节剂,为减少钾素和缩节胺施用次数,实现两者在同一时空条件下的一体化调控,研究一次性施用控释含缩节胺氯化钾(CRKMC)对棉花叶片生理及土壤钾素形态的影响。试验设置空白对照、氯化钾、控释氯化钾、控释含缩节胺氯化钾、减量20%的控释含缩节胺氯化钾处理。结果表明:CRKMC较KCl处理显著提高盛花期叶绿素b和可溶性蛋白含量,增强过氧化物酶和超氧化物歧化酶活性,减少丙二醛产生量,但不同类型钾肥对叶绿素a无显著影响;棉花生育期内,土壤水溶性钾呈下降趋势,速效钾和交换性钾呈动态波动变化,自盛花期以后,CRKMC处理各形态钾素较KCl显著增加;等量施钾条件下,CRKMC较KCl处理皮棉增加13.31%,钾素农学利用率提高2.19 kg·kg^(-1),减少20%钾素用量的CRKMC皮棉仍较KCl增加9.20%。因此,在棉花上一次基施CRKMC可改善叶片生理特征,延缓叶片衰老,合理调节不同形态钾素供应,利于实现棉花轻简化和高产化栽培。

Potassium is an essential nutrient element of cotton,mepiquat chloride(MC)is an important regulator to control the vigorous growth of cotton plant.A field experiment was conducted to investigate the effects of controlled-release potassium chloride containing mepiquat chloride(CRKMC)on leaf physiology and soil potassium fraction,in order to reduce frequency application of potassium and MC,and also realize the integrated control of MC and K under the same time/space conditions.Five treatments were conducted with three replicates:no K fertilization,common KCl,controlled-release KCl,CRKMC,CRKMC with reduced 20%K dosage.The results showed that:CRKMC significantly increased the content of chlorophyll b and soluble protein,enhanced the activity of superoxide dismutase(SOD)and peroxidase(POD),reduced malondialdehyde content,compared with KCl treatment.However,the types of K fertilizers had no significant effect on chlorophyll a.During the growth period of cotton,the water-soluble potassium in soil showed a decreased trend,the available potassium and exchangeable potassium showed trend with fluctuated dynamically,but the contents of different fraction potassium of CRKMC significantly increased than KCl treatment.The lint yield of CRKMC increased by 13.31%,Kagronomic use efficiency increased by 2.19 kg·kg-1,compared with KCl treatment at the same K dosage fertilization.Even with the reduced potassium by 20%of CRKMC,the lint yield increased by 9.20%compared with KCl treatment.Therefore,the basal application of CRKMC improved the physiological characteristics of leaves,delayed the senescence of leaves,and adjusted different fraction of potassium,which was beneficial to realize the cultivation of cotton with light simplification and high yield.