追施不同形态氮肥对不同钾效率基因型棉花生长及产量品质的影响

Effects of Different Nitrogen Applied on the Growth,Yield,and Fiber Quality of Cotton Genotypes with Different Potassium-Use Efficiency in Florescence

【目的】探讨高、低供钾水平下,追施氮肥形态对棉花生长、钾素吸收利用以及产量、品质的影响。【方法】选择钾高效棉花品种辽棉18、冀棉958和钾低效棉花品种新棉99B为材料,进行营养钵培养试验,设置38.01mg·kg^(-1)和152.24 mg·kg^(-1)两个供钾水平,追施铵态氮肥(硫酸铵)和硝态氮肥(硝酸钙)两种形态氮素肥料。【结果】供钾不足会降低棉花果枝始节和单株成铃数,高钾处理棉花干物质积累量、钾累积量、钾利用指数以及产量显著高于低钾处理;与追施硝态氮肥相比,追施铵态氮肥会降低棉株高度、果枝数和单株成铃数,减少籽棉产量和总干物质积累量;追施铵态氮肥处理棉花对钾素的吸收和利用显著低于追施硝态氮肥处理。【结论】钾低效基因型品种棉花在钾素供应不足时对追施铵态氮肥更敏感,且棉花成熟越晚受到追施肥料氮素形态影响越大。

[Objective] The purpose of this study was to characterize the changes to cotton growth, yield, and fiber quality induced by different nitrogen applied in florescence under different soil available potassium （K） concentrations. [Method] High K-use efficiency cotton genotypes （Jimian 958 and Liaomian 18） and a low K-use efficiency cotton genotype （NuCOTN99B） were grown in pots with low （38.01 mg·kg^-1） or high （152.24 mg·kg^-1） soil K concentrations. Ammonium sulfate （as ammonium nitrogen） or calcium nitrate （as nitrate nitrogen） was applied in florescence, respectively. [Result] The plants grown under low soil K conditions had lower first fruit node and fewer bolls than the plants exposed to high soil K contents. Additionally, the whole plant dry weight, total K accumulation, total K utilization index, and seed cotton yield were significantly higher in plants treated with a high soil K concentration. Furthermore, the NH4^＋ treatment produced shorter stems, fewer fruit branches and bolls, and lower seed cotton yields and the whole plant dry weight than the NO3^- treatment. The NH4^＋ treatment also resulted in a lower accumulation of total K and a lower total K utilization index. [Conclusion] The low K-use efficiency cotton genotype was sensitive to the adverse effects of NH4^＋ applied in florescence, which had more serious consequences for the later mature cotton cultivar.