摘要
采用田间试验,研究稻草还田条件下不同施钾水平对晚稻产量、产量构成因素及钾素吸收利用和钾素表观平衡的影响。结果表明,在4 500 kg/hm2稻草还田条件下,增施K2O 37.5 kg/hm2的处理稻谷产量最高,钾肥再增加,稻谷产量随施钾量增加而减少;稻草产量则随施钾量的增加而增加。施用钾肥促进了水稻株高、单位面积有效穗数与千粒重的提高。研究还发现,施钾促进了水稻对钾素的吸收,随着施钾量的提高,稻谷和稻草的钾含量及钾素积累量均呈增加趋势;无肥(CK1)处理土壤钾素处于亏损状态,稻草还田及稻草配施化肥处理的土壤钾素均有盈余。综合考虑水稻高产和土壤培肥,在4 500 kg/hm2稻草还田条件下,推荐该地区晚稻的钾肥(K2O)适宜用量为25～50 kg/hm2。
Using field experiment to study influences of different potassium（K） fertilizer rates on yield,yield components,absorption and utilization of K and K apparent equilibrium of late rice under rice-straw returning mode.The results showed that under 4 500 kg/hm2 of rice-straw returning mode,applying 37.5 kg/hm2 of K2O had the highest yield of rice grain;if K fertilizer rate increasing further,the yield of rice grain decreased with increasing K fertilizer rate,but yield of rice-straw increased.Applying K fertilizer promoted the increase of rice plant height,effective panicles per unit area and 1 000 grain weight;it also promoted the K absorption by rice.With the increasing K fertilizer rate,the content and accumulation of K in rice grain and rice straw all showed an increasing trend.K content in soil with non-fertilizer application treatment（CK1） showed a depletion status,but K content in soil with rice-straw returning treatment and treatment of rice-straw returning combined with fertilizer application all showed a surplus status.Comprehensive considering high yield of rice grain and soil fertility,under 4 500 kg/hm2 of rice-straw returning mode,the recommended K fertilizer rate for late rice is 25-50 kg/hm2 in this area.
出处
《湖南农业科学》
2011年第4期57-60,共4页
Hunan Agricultural Sciences
基金
国家"十一五"科技支撑计划(2008BADA4B08)
国际植物营养研究所(IPNI)合作项目(Hunan-14)
湖南省农业科学院科技创新项目(2010hnnkycx56)
关键词
钾肥
稻草还田
晚稻
产量
钾素吸收
potassium fertilizer
rice-straw returning
late rice
yield
potassium absorption
