湖南省晚稻施钾效应及土壤速效钾丰缺指标研究

Study on Response of Late Rice to K Application and Abundance and Deficiency Indices of Soil Available K in Hunan Province

[目的]研究钾肥对晚稻产量、经济效应的影响,建立湖南省晚稻土壤速效钾的丰缺指标。[方法]2005~2008年在湖南省湘北、湘中-湘东及湘南3个地区的稻田土壤上共布置159个钾肥晚稻田间试验。[结果]晚稻施钾有明显的增产及增收效应,3个地区晚稻施钾平均增产803~871 kg/hm2,平均增产率为13.1%~13.7%;施钾平均增加利润704.01~798.39元/hm2,平均产投比1.94~2.31。施钾增产趋势及经济回报均随土壤速效钾含量的提高而减缓或降低。晚稻种植体系中,湘北区土壤速效钾＂低＂、＂中＂、＂高＂丰缺指标分别为〈45.8、45.8~143.0和〉143.0 mg/kg;湘东-湘中区分别为〈42.9、42.9~125.2和〉125.2 mg/kg;湘南分别为〈38.8、38.8~139.1和〉139.1 mg/kg。[结论]湖南省晚稻种植体系中,严重缺钾土壤较少,土壤钾素主要为中等水平,8%左右的土壤速效钾含量较高。

[Objective] The objective of this research was to investigate the effect of K on late rice yield and profit,and determine abundance and deficiency indices of soil available K.[Method]159 late rice field trails of potassium fertilizer（K） application for late rice were conducted in 3 main double-rice cropping regions of Hunan Province such as the south region,the east-central region and the north region during 2005-2008.[Result]K fertilizer application increased the yield and the profit of late rice compared with no K application significantly.The average increase rice by K application in 3 regions was 803-871 kg/hm2,increase rate was 13.1%-13.7%,increase profit by K application was 704.01-798.39Yuan/hm2,and VCR was 1.94-2.31.There was significantly negative correlation between yield increment,VCR and soil available K.The low,medium,high indices for soil available K in the north region were 45.8 mg/kg,45.8-143.0 mg/kg and 143.0 mg/kg,and in these the east-central region were 42.9 mg/kg,42.9-125.2 mg/kg and 125.2 mg/kg,and these in the south region were 38.8 mg/kg,38.8-139.1mg/kg and 139.1 mg/kg,respectively.[Conclusion]The content of available K in the main area of whole province was at medium level,and in about 8% of the whole area were at high level,only small area were at low level.