贵州省水稻土速效钾的临界水平和丰缺指标及在水稻钾肥施用中的应用

CRITICAL AND SUPPLYING LAVEL OF AVAILABLE POTASSIUM IN PADDY SOIL IN GUIZHOU AND ITS APPLICATION IN THE POTASSIUM FERTILIZER RECOMENDATION

根据21个水稻钾肥田间试验中钾肥效应与土壤速效钾含量关系的分析,并根据贵州省不同区域社会经济条件的差异,提出了土壤速效钾含量临界值和丰缺指标的两套标准。对于经济条件较好的地区,建议以相对产量95％为临界标准,相应的土壤速效钾含量为146ppm。其丰缺指标为:大于146ppm为“高”,68～146ppm为“中”,34～68ppm为“低”,小于34ppm为“极低”。对于社会经济条件较次的地区,建议以相对产量90％为临界水平的标准,相应的土壤速效钾含量为112ppm。各级指标分别为:大于112ppm,59—112ppm,34—59ppm和小于34ppm,还提出了根据临界值和丰缺指标计算建议施用钾肥的方法。

Based on 21 field expelments for rice response to potassium fertilizer,two indexes of critical and supplying level of soil available potassium were suggested. The available potassium is extracted with 1N NH4AC and divided into four levels: "High", "Medium", "Low" and "Very low". For first area where the social-economical conditions are better, the four levels are greater thanl46ppm,68-146ppm,34-68ppm and less than 34ppm respectively.For second area where the social-economical conditions are worse, the four lovels are greater than 112ppm, 59-112ppm, 34-59ppm and less than 34ppm, respectively.