安徽省油菜钾肥施用效果及土壤速效钾丰缺指标研究

2005—2009连续4个年度在安徽省冬油菜生产区布置油菜钾肥肥效试验73个,研究施用钾肥对油菜产量和经济效益的影响;并通过建立油菜籽粒相对产量和土壤速效钾含量的关系,确定土壤速效钾丰缺指标。结果表明,油菜施用钾肥具有明显的增产效果,施钾后油菜平均产量达2 558 kg/hm~2,比不施钾增产509 kg/hm~2,增产率为28.1%。施钾每公顷平均增收1 349元,67.1%的试验点产投比2.0,施钾收益显著。13.7%的试验点施钾后增产不增收。以相对产量60%、60%~75%、75%~90%、90%~95%和95%为标准,将土壤速效钾分为"严重缺乏"、"缺乏"、"轻度缺乏"、"适宜"和"丰富"5个等级,处于各等级的土壤面积的比例分别为2.7%、17.8%、65.8%、6.8%和6.8%,对应的丰缺指标分别为30、30~60、60~110、110~140和140 mg/kg。此研究建立的土壤速效钾丰缺指标可为安徽省冬油菜的钾肥管理提供依据。

Study on the Effect of Potassium Fertilizer and Abundance and Deficiency Indices of Soil Available Potassium on Rapeseed in Anhui Province

73 field trials of potassium fertilizer (K) application on winter rapeseed were conducted in rapeseed production regions of Anhui Province during 2005 to 2009 to study the effect of K application on rapeseed yield and profit. The abundance and deficiency indices of soil available potassium were determined based on the relationship between rapeseed relative yield and soil available potassium. The results showed that K application significantly increased rapeseed yield compared with control treatment. The average values of rapeseed yield, and increment and increase rate of the yield were 2 558 kg/hm2, 509 kg/hm2and 28.1%, respectively. The net profit was 1 349 Yuan/hm2with K application and the value cost ratios were higher than 2.0 at 67.1% of the field trails. While at 13.7% of the field trails, rapeseed yield increased by K application, but farmers’ income was not increased. The rapeseed yields of the K application treatment were compared with that of control to obtain the relative yields, then the relative yields of <60%, 60% – 75%, 75% – 90% and >95% were selected to establish the abundance and deficiency indices for soil available potassium. The land areas of extreme deficiency, deficiency, slight deficiency, optimum and abundance indices of K occupied 2.7%, 17.8%, 65.8%, 6.8% and 6.8% of total area for winter rapeseed in the province. The extreme deficiency, deficiency, slight deficiency, optimum and abundance indices for soil available potassium were<30, 30 – 60, 60 – 110, 110 – 140 and>140 mg/kg, respectively. The soil available potassium critical indices can be used as guidance for potassium fertilization on winter rapeseed in Anhui Province.