广西甘蔗种植区土壤钾素肥力分级研究

A Classification System for Potassium Availability in Soils for Sugarcane Planting Regions in Guangxi

统计分析 1991年至 2 0 0 1年在广西来宾、合浦、贵港、博白等县的红壤、赤红壤和砖红壤上进行的 82个施钾肥增产效应田间试验资料 ,分砂土、壤土、粘土质地对广西甘蔗种植区土壤钾素肥力进行分级。结果表明 ,甘蔗种植区土壤速效钾肥的临界值为 :砂土 4 6 .2 m g/ kg,壤土 5 1.4 mg/ kg,粘土 6 0 mg/ kg。砂土、壤土和粘土土壤速效钾肥分级指标分别为 :低 <4 6 mg/ kg、 <5 2 mg/ kg和 <6 0 mg/ kg,中 4 6～ 90 mg/ kg、 5 2～ 110 mg/ kg和6 0～ 12 0 mg/ kg,高 >90 mg/ kg、 >110 mg/ kg和 >12 0 mg/

From 1991 to 2001,82 field experiments were carried out on sugarcane in Laibin,Hepu,Guigang and Bobai Crop response to K as affected by the K status (available K) was measured and statistically analysed Calculated critical values depended on the soil texture,characterised by sands,loam soils and clays For sugar cane cultivated on all three soil textures,the calculated critical K values were,46 2,51 2 and 60 mg/kg of available K in sandy,loamy and clayey soils,respectively Accordingly,potassium supply classes for soils of cultivating sugar cane were established For the three soil textures,the following supply classes were defined:(1)Low K supply:<46 mg/kg,<52 mg/kg and <60 mg/kg,(2)Medium K supply:46~90 mg/kg, 52~110 mg/kg and 60~120 mg/kg,(3)High K supply:>90 mg/kg,>110 mg/kg and >120 mg/kg,for sandy,loamy and clayey soils,respectively