Potassium Indexing of Crops Grown on Eight Benchmark Soil Series of India

Surface soil (0-15cm) and foliar samples of wheat, rice, sugarcane, and cotton crops growing in eight intensively cultivated soil series of India were collected from farmers' fields during 2004 and 2005. Analysis of soil and leaf samples indicated widespread potassium (K) deficiency in soils and crops. Potassium deficiency in wheat growing in Lukhi series (Udic Ustocrept) and Akbarpur series (Udic Haplustulf) and in cotton growing in Typic Torrifluvent were comparable to 1N ammonium acetate (NH4OAc)-K (available K) soil test values. Rice cultivated on Udic Ustocrept soils in summer monsoon season showed relatively less K deficiency in comparison to winter wheat, and K deficiency in growing rice did not match 1N NH4OAc-K soil test values. In the Khatki series, K deficiency in sugarcane was much less than 1N NH4OAc-K soil test values. In the Arsia series (Typic Haplustert), despite the high 1N NH4OAc-K status of soils, K deficiency in growing wheat was observed.