Potassium deficiency in soils and crops: an emerging problem in Karnataka.
Naidu L. G. K., Ramamurthy V., Rameshkumar S. C.
Author Affiliation: National Bureau of Soil Survey and Land Use Planning, Regional Centre, Hebbal, Bangalore - 560 024, India.
Indian Journal of Fertilisers 6 : 32-38
Abstract : Potassium is involved in number of physiological processes, protein synthesis and activation of enzymes. Though it is considered rich in Indian soils but the recent studies showed declining status is most of the states, which lead to severe fertility degradation. Available soil K status map for Karnataka was prepared using soil samples collected at 10-km grid internal. Long-term changes in soil K status were monitored using earlier soil test summaries. Red, lateritic and shallow black soils have shown K depletion shifting either from high to medium or medium to low status over years. High crop K removal than K addition by farmers was found causing large-scale K mining leading to emergence of K deficiency in soils and crops. Some pockets in Kodagu, D. Kannada, Chikmagalur, Shimoga and Bijapur districts have undergone K fertility degradation. Widespread K deficiency was identified in horticultural, plantation, ornamental, aromatic and avenue plants in and around Bangalore plateau. Visual K deficiency symptoms on wide range of crops were documented. Corrective measure for K deficiency in mango and guava was developed. The current fertilizer recommendations based on agro-climatic zones are very generalized not taking into consideration of the soil types. More than one soil type occur in each zone need separate K recommendation. Awareness on K use by farmers in K deficient regions needs more emphasis.