Assessment of critical limit of available boron for pea in acidic Alfisols of East Sikkim, India

Abstract

A study was conducted in 20 acidic Alfisols of East Sikkim (India) to estimate the critical limit of soil boron(B) and pea plant for predicting the response of pea ((Pisum sativum) to B application. The hot water soluble B in these soils was found to be positively and significantly correlated with organic carbon(r = 0.71**), CEC(r = 0.46*), Bray’s percent dry matter yield (r = 0.87**), B concentration in plant tissues (r = 0.86**) and B uptake by shoots(r=83**). The critical concentration of soil available B and plant tissues B was worked out to 0.55 and 24.5 mg kg 1, respectively. Soil containing available B below the critical limit responded appreciably to B fertilization. A negative response to B application was also observed at its higher level. The average dry matter yield increases with increasing level of B application up to 1.0 mg kg 1. The response to B application in pea on B deficient soils was found to be 29.8%. Based on critical value of 0.55 mg kg-1, 8 soils were rated to be adequate and 12.5% soils belonging to this category responding to B application. Whereas, 100% soils below the critical value showed the positive response to B application.