Determination of the P critical limit for French bean in the acidic soil of Mizoram

Abstract

An experiment was conducted through pot culture from soils collected across the upland and lowlands of Kolasib district, Mizoram, to study French bean cv. Zorin bean response to different doses of phosphorus (P) application to determine the P critical limit. The critical limit of a nutrient and a suitable extractant is necessary for site-specific nutrient management. The collected soils across the region were acidic with a mean pH value of 4.64 ± 0.11, SOC content 8.13 ± 0.93 g kg-1 and soil texture ranging from loam to sandy clay loam. Phosphorus (P) was applied @ 0, 50 and 100 kg ha-1, while nitrogen (N) and potassium (K) were applied @ 50:50 kg ha-1. Available P in soils and concentration in the plants increase significantly with an increased in the level of P application. Dry matter yield and plant uptake were also found to increase with P application @ 50 kg P ha-1. Bray’s percent yield (BPY, r=0.79**) and Bray’s percent uptake (BPU, r=0.72**) showed the highest significant positive correlation with Melich-1 extractant. The P critical limit in soil was 15 mg kg-1 for Olsen, 8 mg kg-1 for Bray‒1, and 10 mg kg-1 for Mehlich-1, respectively. The P critical limit in the French bean (Zorin bean) plant was observed to be 0.16%.