Residual Soil Fertility, Nutrient Uptake, and Yield of Okra as Affected by Bioorganic Nutrient Sources

Abstract

ABSTRACT A two-year experiment was undertaken during kharif seasons of the year 2019 and 2020 to investigate the effect of bioorganic nutrient sources (farmyard manure, vermicompost, jeevamrit, and ghanjeevamrit) and inorganic fertilizers on residual soil fertility, nutrient uptake, and fruit yield of okra in Entisols of Himachal Pradesh. The experiment consisted of nine treatments with varying combinations of nutrient sources. Treatment T3 [jeevamrit application (100% N equivalence) + farmyard manure @ 10 t ha−1] resulted in highest residual soil organic carbon (12.00 g kg−1), culturable microbial count (69.67 cfu g−1 soil × 105), microbial biomass carbon (67.43 mg kg−1) and nitrogen (37.40 mg kg−1) as well as maximum plant-available N (309.3 kg ha−1), P (23.2 kg ha−1), K (187.9 kg ha−1), S (60.3 kg ha−1), Fe (15.55 mg kg−1), Cu (1.92 mg kg−1), Mn (11.73 mg kg−1) and Zn (1.62 mg kg−1) contents. Further, the treatment T6 [jeevamrit application (100% N equivalence) + vermicompost @ 2.5 t ha-1] obtained the greatest value for okra yield (11.95 t ha-1) along with more uptake of macro and micro nutrients by the plants. This superior combination (T6) recorded an increase of 21.3% in yield over T2 (RPMF) as well as the highest net returns (₹ 1,50,258/ha) and B:C ratio (2.69). Thus, it can be inferred that the conjoint use of jeevamrit (100% N equivalence) with farmyard manure or vermicompost is beneficial for improving residual soil fertility, nutrient uptake, and sustainable okra production with 100% net saving of fertilizers.