Effect of long term conservation agriculture and nitrogen management on soil nitrogen, phosphorus and sulfur fractions under maize–wheat–mungbean cropping system

Abstract

Conservation agriculture (CA) covers nearly 3.5 mha in Indian. And there is lack of studies on the CA effects soil nutrient dynamics. So, this study examines the effects of nine years of conservation agriculture on soil nitrogen (N), phosphorus (P), and sulfur (S) fractions in an Inceptisol under maize–wheat–mungbean cropping system. Different tillage and nitrogen management practices were evaluated to understand how nutrient management in CA, contrasts with conventional methods. The CA practices and N fertilizer addition significantly enhanced the soil mineral N, alkali-permanganate N, potentially mineralizable N and microbial biomass N. The CA and N fertilization enhanced soluble and loosely bound P by dissolving the iron-bound, aluminum-bound, reductant soluble and calcium-bound P. All the soil S fractions i.e. available S, total water-soluble S, heat soluble S, sodium bicarbonate extractable S, inorganic sulfur, organic sulfur and total sulfur was positively affected by CA and N fertilization practices over conventional tillage and control plots, respectively. It is important to note that the green seeker-based N management options especially with urea super granules showed tendency in enhancing the available nutrient pools of N, P and S compared to recommended dose of N (RDN) applied and control plots indicating that in due course of time it may reduce the amount of RDN without hindering any soil nutrient dynamics. These findings contribute crucial knowledge for sustainable development by offering valuable perspectives on N, P and S management strategies.