BIOGEOCHEMICAL CYCLING OF NITROGEN IN AGRICULTURAL SOILS: IMPLICATIONS FOR SUSTAINABLE NUTRIENT MANAGEMENT IN PAKISTAN

Abstract

Nitrogen (N) plays a pivotal role in agricultural productivity, but its biogeochemical cycling in soils is highly complex and influenced by multiple microbial, chemical, and physical processes. In Pakistan, where agriculture is a primary economic activity, understanding nitrogen dynamics is critical for improving fertilizer use efficiency and mitigating environmental impacts. This study examines the key pathways in the nitrogen cycle—including mineralization, nitrification, denitrification, and nitrogen fixation—within the context of diverse agro-ecological zones of Pakistan. Using field data, soil sampling, and GIS-based nutrient modeling, we highlight the spatial variability of nitrogen fluxes and losses. The research also explores the influence of climatic conditions, irrigation regimes, and organic matter content on nitrogen transformations. Finally, we present evidence-based recommendations for integrated nitrogen management practices to enhance sustainability and reduce nitrogen-related pollution in agricultural ecosystems.