Soil Fertility Management Practices for Enhancing Crop Yield: A Review

Abstract

Soil fertility is the foundation of crop productivity, yet nutrient depletion, organic matter loss and physical degradation currently affect roughly a third of the world's agricultural soils, threatening food security under a growing global population. This review synthesizes recent evidence on the major soil fertility management (SFM) practices used to sustain and enhance crop yield, including organic amendments (farmyard manure, compost, crop residues and biochar), inorganic and precision nutrient management, biological approaches (biofertilizers and plant growth-promoting rhizobacteria), legume-based crop rotation and cover cropping, conservation tillage, and Integrated Soil Fertility Management (ISFM), which combines these approaches with locally adapted germplasm. Drawing on global meta-analyses, the review shows that organic amendments increase yields by an average of 27% relative to mineral-only fertilization, with farmyard manure alone contributing up to 49%; biofertilizer inoculation raises yields by 8.5–20% depending on climate; biochar effects are strongly context-dependent, ranging from negligible in temperate soils to 25% in the tropics; legume-based rotations raise subsequent crop yields by approximately 20%; and no-till alone tends to reduce yields by around 5.7% unless combined with residue retention and diversified rotation. The evidence converges on a central conclusion: no single input consistently maximizes yield across all environments, and the largest, most stable gains arise from integrating organic and inorganic nutrient sources with biologically and physically sound soil management, tailored to local soil, crop and climatic conditions. The review closes by identifying key constraints to adoption and priority directions for future research and extension.