Impacts of Conservation Tillage and Biochar on Restoration of Soil Quality by Altering Rhizospheric Nutrient Cycling, Biocrust Formation and Crop Productivity: A Review

Understanding soil–plant–microbe inter- and interactions is essential for ensuring proper soil health, quality, and soil-mediated ecosystem services (e.g., nutrient cycling) required for human–plant–animal life. Intensive and unsustainable farming practices can decrease soil microbial biodiversity, fertility, and quality leading to soil degradation, impaired nutrient cycling, and the incapability of soil to support plant growth. Under such a context, soil biological fertility can appear as a regenerative component that has the potential to harmonize and improve soil’s physical, chemical, and biological parameters. The review study expresses the micro biome in the rhizosphere, microbial nutrient cycling, and biological soil crusts as the major components of soil biological fertility, and explores the answers to the questions: (i) How does the rhizosphere promote plant growth, development, and nutrient cycling through soil microorganisms, (ii) How can soil microorganisms regulate macronutrient cycling and facilitate bio crust formation. Soil biological fertility is crucial for increasing crop resilience and productivity as well as sustainability in agriculture. Additionally, the reintroduction of plant growth promoting rhizo bacteria, a quantitative estimation of the root exudate’s composition, identifying the spatiotemporal dynamics of potassium solubilizing bacteria, and establishing biological soil crusts in agricultural lands remain the major tasks for improving soil biological fertility and the transition towards regenerative agriculture. Despite the promising potential of conservation tillage and biochar, the study meets problems such as diversity in soil types, climatic circumstances, and the long-term stability of biochar effects, which limit the generalization of results. However, by combining the most recent research on how these approaches boost crop productivity, encourage the formation of biocrusts, and enhance rhizospheric nutrient cycling, this review makes a substantial contribution and provides insightful information for long-term soil restoration plans.