Soil Carbon Sequestration Practices for Enhancing Agricultural Sustainability and Climate Mitigation: A Comprehensive Field-Based Assessment Across Diverse Agroecological Zones

Abstract

In detail, eighteen agricultural research farms across seven agroecological zones were assessed in-depth through field-based assessments both for success and effectiveness of soil carbon sequestration strategies to increase farms' sustainability and climate mitigation potential. The study consisted of a Randomized Complete Block Design (RCBD) comprising three cropping seasons and ten practices, including conservation tillage, no-till farming, use of organic manure, incorporation of biochar, different agroforestry systems, integrated nutrient management systems, crop rotation, and green manuring with 360 experimental plots. The soil samples were analyzed for several soil features, including soil organic carbon, microbial biomass carbon, bulk density, and availability of soil nutrients, as well as GHG emissions throughout the photosynthetic period, with the help of automated weather stations. We found that the SOC had an increase of 32.8%, and soil organic matter (SOC x 1.72) and microbial biomass carbon (MBC) increased 27.4% and 23.9%, respectively, with water-use efficiency is increasing 21.6%, and crop yield is 26.3%. Soil organic carbon (Csoil) showed the highest value of coefficient of agricultural sustainability (β) (p < 0.001, β = 0.48), and it explained 77.1% of the variation. Soil carbon accumulation, crop productivity, and GHG mitigation were identified as three main principal components with 83.7% of the total variance implemented. The practices led to a reduction of the net GHG emissions by 20.8% compared to conventional farming. What is new is that they evaluated the impacts of diverse carbon-sequestering practices in each of a set of agroecological zones – and they measured their impacts in concrete, real-world terms, well establishing the benefits of conservation tillage, cover cropping, agroforestry, biochar application, and integrated nutrient management for agricultural sustainability.