Soil quality changes along an agroecological transition: Evidence from natural farming in Madhya Pradesh, India

The scale and intensity of current agricultural practices have negative impacts on soil quality. Shifting to agroecological and natural farming practices, which replace chemical inputs with biological inputs and processes, can reduce these impacts. Yet, transforming conventional farms into more sustainable farms requires an “agroecological transition”, with multiple pathways to replace pesticides and fertilizers. We measured multi-year soil indicators in a chronosequence of farms at various phases of transitioning to natural farming in central India: conventional, newly transitioned with no chemical pesticides, newly transitioned with no chemical pesticides and fertilizers, fully established with no chemical pesticides and fully established with no chemical pesticides and fertilizers. Over two years, we measured soil carbon (C) pools (total C and active C), nitrogen content, enzyme activity, bulk density, and microbial communities. Our results show that fully established natural farms exhibit improved soil quality indicators year over year. We observed higher soil C pools even after the initial steps toward natural farming, for instance, recently transitioned farms averaged 2.9 % soil C and 789.48 mg kg −1 active C, compared to 1.1 % and 437.56 mg kg −1 in conventional farms, indicating their sensitivity to changes in management practices early in an agroecological transition. Soil microbial composition also significantly differed across the transition phases, indicating strong management effects on soil functioning. Understanding soil quality along various management pathways is essential to provide actionable soil quality assessments, as well as to provide important indicators to motivate even the most risk-averse farmers to undertake agroecological transitions. • In natural farming systems, bio-inputs improve soil health indicators. • Enhanced soil quality is observed even in early phases of natural farming transition. • Soil microbial communities significantly shift with reduced chemical inputs. • Carbon-based indicators are most sensitive to agroecological transition.