Regenerative organic agriculture and soil ecosystem service delivery: A literature review

Abstract

Regenerative Organic Agriculture (ROAg) can have several beneficial effects on soil health and the delivery of important soil ecosystem services. Yet, the net effect of multiple ROAg practices (i.e. minimum soil disturbance, crop rotation, cover cropping, organic fertilization, etc.) on soil health and ecosystem service delivery has been rarely assessed. The challenge remains to compare how diverse ROAg practices vs. conventional agriculture might influence soil biogeochemical properties using replicated field experiments lasting at least few years.

We performed a systematic literature review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) approach and selected English written peer-reviewed scientific papers focused on the effects that ROAg might have on soil health and soil ecosystem service delivery. Findings were analysed with a vote-count procedure and data extracted from comparative studies between conventional and regenerative organic agriculture were utilized to calculate an impact score. After screening 271 records, 24 studies met all the inclusion criteria. Among them, 17 research studies experimentally compared ROAg vs. conventional practices and quantitative data extracted from 63 observations were used for the impact assessment.

Our findings show that ROAg improved soil health and soil ability to deliver multiple ecosystem services. The vote-count including 45 observations from 24 selected studies, shows how ROAg had positive effects on soil ecosystem services in 64% of the total number of observations. The impact assessment analysis, which included quantitative data extracted from 63 experimental observations, also show positive effects on multiple soil ecosystem services and soil biogeochemical parameters. ROAg increased soil organic C (SOC; g kg⁻¹) by 22 %, soil total nitrogen (STN; g kg⁻¹) by 28 %, and soil microbial biomass carbon (MBC; g kg⁻¹) by 133 % compared to conventional agriculture. The highest number of positive ROAg effects were associated with supporting services (e.g. SOM dynamics, soil nutrient and water cycling). A negative ROAg effect was observed on the ‘food and fiber production’ provisioning service, where yields (food quantity) were 24 % lower when compared to conventional agriculture. However, the only data available on potential links between soil management and plant health, shows ROAg positive effects on plant nutrient density (food quality).

Our review demonstrates that ROAg has significant positive impacts on soil health and ecosystem service delivery and highlights the need for long-term comparative studies across world regions to address knowledge gaps and assess potential economic, social and human health benefits associated with a greater implementation of ROAg practices.