Soil Quality Indicators in Agroecological Practices: Lessons From a Systematic Review of Long-Term Experiments

Abstract

In recent decades, there has been increasing recognition of soil as a vital and non-renewable natural resource that provides essential environmental, economic, and social benefits. Agronomic and soil management practices—such as tillage systems, crop rotation, and nutrient applications—significantly influence near-surface soil properties and related ecosystem services. There is growing interest in defining soil quality and establishing specific indicators regarding conservation practices. This systematic review was focused on Long-Term Field Experiments (LTEs) conducted in seven countries: Czech Republic, Italy, Latvia, Lithuania, Poland, Spain, and Turkey. The review examined the most frequently studied soil quality properties related to agroecological practices. Our goal was also to standardize the results based on the advanced works in recent years on soil ecosystem services. The findings underscore the strong interest in sustainable production with a particularly high presence of agroecological soil practices in Long-Term Field Experiments (LTEs), especially in Italy and the Czech Republic. Cereals are among the most extensively studied crops under organic amendments and tillage intensity trials in the reviewed papers. Soil properties related to climate and environmental services (such as organic carbon) are the main indicators studied. Additionally, the review highlights a significant gap in soil biodiversity indicators in the agroecological long-term studies analysed. As a future direction, it is crucial to develop new, holistic soil quality indicators that encompass chemical–physical and biological aspects for soil monitoring and conservation.