Intercropping and Sustainable Farming Practices Increase Soil Carbon Reserves

The Diverfarming project evaluates the impact of intercropping and agricultural management on the dynamics of soil organic carbon in four climate regions in Spain, Italy, and Finland

Sustainable agriculture arises as a key strategy to reach the Objectives of Sustainable Development of the 2030 Agenda, which seeks to reduce poverty and hunger, and deal with climate change while preserving natural resources. In this respect, the increase in soil organic carbon reserves can represent an important step towards the development of more sustainable agricultural systems. Bearing in mind that soil organic carbon is considered one of the most important indicators of soil quality and agronomic sustainability due to its impact on other physical, chemical, and biological soil properties, the increase (or loss avoidance) in soil carbon will be determinant in this march towards agricultural and environmental sustainability.

With the aim of assessing the impact on the soil carbon cycle of those intercropping and low input practices that have been implemented within the project, a team of researchers from the University of Portsmouth, the CSIC Aula Dei Experimental Station, University of Cartagena, the Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria in Italy (CREA) and the Natural Resources Institute LUKE in Finland have assessed the changes in soil organic carbon in four case studies in which they have trialed intercropping and sustainable farming practices for more than eight years.

The use of a modified ECOSSE model to assess the impact of intercropping and agricultural management on the dynamics of soil organic carbon revealed that crop type, tillage and type of organic amendment are the factors that have the greatest impacts on soil organic carbon.

In the Spanish case study of Murcia, in nine years the addition of compost and use of vegetable covers in the diversified systems produced an increase in soil organic carbon, in comparison with conventional management. With regard to the case studies in Foggia (Italy) and Huesca (Spain) the effect of tillage was modeled on the reserves of soil organic carbon in dryland, and a positive impact was predicted when the decision was of no-tillage.