Asociación de cultivos en horticultura para incrementar la productividad agraria y los servicios ecosistémicos

Abstract

This study focuses on the impacts and benefits of implementing intercropping systems, specifically between melon-cowpea and broccoli-fava bean, along with reduced tillage and addition of crop residues, all under organic management, compared to their respective monocultures. The investigations aimed to enhance crop yield and quality, improve soil physicochemical properties, increase soil organic matter, soil fertility, biodiversity, reduce fertilizer use and mitigate greenhouse gas (GHG) emissions. In both melon-cowpea and broccoli-fava bean intercropping systems, fertilization was reduced by 30%, and various intercropping patterns were tested, including mixed intercropping, row intercropping 1:1, and row intercropping 2:1. Over three crop cycles, the intercropping systems maintained soil organic C levels and significantly increased soil total N, available P and exchangeable K compared to the monocultures. Moreover, they showed significantly higher total production and a land equivalent ratio >1, which highlight the benefits of crop diversification. The study also evaluated the implications of intercropping systems on GHG emissions. CO2 emission rates were higher in broccoli-fava bean row 2:1 and row 1:1 intercropping systems, and melon-cowpea mixed intercropping system compared to fava bean and cowpea monocrops respectively. Soil N2O emission rates were not affected by crop diversification, with very low values recorded. Soil CO2 and N2O emissions were not correlated with environmental factors, soil properties, or crop yield and quality, suggesting that crop management and plant density and growth were the main factors controlling GHG emissions. Despite this, when GHG emissions were expressed on a crop production basis, lowest values were observed in intercropping systems, owing to higher crop production. Therefore, intercropping systems, have the potential to contribute to sustainable agriculture by increasing land productivity, reducing the need for synthetic fertilizers, and decreasing GHG emissions per unit of product. The introduction of legumes, cowpea in melon cropping and fava bean in broccoli cropping, associated with reduced tillage and the incorporation of crop residues, proved to be a viable strategy for sustainable agriculture.