Corn and bean in an agroforestry system: growth, yield, and efficiency of solar radiation interception

Abstract

The cultivation of maize and beans in agroforestry systems can be a sustainable strategy, however, the reduction in available solar radiation may pose a challenge. This study aimed to evaluate solar radiation availability, the extinction coefficient, and radiation interception efficiency, as well as to quantify precipitation deficits and analyze crop growth and productivity under different shading conditions. Experiments were conducted using a randomized block design in a factorial arrangement (2 × 4, two maize cultivars, BRS 015FB and BRS 019TL, and four tree distances: 1.3, 2.1, 2.1, and 1.3 m) for maize, and a monofactorial design (7 tree distances: 1.3, 1.7, 2.1, 2.5 m center, 2.1, 1.7, and 1.3 m) for beans. We evaluated the crop coefficient and efficiency of photosynthetically active radiation interception of the species, as well as plant growth and yield. The results show that at noon, solar radiation is reduced by 50.7% for maize and 54.9% for beans. Maize had a lower extinction coefficient and higher efficiency in intercepting photosynthetically active radiation compared to beans. The precipitation deficit was more pronounced in the 2022/23 crop season, with 85 mm during the bean cycle and 118 mm during the maize cycle. For maize, productivity was not affected by tree distances, while for beans, the highest productivity occurred in the central rows between the trees.