Condições ambientais em sistemas agroflorestal e a pleno sol e seus efeitos sobre as características fitotécnicas do milho e do feijão

Abstract

Corn and common bean are essential foods for ensuring the sovereignty and food security of the Brazilian population. However, the agricultural model based on monoculture, with intensive use of synthetic inputs and pesticides, generates environmental and health impacts. The growing interest in organic products has driven the search for more sustainable farming systems, such as intercropping and agroforestry. Nevertheless, studies on corn-bean intercropping in agroforestry systems (AFS) are still scarce. This study aims to compare the growth and productivity of corn and bean plants grown individually and intercropped in agroforestry systems and full-sun cultivation. Two experiments were conducted in 2021 and 2022, in an AFS established in 2013 and a full-sun (FS) cultivation area. The study used the corn cultivars 'BRS 019TL' and 'BRS 015FB' and the bean cultivar 'BRS Paisano'. The experimental design consisted of randomized blocks with treatments comprising two cultivation environments (AFS and FS), three planting arrangements (sole, 1:1 intercrop, and 2:2 intercrop), and two corn cultivars ('BRS 019TL' and 'BRS 015FB'). Analyses included micrometeorological characterization of the environments and their effects on plant growth, productivity, seed quality, and land-use efficiency parameters. Statistical analyses were performed using variance tests, t-tests, and correlations in R software. The results indicate that the AFS generally exhibits lower air temperatures and potential evapotranspiration due to reduced solar radiation, promoting greater plant height and leaf area growth but lower productivity compared to the FS environment. Corn-bean intercropping proved viable, although beans showed higher productive potential when grown individually. Under intense water deficit conditions, intercropping demonstrated more efficient land use in the AFS compared to FS. Despite the reduced solar radiation near tree rows, the distance only influenced bean productivity, which was higher in central rows. Among the corn cultivars, 'BRS 019TL' exhibited superior growth and yield parameters. The shading provided by the agroforestry system and intercropping increased the first count in the corn germination test. Therefore, AFS emerges as a promising productive strategy, especially considering the growing meteorological challenges that require resilient and agroecologically sustainable farming systems. Moreover, although grain production in AFS is lower due to reduced energy availability, the quality of corn seeds produced was higher, highlighting the potential of this system for organic seed production.