Bean-soybean succession under full sun and in agroforestry systems: Impacts on radiation use efficiency, growth and yield

Simultaneous cultivation of agricultural and forest species may result in changes in plant community interactions, generating microclimatic changes within the understory and then modifying growth and yield characteristics of the intercropping systems. Thus, this study aimed to assess the radiation use efficiency, growth and yield of bean and soybean cultivated in succession under two arrangements of agroforestry and full sun. To these ends, two field experiments were conducted in Southern Brazil: bean in-season and soybean off-season. Absolute and relative growth rates, net assimilation rate, leaf weight ratio, leaf area ratio, specific leaf area, radiation use efficiency and yield of bean and soybean were assessed. The solar radiation flux was modified by plant arrangement and tree canopy characteristics. Shading affected growth and yield characteristics and the radiation use efficiency of the studied crops. From the results obtained in this study, it is possible to recommend crop bean cultivation in agroforestry systems. However, for soybean, due to the reduced yields obtained in agroforestry systems, further research should be conducted in order to study more spaced arrangements and crop insertion in the early years of agroforestry, in order to enable its insertion in agroforestry systems in Southern Brazil.