Assessment of maize-cowpea intercropping response to row orientation in diverse agro-ecologies of Côte d'Ivoire

Abstract The stability of cropping systems in a changing climate context depends on numerous factors, including row orientation, to optimize the use of environmental resources. This study aimed to evaluate the performance of agricultural systems based on the row orientation of cowpea (Vigna unguiculata) and maize (Zea mays) in three different ecological conditions in Côte d’Ivoire, in 2020 and 2021. An experimental design with plots divided into three complete randomized blocks with six subplots per block and three repetitions was set up, varying the row orientation in intercropping and monoculture. Row orientation, cropping system used, and ecological zone significantly influenced crop yield and its components. In intercropping, cowpea (tiligré) showed the best yields when oriented North–South (NS) in the tropical rainforest zone and the sub-Sudanian savannah, while East–West (EW) orientation was optimal in the forest-savannah mosaic zone. In contrast, maize (GMRP18) yielded the best in intercropping when rows were oriented East–West, regardless of the season. In monoculture, cowpea yielded best when oriented EW in the tropical rainforest zone (488.17 kg ha−1) and in the forest-savannah mosaic zone (1262.12 kg ha−1), while NS orientations were preferable (228.6 and 259.54 kg ha−1) in the sub-Sudanian savannah zone. For maize monoculture, EW orientation was also preferable. Throughout the study, for both seasons, the highest yield advantages in maize-cowpea intercropping were obtained in EW orientation, regardless of the ecological zone. Overall, the forest-savannah mosaic zone yielded the best cowpea yields (1262.12 and 663.9 kg ha−1).