Diversifying maize monocropping in Benin with vegetables

“Before, we grew fields of maize” explains Calixte Zannou, a smallholder farmer in Allada. “But through the FRESH project, we were told about the benefits from diversifying our crops and our diets, reducing production risks while improving soil health and food security. Now, after training on new approaches, we grow chili pepper, tomato and different beans within our maize fields, giving us vegetables to eat and enjoy, and sometimes selling the surplus for a nice additional income.”

On-farm awareness raising session in Allada

Managing the challenges presented by population growth, climate change and soil fertility decline requires effective strategies to sustainably intensify smallholder farming systems in Africa. One such strategy is through more diversified farming systems, which offer more resilience to climatic and economic shocks compared to monocultures. This also has the potential to improve resource use efficiency, and incorporating nitrogen fixing legumes helps to enrich the soil, that all boost productivity. There is also evidence that intercropping can reduce weed seed germination and weed growth, and suppress crop pests and diseases. Yet, finding suitable options for crop diversification that fit into local farming systems has remained difficult

To maintain communication, a WhatsApp platform was established to share and discuss surveillance results at regular intervals across the region. WorldVeg also keeps in active contact via the platform to provide technical support regarding pest identification and early detection of P. absoluta in high risk areas of participating countries. In 2023, typical symptoms of tomato leaf miner damage were found in Laos, and the material was sent to for analysis. All ASEAN member states stay on alert, but now thanks to this project, they are better armed to reduce risks from this potential new invader.

Preferred sowing systems, one line of maize intercropped with three lines of mungbean (left), and two lines of maize intercropped with two lines of chili (right)

To propose a practical intercropping system with benefits to farmers and the environment that produces more healthy vegetables for consumption, diversification trials were set up in the villages of Ahota, Gbedji, Lanmandji, Sohou and Tokpa-Zounledji, Allada commune, in the heart of Benin’s ‘maize belt’. In each village, three farmers intercropped their maize with either mungbean, chili pepper or tomato, trying four sowing systems – a monocrop of maize or the intercrop, and one line or two lines of each, with additional options for mungbean including one line of maize with two or three lines of mungbean. The plots size for each treatment was 300 m² with organic fertilizers and neem oil supplied, supervised by a trained field technician.

Plant growth parameters (height, stem diameter and number of leaves) of the maize were not statistically different (p<0.05) between monocropping or any or the intercropping trials. However, intercropping proved to be beneficial for the growth of the associated crops (p<0.01), with for example, 30% taller chili pepper plants when interplanted in double rows, compared to monoculture (41 cm compared to 32 cm). The best performances in terms of plant growth and yield of intercrops were from two lines of maize intercropped with two lines of either chili or tomato, and from one line of maize intercropped with three lines of mungbean.

These results were confirmed from the subjective assessments made by pilot farmers during the field days organized across the villages to raise awareness of the tested sowing systems, and that indicate that intercropping maize with vegetables is seen as a beneficial and desirable option for smallholder farmers in the region.

This reports work undertaken as part of work package 3 of the FRESH project: ‘Intensify the production of market garden crops based on crop diversification with the introduction of vegetable crops in major areas of maize production.’ FRESH (Fruit and Vegetables for Sustainable Healthy Diets) is a One CGIAR initiative jointly implemented by WorldVeg and One CGIAR centers, including IFPRI and CIMMYT.

https://www.cgiar.org/initiative/fruit-and-vegetables-for-sustainable-healthy-diets-fresh/

This article can also be found in the World Vegetable Center Annual Report 2023

WorldVeg Annual Report 2023 ! – World Vegetable Center (avrdc.org)