Fertilizers used in tomato production in West Africa

Fertilization is essential for optimizing agricultural production by providing the plant with the needed nutrients. Good fertilization practices can promote healthy crop growth and safe products for consumers. However, the intensive use of fertilizers can lead to negative effects on the environment such as water pollution and soil degradation, as well as on the quality of the product such as shelf life. The present study aimed at assessing the fertilization practices in tomato production in West Africa. Fertilization methods, diversity of fertilizers, doses and frequency of application were recorded. A semi-structured questionnaire was used from September 2021 to November 2022 to collect data in three countries of the region. In total, 405 vegetable growers spread across Benin (204), Mali (78) and Burkina Faso (123) were interviewed. The results revealed that most of the tomato growers were on organo-mineral fertilization (68 to 80%). Noteworthy diversity in organic fertilizers was observed, particularly in Benin. Poultry manure (6 to 59%) and compost (7 to 40%) were part of the main organic fertilizers applied by vegetable growers across all countries. However, NPK was the dominant mineral fertilizer used and a significant concern arises from the overuse of NPK and urea fertilizers across all three countries, surpassing recommended levels. Average urea doses exceeded recommendations (100 kg ha-1) in Benin (+411%) and in Burkina Faso (+313%). The overuse of fertilizers by farmers may be attributed to i) the pursuit of maximum yields, ii) their difficulty of assessing soil reserves, iii) the intensification of tomato production over small areas, and iv) in some cases, soil degradation can lead to over-use of fertilizers. The economic analysis highlighted variations in costs between countries according to the type of fertilization, underlining the need for sustainable fertilization practices. This research contributes to the broader goal of ensuring food security while preserving soil health and environmental sustainability in West Africa.