Assessing Soil Nutrient Status for Optimizing Cassava Cropping Systems in Southern Benin: A DRIS Model Approach

Cassava is one of the widely cultivated and consumed root cropped in Benin. Cassava is also a highly strategic crop for maintaining food security in developing countries like Benin. Cassava production is threatened by declining soil fertility, especially nutritional deficiencies. This study aims to assess nutritional status of soil under cassava cropping system in southern Benin using Diagnosis and Recommendation Integrated System (DRIS). For this purpose, 149 samples of cassava leaves were sampled from farmers' fields in 3 municipalities named Djakotomey, Klouékanmey and Zakpota. Moreover, root yield and nutrients (N, P, K, Ca, Mg, and Zn) content in the leaves were determined for DRIS norms establishment. From DRIS, the order of nutrient deficiency was as follows : K >N > P > Zn > Ca > Mg ; K>Ca > Zn > Mg > N > P and Zn>N > Ca> K > Mg > P for the farmers’ fields in Djakotomey, Kloukanmey and Zakpota respectively. These results also showed that K, Ca and N were deficient in the soil and limit cassava yield while P and Zn was often in excess. DRIS could be an important tool for refining the nutritional needs of cassava plants in Benin Republic's cropping systems and also for setting trial for fertilizer recommendation.