EFFECTS OF GLYCINE MAX AND PHASEOLUS VULGARIS CROP RESIDUES ON MANIHOT ESCULENTA PRODUCTION IN AGRICULTURAL SOIL IN THE KARAMOKOLA AREA, CENTRAL-WESTERN COTE DIVOIRE

A comparative study of previous soybean (Glycine max L.) and bean (Phaseolus vulgaris) crops on the productivity of cassava (ManihotesculentaCrantz) was conducted in the department of Mankono with the aim of developing a cropping system adapted to increasing cassava yields. To this end, a trial was conducted on sandy-loam ferralitic soil, moderately desaturated, that had been left fallow for more than two years. The experimental design was based on a randomized complete block design comprising four elementary microplots corresponding to different crop precedents: (i) control ridged soil with no crop precedent, (ii) bean monoculture, (iii) soybean monoculture, and (iv) bean-soybean combination. Cassava cuttings were planted in each ridge at an angle, with two buds left above the soil. The results show that legume-based previous crops improved soil fertility, positively influencing the growth, agromorphological development, and productivity of cassava. Compared to the control (18.42 t/ha), yields were significantly higher in the three other plots previously cultivated with legumes: 35.26 t/ha in bean monoculture, 31.96 t/ha in bean-soybean combination, and 26.79 t/ha in soybean monoculture. Thus, the integration of legumes as a previous crop is an effective agronomic strategy for increasing cassava productivity. Bean monoculture and bean-soybean combination appear to be particularly favorable, confirming the value of diversifying cropping systems to optimize yields.