Effet du biochar et des feuilles de Tithonia diversifolia combiné à l'engrais minéral sur la culture du maïs (Zea mays L.) et les propriétés d'un sol ferralitique à Kinshasa (RDC)

Effect of the use of biochar and leaves of Tithonia diversifolia combined with mineral fertilizer on maize (Zea mays L.) and the properties of ferralitic soil in Kinshasa (DRC). Description. This article deals with the improvement of the productivity of (poor) sandy and acidic soils in Kinshasa (DRC) using local natural resources in addition to mineral fertilization. Objectives. The objective of this study was to evaluate the effect of ground charcoal (biochar) and Tithonia diversifolia leaves combined with mineral fertilizer on soil properties and on the performance of the maize crop. Method. Five treatments and an eyewitness: T0 (control), T1 (N120 P141 K134), T2 ([N60 P71 K67] + 30 t·ha-1 biochar), T3 ([N60 P71 K67] + 8 t·ha-1 T. diversifolia), T4 ([N120 P141 K134] + 30 t·ha-1 biochar), T5 (N160 P188 K179) repeated four times were compared in a randomized complete block. Physical and/or chemical analyses were carried out on the ground, on T. diversifolia leaves and on maize biomass. Results. The results showed that application of biochar and T. diversifolia leaves combined with mineral fertilizers increased the carbon content, the potassium content and the cation exchange capacity of the soil as well as grain yield, exports of mineral elements and the apparent coefficient of mineral elements use by the crop. Treatments under biochar reduced acidity and aluminum saturation with an improvement of the soil's phosphorus availability. Taking into account the acceptability index, the T3 (AI = 3.06), T4 (AI = 2.92) and T2 (AI = 2.14), it would be possible for these treatments to be easily accepted by farmers. Conclusions. The results of this study provide an opportunity to improve the productivity of poor soils in Kinshasa and to increase the crop performance for a period of two campaigns with the use of biochar and T. diversifolia leaves in addition to mineral fertilizer.