Towards Management of South Kivu Ferralsols by the Contribution of Different Types of Fertilizers: Their Influence on the Biofortified Climbing Bean Behaviour

For many tropical and subtropical countries, poor soil fertility management is still a major problem in agricultural production and requires sustained attention. This study was carried out to evaluate the effect of the combination of fertilizer types on the improvement of ferralsol properties and on biofortified climbing bean yield in South Kivu. The experimental field was conducted by using a CRB plot with three replications. Ten treatments were followed consisted of a control, mineral fertilizer NPK (150 kgha-1), farmyard manure (30 tha-1), liming (1.3 tha-1), fresh biomass of Tithonia diversifolia (30 tha-1), and their combinations. The results obtained show significant differences between the treatments and their ability to improve the chemical properties (acidity, OM, N, and K) of the ferralsol during the two cropping seasons. This improvement has led to improvements significantly in the growth, yield, and profitability of climbing beans. The combination of farm manure and NPK (2.6 tha-1); liming-NPK and straw biomass of Tithonia sp. presented the same yield performance. With a profit margin of 900 and 850 USDha-1, Tithonia sp. could replace expensive mineral fertilizers. This study shows that liming coupled with low rates of fertilizer or Tithonia sp. on ferralsol in eastern RD Congo conditions and have the potential for improving the availability of soil nutrients and providing the quantities required nutrients needed for growing biofortified climbing beans and thus reduce malnutrition in the region subsequently fight against Fe and Zn micronutrient deficiency.