Nutrient Requirements of Cassava under Different Management Systems in South-Kivu, D.R. Congo
Wivine Munyahali1,3, Rony Swennen2, Roel Merckx3
1Université Catholique de Bukavu (UCB), DR Congo
Previous works have shown that cassava is highly responsive to fertiliser additions and benefits from improved management. Yet the yield responses of cassava to mineral fertilisers often remain highly variable and are not always clearly related to soil fertility levels. The objective of this study was to investigate and understand factors limiting yield responses of cassava to mineral fertilisers and their interactions with the different agricultural management practices in South-Kivu.
Two types of experiments were carried out in multi-locational participatory farmer trials during two consecutive seasons (LR2014 and LR2015): The first type consisted of macronutrient (N, P or K) omission experiments including a manure treatment (FYM) as well as a full NPK, NPK+FYM and NPK+Ca-Mg-S-Zn treatments, to evaluate possible limiting nutrients to cassava growth and yield, and they were established with an improved cassava variety (sawasawa). A control and NPK+FYM treatments with a local variety (nambiyombiyo) were also included for comparison; The second type were leaf management trials with two factors including leaf harvesting effect as the main factor with 3 levels (no leaf harvesting, harvesting every 2 weeks, or 4 weeks, from 4 months after planting) and fertilisation effect (with or without fertiliser application) as the second factor.
Keywords: Cassava yield, leaf harvesting, mineral fertiliser, nutrient balances, organic input
Contact Address: Roel Merckx, KU Leuven, Dept. of Earth and Environmental Sciences, Kasteelpark Arenberg 20 / P.O. Box 2459, 3001 Leuven, Belgium, e-mail: roel.merckxkuleuven.be