Fertiliser requirements for balanced nutrition of cassava across eight locations in West Africa

Abstract

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Nitrogen, phosphorus, and potassium fertilizer effects on cassava tuber yield in the coastal district of Dondo, Mozambique

“…Figure 2 shows a decrease in cassava tuber yield with increasing K rates (treatments 14 through 20). These findings contrast a recent study conducted in Northeastern Thailand by Polthanee and Wongpichet (2017), who reported that cassava had removed the greatest quantity of K in the storage roots compared to leaf and stems, and another in West Africa by Ezui et al (2016) where K was found to be the primary cassava tuber yield limiting nutrient with requirements ranging from 140 to 160 kg/ha (CTCRI, 1983). This decrease in cassava tuber yield with increasing K rates agrees with Agbaje and Akinlosotu (2004); only sufficient K levels are required to stimulate cassava response to other nutrients such as N, as their excess may result in more biomass at the expense of tuber production as is common in sugarbeet production (Moraghan and Horsager, 1991).…”

“…Table 2 summarizes the average cassava tuber yield (fresh weight basis) responses in tons/ha to different combinations of contrasting N, P, and K fertilizer rates. The results showed that there was a significant increase in no-till cassava tuber yield due to fertilizer addition (p < 0.05), demonstrating that the crop responds to fertilizer application as was reported in several studies (Polthanee and Wongpichet, 2017;Ezui et al, 2016;Osundare, 2014;Agbaje and Akinlosotu, 2004;Graner and Coury, 1955;Krochmal and Samuels, 1970;de Cequeira and Howeler, 1980). Application of selected single fixed rate of K resulted in higher yield than that of N but equal to that of P (treatments 4 vs. 2 and 3, Table 2).…”

“…Agronomic research demonstrates that significant increases in cassava yield are possible when optimum fertilizer rates are applied (Howeler, 1981;Howeler and Cadavid, 1990;Graner and Coury, 1955;Ezui et al, 2016;de Cequeira and Howeler, 1980;Howeler et al, 2006). Kamaraj et al (2008) reported cassava response to an increased level of N, P and K fertilizer up to 150% over the normal recommended rate of 60-60-160 kg/ha N-P 2 O 5 -K 2 O for optimum yields in a study conducted on poor sandy loam and sandy clay loam soils (classified as Typic Ustropepts) (Soil Survey Staff, 2010) in Northwestern India.…”

Effect of Chicken Manure Application on Cassava Biomass and Root Yields in Two Agro-Ecologies of Zambia

“…However, Vanlauwe, et al [6] emphasized that the production increase was a result of area expansion rather than an increase in yield per unit area. Available information also indicates that input use in cassava fields is very limited or absent among smallholder farms in SSA [7][8][9][10].…”

Crop yields and NPK use efficiency of a long-term experiment on a former sea bottom in the Netherlands

“…It is not easy to deal with the equilibrium or balance among N, P and K when their quantities are expressed in mass units such as kilograms (kg), because one kg of N has another effect on yield than one kg of P, or one kg of K. To facilitate quantitative comparison of N, P and K, it was proposed (Janssen 1998, 2011, Ezui et al, 2016 to express the quantities of N, P and K in crop nutrient equivalents (CNE), using conversion factors CFP and CFK. The procedure to calculate CFP and CFK is explained in Appendix 4, Equations A.4.1a and A.4.1b.…”