Nutrient Deficiencies Are Key Constraints to Grain Legume Productivity on “Non-responsive” Soils in Sub-Saharan Africa

Abstract

Leguminous plants are known to require phosphorus fertilizers and inoculation with nitrogen fixing rhizobia for optimum yield but other nutrients may also be lacking. In this study, the most limiting nutrients for legume growth were determined in soils where the crops had not responded to P and rhizobial inoculation in field trials, using the double pot technique. Soils were collected from 17 farmers' fields in West Kenya, Northern Nigeria, Eastern and Southern Rwanda, South-west and North-west Sierra Leone. Plant growth and mean biomass were measured on soils to which a full nutrient solution, containing phosphorus (P), potassium (K), magnesium (Mg), sulfur (S) and micronutrients (MN) were added, and which were compared to a control (no nutrient added), and individual omissions of each nutrient. The relationship between soil properties and nutrient deficiencies was explored. Nutrient limitations were found to differ between soils, both within and across countries. Generally, each soil was potentially deficient in at least one nutrient, with K, P, Mg, MN and S emerging as most limiting in 88, 65, 59, 18, and 12% of tested soils, respectively. While K was the most limiting nutrient in soils from Kenya and Rwanda, P was most limiting in soils from Nigeria. P and K were equally limiting in soils from Sierra Leone. Mg was found limiting in two soils from Kenya and three soils from Rwanda and one soil each in Nigeria and Sierra Leone. Micronutrients were found to be limiting in one soil from Nigeria and one soil from Rwanda. Estimates of nutrient deficiency using growth and mean biomass were found to be correlated with each other although the latter proved to be a more sensitive measure of deficiency. With few exceptions, the relation between soil parameters and nutrient deficiencies was weak and there were no significant relations between deficiency of specific nutrients and the soil content of these elements. Although our results cannot be translated directly to the field, they confirm that individual and multiple nutrient deficiencies were common in these “non-responsive” soils and may have contributed to reported low yields. This highlights the need for balanced nutrition in legume production in SSA.

Consistency, variability, and predictability of on-farm nutrient responses in four grain legumes across East and West Africa

“…Negative responses seem to occur in cases where K is not limiting, caused by a damage to plant roots ( Kihara et al, 2017 ). Still, recent pot experiments in soybean ( Baijukya et al, 2021 ) identified K as being potentially limiting on a number of soils collected in East and West Africa and there are several field studies reporting grain yield responses between 100 and 300 kg ha −1 for groundnut, common bean and cowpea ( Moses et al, 2018 , Serme et al, 2018 , Smithson et al, 1993 , Tarfa et al, 2017 ) and even an exceptional 700 kg ha −1 in common bean ( Kaizzi, 2018 ). Such studies may allude to either localised deficiency of K (cf.…”

Biological nitrogen fixation and prospects for ecological intensification in cereal-based cropping systems

“…However, in general terms, imposed management strategies would need to consider time of sowing in relation to soil water availability and seasonal water supply, and the length of the effective growing season, as well as avoiding sensitive periods of growth and flowering when there is an elevated probability of frost, drought or high temperatures ( Beck et al, 1991 , Peoples et al, 2009a , Santachiara et al, 2019 , Tagliapietra et al, 2021 ). Unfavorable and hostile soils which either limit legume root exploration (e.g., soil compaction, sodicity, salinity), inhibit nodulation, or restrict shoot growth (e.g., soil acidity, nutrient deficiencies) should also be ameliorated ( Giller and Cadisch, 1995 , Peoples et al, 2009a , Santachiara et al, 2019 , Vanlauwe et al, 2019 , Baijukya et al, 2021 ). Attention would also need to be given to reducing the incidence of pests, diseases and weed competition responsible for lowering productivity ( Beck et al, 1991 , Peoples et al, 1995a , Singh et al, 2009 ; Table 13 ).…”

The use of soil microbial potassium solubilizers in potassium nutrient availability in soil and its dynamics

“…Norton (2022) reported K deficiency in soils of most Australia states. K had also been found to be the most limiting nutrient in 88% of soil from some sub-Saharan Africa countries such Kenya, Rwanda, Nigeria, and Sierra Leone (Baijukya et al, 2021). More also Kaiser and Rosen (2018) reported that even though some K are supplied by Minnesota soils, fertilizer program to supply K is employed when there is an inadequate supply from the soil.…”