Investigating the effects of smallholder cowpeas farmers' management practices on soil fertility: A case study of the Kavango region, Namibia

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Namibia University of Science and Technology


The declining trend of soil fertility of smallholder farms due to continuous land cultivation is a factor that limits crop production and threatens food security. Improving soil fertility is a major concern for the farmers, researchers and the government. Most smallholder farmers have scarce resources to invest in chemical fertilizers, composts, etc. to improve soil fertility. The planting of legume has been promoted by the researcher in that it can improve soil fertility by the nitrogen fixation process and this can be some form of affordable technology for the farmers. However, how long legume fixation becomes significant is still not clear. The objective of this study was to determine the effects of smallholder cowpea farmers’ management practices on soil fertility. The cross-sectional data were collected through questionnaires from 90 households in the Kavango East and West regions of Namibia which were used for the present analysis. Descriptive statistics and frequencies were used to outline the responses. The principal component analysis was used to reduce the dimension of data to avoid multicollinearity. PCA was performed using the eigenvalue and vector of 10 principal components. The eigenvalue of the first 10 principal components (PC1-PC10) was greater than 0.9 and their cumulative variance proportion was 72.07 percent. Multinomial logit was also used to determine factors that affect farmers’ soil management practices. The result from multinomial logit model showed that farming experience, planting date, climatology services transportation/extension services and access to farm tools and gender significantly influence planting millet only or intercrop millet with cowpea at 5 percent level of probability. The Wilcoxon rank test was used to ascertain the effects of cowpea on soil fertility for a season. The results showed that there was no significant influence of planting cowpea between the 2017 and 2019 growing season (p-value=0.103). The only significant difference occurred between the farmers’ regions (p-value =0.009). The farmers in the Kavango East region had an average higher score. The difference in soil fertility in the two regions may be due to the different soils in the regions. It is recommended that improving the policy on access to climatology service, transportation/extension service, and farm tools can help the farmers to make a better decision on farming practices that can improve their soil fertility. There is also a need to find an innovative way to meet food security and improve soil fertility for the smallholder farmers. This should be based on the direct benefit to the farmers and soil improvement.




Katjana, K.J. (2020). Investigating the effects of smallholder cowpeas farmers' management practices on soil fertility: A case study of the Kavango region, Namibia. [Unpublished Masters thesis]. Namibia University of Science and Technology.