Screening of Polyalthia longifolia and Aloe vera for their phytoextractability of heavy metals in tropical soil of the Niger Delta

The work focuses on the screening of Polyalthia longifolia and Aloe vera for their phytoextractability of heavy metal in soil of the Niger Delta. 5kg of soil was polluted with 100 mg of Zn, Fe and Pb each replicated 9 times. Each set was separated into 3 subgroups. The subgroups were phytoextracted with Polyalthia longifolia and Aloe vera alongside a control (no phytoextraction) respectively. After 12 weeks, the concentration of Lead, Iron and Zinc in soils, roots and shoots was determined. Results showed that the two plants have phytoextraction ability with reductions in Zn, Fe, and Pb in the phytoextraction soil . Metal transfer factor was PB: Aloe vera (0.881) > P. longifolia (0.315); Zn: P. longifolia (0.614) > Aloe vera (0.606); Fe: Aloe vera (0.812) > P. longifolia (0.774). Translocation factors for the two plants were in the order: Zn: P. longifolia (0.79) > Aloe vera (0.36); Fe: P. longifolia (0.63) > Aloe vera (0.05); Pb: P. longifolia (0.57) > Aloe vera (0.23). Since the translocation factors were < 1, the plants can be classified as non- hyperaccumulators for these metals.

DETERMINANTS OF THE ADOPTION OF INTEGRATED SOIL FERTILITY MANAGEMENT TECHNOLOGIES IN MBALE DIVISION, KENYA

The agro-climatic conditions in western Kenya present the region as a food surplus area yet people are still reliant on food imports, with the region registering high poverty levels. Depletion of soil fertility and the resulting decline in agricultural productivity in Mbale division has led to many attempts to develop and popularize Integrated Soil Fertility Management (ISFM) technologies that could restore soil fertility. These technologies bridge the gap between high external inputs and extreme forms of traditional low external input agriculture. Some of the ISFM components used by farmers are organic and inorganic inputs and improved seeds. However, the adoption of these technologies is low. The study aimed to examine the factors that influence the adoption of ISFM technologies by smallholder farmers in Mbale division, Kenya. The study was conducted in 9 sub-locations in Mbale division. Purposive sampling was used in selecting the 80 farmers to get the data based on a farm-household survey. Self-administered questionnaires were used to collect data on the determinants of the adoption of ISFM technologies from the sampled farmers in the study area. The study sought to answer the research question: What factors influence the uptake of ISFM technologies by farmers in Mbale division? The hypothesis tested was that the adoption of ISFM technologies is not influenced by age, education, extension services, labour, off-farm income and farm size. Data was analyzed using descriptive statistics. Cross tabulation was used for examining the relationship between categorical (nominal or ordinal) variables, and the bivariate correlations procedure was used to compute the pair wise associations between scale or ordinal variables. Probit regression was used to predict the socio-economic factors influencing the adoption of ISFM technologies among smallholder farmers. Results of the study indicated that education of household head, membership in social groups, age of the household head, off-farm income and farm size were the variables that significantly influenced the adoption of ISFM technologies. The findings show that there is need for a more pro-poor focused approach to achieve sustainable soil fertility management among smallholder farmers. The findings will help farmers, extension officers, researchers and donors in identifying region-specific entry points that can help in developing innovative ISFM technologies.

FERTILISER CREDIT AND AGROECOLOGICAL USE OF ORGANIC SOIL AMENDMENTS IN NORTHERN GHANA

Contemporary African agricultural policy embodies the African Green Revolution’s drive towards modernisation and commercialisation. Agroecologists have criticised this movement on ecological, social and political grounds. Northern Ghanaian fertiliser credit schemes provide a good example through which these critiques can be examined in a context where agricultural policy reflects the African Green Revolution’s ideals. This study aimed to determine the relationship of such credit schemes to farmers’ use of organic amendments, elucidate other factors related to organic amendment use, and comment on the relevance of this modernisation policy and its relationship to agroecology. A first research phase employed semi-structured key informant interviews. Qualitative data from these informed construction of a semi-structured questionnaire that was used in a survey of 205 farmers. Multistage sampling purposively identified five villages and selected farmers within who had joined government and donor-funded fertiliser credit schemes. The use of organic and inorganic amendments was compared to that of peers who had not taken part in such schemes. Quantitative data were used in binomial logistic regression, inferential and descriptive statistics. Qualitative data were content analysed. Credit group membership was associated with higher fertiliser application and yield, but had little influence on the extent of commercialisation. Farmers who applied organic amendments were 40% less likely to belong to a fertiliser credit scheme than not, indicating substitution between organic and inorganic fertilisers. Organic amendments were 40% more likely to be applied to compound farms than outfields and six times more likely to be applied by household heads than other household members. However, household heads also preferentially joined credit groups. This was part of an agroecological soil fertility management strategy. Household heads appreciated the soil moisture retention properties of organic amendments, and applied them to compound farms to reduce risk to their household food supply in a semi-arid environment. They simultaneously accessed fertiliser to enhance this household provisioning strategy. They appreciated the increased yields this achieved, yet complained that the repayment terms of credit schemes were unfair, fertiliser did not enhance yields in dry conditions and fertilisers were supplied late. Farmers’ use of credited fertiliser alongside their existing agroecological strategy is helpful to the extent that it raises yields, yet is problematic in that it conflicts with risk-reduction strategies based on organics. There is some potential for modernised and agroecological management paradigms to coexist. For fertiliser credit to play a role in this, schemes must use fairer repayment terms and involve a focus on simultaneous use of organic amendments.