Gliricidia Agroforestry Technology Adoption Potential in Selected Dryland Areas of Dodoma Region, Tanzania

Abstract

Declining soil fertility is one of the major problems facing producers of field crops in most dryland areas of Sub-Saharan Africa. In response to the declining soil fertility, extensive participatory research has been undertaken by the World Agroforestry (ICRAF) and smallholder farmers in Dodoma region, Tanzania. The research has, amongst others, led to the development of Gliricidia agroforestry technology. The positive impact of Gliricidia intercropping on crop yields has been established. However, information on farmers’ willingness and ability to adopt the Gliricidia agroforestry technology on their farms is limited. This study predicts the adoption of Gliricidia agroforestry and conventional mineral fertilizer use technology. Focus Group Discussions (FGDs) were conducted with groups of farmers, purposively selected based on five sets of criteria: (i) at least 2 years of experience in either trying or using Gliricidia agroforestry technology, (ii) at least 1 year of experience in either trying or using the mineral fertilizer technology (iii) at least 10 years of living in the study villages, (iv) the age of 18 years and above, and (v) sex. The Adoption and Diffusion Outcome Prediction Tool (ADOPT) was used to predict the peak adoption levels and the respective time in years. A sensitivity analysis was conducted to assess the effect of change in adoption variables on predicted peak adoption levels and time to peak adoption. The results revealed variations in peak adoption levels with Gliricidia agroforestry technology exhibiting the highest peak of 67.6% in 12 years, and that the most influential variable to the peak adoption is the upfront cost of investing in Gliricidia agroforestry and fertilizer technologies. However, in Gliricidia agroforestry technology most production costs are incurred in the first year of project establishment but impact the long term biophysical and economic benefits. Moreover, farmers practicing agroforestry technology accrue environmental benefits, such as soil erosion control. Based on the results, it is plausible to argue that Gliricidia agroforestry technology has a high adoption potential and its adoption is influenced by investment costs. We recommend two actions to attract smallholder farmers investing in agroforestry technologies. First, enhancing farmers’ access to inputs at affordable prices. Second, raising farmers’ awareness of the long-term environmental benefits of Gliricidia agroforestry technology.

Profitability of Gliricidia-Maize System in Selected Dryland Areas of Dodoma Region, Tanzania

“…The theory on diffusion of innovation was relevant as Gliricidia agroforestry intercropping is a new technology that can spread within the community. Feder et al [60], Rogers [61], Kadigi et al [8], and Swamila et al [4] argue that individual farmers' adoption of improved agricultural technologies in a long-run equilibrium depends on access to full information about relative advantages. According to [45,62], a relative advantage of this technology compared to others is its short (≤5 years) and long-term (>10 years) profitability.…”

“…The sustainable productivity of field crops such as cereals and pulses in most dryland areas of sub-Saharan Africa (SSA) is limited by declining soil fertility and high vulnerability to weather and natural disasters [1][2][3][4]. Most cereal food crops such as maize are produced under low nitrogen (N) and phosphorous (P) conditions that have contributed to the yield gap of between 200% and 300% [5][6][7][8].…”

“…The sub-optimal or lack of use of mineral fertilizers is exacerbated by low availability, high prices, and low N fertilizer use efficiency of cereal crops in drought-prone environments [4,5,12,14,15]. Although 75% of farmland is experiencing soil fertility degradation in Tanzania, as few as 3-13% of smallholder cereal food producers apply around 8% of the recommended amount of fertilizer per hectare [16,17].…”

“…Studies in Zambia [12] revealed the increase, up to three times, in financial returns of maize in the Gliricidia-Maize system over the unfertilized sole maize system. However, [4,40,46] argue that due to site-specific factors such as climate the effect of the improved agricultural technologies on biophysical and economic components varies with agro-ecological zones. Therefore, [47,48] recommended the consideration of context vari-ations in developing agroforestry technologies across the wide range of farming agroecologies.…”

Integrating evidence of potential impacts of climate-smart agriculture in Tanzania.

“…These findings highlight the challenge of adopting impactful adaptative practices in the context climate variability, when practices that achieve both productivity and resilience outcomes under conditions of natural water scarcity (drought) underperform in other conditions. Another study, which modeled Gliricidia agroforestry adoption rates, showed complex findings (Swamila et al, 2020). On one hand, the perceived climate and economic resilience benefits of Gliricidia agroforestry were considered a motivating factor in predicting adoption rates of the practice by smallholder farmers.…”