Conservation agriculture in the southern highlands of Tanzania: learnings from two decades of research for development.

Abstract

Abstract Since its introduction into the Southern Highlands of Tanzania by researchers 25 years ago, Conservation Agriculture (CA) has been well received, researched and the concept proven to be increasing productivity and incomes, enhancing resilience of livelihoods and contributing to reducing greenhouse gas emissions. CA research, as defined by the three interlined principles, was introduced into the Southern Highlands by the Tanzania Agricultural Research Institute (TARI) Uyole, formerly Agricultural Research Institute (ARI) Uyole around 1995. Research results showed a labour saving of up to 70% in CA compared to conventional tillage, yield increases of 26%-100% and 360% for maize and sunflower, respectively, partly attributed to higher moisture content (18%-24%) in CA systems. CA was also found to be much more effective in mitigating dry spells and increasing productivity in maize production in areas where average annual rainfall is less than 770 mm. Economic analysis of maize production showed that profits in CA were three times more than in conventional tillage production at US$526.9 ha-1 and US$ 176.6 ha-1, respectively. Profits were twice as much for beans under CA at US$917.4 ha-1 compared to US$376.3 ha-1 for conventional practice. Studies confirm that 5% of farmers in the Southern Highlands have adopted CA. Increased uptake requires addressing challenges including resistance to change in mindset, inaccessibility of appropriate mechanization and cover crop seeds, traditions of free-range communal grazing of livestock (which makes it difficult for farmers to retain crop residue in their farms) and shortage of investment capital. A holistic value chain approach is recommended in CA interventions, bringing together various stakeholders including scientists, trainers, extension workers, administrators, policy makers, agro-inputs and machinery dealers, machinery service providers, agro-processors and financial institutions. The innovations adaptation set-up brings service providers closer to farmers for co-innovation. Long-term CA programmes are recommended, with farmers being taken through the complete learning cycle in testing CA technologies under their own farm environments. This should be complemented by entrepreneurial CA machinery hire services provision to increase the availability of farm power to smallholders unlikely to have the capital or skills to buy and manage their own machinery. The proof of application of the CA concept in the Southern Highlands has set the stage for further scaling the adoption of CA through support from national policies and programmes.