Farmers in Tanzania are limited resource producers with small acreage
dedicated primarily to maize. Production of this crop is natural for farmers because
maize is a stable that is consumed daily by almost all Tanzanians. Yet, farmers
struggle to increase their incomes from maize production because of land constraints.
With an average farm size of just two hectares and almost no opportunities for farmers
to purchase additional land, farmers must explore other options to increase their farm
income. One option that is explored extensively in this research is agroforestry.
Described generally, this method of farming allows farmers to add fruit trees around
the perimeters of their farms, intersperse trees within maize crops, or add them in
separate but side-by-side plots. Whatever method is used, farmers must exercise care
to avoid overshadowing and stunting the growth of maize.
Based on survey data gathered from farmers, four fruit crops offer strong
income-generating opportunities for maize farmers. These crops are: bananas,
coconuts, mangoes and pineapples. A key difference among these four fruits is that
bananas and pineapples bear fruit annually, whereas coconuts and mangoes are
defined by a 5-year lag between planting and first harvest. These conditions mean that
farmers must define their rate of time preference for income and also assess the risk
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and uncertainty associated with each fruit crop. Using the knowledge that maize
producers generally receive one of three levels of production from their farms, this
researcher analyzed benefits and costs farmers can expect to receive from combining
maximum fruit production with all possible levels of maize production.
Although agroforestry methods varied from inter-cropping to twinning
cultivation and twinning agroforestry, each method allowed for a direct comparisons
of benefits and costs for each crop combination. Relative to inter-cropping, benefitcosts
calculations showed that maize and coconuts are more profitable for farmers
than maize and mangoes. By definition, bananas and pineapples are not inter-cropped
because they yield annual fruit. With respect to twinning agroforestry, mangoes
produced together with maize are shown to be more profitable than maize and
coconuts. Yet, farmers express a stronger preference for maize and coconuts and this
preference function suggests that there are factors that go into farmers’ decisionmaking
that may not be observable to researchers. For example, farmers may
associate a higher degree of risk and uncertainty to the 5-year time lag between
planting and harvest for pineapples than they do to the 5-year time lag for coconuts.