Estimating the causal effect of improved fallows on environmental services provision under farmers' field conditions in Chongwe, Zambia.

The provision of environmental services on-farm by the improved fallow (an agroforestry technology) has largely remained empirically untested in sub-Saharan Africa. Where effects of planting trees have been used to estimate the impacts on consumption of fuel wood from public land, actual estimates of the size of fuel wood consumption changes have been lacking. Using data from a survey of 324 households in the Chongwe district of Zambia, we tested the hypothesis that households embracing improved fallows use less fuel wood from public land since the technology provides wood as a by-product. Estimates from ordered probit and matching strategies showed that the technology had a significant causal effect of reducing the consumption of fuel wood from public land. Therefore, in addition to promoting it for soil fertility improvement, the extension messages should explicitly reflect the technology's potential to provide on-farm environmental quality.