Modeling land degradation & food import This research develops a soil conservation model for smallholder farmers who apply little or no fertilizer. Empirical results drawn from northern Tanzania imply that ignoring the fertility mining problem in model specification leads to overestimation of profits for farms that apply little or no fertilizer. Wheat cultivation in the Hanang wheat complex, northern Tanzania erodes an average of 11 mm of soil each year. The rate of soil fertility mining averaged 22.2 kg of nitrogen/ton of wheat. Consequently, wheat yields in HWC have been...