survey data with potential yield estimates from the FAO’s GAEZ database allows for an estimate of production gains if the technology set, or intensity of input use, is dramatically improved.

The results clearly illustrate the production penalties for cultivating maize on land that is not highly suitable for maize production, particularly when using MAPS plot-specific soil samples. The use of AFSIS geospatially-derived soil data provided a close approximation to the results of the MAPS-based results on the overall sample but failed to distinguish between soil suitability classes to the same degree as, and in a consistent manner with, the MAPS plot-level soil data. The MAPSbased analysis reveals that farmers cultivating only marginally suitable land are operating with higher technical efficiency and, thus, have less room for improvement than farmers cultivating more agronomically suitable land, given the condition of their soil. This result has implications for agriculture-based poverty reduction and food security policies. Effectively, by cultivating maize on land that is only marginally suitable rather than highly suitable, farmers limit their production potential by as much as 1,694 kg/ha, or 129 percent. Extrapolating the potential yields to the household level, based on multiply-imputed total maize area per household, suggests that given the current set of inputs and soil constraints households only have the potential to increase the value of production by USD 90 per bi-annual season. Assuming equal production in both agricultural seasons, and given the average household size of 6.12 persons, this translates into a gain of USD 0.08 per capita per day on average, not considering additional expenditures that may be required to reach that production frontier. For those cultivating marginally-suitable soils, they can hope to earn only an additional USD 0.05 per capita per day. If soil constraints were addressed such that all households operated on highly-suitable soils, potential gains would increase to USD 0.21 per capita per day on average. Enhancing the technology set and achieving the GAEZ highinput use potential yield on highly-suitable soil would increase gains to USD 0.79 per capita per day. Although these estimates of potential economic gains from agricultural production are only for maize, maize makes up 66 percent of cultivated land across all households.

The findings hint that realizing agricultural production potential alone, given the current set of inputs and soil constraints, may not be sufficient for significant welfare gains. In order for agriculture to act as a key mechanism for poverty reduction, policies can include (i) significantly boosting the quantity and quality of inputs used by smallholder farmers, and (ii) implementing crop-specific agricultural interventions based on high-resolution soil data with the aim of increasing crop-specific soil suitability. Addressing specific soil deficiencies that render the land sub-optimally-suitable for a given crop, which can be identified with this dataset for example, can result in gains in agricultural productivity and associated income. Future research may include the analysis of interventions aimed at triggering a shift from one soil-suitability class to the next, and whether, considering the costs required for the shift, that would result in net gains for smallholder farmers. Additional work, in partnership with agronomic specialists, should be conducted on the application of an unequal weighting scheme in the suitability classification framework to confirm 28