Resumen
In deciding what crops to grow, farmers will look at, among other things, the economically most productive use of the water and land resources that they have access to. However, optimizing water and land use at the farm level may result in total water and land footprints at the catchment level that are in conflict with sustainable resource use. This study explores how data on water and land footprints, and on economic water and land productivity can inform micro-level decision making of crop choice, in the macro-level context of sustainable resource use. For a proposed sericulture project in Malawi, we calculated water and land footprints of silk along its production chain, and economic water and land productivities. We compared these to current cropping practices, and addressed the implications of water consumption at the catchment scale. We found that farmers may prefer irrigated silk production over currently grown rain-fed staple crops, because its economic water and land productivity is higher than that for currently grown crops. However, because the water footprint of irrigated silk is higher, sericulture will increase the pressure on local water resources. Since water consumption in the catchment generally does not exceed the maximum sustainable footprint, sericulture is a viable alternative crop for farmers in the case study area, as long as silk production remains small-scale (~3% of the area at most) and does not depress local food markets.