The objective of our research is to evaluate the causes and consequences of agricultural development in the Yaqui Valley of northwestern Mexico. The Yaqui Valley is the home of the Green Revolution for wheat, and one of the most productive breadbaskets of Mexico. Until the first half of this century, it was primarily a desert scrub ecosystem development of irrigation and fertilization systems has lead to dramatic changes in the Valley, and potentially in surrounding regions as well. We are analyzing the critical links among agricultural policy and agricultural extent and productivity within the Valley, as they have changed over the last fifty years and continue to change. Moreover, we will utilize remote sensing data to evaluate the off-site consequences of these agricultural land-use decisions for land-use and land-cover in the surrounding region, focusing on 1) the extensive changes in land use in the areas surrounding the agricultural valley (e.g., expansion of grazing systems in the scrub desert ecosystems at the edge of the Yaqui Valley) and 2) alteration of native ecosystems as a result of down-wind deposition of anthropogenic nitrogen from the Valley.