Evaluationing the Site-Specific Potential for Spring Wheat Production in Mexico Under the Uncertainty of Future Climate.

Global air temperature has risen by 0.6C over the last one hundred years due to increased atmospheric greenhouse gases. Moreover, this global warming trend is projected to continue in the future and this climate change has caused maize and wheat production instability and is threatening the global food security. Various climate scenarios have been provided recently. They all have uncertainties and crop yield predictions based on only these climate scenarios would also have these uncertainties. But there will be increased reliability in the yield predictions of the crop models based on the quality of other input data (eg. soil profile, irrigation information, and genotype etc) even if the climate scenarios have uncertainties. This study was carried out to evaluate spatial variations in Spring Wheat production areas in Mexico by simulating Spring Wheat-growth, development as well as yield and mapping the geographic distribution under the climate change. We chose Toluca (2640m) as representative region for Highland Spring Wheat and Obregon (38m) for Lowland Irrigated Spring Wheat. We also acquired the bio physiologic and climatologic parameters for Spring Wheat production adapted to these areas by running CERES-Wheat with historical meteorological and treatment data from 1990s to 2000s. We then applied the climate projections based on three major SRES emission and population growth scenario families (A1B, A2, B1), implemented by three modeling groups (CSIRO2, Australia, ECAHM5, Europe; MIROC3.2, Japan) for 50 years (2050s: 2040-2069 and 2080s: 2070-2099) to map the geographic shift and distribution as well of changes in yield potential of Spring Wheat in Mexico in the future. If the crop prediction system which is based on the reliable crop model is deployed and utilized throughout the country, it will help the stabilization of wheat production in Mexico by allowing policy makers and researchers to plan ahead for adaptation measures. Furthermore we can discuss that the adaptation of cropping systems in Mexico to climate change will play an important role in achieving food security, such as the introduction of new crops and varieties, changes of the cropping systems themselves, and shifts of growing seasons and areas in the country. Key words: Spring wheat, climate change impacts, CERER-Wheat, uncertainty