If you are interesting in global patterns of agricultural change, as I am, you might find this recently published paper helpful for selecting the most appropriate global framework.
van Wart, J., van Bussel, L. G., Wolf, J., Licker, R., Grassini, P., Nelson, A., Boogaarde, H., Gerberf, J., Muellerf, N. D., Claessensg, L.,
van Ittersum, M. K. & Cassman, K. G. (2013). Use of agro-climatic zones to upscale simulated crop yield potential. Field Crops Research.