Soil fertility alteration due to the climate change and its effect on agricultural crop productivity

The predictions of vulnerability of agricultural crops productivity in relation with existing scenarios of climate change during the 21(st) century are usually carried out without taking into account the alteration in soil fertility due to climate change. The goal of the present work is to assess the role of such factor in the rainfed maize (C-4) and wheat (C-3) productivities in different reference sites of Mexico, using the climate change scenarios developed by the Center for Atmospheric Sciences, Universidad Nacional Autonoma de Mexico, for the case of atmospheric CO2 doubling by the end of 21(st) century. The relationship between the integral soil fertility index F (for genetically homogeneous soils) and climatic index was established in order to assess the soil fertility alteration. The real and potential productivities of the crops, F index and water availability change were predicted. The soil fertility alteration can cause crop yield changes of up to 20%, which indicates its importance for crop productivity predictions. The results predict the growth of maize yield up to 463kg(.)ha(-1) in and and semiarid zones, and its reduction in up to 392kg(.)ha(-1) in humid and semihumid zones. In the case of wheat it is expected, in general, a crop yield growth of up to 1100kg(.)ha(-1).