FOSSIL-FUEL CARBON EMISSION CONTROL IN IRRIGATED MAIZE PRODUCTION

To evaluate optimal management strategies which reduce fossil-fuel car bon emissions, an idealized gross returns objective function was devel oped for the production of irrigated maize with the inclusion of a dis incentive carbon-taxing term. The gross returns objective function is multivariant and optimized through a gradient search procedure. Carbon emissions emanating from maize production stem from the utilization o f fossil-fuel energy on the farm as well as that utilized to manufactu re many of the production inputs (i.e. fertilizers and pesticides). Pa rticular emphasis was placed on determining fertilizer (nitrogen) and irrigation (furrow) management strategies which reduced fossil-fuel ca rbon emissions at a minimum reduction in gross returns. Total emission s and optimal maize yield were reduced slightly at high carbon-taxing rates, whereas gross returns decreased considerably. Decreases in opti mal maize yield were a consequence of reducing applied water and nitro gen fertilizer, both of which are energy-intensive production inputs. The most effective means of reducing fossil-fuel carbon emissions asso ciated with maize production at minimum reductions in gross returns is increasing the price of nitrogen fertilizer rather than levying a car bon tax. (C) 1997 Elsevier Science Ltd.