Agricultural production has been determined to be a major source of ground water and sediment pollution in the Western Lake Erie basin of Ohio. Before conservation practices to reduce farm pollutants can be required or even encouraged, there must be an investigation that provides reliable information detailing relationships between agricultural production and environmental impacts. Such an investigation must provide alternative management practices with comparable profit levels and long term stability in producing major crops for the individual farm producer.
Conventional, conservation, and no-till management systems were compared in a bioeconomic model maximizing returns above total costs. Crop budgets were established for various management systems comprised of three tillage systems, three fertilizer and chemical input levels, and four rotations of corn, soybeans, and wheat. The Erosion/Productivity Impact Calculator (EPIC) simulated crop yields and farm effluents of soil erosion, organic nitrogen, nitrates, phosphorus lost in sediment, and pesticides runoff. An integer programming model then selected the optimal management system and determined farm size by the selecting the most profitable and efficient user of limited field time. In addition, optimal farm level results were scaled to model a regional adoption of conservation and no-till management systems.
No-till management systems were found to be the most profitable, and on average contributed the least environmental pollution. The regional comparison indicated that a no-till dominated region would earn 43 percent more profit on Hoytville soil and 19 percent more profits on the Blount-Glynwood-Pewamo soil association than the same region dominated by conventional management systems. At the same time, environmental impact, measured by the average percentage change in effluent leaving the field, would decrease by 19 and 20 percent when converting from the conventional dominated region to the no-till dominated region. Environmental tradeoffs would occur in the transition from conventional to no-till management. Effluents related to soil particles such as organic nitrogen, phosphorus, and soil erosion would decrease up to 47 percent, while effluents lost in water runoff such as pesticides and nitrates would increase up to 20 percent.
The average farm size would grow as the region moves to no-till and the number of farm producers in that region decrease. Low and medium fertilizer and chemical inputs were determined to be more profitable than high input levels.