AN ECONOMIC COMPARISON OF CONVENTIONAL AND CONSERVATION TILLAGE SYSTEMS IN THE SOUTHEAST SAGINAW BAY COASTAL DRAINAGE BASIN (MICHIGAN)

摘要

There is concern over the quality of Michigan lakes and waterways, and over decreasing soil productivity due to the loss of top soil as a result of water and wind erosion. This concern has prompted the Agricultural Conservation Program (ACP), a USDA agency, to promote, through cost share programs, conservation tillage practices that are known to reduce erosion and the associated pollution. Voluntary adoption, however, is uncertain because of the lack of knowledge of the economic impacts of such practices on farmers. Therefore, this study was initiated to make comparative economic analysis of the conservation tillage systems being encouraged to the tillage practices traditionally used in the Southeast Saginaw Bay Watershed area.;Cooperating farmers were asked to set aside a parcel of land (2 to 4 hectares) and to prepare half of it with a normal method of tillage and the other half using conservation tillage equipment like the regular or modified chisel plow. Data on machinery management, agronomic requirements and crop performance were collected from these side-by-side plots.;Results of the first two years of a three year study show that conservation tillage performed as well or better than conventional tillage in most areas. No increase in pesticides use was required due to conservation tillage. Seed moisture at harvest was not significantly different between the two types of systems. Soil moisture was available to plants for a longer period in conservation tilled plots. There was no statistically discernible difference in yield between systems in 1980. In the 1981 season differences were statistically discernable between individual plots due to abnormal weather patterns.;A machinery selection model was developed to analyze machinery requirements for different tillage systems. The model was used to determine the optimum size machinery for conservation and conventional tillage based upon performance and economic criteria.;Only input/output items that differ across both systems were considered. Partial budgeting techniques were used to evaluate the economics of conservation tillage systems relative to conventional systems. Results for different crop sequences on different farm sizes depict that conservation tillage can always provide a lower cost of producing the same crop or crop sequence.