CHAPTER II: STUDY PROCEDURE General Study Procedure A typical or representative farm was selected in the Adair-Grundy-Haig soil association in southern Iowa·. The farm was identified by size in acres and soil type. Alternative tillage and soil management systems were identified and selected for use in reducing soil loss. Alternative pasture forage pr oduction and utilization systems were also identified and selected. The universal soil loss equation was used to define rotations and management

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... actices for the alternative tillage operations within selected soil loss limits. Production inputs such as herbicides, insecticides, fertilizers, and seed with corresponding yields were defined by crop sequence and tillage system. Monthly production distribution was defined for the pasture forage alternatives on an available total digestible nutrient (TDN) basis. Machinery investment and ownership costs were established for alternative tillage and forage systems. A computerized budget generator was used to establish enterprise budgets for the alternative tillage operations and forage systems. Production standards and assumptions were defined for beef and swine production. Alternative winter rations were established for the beef cow enterprise. Alternative rations were also established for beef heifer and steer finishing activities. Enterprise budgets were developed for the a lternative beef ration activities and a swine 9 enterprise. Fixed costs and capital requirements were defined for the livestock enterpri s es. Relative prices for farm products were establis hed bas ed on an average co rn price of $2.30. A range of beef prices was established which correspond to the most recent beef price cycle . A linear programming model was developed to combine the various alternatives which were defined. The model incorporated row crop , forage and livestock enterprises. It was used to analyze the impact of reducing soil loss. Detailed Procedure Study area The Adair-Grundy-Haig soil association was selected for use in this study. The Adair-Grundy-Haig association occurs in south central Iowa and occupies 2400 square miles, primarily in Ringgold, Clarke and Lucas counties. Approximately half of this soil association is cultivated with the remainder primarily in pasture and s aall areas of timber. Row-crops occupy the upland flats , gentle slopes and stream bottom flood plains, with pasture genera lly occupying the steeper areas (26). The farms in this area are typically diversified grain and livestock operations and rely on operator-family labor. Representative farm selection A representative farm of 360 acres was developed in the Adair-Grundy-Hai g soil association. Soils were group ed into classes by