Document Type

Thesis - Open Access

Award Date


Degree Name

Doctor of Philosophy (PhD)


Agricultural Economics


A profit maximizing linear programming model was used to arrive at optimum plans for a typical ranch in the Willimas-Tetonka-Cavour soil association are of central South Dakota. The typical ranch used for the analysis had 500 acres of cropland and 1056 acres of native grass. Low, medium and high levels of efficiency were assumed in grain crop and livestock production. Forage production was obtained from different management systems on tame grasses and native grasses. Tame grasses included brome-alfalfa, crested wheatgrass, Russian wild rye, and sudan grass. Native grass production was obtained from alternative management systems including renovated pasture, fertilized pasture, continuous grazed, or deferred grazing systems. Optimum plans, under five different levels of capital restriction, were developed for various combinations of the efficiency levels in crop and livestock production. It was found in this study that crop production had priority on the use of capital at all levels of efficiency. When capital was very limited, profits were maximized by limiting the size of the beef cow herd and permitting pasture land to go idle. As capital became available it was profitable to place it first into crop production through the use of fertilizer, weed and pest control, and improved crop varieties. The optimum plans, obtained when efficiency levels were permitted to vary, added-capital beyond the cropping program by first investing in low efficiency livestock. This permitted a larger volume livestock program and more acres of native pasture to be utilized. As capital became more available, livestock numbers were expanded and livestock efficiency was increased by investing in better breeding stock and improved management programs. Livestock fattening activities were also added as more capital became available. The typical program, when capital was not limited, maintained a cow herd under a 5 and ½ months grazing program. The calves were wintered on pasture and hay, grazed the following summer and then placed in a drylot fattening activity. The most profitable crop program was highly dependent upon the relative crop production efficiencies and the assumed price relationships. Individual operators must evaluate their own production efficiency in the various crops and determine which crops to produce through the budgeting procedure. In this study, it was only under a high efficiency level in both crops and livestock that it became profitable to interseed the 25 percent condition rangeland. In all other situations this rangeland was utilized through a deferred grazing program. The resulted of this study indicate that the renovation of native pastures in central South Dakota in not profitable unless there is a high efficiency in both crop and livestock production and capital is not a limiting factor. As the efficiency in crop production increased it became more profitable to use cropland to produce cash crops. Forage production for livestock then came from native grassland. It was not profitable to invest in range improvement unless the efficiency in livestock production was relatively high. It must be recognized, however, that this study has placed no value upon the risk and uncertainty involved in crop production. The second part of this study used a multiple correlation analysis to relate various factors to the amount of pasture improvement work done by ranchers. Those factors that contributed most significantly to variation in the amount of pasture improvement work done were (1) innovativeness of the rancher, (2) his expectations regarding a satisfactory stand from a new seeding, and (3) his opinion regarding the profitability of range improvement relative to other alternatives.

Library of Congress Subject Headings

Farm management -- South Dakota

Agriculture -- South Dakota -- Economic aspects

Pastures -- South Dakota



Number of Pages



South Dakota State University