カンザス州サンドヒルズにおける土地所有と土地利用の変化

抄録

The adoption and diffusion of center pivot irrigation systems transformed the traditional landscape of the High Plains. While Finney County in southwest Kansas has been known as one of the most advanced irrigation districts of the High Plains, vast sandhills on the right bank of the Arkansas River remained extensive cattle pasture until center pivot irrigation systems had completely changed the farming landscape during the 1970s. The new irrigation technology and feed crop cultivation combined to develop the feedlot and beef packing industries in the region. This paper examines the transformation process of landownership and land use in the sandhills of Finney County with special reference to the diffusion of center pivot irrigation systems.
Cattle industry began in the Garden City area in the late nineteenth century, and large landholdings and extensive cattle raising continued to dominate the sandhills up to the 1960s. Large landholdings with over 10, 000 acres included Brown, Cowgill, Burnside, Douglas, and Jones ranches. They purchased calves from ranchers of the western states, raised them on the natural pasture, and shipped them to the corn belt for finishing. Some ranchers specialized in breeding high quality beef cattle, and others took care of the calves born in the local farms from spring through fall. The region, blessed with ground water and natural pasture, was also known as winter refuge for animals.
Land register maps and aerial photos reveal substantial changes which took place in the sandhills during the 1970s. Large feedlot companies and agribusinesses came to own large tracts of land by purchasing traditional cattle ranches, while descendants of homesteaders also participated in the irrigation development. Gigot Irrigation Co. first demonstrated the effectiveness of center pivot irrigation systems in developing additional sandhills land which they purchased, while acting as a sales agent of the Valley brand irrigation systems. The company sold 600 sets of center pivot irrigation systems annually in two boom years of 1972 and 1973, while the company's average annual sales amounted to around 200 sets in the following years. Thus, the rich ground water resources of Ogalalla aquifer were exploited. The rapid process of adopting the new technology transformed the traditional barrens into the fertile farming regions irrigated by big circles.
Large land holders are typically found in the sandhills. Circle Land and Cattle Inc. owned by Gigot families manage more than 20, 000 acres. Brookover Feedyards, which started cattle feeding in the early 1950s just northwest of Garden City, expanded their business in the sandhills by introducing center pivot irrigation systems, developing subdivisions, and managing golf courses. IBP, a beef packing company operating the world's largest packing plant just west of Garden City, and Tim Dewey Farms and Cattle Co. also started irrigation farming by purchasing land in the sandhills. Corn and alfalfa are the two major irrigation crops, which are consumed locally at large feedlots. Because of these developments since the 1970s, lowering the water table of the Ogalalla aquifer is considered a serious problem in order to sustain the highly water consuming farming of the sandhills.