Soil Fertility on an Agricultural Frontier: The US Great Plains, 1880-2000

In contrast to most long-settled agricultural landscapes, the US Great Plains presents a rare example of well-documented agricultural colonization of new land. The Census of Agriculture provides detailed information about evolving grassland farm systems from the beginning of agricultural expansion and then at some two dozen time points between 1880 and the present. From early sod-busting, through drought and depression, and into late-twentieth-century modernization, it is possible to track how farmers used their land in any county. Treating farmland as an agroecosystem, a hybrid human-natural landscape, this article asks how farmers captured, altered, and replenished soil fertility. Did they extract more soil nitrogen than they returned, or did they maintain a balance? The article assesses land use from a soil nutrients perspective in several plains environments to capture variation in climate (especially rainfall), native soil quality, and availability of irrigation water. It traces farm management strategies through time to understand agricultural crises, growth periods, and technological transitions in the context of soil fertility. Soil management on an agricultural frontier was markedly different from that in places that had been farmed for centuries. A shortage of people and livestock and an abundance of deep, rich soils in the plains informed farmers' calculations as they juggled labor, capital, and market forces against family and financial strategies. Uniform methods of estimating and representing soil nutrient processes make possible a direct comparison of the relative sustainability of historical agroecosystems.