Sustaining Soil fertility: Agricultural Practice in the Old and New Worlds

Abstract

Abstract During the late nineteenth and early twentieth centuries, tens of millions of Europeans migrated to the Americas. Many traded rural lives for industrial jobs in growing cities, while a significant number travelled west to make farms on the Great Plains. Using case studies from Austria and Kansas, this paper compares the socioecological structures of the agricultural communities immigrants left to those that they found and created on the other side of the Atlantic. It employs material and energy flow accounting (MEFA) methods to examine the social metabolic similarities and differences between Old World and New World farm systems at either end of the migration chain. Nine indicators reveal significant differences in land use strategy, labor deployment, and the role of livestock. Indicators include population density, average farm size, land availability, grain yield, area productivity, labor productivity, marketable crop production, livestock density, and nitrogen return to cropland. Whereas Old World farms had abundant human and animal labor and a shortage of land, Great Plains farms had excess land and a shortage of labor and livestock. Austrian farmers returned over 90% of extracted nitrogen to cropland, thus sustaining soils over many generations, but they produced little marketable crop surplus. A key difference was livestock density. Old World communities kept more animals than they needed for food and labor, primarily to supply manure that maintained cropland fertility. Great Plains farmers used few animals to exploit rich grassland soils, returning less than half of the nitrogen they extracted each year. Farmers depleted soil fertility over six decades, relying on a stockpiled endowment of nitrogen. They produced stupendous surpluses for market export, but watched crop yields decline steadily between 1880 and 1940. Austrian immigrants to Kansas in the late nineteenth century found that their return on labor could increase by 20 times over what they were used to. But by the early twentieth century Austrian productivity had increased while in Kansas it dropped steadily lower. Both farm systems were efficient in their own way, one producing long-term stability, the other remarkable commercial exports. Kansas farmers faced a soil nutrient crisis by the 1940s, one that was solved in the second half of the twentieth century by the massive importation of fossil fuels. Austrian and Great Plains agriculture converged thereafter, with dramatically increased productivity based on oil, diesel fuel, petroleum-based pesticides, and synthetic nitrogen fertilizers manufactured from natural gas.