Effects of agriculture on the classification of Black soils in the Midwestern United States

Abstract

Veenstra, J. J. and Burras, C. L. 2012. Effects of agriculture on the classification of Black soils in the Midwestern United States. Can. J. Soil Sci. 92: 403–411. Soil surveys are generally treated as static documents. Many soil survey users assume that pedon data generated 30 to 50 yr ago still represents today's soil, as short-term changes in soil properties are perceived to be limited to the soil surface and thus pedologically insignificant. In this study, we re-sampled and re-analyzed 82 pedons with historical descriptions and laboratory data in Iowa, United States, to evaluate changes in soil profile properties and taxonomic classification after approximately 50 yr of agricultural land use. Using historical and current data, we classified sampled pedons using Canadian Soil Taxonomy, US Soil Taxonomy and the Food and Agriculture Association World Reference Base (FAO-WRB). Our results show that soil characteristics have changed significantly enough to change the classification. In each taxonomic system, the classification of 60% or more of the sampled pedons differed from the original. Classification of 15 to 32% of the sampled pedons changed at the Order (or equivalent) level with 11 to 33% of the pedons originally classified as Black soils – Mollisols, Chernozems or Phaeozems – no longer classified as Black soils. The change in soil classification over such a short-time period challenges the validity and usefulness of treating existing soil maps as static documents as well as traditional soil classification hierarchies.

Prairie strips improve biodiversity and the delivery of multiple ecosystem services from corn–soybean croplands

“…Agroecosystems dominate the region (3) and are primarily composed of corn and soybean croplands, which cover 43% of the Midwestern Corn Belt and 69% of Iowa (4). While producing one-quarter of global corn and soybean supplies (5), these agroecosystems are also associated with loss of native habitat and contingent biodiversity (3,6,7), degradation of air, water, and soil quality (8)(9)(10), and declines in rural communities (11). Impacts are not restricted to the region: Loss of nutrients from corn and soybean agroecosystems in the Midwest is linked with persistent environmental and economic problems of national and global concern, including hypoxia in the Gulf of Mexico (12) and greenhouse-gas emissions (13,14).…”

Soil mapping, classification, and pedologic modeling: History and future directions

“…However, for the great majority of the Earth's surface, the best available soil data is in the form of -or derived from -legacy soil maps. The change in the soil landscape since the creation of the map adds an additional source of uncertainty (Lagacherie, 2008;Veenstra and Burras, 2012). This situation reiterates the need for investment in modern soil mapping efforts, including an emphasis on understanding changes in the soil landscape.…”

“…It is also difficult to revisit soil maps created in the past and test uncertainty because the soil system is not static. Soil properties and classifications can change within decadal time scales (Mokma et al, 1996;Veenstra and Burras, 2012;Busch and Presley, 2014). Although many soil maps associate map units with quantified ranges of expected soil properties, those who would use the data for environmental models generally consider the spread of those ranges to be either too wide or not an accurate representation (Gessler et al, 1995;Di Luzio et al, 2004;Thompson and Kolka, 2005;Miller, 2012).…”

Meteoric Beryllium‐10 as a Tracer of Erosion Due to Postsettlement Land Use in West‐Central Minnesota, USA

“…There is strong evidence that soils currently mapped as Inceptisols in the study area are in fact eroded Mollisols (Jelinski & Yoo, ) and have been recognized as such in both Pope County, Minnesota, and surrounding counties (Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture, ). Mollisols are particularly susceptible to classification change under high erosion rates, because the major diagnostic feature utilized for classification is the mollic epipedon (Veenstra & Burras, ). In the absence of other subsurface diagnostic features such as an argillic horizon, these soils become Inceptisols or Entisols if the thickness of the mollic epipedon is reduced through erosion until it no longer meets mollic criteria (Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture, ).…”