Historical reduction of airborne dust in the Red River Valley of the North

ABSTRACT:

Seasonal extremes in temperature, moisture, and snow cover cause the formation of very fine aggregates, resulting in periods of severe wind erosion in fine-textured soils of the Red River Valley of the North. Changes in trends of dust observations have not been quantified in previous studies. The study compiled the number of airborne dust observations for the Fargo National Weather Service Office for the period 1948 to 1994 to document the historical frequency of airborne dust in the Red River Valley of the North. Concurrent trends in agricultural land use patterns, selected climatic data, and farm management practices also were evaluated. Results indicate a decreasing frequency of occurrence of airborne dust observations over time. Historical land use patterns and climatic trends were unable to explain the observed reduction in the wind erosion hazard. The best explanation for the reduced incidence of airborne dust appears to be the adoption of improved farm management practices. This includes the development of an extensive system of shelterbelts, improved farm technology, and basic changes in cultural practices, such as conservation tillage, crop residue management, and land retirement programs. It is difficult, however, to determine the relative contribution of these specific changes upon the observation of airborne dust events because many economic, social, political, and technological factors have combined to create fundamental changes in agriculture and farming practices in the Red River Valley.