Conservation agriculture is a 'no blow'

Indian Head, Sask., June 5, 2012:

Wind erosion has been a serious concern on the Canadian prairies during times of droughts and high winds in the 1930's and 1980's. The loss of topsoil and nutrients reduces soil quality and crop yields. In addition to the economic losses, wind erosion reduces visibility, air quality and can cause human health issues.

Recently researchers from the Universities of Lethbridge and Calgary carried out a study to examine the frequency of blowing dust from agricultural fields (Thomas Fox, Thomas Barchyn and Chris Hugenholtz, 2012). The purpose of the study was to examine long-term trends in dust emissions on the Canadian prairies and determine whether the efforts of soil conservation have had a measurable impact on dust frequency. The researchers examined records of airborne dust frequency from seven weather stations over the period 1961 to 2006. They identified a substantial reduction in dust frequency from 1991 to 2006, which they attribute to changes in farm management practices in the late 1980s. This finding was supported by the reduction in dust that occurred in the droughts of 2001–2002.

The 1980s was a period of increased promotion of soil conservation practices such as direct seeding and the reduction in summefallow acreage. Federal and provincial soil conservation programs and the technology transfer programs of producer groups such as the Alberta Conservation Tillage Society, Saskatchewan Soil Conservation Association, Manitoba-North Dakota Zero Tillage Farmer's Association and Soil Conservation Council of Canada all contributed to an increased adoption of conservation practices and a reduction in soil erosion across the Canadian prairies.

Drought and persisted high winds can still cause wind erosion in the spring, however the risk is greatly reduced by conservation practices that maintain crop residue cover on the soil surface. Anchored residue not only helps with reducing evaporation and infiltration, it keeps the soil where it belongs to nurture the next crop. Practising continuous conservation agriculture enable farmers to turn any extreme wind event into a "no blow" soil event!

(Fox, T.A., Barchyn, T.E and Hugenholtz, C.H. 2012. Successes of soil conservation in the Canadian Prairies highlighted by a historical decline in blowing dust. Environmental Research Letters 7(1): 7p. Accessed May, 2012 here.)