The Columbia Plateau Wind Erosion / Air Quality Project: predicting and controlling windblown dust

Several locations within the Columbia Plateau have failed to meet federal clean air standards for PM10 due to the occurrence of blowing dust originating from fallow dryland fields. For the past decade, a multi-disciplinary team of scientists has attempted to simulate and measure PM10 emissions from agricultural fields and identify management strategies to reduce emissions. The regional PM10 transport model predicts that PM10 concentrations can be held below the federal standard by maintaining 25% crop residue cover on the soil surface. This percent residue cover can easily be maintained throughout the 13-month fallow period using the under cutter method of conservation tillage, even when the grain yield from the preceding wheat crop is as low as 1600 kg/ha , with no agronomic or economic disadvantage compared to traditional tillage. Increased cropping intensity (i.e., less fallow), especially using no-till, are effective at reducing dust emissions, but are not economically competitive with winter wheat – summer fallow with current technology. Many questions yet remain about the dynamics of dust emissions and control strategies to reduce PM10 emissions during dust storms on the Columbia Plateau. Future research will include continued development of best management farming practices.