Dust and air quality are everyone’s concern, urban and rural
Does it seem to you that we have more wind than we used to have? We have had plenty of wind and in some cases dust and other stuff blowing around. Air quality is a real concern for parts of Yuma County.
Under the federal
Clean Air Act, emissions, including dust, from all significant sources in areas not meeting the national ambient air quality standards need to be controlled through effective programs. A study done in 1995 by the Arizona Department of Environmental Quality identified agricultural activities as a source that contributes to production of particulate matter (PM).
PM10 is a particle that is 10 microns or less in diameter. A human hair is 70 microns in diameter. These particles are so small that they can invade the natural defense mechanisms of the human respiratory tract, penetrating deep into the lungs. Consequently, PM10 particles can cause a wide variety of harmful health effects, especially for children, the elderly and
people with pre-existing respiratory and cardiovascular disease.
Members of the agricultural community met with ADEQ in a series of meetings starting in 2002. The results of their work is information and guidance on how to effectively implement individual Best Management Practices (BMPs). There are three categories of farming activities with BMPs: tillage and harvest, non-cropland and cropland.
Tillage and harvest practices that physically disturb cropland or crops on a commercial farm of 10 acres or more have numerous practices that can be incorporated into the farming operations to
reduce dust. Examples are:
1. Combining tractor operations to perform two or more tillage operations, cultivation, planting or planting with a single tractor reduces the number of trips over the fields.
2. Conducting soil disturbing operations at night when moisture levels are higher and normally there is less wind is another approved practice. With the extensive use of satellites and GPS to guide equipment, night operations are much more feasible.
A non-cropland practice is applying water to reduce dust. During our winter produce season, growers spend thousands of dollars on equipment and water
to keep county and private roads that surround their farm fields from producing dust. Dust is a food safety concern and it is a priority issue to be controlled.
The third category is cropland during the time between crop harvest and the emergence of the next crop. With the harvest of the wheat crop that is now growing, there is an opportunity to prevent dust by allowing the wheat stubble left in the field to remain undisturbed until preparing the field for the next crop. Even the short stubble left after baling the wheat straw will keep the soil surface from being affected by wind.
If tillage is needed,
leaving the soil in a cloddy condition will prevent soil movement. Clay soils and silty soils are most vulnerable to blowing dust.
Burning of fields is a negative practice for soils because it seals the soil surface and adds salts (ashes) to the soil and the smoke is a source of PM10 particles.
Farm Bureau members Art Allen, Harold Maxwell and David Sharp have been the warriors working with ADEQ to get Yuma County designated as in attainment for PM10. Attending multitudes of meetings, explaining that natural events are the major source of PM10 and fighting for common sense solutions that will not unnecessarily burden farming has spread over 30 years. Everyone involved wants to resolve this problem, but the major stumbling block is to get the agencies to recognize that we have no control over exceptional events, winds over 25 miles per hour.
With only 7% of the land in Yuma County privately held, the majority of the PM10 particles measured in exceptional events is from federal, state, military, Native American or other federal, state, county and city sources.
It is important to note that dust is not strictly a farmland problem. Offroad activities in the local desert areas, construction activities without dust control, uncovered haul trucks with dusty loads and driving on canal roads all contribute to the PM10 problem. Dust and PM10 control is everyone’s concern, urban and rural.
Logic and common sense tells us that the irrigated cropland is not the major contributor to PM10 measurements within the non-attainment. I would like to put up a sign that says: “It’s the wind storms, out of our control.”