Efforts of the San Francisco Public Utilities Commission to gain control of water used by local farmers captured many recent newspaper headlines, but little attention has been given another insidious problem, the loss of farm land top soil.
Some dubious farming practices are a threat to the viability of farming in the San Joaquin Valley. Loss of essential top soil can be as damaging as the inability to secure an adequate water supply.
The loss of top soil is easy to see. When farmers plow their dry fields on windy days, large quantities of dust blow away. During the nut harvest, blowers raise large plumes of dust throughout the valley that blow into the cities, the foothills, and the upper atmosphere.
In the past 12 years, the soil in residential areas of Modesto has built up as much as 2 inches as a result of the frequent deposit of dust blown in from nearby farms. Since city residents keep plants watered and the soil wet, nearly all the soil is retained, building up over time.
The Magnitude of the Problem
Nearly one third of the farm land in the Central Valley is no longer arable due to excess concentrations of salt and acidic soil at the surface. When top soil is blown away, the soil becomes more difficult and less productive to farm. The remaining soil gradually degrades until nothing will grow.
If you want to see how land has changed because of dubious farming practices, take a drive on State Route 45 south of Wasco. Large swaths of land are no longer farmed. The barren soil has turned alkali white. Almost nothing grows there. This is in sharp contrast from the years before the land was first farmed, when water-filled wetlands produced dense vegetation and abundant wild life.
The San Joaquin Air Pollution Control District is worried about PM-10, which is fine dust blown into the air from farms. The dust, which is also valuable top soil, is a form of air pollution. The air pollution is a major health concern, getting into lungs to aggravate asthma sufferers. One in six children living in the southern Central Valley has asthma, most likely as a result of inhaling air borne dust pollution. Valley Fever is also believed to originate in the top soil. The organism grows in the soil, the wind picks it up, and people inhale it.
Blowing dust, sometimes from farms, has caused multi-car accidents on Freeway 99 and Interstate 5 in the Central Valley, as well as on other area highways.
Considering the negative impacts of blowing dust, farmers should realize that the wisest practice is to keep the soil from blowing away. However, anyone who lives here during the nut harvest can see that the best farming practice is not being observed by a substantial percentage of growers.
The Government Solution
While government could legislate dust control, farmers would be wise to consider voluntarily changing some of their practices. Given the fact that farmers generally dislike government regulation, self-regulation may be wise before the government decides to intervene. Since the San Joaquin Valley has already missed its deadline to meet federal air pollution standards, time is growing short for farmers to voluntarily improve the way they manage their top soil.