Growers in the four-county Lower Rio Grande Valley area are encouraged to take advantage of a free soil-testing program designed to improve farm management practices and conserve water.

The program is a USDA-funded project coordinated by the Texas Water Resources Institute and Texas Cooperative Extension.

“Soil testing is the cornerstone of an economically and environmentally sound nutrient management program,” said Brad Cowan, an agricultural Extension agent for Hidalgo County. “It involves the chemical analysis of soil to determine whether there is an adequate supply of the nutrients essential for plant growth.”

The special soil-testing program will be conducted through Nov. 20.

To participate in the free campaign, agricultural producers should contact their local county Extension offices to obtain the Special Soil Test Information Sheet, which must be submitted with samples.

Results of the laboratory tests will be mailed directly to growers for use in developing nutrient management plans. For more information, call 956-383-1026.

Cowan said there are about 12 essential elements that can become deficient in Texas soils. These include nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, chloride, iron, manganese, copper and zinc. If one or more of these elements is not available in an adequate supply, plant health, crop quality and crop yield can suffer.

“Poor plant nutrition can also reduce water use efficiency, which increases the amount of water required to produce a given yield. But by the same token, if nutrients are applied unnecessarily, production costs increase with no increase in returns. So soil testing can be critical to achieve maximum economic crop yields.”

Soil testing can identify those soils with residual nutrients or naturally high levels of nutrients that can supply all plant needs without additional supplemental fertilizer.

“Over-fertilization is a concern for several reasons,” Cowan said.

“Excess fertility reduces the efficiency of water use by crops. This can be caused by poor root development or by excess vegetative growth. These excess nutrients can also find their way to water supplies, which can lead to eutrophication.”

Eutrophication, he said, is the nutrient enrichment of water, which can lead to reduced quality, algal blooms and potential fish kills.

“Most fields should be tested every two to three years, at a minimum, to make sure that both production economics and environmental quality are addressed,” Cowan said.

rsmith@primediabusiness.com