Nitrogen management work earns team AgriLife Extension Superior Service Award

COLLEGE STATION – A team of Texas AgriLife Extension Service and Texas A&M University soil and crop science department specialists has received a 2011 Superior Service Award for their deep-profile soil testing and nitrogen management work.

Team members are Dr. Mark McFarland, soil fertility specialist, College Station; Dr. Tony Provin, state soil chemist, College Station; Dennis Coker, AgriLife Extension program specialist, College Station; Jeff Stapper, AgriLife Extension agent, Nueces County; Dr. Frank Hons, soil science professor, College Station; and Dr. Dan Fromme, AgriLife Extension agronomist, Corpus Christi.

Because of the increasing cost of fertilizer inputs, particularly nitrogen fertilizers, has narrowed profit margins for many row-crop and grain producers, many agricultural producers have actively sought ways to reduce their fertilizer inputs and improve profitability, said Provin, in his nomination of the team.

While evaluating a new experimental soil test for nitrogen and nitrogen responses to new grain and cotton cultivars, this team found study sites that failed to respond to nitrogen fertilizer, he said. The lack of response suggested that existing soil testing methodology for determining residual soil test nitrogen was either inaccurate, unreliable and/or lacked adequate calibration.

Provin said the team surveyed what influenced producers’ fertilization practices, documenting actual nitrogen rates and subsequent yields, evaluation of nitrogen throughout the rooting zone, and placement of labeled nitrogen fertilizers at different depths within the rooting zone and measuring crop uptake using isotopic mass spectrometry.

The team determined that in many cases the lack of crop response to added nitrogen was due to surplus residual available nitrogen found at deeper depth in soils, he said. This finding resulted in the recommendation that producers sample soil to at least 18-24 inches where possible for residual nitrogen compared to the previously recommended sampling depth of 0-6 inches.

The team quickly realized that while Texas has led the southern states in nitrogen management research and outreach, many producers were either misinformed or lacked adequate knowledge of nitrogen and plant nutrient management, Provin said.

This led to the development of a number of crop–specific and basic nitrogen management publications, presentations and trainings on soil fertility, and extensive result demonstration and research studies throughout the state, he said.

As a result, the U.S. Department of Agriculture Natural Resources Conservation Service adopted an Environmental Quality Incentives Program for producer use of profile nitrogen testing based on the research studies directed by the team, Provin said.

Also, the Texas A&M Soil, Water and Forage Testing Laboratory adopted formal deep-profile nitrate soil tests for crediting residual nitrate-nitrogen, after interacting with the Oklahoma State University soil testing program to establish regional methods and sampling protocols to enhance producer adoption.

The team worked with Cotton Incorporated to develop a multi-regional Cotton Belt research and outreach program addressing nitrate-nitrogen testing and nitrogen management for the cotton industry.

Through the program, AgriLife Extension specialists and agents conducted more than 180 educational events on the importance of soil profile testing for nitrogen, generating more than 13,000 contacts and distributing more than 3,330 publications.

The outcomes of this program have been broader than just the adoption of profile nitrogen testing, Provin said. Producers are becoming more aware of overall nitrogen management for grain and row-crop production and potential impacts on the pocketbook and environment when improperly managed.

Through educating producers on the importance of evaluating the subsoil for residual nitrogen, the team observed many producers were more likely to begin taking routine surface soil samples, the first step required before adopting profile sampling, he said.

Through county-based soil testing campaigns, the team estimates that these producers reduced their planned fertilizer applications by 5.6 million and 4.87 million pounds of nitrogen and phosphate fertilizers, respectively.

These reductions in fertilizer applications during the 2006-2010 cropping seasons account for an additional economic impact of $5.48 million, Provin said.

“The team’s clear, end-user focused and adoptable approach to assisting our clientele has further strengthened the AgriLife Extension reputation, with not only our agricultural clientele, but with both state and federal agencies and our fellow Extension colleagues in other states, all of whom have relied on the team’s expertise and dedication to improving our agricultural competitiveness while protecting the environment,” he said.

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