UNL CropWatch May 21, 2010: 100 Years of Soil Fertility Research at UNL's Panhandle REC

UNL CropWatch May 21, 2010: 100 Years of Soil Fertility Research at UNL's Panhandle REC

May 21, 2010

Editor’s note: This is one of a series of articles about the people and programs that are part of the history of the University of Nebraska–Lincoln Panhandle Research and Extension Center (PHREC) at Scottsbluff. The Panhandle REC is celebrating its centennial in 2010. For more stories.

Sustaining soil productivity has always been an important part of the work at the UNL Panhandle Research and Extension Center at Scottsbluff. Although some aspects of enhancing or maintaining soil fertility have been known for centuries, the needed materials have been limited. When the native sod was broken, the residual fertility from this virgin prairie was enough to keep the land productive for several years. However, to sustain a reasonable level of productivity, new methods needed to be developed.

Photo - Panhandle REC soils research

Research technician Rex Nielsen collects soil samples from a research plot at UNL's Panhandle Research and Extension Center.

Photo - Panhandle REC soils research

 UNL Research Technician Rex Nielsen and Extension Soil Nutrient Specialist Gary Hergert set up a fertilizer trial on sugarbeets.

Scientists at the Panhandle Center, as it was originally known, were soon called on to find new solutions. Traditional methods of sustaining soil fertility included crop rotation, green manures, and the application of livestock manure. As early as 1912 Fritz Knorr, the first station director, established a large set of research plots: Nine in continuous cropping and 25 were in rotations, with several including alfalfa and manure. A few years later, then director James Holden reported dramatic yield benefits of rotating alfalfa. He also noted that with longer rotations certain crop diseases and pests were significantly decreased.

WWII Leads to New Fertilizers

Commercial fertilizer products were limited and expensive in the early 20th century. In western Nebraska, legumes and livestock manure were the predominant means for enhancing soil fertility. However, World War II dramatically changed the availability of manufactured fertilizers because it created a large need for munitions. The United States expanded production of anhydrous ammonia from the Haber-Bosch process and made ammonium nitrate for munitions.

At the end of the war, the excess products (ammonium nitrate and ammonia) were made available for agricultural use at economical prices. The large-scale production of sulfuric and nitric acids also provided the means to begin commercial phosphate production by acidulating rock phosphate.

1950s – 1960s

Publications written by Lionel Harris and Vance Pumphrey in the 1950s report the benefits of nitrogen fertilizer on corn. Publications at the time noted that as little as one pound of nitrogen fertilizer could produce an additional bushel of corn.

Research also demonstrated the benefits of applying phosphorus to sugar beets and corn. Most of the fertilizers we have today came from research at the Tennessee Valley Authority (TVA) Fertilizer branch in Muscle Shoals, Ala., created by legislation authored by Senator Frank Norris of Nebraska. The first products were ammonium nitrate and ordinary superphosphate. Later products included triple super phosphate (0-46-0), urea-ammonium nitrate solution (32-0-0), and ammonium polyphosphate (10-34-0). TVA conducted a national demonstration effort in conjunction with land-grant universities to promote the use of fertilizer from the 1960s into the 1990s.

Too much fertilizer can be as much of a problem as too little fertilizer. In the 1950s Great Western Sugar Company stipulated in beet contracts that farmers apply 200 pounds of superphosphate per acre. Dr. Gary Peterson (former Nebraska scientist) found that the excess phosphorus induced micronutrient deficiencies in corn. These problems were particularly evident on high pH soils in the North Platte Valley. Lower phosphorus rates and soil testing helped address the problem.

In the 1960s, Frank Anderson conducted numerous experiments with various zinc fertilizer products on corn. Anderson also researched the fertilization of potatoes with various combinations of N, P and K to develop the quality needed for chipping. In the late 1960s, Anderson and Gary Peterson initiated a series of experiments to calibrate the nitrogen soil test for sugar beets by measuring soil nitrate content to six feet. Their calibrations were adopted by Great Western Sugar Company to improve yield and quality.

1960s – 2010

In the 1960s-1970s Extension Soil Scientist Louis Daigger did extensive work on small grains and other crops. In the 1980s, Frank Anderson researched fertility of dryland crops and conducted numerous experiments on N and P for winter wheat under different types of fallow tillage methods. When Anderson retired in 1990, Dr. Greg Binford began research designed to develop fertilizer recommendations for sunflowers and to identify why corn yields sometimes were depressed following beets. He worked with spoked-wheel fertilizer applicators and did extensive work with chlorophyll meters.

Dr. Jurg Blumenthal followed Binford. He did extensive research on precision fertilizer applications on both sugar beets and corn using GPS technology. He modified a full-size sugar beet harvester to monitor sugar beet yields as it was pulled through the field. He also collected and isolated new strains of native nitrogen-fixing bacteria for dry edible bean inoculation.

In 2004, after being at the West Central Research and Education Center for 26 years, Dr. Gary Hergert became the PHREC's soil scientist. His research focuses on soil and nutrient management to improve fertilizer use efficiency for corn, dry beans, winter wheat, canola, sugar beets and irrigated grasses. It includes iron chlorosis on high-pH soils, manure management, and a major project on no-till, limited irrigation systems designed to help farmers adapt to restricted irrigation water use. Rex Nielsen has served as a technologist for all the soil scientists beginning with Frank Anderson and has been instrumental in managing the Knorr-Holden Long Term Manure plots plus other soil fertility experiments.

Gary Hergert, Soil Fertility and Nutrient Specialist
Rex Nielsen, Research Technician
Both at the Panhandle Research and Extension Center