Soil fertility research in western Nebraska

Gary W. Hergert, Soil Fertility and Nutrient Specialist
Rex A. Nielsen, Research Technician
Panhandle Research and Extension Center

Sustaining soil productivity was an important part of at the Panhandle Station which later became the University of Nebraska Panhandle Research and Extension Center. Although some aspects of enhancing or maintaining soil fertility have been known for centuries, materials useful for enhancing soil fertility were 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. Station scientists were soon called on to find solutions to these problems.

Traditional methods of sustaining soil fertility included crop rotation, green manures and adding livestock manure. As early as 1912 Fritz Knorr, the first station director, established a large set of plots, containing 9 with continuous cropping and 25 with different crop rotations, 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.

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. There was excess of these products (ammonium nitrate and ammonia) at the end of the war, and they became 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.

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 efforts in conjunction with land-grant universities to promote the use of fertilizer from the 1960’s into the 1990s.

Too much fertilizer can be a problem just like deficiencies. 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 phosporus induced micronutrient deficiencies in corn. These problems were particularly evident on high pH soils found in the North Platte Valley. Lower P 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 did research on fertilization of potatoes.with various combinations of N, P and K. The primary thrust was the quality of the potato 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 and it improved yield and quality.
Louis Daigger was an extension soil scientist who did extensive work on small grains in the 1960s and ‘70s plus other crops. In the 1980’s, Frank Anderson assumed responsibility for fertility work for dryland crops as well and conducted numerous experiments on N and P for winter wheat under different types of fallow tillage methods.

When Frank Anderson retired in 1990, Dr. Greg Binford worked on developing fertilizer recommendations for sunflowers. Corn research determined why corn yields were sometimes depressed following beets. Dr. Binford 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.

Dr. Gary Hergert came to the panhandle in 2004 after 26 years at North Platte. His research efforts focus 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 that is designed to help farmers adapt to restricted irrigation water use. Rex Nielsen has served as 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.

Research technician Rex Nielsen collects soil samples from a research plot.

Research technician Rex Nielsen and Gary Hergert, soil fertility and nutrient specialist, set up a fertilizer trial on sugarbeets.