Professor, Extension Soil Specialist 
Soil Science Department


BS, MS, and Ph.D. from University of Illinois, Urbana, IL. 18 years as agronomist and manager in the retail fertilizer business in East Central Illinois. Completed Ph.D. in 1993, with thesis addressing field variability of P, K, and soil pH in two Illinois fields. Results are published and publications are listed on this page. Joined NDSU faculty in June, 1994.

Professional Duties:
Provide educational programs on soil and soil fertility topics to extension agents and specialists, industry professionals, farm producers and the public. Material is presented using meetings, field tours, written material, radio, TV, video and internet resources. Perform applied soils research projects as are relevant to North Dakota producers.

Site-specific Nutrient Management:
I was hired in June, 1993 as Extension Soil Specialist in spite of my background in precision agriculture, corn and soybean production and tile drainage. Now, most of my presentations and research activities are in these areas. My previous Illinois research indicated that it took about 1 soil sample per acre in a grid pattern to depict the soil nutrient (P, K, soil pH) patterns in a field. My work in North Dakota resulted in the same conclusion. A 2 ½ acre grid in the ‘I’ states is only ‘successful’ because the values are mostly in the ‘high’ range, and although variability is present at a smaller spatial scale, the recommendation for P, K is the same; soil pH being the exception. However, into the second year of North Dakota sampling research it became clear that residual nitrate levels form patterns (zones) that are stable from year to year, related to topography. A number of zone delineation tools were researched across Montana, North Dakota and western Minnesota under a mutual USDA grant and we found that these zone delineation tools, including soil EC sensor, aerial photography, satellite imagery, multi-year yield maps, and particularly topography, were useful in forming relevant zones across the region. Today, zone sampling is the most-utilized method of sampling for site-specific nutrient management. The method is preferred over any grid sampling for residual nitrate, but also for all other soil nutrients, except where large buildup quantities of nutrients have previously been applied or large manure applications have been made to a field. After this work, it was also clear that the soil nutrient recommendations for North Dakota were inadequate to relate to the new sampling science. Therefore, from 2005 through the present, significant energy and funds were expended to modernize spring wheat/durum wheat, corn and sunflower recommendations. As part of these studies, active-optical sensors were also used to relate readings with yield prediction. Corn algorithms for use with active-optical sensors to direct side-dress N application for corn have now been published, with investigations on-going for sunflower, wheat and sugar beet. For more detailed information, see my published works under Extension publications and Scientific publications.

Soil fertility research:
Modern N recommendations are now available through Extension publications and on web-based N calculators and phone apps for corn, spring wheat/durum, and sunflower. The basis for these new recommendations are based on hundreds of site-years of data mostly conducted since 2005. The recommendations are not yield-goal based. I found that similar N rates are required in a low yielding environment as in a high yielding environment due to low N mineralization rates and N up-take efficiency in low-yielding environments, and high N mineralization rates and highly efficient N up-take in high-yielding environments. All of our nutrient recommendations will not be yield-based in the future. Modern nutrient recommendations are also available for soybean, field pea, lentils, canola, dry edible bean, barley, rye and winter wheat. Other minor crops will be updated in the next couple years.
Major changes in nutrient recommendations are that P is no longer recommended for flax and sunflower. No yield increases due to P application have been recorded at a frequency that is economically beneficial to either of these crops. The N calculators for corn, spring wheat/durum and sunflower are based on economic production functions, where the yield increase (or decrease) of a crop due to nutrient application is considered for its economic value, less the value of the nutrient required to produce it. I understand that the wheat recommendations are now taught at NDSU in their agricultural economics program as one of the only example of an economic production function in practical use.
Considerable effort has been made in the past few years regarding the use of effective nitrification inhibitors and urease inhibitors. The NCERA-103 committee has a new publication available to highlight chemistries with effective properties and some that have no use for these purposes. The compendium search engine for non-conventional additives and amendments is available with a link at the bottom of my webpage.

Soil and Nutrient Loss from Wind Erosion:
Until a few years ago, I was aware of historical loss of topsoil from North Dakota, but I was unaware of the huge scale of losses incurred, and the scale of ongoing losses. A voice-over YouTube PowerPoint presentation is now available for viewing. It is 38 minutes long. In addition, the NDSU Soil Health website has several items on this topic. A strategy to move towards a no-till/strip-till tillage system should be a long-range goal of every producer in this state, and growers that practice these systems should be on the land-rent ‘A-list’ of every landowner in the region. If not, future farmers will be farming subsoil, not topsoil. Some farmers already have this challenge, and know that these fields are the first to suffer from salt damage, soil crusting, poor soil tilth, wetness issues, greater susceptibility to drought and greater nutrient requirements. They might not be aware that these poor soil qualities are the result of historic and often continuing topsoil loss, but they are.

Scientific Publications

Extension Publications and Programs

Peer-Reviewed proceedings paper/book chapter

Searchable compendium of non-conventional soil additives and amendments


Top of page