Dr. Dave Franzen
Extension Soil Specialist
NDSU, Dept 7180
Fargo, ND 58108-6050
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.