Minnesota Crop News

Greg Klinger and Anne Struffert, Extension Educators  Not all fall-applied nitrogen sources are equal. Fall-applied anhydrous ammonia behaves very differently than fall-applied urea. Anhydrous ammonia is as harmful to microorganisms as it is to people, so the microbes that convert ammonium to nitrate in the soil are typically killed in the area right around the injection band. These microorganisms will eventually recolonize the injection zone and ammonium will begin converting to nitrate. Urea does not inhibit the activity of these microorganisms. As a result, anhydrous ammonia delays the conversion to nitrate by at least 2 weeks longer than urea and other fertilizer forms. 

Greg Klinger and Anne Struffert, Extension Educators  Substantial nitrogen loss from fall applied fertilizer can happen under a few key conditions: Warm temperatures (especially above 50°) that increase the activity of nitrifying microorganisms A large portion of nitrogen in the soil in the form of nitrate nitrogen (NO3-N), usually due to nitrifying microorganisms, Significant precipitation.

By Sara Berg, South Dakota State University; John Thomas, University of Nebraska Lincoln; Lizabeth Stahl, University of Minnesota; Josh Coltrain, Kansas State University Photo: Sara Berg, SDSU Extension With technology being so prevalent in today’s culture, data and marketing information has become a key part of life. Farmers especially have been targeted with large quantities of new technology to generate more efficient farming systems and easy real-time data access. With large amounts of data and fast access to information and product marketing being the new norm, producing a commodity requires many decisions. While the number of US farms has dropped, average farm size has risen 23 percent from 2009 to 2016 (USDA, 2017). At the same time, producers have seen a shift in the types of ag services available. With such a wide scope of products and options available, it can be difficult to determine what products or technologies to invest in and what to leave on the shelf.

Paulo Pagliari, Nutrient Management Specialist Among the major nutrients (nitrogen, phosphorus and potassium), phosphorus (P) has the least mobility. As the fertilizer granule dissolves, most of the P in the fertilizer will likely only move a couple eights of an inch away from the granule, primarily by diffusion. The dissolved P will then start to react with cations in solution such as calcium, aluminum, and iron, and will start to adsorb onto soil particles. In general, tie up of P as calcium phosphates is a concern when the soil pH exceeds 7.3. Soils will become more acidic over time if they are not limed. With the decrease in pH, the availability of P will change. When the pH of soils range between 4.8 and 5.5, P is more reactive with aluminum in the soil and is tied up as aluminum phosphates that are not available to the plants. Liming of the soil can help to increase P availability from Fe and Al bound forms. The reaction of sorption and precipitation will limit P availabilit

Melissa Wilson, Manure Management Specialist Animal manure - or “brown gold” as some like to call it - is a valuable source of nutrients for growing crops when applied at agronomic rates. In Extension, we often get questions about how to manage manure nutrients. Unfortunately, there is not a simple answer. The nutrient content and availability depend on many factors.

By Liz Stahl, Dave Nicolai and Jeff Coulter Photo: Liz Stahl There is a significant amount of corn to be harvested throughout the Upper Midwest. Grain moisture for most of this corn is not at a level safe for long-term storage, ranging from 17 to 20 percent. Dr. Kenneth Hellevang, Extension Engineer with North Dakota State University, is a regional expert on corn storage issues. Suggestions from Dr. Hellevang and publications for dealing with wet corn and a late harvest include the following:

Daniel Kaiser, Soil Fertility Specialist Once you’ve taken the basal stalk nitrate test , it’s time to interpret your results. Remember that this test is diagnostic, not predictive. The results will come in measurements of PPM, or parts per million. This is an indication of nitrogen availability throughout the season. Watch the video below for more on how to interpret these results.