Although UAN (urea-ammonium nitrate) and many pre-emergence products can be applied to emerged corn, using UAN as a herbicide carrier enhances the foliar activity of products and may result in foliar damage.
Nitrogen is the most important nutrient for plant growth, development and reproduction, but the minute nitrogen hits soil, it starts transforming. These transformations can greatly impact nitrogen use efficiency in cropping systems.
Volatilization losses of ammonia from urea have been a major concern of producers and agronomists because of the lack of precipitation. The nitrogen (N) cycle is very complex as it includes all forms of matter: solid (fertilizer and manure), liquid (dissolved N as nitrate and ammonium) and gas (ammonia).
Applying any urea containing fertilizer to the soil surface during warm, dry, windy conditions will maximize the potential for N volatilization losses. This loss occurs quickly, starting within hours following application with most of the loss occurring within 2 days following application.
One question that commonly comes up with continuous no-till operations is: “How deep should I sample soils for pH?” The next common question is: “How should the lime be applied if the soil is acidic and the field needs lime?”
The North American urea fertilizers market is estimated to grow at a compound annual growth rate (CAGR) of 2.8% from 2014 to 2019. The North American market is a leading market in global urea fertilizer production and consumption.
Managing nitrogen is not a one-time event. For optimized crop growth and yield potential, nutrient management is as important in the middle of the season as it is at planting, says Eric Scherder, Ph.D., field scientist, Dow AgroSciences.
Urea based N fertilizers are in an organic commercial form that requires a biological enzyme to promote degradation to ammonia. Ammonia exists as a gas at normal temperature and pressure, thus it may be lost by volatilization if not exposed to water. Ammonia loss potential by volatilization for incorporated urea products is negligible because soil holds enough water to capture ammonia as ammonium that can be held on the soil’s cation exchange complex. Surface applications of urea are at risk of loss because there is no opportunity to capture the ammonia as it is produced.
By Edited from a newsletter by Erick Larson, State Extension Specialist - Grain Crops, Larry Oldham, Extension Soils Specialist and Bobby Golden, Agronomist, Delta REC, Mississippi State University
Mississippi’s warm, wet climate can pose considerable issues with nitrogen fertilization, particularly for crops which are known to be responsive and demand high amounts for optimal productivity, such as corn. Nitrogen, unlike some other nutrients, is very subject to change forms in the soil, which can substantially affect its availability to plants. The South’s warm, high rainfall climate greatly increases potential nitrogen loss through denitrification and leaching, compared to drier and colder climates. Therefore, optimizing your fertilizer dollars can involve considerable more planning than simply applying a given fertilizer rate.