In this podcast episode, Dr. Nutifafa Adotey and Dr. Jake McNeal addresses post-harvest soil and nutrient management questions sent in by local UT Extension agents.
You can learn more in the publications on estimating supplemental nitrogen following extended flooding and urease inhibitors, as referenced in the episode.
Check back soon for more segments covering topics related to soil and row crop agriculture!
From late April and throughout the month of May, many parts of Middle and West TN have received persistent rainfall that is well above the average for this period. These rains have produced persistently wet soil conditions and have coincided with sidedress N fertilizer application where most or all of the recommended N is applied. With this much rain, there is potential for N loss. Continue reading
By Nutifafa Adotey, Assistant Professor & Soil and Nutr. Magt Specialist, Forbes R Walker, Professor & Envt. Soil Specialist, and Frank Yin, Professor & Cropping System Scientist, University of Tennessee
Poultry litter has become readily available to producers in Tennessee. However, poultry litter cannot supply all the nitrogen needed for corn and thus supplemental N is required to obtain optimal yield. The amount of supplemental N can be estimated using the Pre-Sidedress Nitrate Test. The Pre-Sidedress Nitrate Test is recommended only for corn producers using animal manure, poultry litter or biosolids, who want to estimate and fine-tune their sidedress N fertilizer applications following manure/poultry litter application. This article provides a guide for Tennessee corn producers using poultry litter on how to estimate sidedress N rate using the Pre-Sidedress Nitrate Test. Continue reading
By Nutifafa Adotey, Assistant Professor & Soil and Nutr. Magt Specialist, Forbes R Walker, Professor & Envt. Soil Specialist, and Frank Yin, Professor & Cropping System Scientist, University of Tennessee
In Tennessee, the primary N fertilizer sources used are urea and urea ammonium nitrate (UAN). Other sources of N fertilizers, such as anhydrous ammonia, are used in some counties in Central and West Tennessee. It is a known fact that ammonia volatilization from applied N fertilizers may occurs from (1) unincorporated, surface-applied urea-based fertilizer; (2) anhydrous ammonia due to poor equipment calibration; and (3) unincorporated, surface-applied ammonium-based fertilizer on alkaline soils. This N loss from these fertilizers is governed by a complex interaction of prevailing environmental conditions, soil properties and management practices. Soil properties determine the potential of ammonia loss while the extent of the loss is dictated by environmental conditions and management practices. Continue reading
Most of the commercial and state soil testing laboratories in and around Tennessee use and prescribe fertilizer recommendations based on Mehlich 3 soil test extraction method. Most growers may receive soil test results from laboratories that utilizes Mehlich 3 soil test extraction method. However, The University of Tennessee gives fertilizer recommendations based on the Mehlich 1 extractant. This makes it difficult for growers to take advantage of The University of Tennessee fertilizer recommendations. Currently, the Mehlich 1 and 3 conversion equations used in TN were derived from the University of Kentucky, which were based on Kentucky soils (Table 1). Continue reading
The unusually dry soil conditions during most part of the growing season this year limited nitrogen (N) uptake and lessened the potential for N loss through denitrification or leaching. Intuitively, the unused N, which would be in the nitrate form may remain in the soil. However, since August, there has been considerable amounts (more than 12 inches) of rainfall which can affect the availability of nitrate-N. This has raised questions about how much nitrate-N would be available in the soil after drought and late season rainfall? Continue reading
Abnormally dry soil conditions as a result of rainfall amounts far below average during this corn growing season present unique nutrient management decisions after harvest, particularly for growers considering wheat crop this fall. This article will address two key questions that may come handy in making management decisions: Is there be considerable amounts of residual soil N left after the 2022 corn crop? and if the residual soil nitrate is sufficient to meet N demand of the wheat crop in the fall? Continue reading
Due to the ongoing drought, I’ve recently received questions along the lines of, “how much N is still available after the prill sits on the soil surface without rain for 35 plus days?” and, “should I begin a foliar fertilizer regiment to meet plant N/K/S/B demands?” In this blog, I tackle both of these questions and share N response curves generated from Tennessee data over the past 5 years.
“I applied urea and it didn’t rain for a month. Will my cotton crop have the N required to make close to maximum yields?”
For growers that have applied 60-90 lb as urea, the simple answer is yes; the amount of soil nitrate released from the urea you applied will likely meet cotton N demand without additional N fertilizers given plant available water increases significantly in the coming week. Generally, if surface applied urea fertilizer is not incorporated into the soil, some of the N may be lost as ammonia into the atmosphere depending on weather, soil properties and management practices. Continue reading