How to estimate N loss resulting from saturated soils

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

click image to zoom Persistent rain and saturated soils have generated concern about nitrogen fertilizer loss. Nitrogen fertilizer is subject to considerable loss from excessive rainfall and wet, saturated soils. The loss resulting from saturated conditions and flooding occurs primarily through denitrification, particularly in heavy textured soils. Denitrification occurs when nitrate nitrogen is converted into nitrogen gas by microorganisms and escapes into the air. Two to three days of saturation are required for the process to begin.

The amount of nitrogen loss is very difficult to predict, and depends upon many factors. The primary factors affecting loss are fertilizer application timing, nitrogen source, and quantity applied, relative to the duration of saturated conditions and soil temperatures during this time. Essentially, seasonal nitrogen loss can be quite high, if a lot of nitrogen is exposed to numerous days of saturated conditions, particularly when soil temperatures are warm – in other words, early nitrogen application increases potential loss. This is why we strongly advocate applying nitrogen fertilizer to corn using split application methodology.

Warm soil temperatures accelerate the denitrification process. Research indicates denitrification rates range from 2-3% per day at soil temperatures from 55-65 F or 4-5% per day if soil temperatures exceed 65 F.  Fortunately, the cool temperatures thus far this spring, should have limited daily denitrification rates to the low range of this scale.

click image to zoom Timing of nitrogen application and nitrogen source affect the amount of applied nitrogen that will be in the nitrate form. This is important, because only the portion of nitrogen fertilizer present in the nitrate form is subject to denitrification. The following table estimates percentage of fertilizer present in the nitrate form for different nitrogen sources depending upon the time after application (adopted from “Evaluating Flood Damage in Corn”, Lee et al., Univ. of Kentucky, AGR-193).

For example, if you applied 200 pounds/a  of N as  UAN (32%) three weeks before the field became saturated and soil temperatures were about 60 degrees F, about 120 pounds N (200 x 60%) are present in the nitrate form. Each day of saturation after the initial two days results in an approximate nitrogen loss of about 3.6 lbs. of N per day (120 x 3%).   Thus, if this field has been saturated for about 12-14 days, then anticipated N loss would be about 40 lbs./a.


Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...


Comments (2) Leave a comment 

Name
e-Mail (required)
Location

Comment:

characters left

chris engle    
St.Louis, MI  |  May, 21, 2013 at 10:05 AM

Great article , makes the math easy.

mike reinbott    
parma, mo.  |  June, 02, 2013 at 06:02 PM

what happens when you use agrotain with the urea and apply about 6" tall


1325 Bushel Grain Cart

Equipped with a 22” computer balanced auger with 5/16” flighting,the unloading speed is 50% faster than smaller grain carts with ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form