Pre-sidedress soil nitrate test will save money on N

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

Pre-sidedress soil nitrate test (PSNT) is an excellent tool to determine the available soil nitrogen (N) on fields that have a high N mineralization potential. These are fields that have a previous history of manure or alfalfa. Studies have shown that farmers could reduce their N fertilizer application rate on corn without risking yields if the test is properly carried out. With the price of N fertilizer rising, growers may be able to save an average of $50/A based on this test.

Some prep work is necessary to achieve the desired results from the PSNT. Here are some points to remember.

The test is ideally suited for fields with high N mineralization potential, i.e., fields with high organic matter, manure or legumes. Other fields that will have high nitrate levels are loam, clay loam and clay soils that have been heavily fertilized in previous years. The test measures both residual nitrate N from the previous year and recently mineralized N from organic matter.

No broadcast or incorporated preplant N fertilizer should be applied. A modest amount of starter N up to 40lbs/A could be band applied near the seed.

The greatest amount of available soil nitrate usually occurs in the soil once the soil has warmed up and about three to four weeks after corn emergence (V6 to V8 growth stage). At this stage, corn begins to take up N quite rapidly. This is the most appropriate time to apply sidedress N. Since N release from mineralization is an ongoing process, collecting PSNT soil sample as close to sidedress date gives the best information about the appropriate N credit. It takes a few days to collect the samples and get them analyzed.

Soil samples taken earlier will not give a full measure of mineralizable N; therefore, the amount of N credit will be smaller.

Soil cores should be taken midway between the corn rows, avoiding the starter fertilizer band. The sampling depth is 12 inches. Each sample should be a composite of 15 to 20 soil cores and represent no more than 20 acres.

Air-dry the sample in paper bags near a fan or heated air vent. Drying the sample is very important. Do not place soil in plastic bags.

The test will measure the nitrate concentration in parts per million (ppm). The critical level is 25 ppm, above which no N fertilizer is recommended. When the concentration is below 25 ppm, the N fertilizer recommendation is adjusted accordingly. See Michigan’s Soil Nitrate Test for Corn for more information.

Dry soil samples should be sent for testing as soon as possible. The address is:

MSU Soil and Plant Nutrient Laboratory
Plant and Soil Sciences Building
1066 Bogue Street, Room A81
East Lansing, MI 48824-1325

The contact number for the MSU Soil and Plant Nutrient Laboratory is 517-355-0218. Some county Extension offices may have arranged certain dates to deliver samples to MSU. Contact your local MSU Extension office. The turnaround time is 48 hours. The fee is $10 a sample. The results will be emailed or faxed. Many private soil test labs offer the same test.


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 (0) Leave a comment 

Name
e-Mail (required)
Location

Comment:

characters left


X-TENDED REACH GRAIN CARTS

YOUR BEST HARVEST IS NOW WITHIN REACH J&M introduces their patented line of X-tended Reach grain carts, featuring a frontfolding single ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form