Cost Savings the with the Pre-sidedress Nitrogen Soil Test

Farmers and reseachers say doní»t apply N fertilizer at planting


Massachusetts farmers have saved thousands of dollars by reducing or eliminating purchases of N fertilizer.  This can be safely done with out sacrificing yield by using the pre-sidedress N test. A $5 to $50 investment might save $200 to $3,000 or more depending on #acres, fertilizer usage and animal intensity.

The test is taken when corn is 12" tall.  Nitrogen in the form of nitrate is extremely soluble and moves freely with soil water as it drains. Applying large quantities of N in the spring before planting can add to production costs as a result of nitrate leaching losses. Similarly, over-application of N from fertilizer and manure can result in N loss through- out the growing season & especially after crop removal in the fall. 

The need for a pre-sidedress N test is because farmers have no accurate way to predict N release from manure and crop residues from year to year due to climatic variability.  Utilization of a pre-sidedress N test, together with a manure management program, has two major benefits.  First, it saves money by establishing how much, if any, N fertilizer is needed.  Secondly, it helps reduce excess N loading to soil, thereby reducing the potential pollution of water supplies.

Sampling Procedure for Nitrogen Soil Test

1) Sample soil when the corn is approximately 12 inches tall.

2) Collect 15 and 20 cores per field to a depth of 12" if possible. If you can't get to 12", sample as deep as you can. Avoid starter fertilizer bands or areas where manure was piled or were an application was unusually heavy or light.

3) Mix together completely all the cores for each field, then dry on the same day a subsample to stabilize the nitrate. Dry in an oven at about 200OF, or in a microwave. Samples can also be air dried if spread out thinly on a nonabsorbent material. A fan will reduce drying time. Do not put wet samples on absorbent material because it will absorb some nitrate.

4) Take one cup of the soil when it is dry and put the sample in bag that has your name, address, sample number and from which field the sample was taken and then send or take the sample together with $6.00 per sample to the: Soil Testing Lab, West Experiment Station at UMASS-Amherst, or to a county USDA-Farm Services Agency office.

5) The sidedress N recommendation will be mailed to you from the testing lab.


Stephen J. Herbert

Dept. of Plant and Soil Sciences

University of Massachusetts Amherst

Crops, Dairy, Livestock News. Vol. 1:1, Mar. 1996

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