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You have a nutrient management plan, now what?

Bill Rogers Published on 25 August 2011
manure spreader

It has been a journey, but you have finally completed the task of developing a nutrient management plan (NMP) or having someone else develop an NMP for your farm; now what?

Unfortunately, the majority of the NMPs developed end up in a filing cabinet and are not looked at again until it must be updated or a regulator asks to see it. If this was all you intended to do with the plan, why did you take the time or spend the money for it?



As a person who develops plans, I could have saved you money and been just as accurate as your current implementation if I told you to apply 10,000 gallons of manure per acre and then apply an additional 50 pounds of nitrogen per acre at sidedress. That recommendation would have worked well for 20 percent of you, and you would have been happy with me since I would have maximized forage production and minimized inputs.

The other 80 percent of you would think I was an idiot. For 40 percent, I would have maximized forage production, but I would have significantly increased your input costs so that you wasted money. For the other 40 percent, I would have minimized input costs, but your yields would not feed your animals through the next year.

Another way to look at this is to evaluate how much nitrogen that 10,000 gallons of manure actually provided you per acre. If I was to use this 10,000-gallon manure application and calculate the amount of nitrogen available to this year’s corn crop, using a 5 percent error on all of the calculations, this application could have applied 85 pounds of available nitrogen per acre on the low end and 120 pounds on the high end.

You have developed a nutrient management plan either because you are a CAFO, your state regulatory agency required it or you were working with an NRCS program; now why not obtain all the value out of that plan and the investment you have made into it?

This is easily done by implementing the items listed in that plan. You paid for it; use it to obtain some value from the process you just completed.


Implementing an NMP includes a few general-area ideas. First, there may be some structural best management practices (BMPs) listed in the plan that need to be implemented.

Second, there is a set of records listed that should be maintained. Third, the NMP will include a list of ongoing, in-season testing that you can complete to “tweak” the recommendations provided in your plan.

Structural BMPs are those physical structures listed in the plan that you will need to build on your operation. These might include manure storages, animal trails, other barnyard items or stormwater projects. Structural BMPs were included in the plan due to there being areas on your operation where large amounts of sediment or nutrients are leaving the operation; installing the BMP will reduce these losses.

The planned BMPs not only reduce the nutrients and soil losses from your operation, but they might also improve your animals’ health. Clean them up and reduce illnesses or reduce the amount of management needed to maintain your animals in the barnyard. The reason for implementation of structural BMPs can be another topic for discussion with your planner.

A section in your NMP will detail the records you need to maintain as part of the plan implementation. At a minimum, you should maintain some of the following records. First, the amount of manure applied, along with when and where you applied it. This can be as simple as noting the size and number of loads you put in each field.

Second, information on the amount of other nutrients applied (other organic sources of nutrients or commercial fertilizers) is necessary so an inspector or your planner can complete a nutrient balance on your fields. Third, you need to document the yields obtained on your farm.


The basic idea of an NMP is to balance the nutrients you are applying (as manure or fertilizer) to meet the needs of the crops you are harvesting; without knowing the quantity of manure or fertilizer applied or your yields, this balancing is impossible.

My experience with most plans is that we are conservative estimating crop yields, and most of the time we underestimate them. With improved crop genetics has come higher yields, normally more than most agencies understand and allow in NMPs. Once you can document these higher yields, you can update the plan with these increased yields.

Also, you should maintain your soil and manure sample results. I recommend you soil sample your fields once every three years and manure sample annually until you have a good baseline.

In your plan, there may be comments about in-season testing. The plan was developed using the best information available.

However, going back to the comment I made at the beginning, there is a wide spread of available nitrogen that could come from your 10,000-gallon-per-acre manure application. This is why it is always recommended to complete in-season testing along with end-of-the-season testing to see how those educated recommendations are working on your farm; each farm can be different.

With corn, you can collect a pre-sidedress soil nitrate test. Using the results from this test and one of many calibrated equations can provide you with a better estimate of additional nitrogen needed at sidedress. It is often about a 50/50 split as to those that need more nitrogen or those needing less nitrogen than the amount listed in the official NMP.

At the end of the year, you can collect a corn stalk nitrate test to evaluate how you did with your nitrogen planning for that year. There are other in-season tests for other forage crops that will allow you to better manage the commercially applied nutrients.

Once you have maintained these records and implemented your current plan, work with your planner to start updating that nutrient management plan. I recommend you do this annually. Now that you have collected and documented what is happening on your farm, your planner can use these items to develop a more accurate NMP for the next growing season.

The take-home message about implementing an NMP is that a plan dropped in the file cabinet has no value; however, a plan that is implemented and maintained can provide an operator many useful bits of information to increase forage production while reducing input costs. PD

PHOTO: The basic idea of an NMP is to balance the nutrients you are applying (as manure or fertilizer) to meet the needs of the crops you are harvesting; without knowing the quantity of manure or fertilizer applied or your yields, this balancing is impossible. Photo by PD staff.

  • Bill Rogers

  • Environmental Specialist
  • AET Consulting, Inc.
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