CFAES Give Today
Agronomic Crops Network

Ohio State University Extension


Nutrient Management Workbook

Nutrient Management Workbook

Do you have a nutrient management plan for your farm? Many producers avoid developing nutrient management plans because they can be time consuming and hard to understand. With that in mind the OSU Extension Environmental Management team and other state agencies with support from the Ohio Soybean Council set out to create a nutrient management plan that farms of every size could easily use.

The Nutrient Management Workbook uses information from crops grown, commercial fertilizers and manure to calculate how many nutrients a field needs and how much is applied. One can easily fine tune a farming operation to prevent over application of nutrients and save money on purchasing commercial fertilizers. It is available in a hardcopy and an electronic version

Working with the Ohio Department of Natural Resources Division of Soil and Water Conservation, we have come up with criteria that can be met by producers that Nutrient management workbook coverwould qualify the plan to be approved by local Soil and Water Conservation Districts. If the plan is approved and followed it can provide the operation with an affirmative defense in a private civil action for nuisances involving agriculture pollution. For example, the amount of manure that was calculated and approved in the Nutrient Management Workbook is applied to the field on a day where no rain was in the forecast but a pop-up storm drops an inch of rain causing run-off and someone complains. If you followed the approved plan, it can be used as a defense against the complaint. If you are interested in pursuing this option, contact your county Soil and Water office.

The workbook is divided into sections with detailed explanations and examples for each section. In Section A: Field Information, the field plan exampleplanned crop, yield goal, previous crop and field size are entered. Soil test information is also taken into account. It is recommended to have soil samples pulled every three years and you must have current soil test information to become approved, but if you do not have soil test values, a chart with maintenance values is included. Maintenance values will have you apply the same amount of nutrients that the crop withdraws from the soil.

Section B: Manure Information goes through everything needed to calculate nutrients available in the manure: when it is applied, whether it is incorporated or not and within how many days it is incorporated. Books values are listed for those who do not have manure tests.

The next sections get into calculating how many nutrients are need and applied. Starting off with crop nutrients needs based on charts from the Tri-state Fertilizer Recommendations and Ohio Agronomy Guide publications. The charts from these publications for major crops in Ohio are included in the workbook. Next, if applied, starter fertilizer is subtracted from crop nutrient needs. An example and formulas are listed for calculating the manure application rate and nutrients applied at that rate. There is another section for additional nutrients applied if a field is side-dressed or has fertilizer applied to it in some other way. After doing the math you are left with the crop nutrient balance. If there is excess potassium and phosphorus, formulas for calculating how many years worth of nutrients that are banked in the field are demonstrated. You can also calculate the value of those excess nutrients based on current commercial fertilizer prices. This will help you realize the value of those nutrients and show that application of more nutrients in the next years would be useless and a waste of money.

If applying manure, one very important step included in the plan is spreadable acres. This will guide you in determining setbacks from sensitive areas and the amount of acres remaining. There is also a section for manure storage management that goes through the amount of manure produced on a farm by the animals, the volume applied to a field and the volume remaining so you can effectively plan when to apply manure to prevent storages from becoming full or the need to apply on frozen and snow covered ground.

This workbook was developed with the average Ohio producer in mind so it is easy to use and does not take a lot of time. Developing long detailed farm plans are pointless if they sit on the shelf. The Nutrient Management Workbook aimed to avoid that situation. To order a hardcopy of this workbook, contact Amanda Douridas at or 937-484-1526.