From Agronomists of the
Potash & Phosphate Institute
655 Engineering Drive, Suite 110
Norcross, Georgia 30092-2837
Phone (770) 447-0335

Winter 2002, No. 2


When growing crops, the concept of building fertile soils requires some careful nutrient bookkeeping. Profitable crop production has high yields as its foundation. High yields do not just happen by chance, but rather are the result of persistent attention to detail in planning and implementing new and improved crop and nutrient management and technology.

Nutrient management has its roots in sound science. This is the science of soil testing, crop residue inputs, crop nutrient removal, fertilizer application rates and timing, and manure analysis and application. All of these technologies and management inputs influence the potential of a soil to produce high yielding crops with the desired quality characteristics. In fact, these are the tools available to each and every farmer to ensure enterprise profitability.

Optimizing nutrient management requires use of the right tools on your farm. Developing a plan with your crop adviser to use these tools is the first step to making nutrient management planning work for you. Balancing inputs with output, monitoring the soil's nutrient status, and taking credit for your crop management are part of this plan.

Soil testing for phosphorus and potassium provide insight into the capacity of your soil to meet crop requirements. Unlike nitrogen and sulfur soil tests, which provide an idea of residual nutrient levels, phosphorus and potassium analysis give you some insight into the capacity of your soil to meet crop requirements. A low soil phosphorus or potassium test indicates that the soil's capacity to meet crop demand is also low, and needs some support through added nutrients. In addition, attempts to improve your soil phosphorus and potassium status requires that you apply more nutrients than the crop removes, in essence banking these nutrients for future high yield opportunities.

Calculating annual inputs and removals is essential to reconciling your nutrient account. Our ability to grow crops is a function of our soils releasing the needed nutrients. Using established average nutrient content values, it is possible to estimate annual nutrient removal for a farm. An example of some crop nutrient content values can be found at the PPI website: Using crop yields, and nutrient removal per unit of yield, you can get an estimate of how much phosphorus and potassium were removed from the field. These values are very important when evaluating your nutrient requirements for established yield goals.

Don’t wait for nutrient management planning regulations—develop your own farm nutrient budget now. By using soil testing, and nutrient removal and replacement calculations, everyone involved in crop production can develop their own nutrient budget. Consult with your crop adviser for help in pulling the pieces together and drawing on the best science for your area. Remember, the tools exist to make nutrient management planning a science-based activity for all farms. Are you using the right tools to position yourself for a successful and profitable crop in 2003?


For more information, contact Dr. Adrian M. Johnston, Western Canada Director, PPI, 12-425 Pinehouse Drive, Saskatoon, Saskatchewan, Canada S7K 5K2. Phone: (306) 956-0619. E-mail:
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