Fertilizer Chooser

Fertilizer Chooser is the final step in preparing a fertilizer program. Fertilizer Chooser assumes that a fertilizer recommendation for balanced plant nutrition is available and helps the user to

• Translate a nutrient recommendation into the correct amounts of different fertilizers needed to make up the right amount of nutrients
• Select a combination of meaningful fertilizer sources
• Select the least costly combination of fertilizer nutrient sources based on quoted prices for fertilizer products and the cost of application, and
• Evaluate the cost of different fertilization programs.

The program uses a linear optimization procedure to find the best combination of fertilizer materials both in terms of suitability and cost. Unless specified otherwise, all calculations are performed under the constraint that the calculated amounts of fertilizer required must supply the amounts of nutrients specified in the recommendations.

The user is encouraged to compare the total cost of different nutrient management recommendations and fertilizer sources to make a final choice. In choosing the right fertilization program, users must also consider other aspects that are not part of Fertilizer Chooser, for example including:

• Product quality and consistency - these are very important factors that influence crop response to fertilizers, application accuracy and time required for application. For example, a product such as ammonium bicarbonate could be the "least costly" source of N available, but it may not be the most profitable in terms of yield response, or it may cause greater environmental problems than higher-quality products. Quality fertilizers are not available in all parts of the world, for example when the nutrient composition of the fertilizer is lower than that stated on the bag. Implementation of the improved fertilizer management strategies may not be effective if farmers are purchasing fertilizer of sub-standard quality.
• Product preference - the user can select specific fertilizer sources when translating a nutrient recommendation into the correct amounts of the preferred fertilizer sources. This may be the case when specific high quality products are to be used or if a fertilizer producer would like to develop a fertilizer program based on official recommendations using company products.

The Fertilizer Chooser User Interface




For further inquires in Asia, please contact:
Dr. Thomas Oberthur
Director, Southeast Asia Program
International Plant Nutrition Institute (IPNI)
PO Box 500 GPO, Penang 10670, Malaysia

Suggested citation:
Fairhurst, T.H., Dobermann, A., and C. Witt. 2004. Fertilizer Chooser. Lincoln, NE: University of Nebraska-Lincoln, Singapore: Pacific Rim Palm Oil Limited, and Los Baños, Philippines: International Rice Research Institute (IRRI).