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Fluid Journal : Fluid Journal 1996-1998
3 Fluid Journal Spring 1997 Commit to keeping accurate, detailed records of inputs and yields, including variability within fields. Collect soil test, nutrient application, and crop yield data on a grid basis, identifying each sample with its exact location and using GPS location referencing if possible. Develop a nutrient management plan that accounts for variability within fields, using spot spreading or variable rate application where appropriate. Use mobile yield measurement of yield variations across fields as a check on responses to site-specific management. Add information annually and begin more detailed analysis of records to refine the site-specific nutrient manage-ment plan. Even though the detail level of different data sets varies, each field point can be associated with each data set if all records are properly geo-referenced. As technology improves, some data sets can be replaced with more accurate or more detailed data sets for the same parameters. Be objective Yield goals should be realistic and profitable, but also progressive. Every field should have a nutrient management plan that integrates information from all sources of data available for the farm. The plan should integrate specific experience, preferences, and goals of the grower. Assessment of potential environmental impact and compliance with applicable regulations should be a part of the plan. Write plans in detail with appropriate supporting records. Include credits for previous crops, manure, sludge, or industrial by-product applications. Consider all nutrient resources and select the best combination for each field. Good nutrition may be expensive, but inadequate nutrition can be even more costly through lost yields and profits! Master producer A sterling example of what proper nutrition and farm management can do for crop yields and profits is the late Herman Warsaw of Saybrook, Illinois. Figure 3. World record yields of Herman Warsaw. In 1985, corn yields for the entire Warsaw farm averaged about 200 bu/A. Warsaw stated at the time that the higher yields per acre helped to reduce the cost of each bushel produced. Included in the averaging was a test plot where yields averaged 370 bu/A--- a world record (Figure 3). A profile of Warsaw's 1985 soil test showed: P at 161 lbs/A, K at 800 lbs/A, Mg at 8.71 lbs/A, Ca at 4.850 lbs/A, CEC 23, 5 at 35 ppm, pH 6.0, organic matter 5.3%, and zinc, iron, boron and copper all "good." The secret to Warsaw's success? His plan was designed for a specific soil, climate, and management system. In other words, his plan was site specific, even though he didn't have access to the computer and satellite technology we have available today. He did the right things for the right reasons in the right place at the right time. It is a concept that fits anywhere in the world! Moving toward 2000 As we move toward the new century, we have a developing technology that offers limitless opportunities. The grower can reach new yield plateaus. Agronomists can provide continuing education, information for growth of knowledge, interdisciplinary research, and personal professional development. It's a great time to be an agronomist! Should you wait? Well, remember. Most profit from new technology or practices comes to the early adopters! Are there hurdles? Oh yes. Lack of research on interactions (correlation among layers of GIS) is one. Shortages of trained agronomists (continuing education, etc.) is another. There's also a need for long-term commitments. But overall, the picture is optimistic. As the technology advances, it is important we remember that site- specific management is not designed to remove variability in field nutrient levels. Rather it is designed to capitalize on inherent variability and build soil tests in more productive areas of fields and reduce fertilizer application in less productive areas. Ultimately, that should lead to the most agronomically sound, economically efficient, profitable, and environmentally responsible nutrient management plan for each field. Dr. Reetz is Midwest director for the Potash & Phosphate Institute.
Fluid Journal 1993-1995
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