AGRI-BRIEFS   AGRONOMIC NEWS ITEMS

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

Winter 1996, No. 4

Yield maps integrate all of the physical resources, biological factors, climate, and management into one illustration. They help show the variability of productivity of different parts of the field. The farmer can use the maps to discuss various sources of variability with the landlord and/or other advisers.

The real power of GIS comes when other data bases can be related to the yield map. Maps of soil test levels can help explain a nutrient problem...such as liming or phosphorus and potassium buildup needs. Matched with the yield maps, these nutrient maps also provide the basis for variable-rate application. Many non-farmer landowners appreciate the more scientific approach to nutrient management, and in some cases the maps can be used to help convince the landowner to invest in the buildup fertilizer as a capital investment.

Other data bases may help show the landlord the need to invest in improving the drainage system on the farm. Linking yield maps with soil survey and topographic maps can provide the basis for this decision.

In other cases, GIS maps and data bases can be used to document and graphically present results of management practice changes and help convince the landlord that the farmer is using good practices. Some farmers are developing a portfolio of maps and data and interpretations that they can use to help sell themselves to prospective landlords when they try to compete for rental land. Presenting a well-documented graphical management plan can be an excellent selling tool.

So besides being a good management practice, site-specific management systems can be a good marketing tool...for the farmer's skills as a manager. They may provide the extra competitive edge and can help build better working relationships with the landowner.