Fertilizing Based On Soil Testing and Sensor Technology.

Plant nutrient management based on soil testing and input cost is important to farming profit and environmental quality protection. An interactive web-based computer program was developed to make sound decisions on fertilizer application considering commodity and fertilizer prices. This program can be accessed at: http://www.soiltesting.okstate.edu under Soil Test Interpretation or run on a stand-alone program for PC if access to the web is not available. This decision support system allows users to obtain fertilizer recommendation based on soil test results and crop nutrient needs, to calculate the amount of fertilizers to reach the potential yield goal.  In addition to provide soil test interpretation, the program can be used to estimate the yield and economic return from a user-specified fertilization practice, and can be used to compare the options based on commodity prices, fertilizer costs, and the amount of fertilizer a producer is willing to apply. If animal manure is used to supply nutrients, the amount of manure is also provided based either on crop nitrogen or phosphorus requirement. The unit price of plant nutrients from commercial fertilizers and the nutrient value of animal manure can be calculated easily. This program is based on fertilizer calibrations conducted in Oklahoma but it can be revised for other sates or other regions of the world. More precise nitrogen recommendation can be obtained by implementing an N-rich strip and sensing data. Rates of top dress N and gross return are calculated at http://www.soiltesting.okstate.edu/SBNRC/SBNRC.php.
These decision support tools make nutrient management more accurate than any other manual methods.