Author
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Hummel, John |
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PRICE, RANDY - UNIV OF ILLINOIS |
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Submitted to: Agronomy Day Program
Publication Type: Abstract Only Publication Acceptance Date: 7/18/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Site-Specific Crop Management (SSCM) was an exciting concept in 1929, when University of Illinois Agronomists C. M. Linsley and F. C. Bauer noted that, "The soils of this state, often within a single field, vary widely in their need for limestone," and "It is important, therefore, that systematic and detailed tests be made of the field so that limestone may be applied according to the need for it." Use of the concept waned over the years as fields and equipment became larger, but today, low-cost, powerful computers, real-time controllers, variable-rate application hardware, and accurate location systems have combined to again make SSCM an exciting concept. Measurement of soil constituents that affect plant growth is a basic task in SSCM. Grid sampling has been shown to produce accurate soil nutrient maps, but may be cost prohibitive in some instances. Selective soil sampling based on soil characteristics may be used, unless fertilizer usage has introduced large differences in nutrient levels. All of these techniques are based on sample collection and laboratory analysis to produce soil fertility maps. Frequently, the close-spaced sampling and analysis needed to adequately map spatial variability is cost prohibitive. On-the-go sensors could potentially reduce the costs while improving the accuracy of the data collection and mapping process. We are investigating ion selective field effect transistors (ISFETs) for on-the-go soil nutrient sensing. ISFETs, which are based on the same chemical principles as ion selective electrodes, can be used in a flow injection analysis (FIA) system to minimize the effects of drift and hysteresis and exploit the specific properties of the ISFETs. |
