REAL-TIME MULTI-ISFET/FIA SYSTEM WITH AUTOMATIC SOIL SAMPLE EXTRACTION

Authors: BIRRELL, STUART - IOWA STATE UNIV; Hummel, John

Submitted to: Computers and Electronics in Agriculture
Publication Type: Abstract Only
Publication Acceptance Date: 10/5/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Successful implementation of the Site-Specific Management (SSM) concept relies on accurate quantification of the spatial variation of important soil factors. There is a tremendous need for the development of sensing technologies that will allow automated collection of soil crop, and pest data. The full benefit of SSM will only be realized if the spatial variation across the field is accurately determined. Data collection on a finer spatial resolution than is feasible with manual and/or laboratory methods is often required to document spatial variability, but cost prohibitive. Therefore, there is a need for the development of sensors to more accurately characterize within-field variability. Ion-Selective Field Effect Transistors (ISFETS) have inherent features such as small dimensions, low output impedance, high signal-to-noise ratio, low sample volumes, and the potential for mass production, which are all required fora real-time soil sensor. However, ISFETs have long-term drift, a disadvantage that is diminished by the use of a flow Injection Analysis (FIA) system. In fact, FIA and ISFETs are complementary since the small sample volume and rapid response of ISFETs allow the miniaturization of the FIA system, dramatically decreasing sample dispersion and thereby increasing both sample resolution and frequency. The objectives of this work were to integrate a multi-sensor ISFET chip with a (FIA) system for on-the-go soil nitrate monitoring, to determine if soil nitrates could be analyzed using real soil solutions, and to develop an automated soil extraction system.