Bioresource and Agricultural Engineering Commons^™

Sensors For Site-Specific Management, Stuart J. Birrell, J. W. Hummel, K. A. Sudduth

Stuart J. Birrell

Site-specific management (SSM, also known as precision farming, precision agriculture, prescription farming, etc.) is a management strategy that seeks to address within-field variability and to optimize inputs such as pesticides and fertilizers on a point-by-point basis within a field. By reducing over-application and under-application of nutrients and pesticides, this strategy has the potential to improve profitability for the producer and also to reduce the threat of groundwater or surface water contamination from agrichemicals. SSM is being adopted by innovative producers across the country. Agricultural equipment manufacturers, farm input suppliers, and a host of other businesses are working along with publicsector …

Comparison Of Sensors And Techniques For Crop Yield Mapping, Stuart J. Birrell, Kenneth A. Sudduth, Steven C. Borgett

Stuart J. Birrell

The implementation of site-specific crop management is dependent on the variations in yield and yield potential within a field. Crop yield maps are important for both the implementation and evaluation of site-specific crop management strategies. Management decisions and evaluations based on yield maps must take into consideration the accuracy and resolution of the maps.

An impact-based yield monitor and a volumetric yield monitor were compared. The effect of different dynamic models of combine grain flow on the calculated instantaneous yields were investigated. Both simple time delay models and first order models could be used to model the grain flow. In …

Evaluation Of Gps For Applications In Precision Agriculture, Steven C. Borgelt, John D. Harrison, Kenneth A. Sudduth, Stuart J. Birrell

Stuart J. Birrell

Location coordinate information is needed in precision agriculture to map in-field variability, and to serve as a control input for variable rate application. Differential global positioning system (DGPS) measurement techniques were compared with other independent data sources for sample point location and combine yield mapping operations. Sample point location could be determined to within 1 m (3 ft) 2dRMS using C/A code processing techniques and data from a high-performance GPS receiver. Higher accuracies could be obtained with carrier phase kinematic positioning methods, but this required more time and was a less robust technique with a greater potential for data acquisition …

Nutrient Mapping Implications Of Short-Range Variability, Stuart J. Birrell

Stuart J. Birrell

Successful site specific nutrient application depends on accurate soil nutrient maps, which are generally developed from grid samples. The implication of short range variability for soil nutrient mapping is investigated. Interpretation of soil nutrient maps must consider the level of confidence associated with estimated values.

Analysis Of Spatial Factors Influencing Crop Yield, K. A. Sudduth, S. T. Drummond, Stuart J. Birrell, N. R. Kitchen

Stuart J. Birrell

The spatial relationship between crop yields and soil and site parameters was modeled using several methods. Yield maps estimated by projection pursuit regression and neural network analysis agreed well with measured yields. These methods also allowed generation of response curves for estimated yield as a function of each of the input parameters. These response curves were useful for investigating the relationship between yields and individual soil and site parameters.

Missouri Precision Agriculture, N. R. Kitchen, K. A. Sudduth, Stuart J. Birrell, S. C. Borgelt

Stuart J. Birrell

A number of projects related to different facets of precision agriculture are being carried out by an interdisciplinary team of scientists and engineers with the University of Missouri and the USDA Agricultural Research Service. This paper provides an overview of those projects.

Crop Yield Mapping: Comparison Of Yield Monitors And Mapping Techniques, Stuart J. Birrell, Steven C. Borgelt, Kenneth A. Sudduth

Stuart J. Birrell

Although the variability in soil nutrients and crop yields has been well documented since the turn of the century (Robinson & Lloyd, 1915; Fairfield Smith, 1938), the mechanization of agriculture and the trend to larger implements has led to larger areas being treated as a single unit. Recent advances, however, in machine technology and improvements in data management have made it possible to reverse this trend by implementing site specific crop management (Goering, 1993).

Comparison Of Variable Rate To Single Rate Nitrogen Fertilizer Application: Corn Production And Residual Soil No3-N, N. R. Kitchen, D. F. Hughes, K. A. Sudduth, Stuart J. Birrell

Stuart J. Birrell

The questions most often asked by farmers when discussing variable rate (VR) fertilizer inputs are "How much will it cost?" and "How will it affect my yields?" Many farmers and custom application services share a reluctance to invest in the time and technology required for variable fertilizer application since studies to answer these questions are few and results have been inconsistent.

Technical Notes: Bidirectional Serial-To-Parallel Converter For Data Acquisition And Control, Stuart J. Birrell, Scott T. Drummond, Kenneth A. Sudduth

Stuart J. Birrell

A bidirectional serial-to-parallel converter was created to allow collection of serial data through the parallel port on a portable laptop computer. The converter consisted of both hardware conversion circuitry and control software. The converter supported both input and output at a variety of transmission formats and adjustable transmission rates. The control software made use of the various I/O registers of the parallel port to collect data and control the hardware circuitry.

Multi-Isfet Sensors For Soil Nitrate Analysis, Stuart J. Birrell, John W. Hummel

Stuart J. Birrell

The management of a field as a heterogeneous area is now being investigated by many researchers in universities, companies, and research institutions. However, for site-specific application of inputs, it is necessary to develop systems to sense the variation of important properties in real time. Several studies have shown that ion selective electrodes can be used to measure soil nitrates. This work involves an investigation in the use of Ion Selective Field Effect Transistors (ISFETs), to measure soil nitrate levels.

Electrically Erasable Programmable Logic Devices As An Aid For Teaching Digital Electronics, Nelson L. Buck, Kenneth A. Sudduth, Stuart J. Birrell

Stuart J. Birrell

Electrically erasable programmable logic devices (PLDs) are digital circuit components which can be programmed to perform complex logic functions. Agricultural engineering students designed circuits using PLDs and programmed and tested them as part of a class exercise in logic circuit design. The devices were erased at the end of the semester for use by the next class. Because the lab assignment required the students to master several new concepts at once, they experienced some initial difficulties; however, they enjoyed the assignment and learned the material well.