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Alternative Farming Systems Information Center of the National Agricultural Library
Agricultural Research Service, U.S. Department of Agriculture

Precision Farming

Agritopics Series no. AT 95-01

Compiled by:
Bonnie Emmert, Water Quality Information Center
Jane Gates, Alternative Farming Systems Information Center
Joe Makuch, Water Quality Information Center

Information Research Services Branch
National Agricultural Library
Agricultural Research Service
U.S. Department of Agriculture

December 1994

 TITLE: Precision Farming
 PUBLICATION DATE:  December 1994
 ENTRY DATE:  April 1995
 CONTACT:  Jane Gates
           Alternative Farming Systems Information Center
           National Agricultural Library
           Room 123, 10301 Baltimore Ave.
           Beltsville, MD  20705-2351
           Telephone:  (301) 504-6559
           FAX:  (301) 504-6409
 DOCUMENT SIZE:  26k (12 pages)
                                                   ISSN:  1052-2255
 United States Department of Agriculture
 National Agricultural Library
 10301 Baltimore Blvd.
 Beltsville, Maryland  20705-2351
 Precision Farming
 Agri-Topics:  AT 95-01
 Compiled by:  Bonnie Emmert, Water Quality Information Center
               Jane Gates, Alternative Farming Systems Information Center
               Joe Makuch, Water Quality Information Center
 Special thanks to:
   Kenneth Sudduth, Agricultural Research Service,
   for his helpful comments in reviewing this publication.
 December 1994 
National Agricultural Library Cataloging Record:
 Emmert, Bonnie 
   Precision farming.
   (Agri-topics ; 95-01)
   1. Precision farming--Bibliography. I. Gates, Jane Potter.  
 II.  Makuch, Joe.  III. Title.
 aZ5073.A37 no.95-01

 Precision Farming
 This publication is a brief guide to information about "precision
 farming" a means of growing crops by making more efficient use of
 inputs such as fertilizers and pesticides.  Other terms for
 precision farming include:  prescription farming, prescription
 agriculture, site-specific farming and site-specific crop
 management.  The expected benefits of precision farming include
 increased farm profits with less possibility of environmental
 damage from agricultural operations.
 Crop management decisions are typically made on a field-by-field
 basis, i.e., entire fields are treated as if they were one
 homogeneous unit.  But soil characteristics (pH, texture, organic
 matter) and other factors such as moisture conditions or weed
 problems may vary considerably within a given field.  Instead of
 managing an entire field based upon some hypothetical average
 condition, which may not exist anywhere in the field, a precision
 farming approach recognizes site-specific differences within fields
 and adjusts management actions accordingly.  For example, based on
 extensive soil testing, different locations within a field may
 receive different amounts of fertilizer.
 Technological advancements make precision farming easier.  Smaller,
 faster, less expensive computers are of critical importance in
 gathering, analyzing, and acting upon information about soils and
 growing conditions in a timely manner.  Soil sensors, variable rate
 applicators, on-the-go yield monitors, and global positioning
 systems (GPS) that use satellite technology to identify specific
 locations within fields are the high-tech tools of the precision
 What's Here
 The articles listed in this publication are from newspapers, the
 scientific literature, and the farm press, and are intended,
 collectively, to give an overview of precision farming.  The
 listing of research projects comes from the United States
 Department of Agriculture's Current Research Information System
 (CRIS) database and serves to acquaint the reader with publicly
 funded research efforts involving precision farming.  
 The inclusion or omission of a citation should not be construed as
 endorsement or disapproval.  Please contact your local, state or
 university library to access the publications.  If unable to locate
 the desired publication, your library can contact the National
 Agricultural Library (NAL). 
 Who We Are
 The Water Quality Information Center (WQIC) and the Alternative
 Farming Systems Information Center (AFSIC) are two of eleven
 centers located at the NAL.  Centers provide in-depth coverage of
 specific subject areas relating to the food and agricultural
 sciences.  Areas of interest between centers frequently overlap, as
 they do in this instance on the subject of precision farming:  WQIC
 is concerned with the relationship between agricultural activities
 and the quality of surface water and groundwater.  AFSIC focuses on
 alternative farming systems that employ methods of farming
 sustainably which protect natural resources while maintaining
 agricultural productivity and profitability. 
 Copies of this and other publications on related subjects are
 available at no charge from either center.  Contact:
 Alternative Farming Systems Information Center
 National Agricultural Library
 10301 Baltimore Blvd., Beltsville Md  20705-2351
  phone 301/504-6559; Fax 301/504-6409
 Water Quality Information Center
 National Agricultural Library
 10301 Baltimore Blvd., Beltsville Md  20705-2351
 Phone 301/504-6077; Fax 301/504-7098
 Internet wqic@nalusdagov
 Agriculture is Reaping the Rewards of Computers
 Johnson, Lori Beckman
 PC Today p. 64-69 (April 1991)
   Computers have a wide variety of uses on farms, from accounting to
 controlling the application of nitrate.
 Area Co-op Tries Focused Fertilizing
 LeDuc, Doug.
 The News-Sentinel, August 30, 1993.  Business Monday, p. 13B
   Cooperating with Purdue University researchers, an Indiana
 agricultural cooperative participates in DeKalb Agra's Variable
 Rate Technology Program.
 Combines with Senses
 Mowitz, Dave
 Successful Farming v. 91 (11):  p. 24-25  (November 1993)
 NAL Call No:  6 S412
   Combines can now be equipped with electronic sensors that weigh
 yields on-the-go or at unloading. 
 Directed Sprayer for Targeting Pesticides
 Morrison, J. E. & Chandler, J. M. 
 Weed Technology v. 6 (2):  p. 441-444 (April-June 1992)
 NAL Call No:  SB610 W39
   Experimental directed sprayer design improvements that deliver
 pesticides to targets at minimum application rates.
 Effects of Spatial Variability of Nitrogen, Moisture, and Weeds on
 the Advantages of Site-  specific Applications of Wheat
 Chancellor, W. J, & Goronea, M. A.
 Transactions of the ASAE 37(3): p.717-724  (1994)
 NAL Call No: 290.9 Am32T
   Evaluates the major differences between spatially determined
 applications and conventional blanket applications of water,
 nitrogen, and herbicide on irrigated winter wheat.  Considers the
 variable efficacy of the site-specific method for short- and
 long-term intervals.
 Environmentally Sound Agricultural Production Systems Through
 Site-Specific Farming 
 Engel, B.A. & Gaultney, L.D.
 Paper-American Society of Agricultural Engineers (90-2566) (Winter
 1990) St. Joseph, MI:  The Society
 NAL Call No:  290.9 AM32P
   Examines site-specific or prescription farming for reducing
 environmental impacts and describes a prescription-farmed field
 Farm by the Foot
 Reichenberger, Larry & Russnogle, John  
 Farm Journal v. 113(6):  p. 11-15 (Mid-March 1989)
 NAL Call No:  6 F2212
   Growers can increase profits by tailoring fertilizer applications
 to soil types.
 Farmers Find GPS Useful Management Tool
 Stock, Elaine
 Farmweek v. 22 (19):  p. 6  (May 9, 1994)
   Global positioning systems (GPS) provide farmers with the ability
 to monitor an exact spot in a field for yields, soil type,
 fertility and chemical problems. Farmers can use these data to
 apply inputs where they are needed.
 Farming Soils, Not Fields: A Strategy for Increasing Fertilizer
 Carr, P. M., Carlson, G. R., Jacobsen, J. S., Nielsen, G. A. &
 Skogley, E. O.
 Journal of Production Agriculture 4(1): p.57-61
 NAL Call No: S539.5 J68, 1991.
   Compares crop yields produced by different soils within fields and
 the economic consequences of using soil-specific applications of
 fertilizer vs. conventional uniform applications.  Generally,
 results indicate potential for increasing fertilizer profitability
 by using the soil-specific method.
 Farming Takes on New Computer Technology 
 Wall, Robin 
 Christian Science Monitor, November 30, 1993.  Economy p. 8
   Examines an agricultural vehicle of the next decade which adopts
 new methods and technologies such as a satellite dish, sensors,
 lasers, and a computer.
 Field Navigation Using the Global Positioning System (GPS)
 Larsen, W.E., Tyler, D.A & Nielsen, G.A.  
 American Society of Agricultural Engineers Microfiche Collection 10
 pp. ill.(fiche no  88-1604) (1988)  St. Joseph, MI:  The Society. 
 NAL Call No:  FICHE S 72
   Describes technology needed for prescription farming.
 Field-Testing the Smart Box
 Holmberg, Mike
 Successful Farming v. 91 (8):  p. 38 (August 1993)
 NAL Call No:  6 SU12
   Technology for the precise application of insecticide granules. 
 Fine-Tuning Agricultural Inputs
 Cooke, Linda 
 Agricultural Research  v. 41 (1):  p. 16-18 (January 1993)
 NAL Call No:  1.98 Ag84
   Prescription farming increases production efficiency and reduces
 potential for water contamination.  Discusses sensors and yield
 variability measurement.
 Harvesting From the Heavens/Farmers Embrace the Computer Age
 Chicago Tribune
 Sacramento Bee, November 26, 1993.  Business, p. B8
   Computers move into the farm fields to launch variable rate
 application of pesticides and fertilizers, and satellite mapping
 for farmland using global positioning systems.
 Herbicide Application to Targeted Patches 
 Miller, P. C. H. & Stafford, J. V. 
 Brighton Crop Protection Conference Weeds v. 3:  p. 1249-1256
 NAL Call No:  SB610.2.B74
   Describes concept for targeting herbicide application to weed
 patches in arable crops so that sprays can be applied only to
 detected patches.
 High Tech is Fertile Ground for Farmers   
 Goering, Laurie
 Chicago Tribune, November 7, 1993. Business, p.1
   Farm equipment outfitted with personal computers, optic-sensors,
 and satellite receivers combines with variable application of
 fertilizers, pesticides, and other inputs.  
 How Much and Where  
 Goering, Carroll E.
 Agricultural Engineering v. 73 (4):  p. 13-15 (July 1992)
 NAL Call No:  58.8 Ag83
   Technical advances make site-specific crop management feasible.
 How Much Fertilizer?  The Satellite Sees All  
 Uhlenbrock, Tom
 St. Louis Post Dispatch, November 8, 1992. News p. 1A
   Ken Gilmore, manager of the prescription farming program for the
 Space Remote Sensing Center, Stennis Space Center, explains the
 application of remote sensing technology on an Oran, Missouri farm.
 In Ohio's Maumee River Valley Precision Put to Test 
 Wanzel, Robert J.
 Dealer Progress v. 25(1):  p. I4-I5, I14 (January 1994)
 NAL Call No:  S631 F44
   Experiences of twelve fertilizer dealers involved in the  Maumee
 Valley Prescription Farming Feasibility Project.
 Index for Describing Spatial Variability in Prescription Farming 
 McCauley, J. D. & Whittaker, A. D. 
 Transactions of the ASAE v. 36 (3):  p. 691-693 (May-June 1993)
 NAL Call No:  290.9 AM32T
   Presents a scalar descriptor of the spatial variability of
 fertilizer application maps with regard to the difficulty an
 applicator may have in matching prescribed rates for site-specific
 Influence of Fertilizer Application Nonuniformity on Crop Response
 Ndiaye, J. P. & Yost, R. S.
 Soil Science Society of America Journal 53: p.1872-1878 (1989) 
 NAL Call No: 56.9 So3
   Examines variable applications of potassium fertilizer in field
 areas with potassium deficient soil.  Using cabbage as an indicator
 crop, results showed that nonuniform fertilizer distribution
 decreased maximum yields about 9.5% 
 Mapping and Cumulative Distribution Function (CDF) as Alternative
 Methods to Address Variability in Soil Test Results
 Beverly, R. B., Hoogenboom, G., Shuman, L. M., & Tollner, E. W.
 Communications in Soil Science and Plant Analysis v. 25 (7&8):  p.
 1057-1070 (1994)
   This case study from field plots in Georgia looks at soil testing
 aspects of precision nutrient management.  The study compares
 strategies for addressing spatial and statistical variability in
 soil characteristics using currently available technology.
 Mapping of Spatially Variable Yield During Grain Combining
 Searcy, S. W., Schueller, J. K., Bae, Y. H., Borgelt, S. C. &
 Stout, B. A.
 Transactions of the ASAE 32(3): p.826-829 (1989)
 NAL Call No: 290.9 Am32T
   A data acquisition system, consisting of a grain flowmeter and
 location detection sensor, was mounted on a combine and used to
 generate grain yield maps that indicated field-site variations. 
 Describes method of analysis used to produce these maps.
 Military Satellites Lock onto Farm Targets
 Keller, Des
 Progressive Farmer v. 108 (10): p.  24-25 (October 1993)
 NAL Call No:  S1 P74
   Satellite positioning technology, on-the-go yield monitors,
 variable rate fertilizer applicators, and sophisticated computer
 programs are making prescription farming a reality.
 New Technology Out of this World - Literally
 Stock, Elaine
 Farmweek v. 22 (19):  p. 6  (May 9, 1994)
   Satellite and computer technology allows farmers to precisely map
 their fields to show variations in nutrient needs, crop yields and
 other data. These very specific data are then used to tailor the
 amount of inputs applied to each part of a field.
 Precision Farming:  Soil Sensors Reduce the Use of Fertilizer for
 The Futurist v. 27:  p. 56 (November-December 1993)
   Electronic sensors measure organic matter and moisture in soil.
 Precision Farming Series (93-ARS-29)
 USDA Research Reports Vidiocassette (VHS; 11 minutes) (1993)
 NAL cataloging in process
   This film consists of five short clips: Introduction, Global
 Positioning Systems (GPS), Remote Sensing, Geographic Information
 Systems (GIS), and Variable Rate Technology (VRT).  For copies or
 more information, contact USDA-ARS Information, Room 456, 6303 Ivy
 Lane, Greenbelt, MD 20770.
 Preparing for the Future Farm
 Krutz, Gary
 Conservation Impact v. 12 (9): p. 1 (October 1994)
 NAL Call No: S604 C66
   The lead article of an issue devoted to precision farming
 technology.  This article examines a prototype vehicle developed at
 Purdue University.  Other articles discuss GIS, GPS and VRT.
 Prescription Farming Based on Soil Property Sensors  
 Gaultney, Larry D. 
 Paper-American Society of Agricultural Engineers (89-1036) (1989),
 St. Joseph, MI:  The Society
   Prescription farming will improve profitability and potentially
 reduce agricultural pollution.  Soil property sensors provide the
 A Prototype Design of a Computer-Controlled Spreader System for
 Prescription Farming Technology
 Tsui, Tak-Lap & Smith, Donald A.
 Proceedings of the North Dakota Academy of Science  v. 46:  p. 64
 (April 1992), Grand Forks, ND:  The Academy   
 NAL Call No:  500 N813
   A database system; knowledge-based system; micro-controller; and
 location sensing system are four parts of a computer-controlled
 prescription farming system.
 Recycling a Concept
 Goering, Carroll E.  
 Agricultural Engineering v. 74 (6):  p. 25 (November 1993)
 NAL Call No:  58.8 Ag83
   Site-Specific Crop Management (SSCM) surfaces again because of
 technological advances and environmental awareness.
 A Review and Integrating Analysis of Spatially-Variable Control of
 Crop Production
 Schueller, John K.
 Fertilizer Research 33: p.1-34 (1992)
 NAL Call No: S631 F422
   Reviews research and development in managing and controlling crop
 production by examining the variability of components within each
 field, such as soils, crops, and pests.  Considers advances in
 various technologies that contribute to this type of sensitive
 analysis. Uses both conventional scientific and non-traditional
 An Rx for Tailor-Made Fertilizers:  Farmers Could Get Prescriptions
 for Their Fields
 Gertz, Deborah
 Quincy Herald-Whig, April 4, 1993.  Business Extra, p. 8
   Farmers could prescribe tailor-made field fertilizer and chemical
 applications using satellite, infrared sensor and on-tractor
 computer technology. 
 Selling Precision at DeKalb Agra...Their Future is Now  
 Wanzel, Robert J.  
 Dealer Progress v. 25(1):  p. I10-I13 (January 1994)
 NAL Call No:  S631 F44
   Technology and techniques utilized by one commercial entity to
 achieve precision farming.
 Sensors, Software and Satellites May Hold Seeds of Better Yields 
 Sugarman, Carole
 The Washington Post, September 7, 1992.  A Section, p. a03
   Satellite farming utilizes global positioning systems and other
 technology to customize agricultural chemical application rates.
 Soil Organic Matter, CEC and Moisture Sensing with a Portable NIR
 Sudduth, K. A, & Hummel, J.W.
 Transactions of the ASAE 36(6): p.1571-1582 (1993)
 NAL Call No: 290.9 Am32T
   Evaluates the accuracy of soil reflectance data gathered with a
 portable spectrophotometer by comparing results with standard
 laboratory analyses.  Movement of soil past the sensor during
 sample collection contributed to a higher error rate for the
 Soil Specific Crop Management:  Proceedings of a Workshop on
 Research and Development Issues, Minneapolis, MN, April 14-16, 1992
 Robert, P. C., Rust, R. H. & Larson, W. E. (ed.)
 Soil Society of America, Inc., Madison, WI 
 NAL Call No:  S596.7 P76 1993
   Conference proceedings with forty-three papers covering a variety
 of topics related to precision farming.  Papers are grouped under
 these section headings:  soil resources variability, managing
 variability, engineering technology, profitability, environment,
 and technology transfer.  Also included is a list of participants. 
 Spectroscopic Sensing of Soil Organic Matter Content
 Shonk, J. L., Gualtney, L. D., Schulze, D. G, & Van Scoyoc G. E., 
 Transactions of the ASAE 34(5): p.1978-1984 (1991)
 NAL Call No: 290.9 Am32T
   Evaluates the effectiveness of a sensor to determine the
 composition of organic matter in soil.  Tests indicate the sensor
 is likely to be useful for prescription application of chemicals. 
 Variable Fertilizer Application Based on Yield Goal, Soil
 Fertility, and Soil Map Unit
 Wibawa, Winny D., Dludlu, Duduzile L., Swenson, Larry, J., Hopkins,
 David G. & Dahnke, William, C.
 Journal of Production Agriculture 6(2): p.255-2611(1993)
 NAL Call No: S539.5 J68
   Examines how fertilizer treatment can be adjusted to meet the
 variable conditions within fields.  Differences in soil fertility
 were determined by preparing grid patterns and soil maps based on
 soil samples for each of several eastern North Dakota fields.
 consisting mainly of Haploborols, Calciaquolls, Argialbolls.  
 Wheat and barley were grown.  Determined that fertilizer
 variability using the sampling method increased yields but the
 increased cost of using this method resulted in a lower net return.
 Variable Rate Fluid Technology Arrives for Dealers
 Peitscher, Alissa
 Solutions v. 36 (5):  p. 31-34 (July/August 1992)
 NAL Call No:  57.8 SO4
   Describes variable rate technology, which offers prescription
 application of fluid fertilizers and crop protection chemicals.
 Varying Fertilizer Applications within a Field
 Buchholz, Daryl D. & Wollenhaupt, Nyle C. 
 Better Crops v. 72 (2):  p. 12-13 (Spring 1990)
 NAL Call No:  6 B46.
   Missouri researchers have found major benefits to managing
 fertilizer applications.  Systems that do this can be termed
 prescription farming.  
 Yield Determination Using a Pivoted Auger Flow Sensor
 Wagner, L. E. & Schrock, M. D.
 Transactions of the ASAE 32(2): p.409-413 (1989)
 NAL Call No: 290.9 Am32T
   Evaluates the use of a grain flow sensor, mounted on a combine, to
 determine yield variations of wheat and sorghum within a field. 
 Examines factors that could influence sensor accuracy, such as
 vibration, vehicle motion, time lag of grain conveyance through the
 combine, and unsteady flow rates.
 This section lists examples of precision farming research projects
 entered on the Current Research Information System (CRIS) database. 
 CRIS is the U. S. Department of Agriculture's electronic
 documentation and reporting system for publicly funded agricultural
 and forestry research.  
 Applying and Recording Agricultural Chemicals Simultaneously via
 Computer Control
 Project No.  SD00189
 To ensure safety plus enhance productivity, applied chemicals for
 crop production need to be feasibly utilized with as much control
 as possible. A machinery system (both hardware and software) is
 being designed to control and adjust the release of pesticides so
 that the on-the-go applied delivery corresponds to the soil
 environment.  A laptop microcomputer (positioned within the tractor
 cab) is the main component and provides simplicity, reliability and
 establishes the capability to record and maintain a chemical-field
  Froelich, D. P., Klosterman, T. & Alcock, R. 
 Agricultural Engineering 
 South Dakota State University 
 Brookings, South Dakota  57007 
 Project Duration:   10/4/89-9/30/93
 Engineering Systems for Field and Vegetable Crop Production
 Project No.  CA-D-AER-5468-H
 The objective of this project is to develop efficient and
 sustainable production systems for field and vegetable crops to:
 reduce soil compaction, energy use and dust generation; enhance
 residue utilization and management; accommodate nonchemical pest
 control alternatives; enhance product quality; allow site specific
 application of inputs, such as pesticides, fertilizers or water. 
 Studer, H. E., Chancellor, W. J. & Garrett, R. E. 
 Agricultural Engineering
 University of California
 Davis, CA  95616
 Project Duration:   8/21/91-9/30/96
 Engineering Systems for Spatially Variable Agricultural Production 
 Project No.  TEX06745
 (1) To develop a computer based system that can obtain data,
 analyze that data and implement management practices on small area
 production units.  (2) To determine the nature of variability of
 parameters affecting agronomic productivity on a spatial basis and
 to determine the economic impact of that variability. 
 Searcy, S. W., Whittaker, A. D. & Coble, C. G.
 Agricultural Engineering
 Texas A&M University 
 College Station, Texas 77843 
 Project Duration:   3/29/91-3/28/96
 Remote Sensing and Associated Technology Transfer to Production
 Project No.  1270-66000-011-03S
 Develop remote sensing based products in cooperation with
 Agricultural Research Service scientists and users that are most
 appropriate for agriculture production management decisions. 
 Assist users in independently evaluating cost effective use.
 Hart, G. F. & May, G. A.
 Institute for Technical Development
 Stennis Space Center, Mississippi  39520
 Project Duration:   9/1/93-8/31/95
 Remote Sensing Laboratory:  Remote Sensing of Agricultural and
 Natural Resources
 Project No.  MIN-40-016 
 The overall project goal is to advance the development and
 application of remote sensing and geographic information systems
 (GIS) in agricultural and natural resource inventory and
 management. The major objectives are: develop a quantitative
 understanding of the relationships of spectral-radiometric
 properties of vegetation and soil to biophysical characteristics;
 and research and develop analysis techniques and capabilities that
 will enable resource managers in Minnesota to effectively utilize
 remote sensing and GIS. 
 Bauer, M. E. & Martin,R.D.
 Natural Resources
 University of Minnesota
 St Paul, Minnesota  55108 
 Project Duration:   7/1/89-6/30/94
 Sensing and Control Technology to Optimize Cropping System Inputs
 Project No.  3622-21000-006-00D
 Establish methods and develop instrumentation for sensing organic
 carbon, depth to clay layer, and other agronomic properties
 important in spatially variable cropping systems management. 
 Develop integrated agrichemical application systems utilizing soil
 and crop spatial data as basis for variable application rate
 control. Assess performance of sensors, application systems, and
 techniques in field evaluations.  
 Sudduth, K. A 
 Agricultural Research Service 
 Columbia, Missouri  65211 
 Project Duration:  10/1/90-9/30/95
 Sensors for Measuring Physical and Chemical Properties of
 Agricultural Materials
 Project No.  IND046056 
 The general objective is to develop reliable methods for sensing
 important physical and chemical properties of agricultural
 materials, particularly grain and soil. The adaptation of these
 sensors for use with real-time process control systems on
 agricultural equipment will be a high priority consideration. 
 Special attention will be given to developing equipment suitable
 for prescription application of pesticides. 
 Gaultney, L. D 
 Agricultural Engineering
 Purdue University
 West Lafayette, Indiana 47907
 Project Duration:  10/1/90-9/30/95
 Spatial Variability of Crop Production Variables
 Project No. ILLU-10-0339
 Investigate alternative navigation systems, then select and
 obtain a system for use in building a Geographic Information
 System (GIS).   Investigate alternative possible organizations
 of geographic information systems and begin to develop a system
 structure suitable for midwest agricultural production.
 Goering, C.E., Reid, J.F. & Hummel, J.W.
 Agricultural Engineering 
 University of Illinois
 Urbana, Illinois  61801
 Project Duration:  10/1/89 - 9/30/94
 Use of Global Positioning System in Production Agriculture
 Project No. NEB-11-094
 The overall objective of this research effort will be to utilize
 GPS as a tool to provide site-specific location:  (1) integrate
 computer, GPS receiver and signal conditioning equipment so
 that sensitivity and reliability can be evaluated (2) develop
 hardware and software to measure seed crop yield and location
 within a field (3) develop a system for using fertilizers or
 pesticide based on site-specific requirements.
 Bashford, L.L.
 Biological Systems Engineering
 University of Nebraska
 Lincoln, ND  68583
 Project Duration:  9/3/92-8/31/97
 Variable Rate Crop Management System
 Project No. 3611-12220-001-02S
 Assess the potential impact of variable rate crop management
 on improving water quality.
 Hummel, J.W., Goering, C.E. & Wax, L.M.
 Illinois Agricultural Experiment Station
 Urbana, Illinois  61801
 Project Duration:  5/20/93-4/30/96

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December 1994