This system consists of: - Automated soil sampler with packaging systems. - Automated work station for the analyses of the physical and chemical attributes of the sample including pH, organic matter, particle size, sesquioxides, carbonates and nutrient elements. - An expert system to consider the analytical results combined with data bases of crop models, fertilizers, chemicals, weather, field history, seed characteristics, yield results, economic criteria and other inputs. The system then uses dynamic simulation to forecast requirements of seeds, nutrients and chemicals. - An implementation system to determine the application program for the crop for seeds, nutrients and chemicals. - An automated applicator to carry out the program.

1. McGRATH DE, SKOTNIKOV AV and BOBROV VA. 1994. A
site-specific expert system with supporting equipment for crop
management. p. 619-635. In: Roberts PC et al. eds. Proc. Of site-
specific management for agricultural systems, march 27-30, 1994.
Amer. Soc. Of Agronomy.
A SITE SPECIFIC EXPERT SYSTEM
WITH SUPPOTING EQUIPMENT FOR CROP MANAGEMENT
D.E.McGrath, A.V.Skotnikov, V.A. Bobrov *
ABSTRACT
Many of the contemporary approacher in solving problems in Site Specific Crop
Management (SSCM) are based on existing or created zonal maps of filds based on soil types or
other charac- teristics. However, it is known that the chemical and physical attributes of soil can
change inside these zones and may overlap between zones.
A direct method of economically determining these attributes will contribute to the
development of SSCM. This concept has drawn significant attention.As a response to this
interest an au- tomated system of equipment, handware and software has been de- signed and
constructed.
This system consists of:
- Automated soil sampler with packaging systems.
- Automated work station for the analyses of the physical and chemical attributes of the
sample including pH, organic matter, particle size, sesquioxides, carbonates and nutrient
elements.
- An expert system to consider the analytical results combined with data bases of crop
models, fertilizers, chemicals, weather, field history, seed characteristics, yield results, economic
criteria and other inputs. The system then uses dynamic simulation to forecast requirements of
seeds, nutrients and chemicals.
- An implementation system to determine the application program for the crop for seeds,
nutrients and chemicals.
- An automated applicator to carry out the program.
The expert is designed to be self instructing. As data on results are accumulated algorithms
are modified to improve fore casting availability.
KEYWORDS. Site specific, Fertilizer, Seeding, Expert System.
INTRODUCTION
A major problem in site specific agriculture (also known as precision farming, site specific
management, etc.) has been the economical collection, correlation and processing of the data
necessary in order to automate the decision making and application of the appropriate nutrients.
Spatially variable maps such as the organic matter map (Gaultney et al., 1988, McGrath et
al., 1990, Alsip and Ellingson, 1991) may be used as an indicator of the approximate rate of
fertilizer to apply. Applicators have used USDA soil maps, grid sampling or other data as basis
for estimating fertilizer requirements.
However, it is know that the chemical and physical attributes of soil can change inside
these zones and may overlap between zones.

2. A direct method of economically determining these attributes contribute to the
development of SSCM. This concept has drawn significant attention.
Work done at the Institute of Experimental Botany of the Academy of Science of Belarus
has suggested a possible method of data collection, evaluation and decision making ABSTRACT
can be combined into a whole package consisting of an Expert System and support equipment. In
this work a complex study of the key factors and mechanism of the production process of plants
(taking into account the mechanical composition and fertility of soil) in accordance with the
methodology of the agro system simulation was done.
As a response to this interest automated equipment, hardware and software has been
designed and constructed.
RESEARCH OBJECTIVE
To develop an economically feasible system that incorporates the theoretical work done
optimizing production of field crops.
SUMMARY
The site specific expert system with supporting equipment de- signed to optimize product
capacity of a field for a given crop (SO) (See Figure 1) is a new approach. It is a complete
package designed by the TYLER firm and includes automated units consis- ting of:
- desktop computer (PC);
- packages of software programs (Fig.2-7);
- automated soil sampler (AS);
- automated workstation for sample analysis (AWAS);
- yield monitoring system (YMS);
- automated system for fertilizer and pesticides application
(ASFA);
- automated system for seed (ASR) variable rate planting.
┌────────┐ ╔════════════╗ ┌──────────────────┐ ┌──────────────────┐
┌┤Location├──────>║ Automatic ╟────┤ Cartrige with │ │Economic solution:│
││ system │ ^ ║soil sampler║ │ the soil samples │ │ - MAX profit │
│└────────┘ │ ╚════════════╝ └────────┬─────────┘ │ - MAX yields │
│ │ │ │ - MIN possible │
│ ┌───────┴──────────┐ ╔══════════════════V═══════╗ │ of applied │
│<──┤Field map with the├┐ ║ Automatic work station ║ │ fertilizer │
│ │program of motion ││ ║ for the analysis ║ └───────^──────────┘
│ └──────────────────┘│ ║ of soil samples ║ │
│ ┌─────────────┐ │ ╚═════════^════════════════╝ │
│ │Date base of ├>──┐ └────┐ │ ┌──────────────────────────┘
│ │field history│ │ │ │ │
│ └─────────────┘ │ ╔═V══════V══V══╗ ┌───────────────┐ ╔══════════╗
│ ┌──────────────┐ │ ║┌────────────┐╟──>┤Sowing program │ ║ Automated║
│ │Date base on ├>─┼───>╢│ ╔══╗ ╔══ │║ │( quantity & ├>─╢ system ║
│ │fertilizers │ │ ║│ ╠══╝ ║ │║ │ type of seed )│ ║ for seed ║
│ │and pesticides│ │ ║└─╨ ╚══──┘║ └───────────────┘ ║ variable ║
│ └──────────────┘ │ ╚══^═════╤═════╝ ║ rate ║
│ ┌─────────────┐ │ │ │ ┌───────────────────┐ ║ planting ║
│ │Prognosis of │ │ │ ├───>┤Application program│ ╚══════════╝
│ │the provision├─>─┘ │ │ │ of fertilizers │ ╔═══════════╗
│ │with heat and│ │ │ │ and pesticides ├──>╢Automated ║
│ │ moisture │ │ └──┐ └───────────────────┘ ║system for ║
│ └─────────────┘ ╔════════╧══════╗ │ ┌───────────────┐ ║fertilizers║
└───────────────────>╢ Yield monitor ║ └─>┤Quantity & type├─────>╢ and ║
╚═══════════════╝ │of fertilizers │ ║pesticides ║
│and pesticides │ ║application║
└───────────────┘ ╚═══════════╝
Fig. 1. Functional diagram of the expert system with supporting equipment

3. ┌─────────┐ ┌──────────┐ ┌──────────┐
│ Precipi-│ │ Air │ ┌ ─ ─│ Wind │
│ tation │──────────────┐ │ humidity │ | │ speed │
└─────────┘ │ └──────────┘ | └──────────┘
│ |
┌─────────┐ █▀▀▀▀▀▀▀▀▀▀▀▀▀█ │ /───────────┐ | ┌──────────┐
│ Irri- │ █ █ ││/ Evapotrans-│<── ─ ┘ │ Air tem- │
│ gation │───────>█ Soil █ │/│ piration │<── ─ ─ ─ ─│ perature │
└─────────┘ █ moisture █ │ ───────────┘ └──────────┘
█ █─────┘ ______ |
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ | / Plant |
/───────────┐ └ ─ ─ ─/develop.<── ─ ─┘
┌─────────┐ ││/ Vertical │ phases /
│ Ground │ │/│ flow │ ______/
│ water │<─────────────┘ ───────────┘
└─────────┘
Fig. 2. The model of soil moisture and yield
┌─────────────┐
│N in soil or-│<──────────────────────────────┐
│ganic matter │───────────────┐ ┌───────── │
│and organic │ ┌────────── │ │ Mineral.-│/│ ┌──────────┐
│fertilizers │─┐│Release of │/│ │ immobil. /││ │ Ammonium │
└─────────────┘ ││inorganic N/││ └─────────/ │ ┌────────────────┤ in preci-│
┌──────────── │└──────────/ │ │ pitation │
│Release of │/│ │ █▀▀▀▀▀▀▀▀▀▀▀▀▀█ ──── └──────────┘
│microbial N /││ └────>█ Plant █ /
└────────────/ └──────────────────>█ available █<─┬────/────█▀▀▀▀▀▀▀▀▀▀▀▀█
┌──────── ┌────█ ammonium █ │ / █ Nitrate and█
│Nitrifi- │/│ █ █ │ / █ ammonium in█
│ cation /││ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ │ / █ solid █
█▀▀▀▀▀▀▀▀▀▀▀▀▀█ └────────/ │ │ │ │ Dis- │ █ mineral █
█ Plant █<─────────────┘ │ │ │ sol- │ █ fertilizers█
█ available █───────────────────────────────┤ │ │ ving │ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀
█ nitrate █────┐ /─────────┐ ┌──────── │ │ └──────┘ │
█ █ ││/ Leaching │ │ Plants │/│ │ ┌────────────┤
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ │/│ │ │ uptake /││ │ │ ┌──────── │
│ ─────────┘ └────────/ │ │ │ Denitri-│/│
│ └────────────────────────────────────────┘ │ │ fication/││
└─────────────────────────>────────────────────────┘ └────────/
Fig. 3. Nitrogen submodel
┌─────────────┐
│P in soil or-│<──────────────────────────────┐ █▀▀▀▀▀▀▀▀▀▀▀▀█
│ganic matter │ ┌───────── │ █ P █
│and organic │───────────────┐ │ Mineral.-│/│ ──── █ in solid █
│fertilizers │ ┌────────── │ │ immobil. /││ / █ mineral █
└─────────────┘ │Release of │/│ └─────────/ │ ┌─────────/────█ fertilizers█
│ │inorganic P/││ │ │ / █ █
│ └──────────/ │ / ▀▀▀▀▀▀▀▀▀▀▀▀▀▀
│ /────────────┐ │ █▀▀▀▀▀▀▀▀▀▀▀▀▀█ /
││/ Release of │ └────>█ P █ │ Dis- │
│/│ microbial P │ █ in plant █ │ sol- │
│ ────────────┘ █ available █ │ ving │
└────────────────────────────────>█ form █ │ │ ┌──────────┐
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ / │ P │
┌───────── │ / │ in soil │
│ Plants │/│ └──────────/──────│ minerals │
│ uptake /││ / │ │
└─────────/ │ / └──────────┘
────
Fig. 4. Phosphorus submodel

4. ┌─────────────┐
│K in soil or-│<──────────────────────────────┐ █▀▀▀▀▀▀▀▀▀▀▀▀█
│ganic matter │ ┌───────── │ █ K █
│and organic │───────────────┐ │ Mineral.-│/│ ──── █ in solid █
│fertilizers │ ┌────────── │ │ immobil. /││ / █ mineral █
└─────────────┘ │Release of │/│ └─────────/ │ ┌─────────/────█ fertilizers█
│ │inorganic K/││ │ │ / █ █
│ └──────────/ │ / ▀▀▀▀▀▀▀▀▀▀▀▀▀▀
│ /────────────┐ │ █▀▀▀▀▀▀▀▀▀▀▀▀▀█ /
││/ Release of │ └────>█ K █ │ Dis- │
│/│ microbial K │ █ in plant █ │ sol- │
│ ────────────┘ █ available █ │ ving │
└────────────────────────────────>█ form █ │ │ ┌──────────┐
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ / │ K │
┌───────── │ / │ in soil │
│ Plants │/│ └──────────/──────│ minerals │
│ uptake /││ / │ │
└─────────/ │ / └──────────┘
────
Fig. 5. Potassium submodel
█▀▀▀▀▀▀▀▀▀▀▀▀▀█
█ █
┌────>█ Humus █─┐
│ █ █ ├─────┐
│ █ █ │ │ /───────────┐
┌───────── │ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ │ ││/ Destruction│
│ Humifi- │/│ │ │/│ │<─ ─ ──█▀▀▀▀▀▀▀▀▀▀▀▀▀█
│ cation /││ █▀▀▀▀▀▀▀▀▀▀▀▀▀█ │ │ ───────────┘ █ N, P, K █
└─────────/ │ █ █ │ └────────────────────>█ in plant █
│ █ Plant █ │ █ available █
├─────█ residues █─(─┐ ┌────────────────────>█ form █
│ █ █ │ │ │ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
│ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ │ │ │ /───────────────┐
│ │ │ ││/ Release of │
│ █▀▀▀▀▀▀▀▀▀▀▀▀▀█ │ │ │/│ inorganic. NPK │
│ █ █ │ ├───┘ ───────────────┘
└─────█ Organic █─┘ │
█ fertilizers █───┘
█ █
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
Fig. 6. Organic matter submodel
█▀▀▀▀▀▀▀▀▀▀▀▀▀█ ______
█ █ / Plant
█ Plant █ - state variable /develop. - calculated parameters
█ residues █ phases /
█ █ ______/
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
┌──────────┐
│ Air │ - external source │
│ humidity │ or factor │ - substrate flow
└──────────┘ │ or transformation
┌───────── │
│ Plants │/│ - process |
│ uptake /││ | - correlation
└─────────/ │ |
Fig. 7. List of symbols

5. ACKNOWLEDGEMENT
his study was funded in part by Fund of Fundamental Research of Belarus. (Director
Vasiljev, E.I.)
Many suggestions and comments from Dr. Nikolaj Kan (Research and Technological
Center "Biomodel", Novocherkask, RUS) and Dr. Tamara Yanchevskaya (Laboratory of
Optimization the Productivity of the Institute Experimental Botany the Belarus Academy of
Science, Minsk, Republic of Belarus) have been incorporated into this chapter and the authors
acknowledge this contribution.
A grant from the "Special American Business Internship Training" (SABIT) program
supported the preparation and presentation of this paper. SABIT is a program of the U.S.
government private sector partnership, providing technical assistance to the independent States
of the former Soviet Union. Managed by the U.S. Department of Commerce in cooperation with
the Agency for International Development. Tyler Limited Partnership of Benson, Minnesota
provided conceptual design and funding for equipment development.
_____________________________________________________________________
* D.E. McGrath, President of General Partner of Tyler Limited Partnership, a Minnesota
limited partnership.
A.V. Skotnikov, Associate Professor, Farm Machinery Department ofthe Byelorussian
Agri-Technical University.
V.A. Bobrov, Chief of Laboratory of Optimization of Agrocenous Productivity of the
Institute Experimental Botany the Belarus Academy of Science, Minsk, Republic of Belarus.