Climate under Cover: Digital Dynamic Simulation in Plant Bio-Engineering

165 Pages·1993·4.072 MB·English

by  Tadashi Takakura (auth.)

CLIMATE UNDER COVER
Climate under Cover
Digital Dynamic Simulation
in Plant Bio-Engineering
Tadashi Takakura
Department ofA gricultural Engineering,
The University of Tokyo, Japan
SPRINGER SCIENCE+BUSINESS MEDIA, B.V.
ISBN 978-0-7923-2105-7 ISBN 978-94-011-1658-9 (eBook)
DOI 10.1007/978-94-011-1658-9
Printed on acid-free paper
ATI Rights Reserved
© 1993 Springer Science+Business Media Dordrecht
OriginaIly published by Kluwer Academic Publishers in 1993
Softcover reprint ofthe hardcover Ist edition 1993
No part of the material protected by this copyright notice may be reproduced or
utilized in any form or by any means, electronic or mechanical,
including photocopying, recording or by any information storage and
retrieval system, without written permission from the copyright owner.
CONTENTS
PREFACE xi
1. INTRODUCTION
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Europe and North America ............................... 2
1.3 Asia ................................................. 3
1.4 Japan ................................................ 3
1.4.1 Covering materials: PE or PVC? ..................... 4
1.4.2 Greenhouse production in Japan ..................... 6
1.4.3 Floating mulch in Japan ............................ 7
1.4.4 Plastic Wastes ................................... 7
Problems ................................................ 8
2. DEFINITION OF COVERING AND PROPERTIES OF
COVERING MATERIALS
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Mulching ............................................. 9
2.3 Row covers (Tunnels) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
2.4 Floating mulches (Floating row cover) ...................... 11
2.5 Rain shelters ......................................... 11
2.6 Unheated greenhouses .................................. 12
2.7 Covering materials ..................................... 12
Problems ............................................... 14
3. DIGITAL SIMULATION
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15
3.2 System dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15
3.3 Simulation languages ................................... 15
3.4 Digital simulation by CSMP .............................. 16
3.4.1 Concept of the analog computer .................... 16
3.4.2 Comparison of CSMP program with
mathematical equations . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
3.5 Model structure and representation ........................ 20
3.5.1 Differential equation ............................. 20
3.5.2 Description of systems ............................ 21
3.5.3 Heat flow and temperature regime in the soil ........... 22
3.6 A model for temperature regimes in the soil (CUC·OI) .......... 25
3.6.1 Model description ............................... 25
3.6.2 Time constant and integration ...................... 28
3.7 Application to steady-state models ......................... 28
Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4. HEAT BALANCE OF BARE GROUND
4.1 Introduction .......................................... 32
4.2 Convective heat transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.3 A model with solar radiation and
air temperature boundary condition (CUC.02) ................ 36
4.4 Mass transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.5 A model with latent heat transfer (CUC.03) .................. 41
vi
4.6 Radiation balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.7 Long-wave radiation .................................... 47
Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
S. SOLAR RADIATION ENVIRONMENT
5.1 Introduction .......................................... 50
5.2 Units of radiation and light ............................... 50
5.3 Solar radiation properties of covering materials ................ 51
5.4 Calculation of transmissivity (CUC-04) ...................... 52
5.5 Solar radiation ........................................ 56
5.6 The sun's altitude and azimuth ............................ 57
5.6.1 On a horizontal surface ........................... 57
5.6.2 On a tilted surface ............................... 59
5.6.3 Transmitted solar radiation (CUC-OS) ................ 60
Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6. TEMPERATURE ENVIRONMENT UNDER COVER
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
6.2 Effect of mulching ..................................... 64
6.2.1 Experimental measurements ....................... 64
6.2.2 A model to simulate temperature regime under
clear mulching (CUC-20) .......................... 65
6.2.3 Modification of the model for black and white
mulching (CUC-21 and CUC-22) .................... 71
6.3 Temperature environment under row covers (CUC-30) .......... 73
6.4 Double layer greenhouse model (CUC-SO) ................... 81
vii
6.5 A pad and fan greenhouse model (CUC-35) .................. 87
Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
7. COz ENVIRONMENT
7.1 Introduction ......................................... 100
7.2 CO concentration in soil layer (CUC-70) 100
2
7.3 CO concentration in a plastic house and
2
ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 104
Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 104
8. WATER AND WATER VAPOR ENVIRONMENT
8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 105
8.2 Water and water vapor movement in soil 105
8.3 Application to water and heat balance in
soil layer (CUC-90) ................................... 108
8.4 Interaction between water movement and heat flow ........... 114
Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 114
9. CONTROL FUNCTION
9.1 Introduction ......................................... 115
9.2 System response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 116
9.3 PID control ......................................... 117
9.4 Temperature control logic (CUC-120) . . . . . . . . . . . . . . . . . . . . .. 118
9.5 Feedback vs. feedforward control ......................... 119
9.5.1 Feedback and feedforward ........................ 119
9.5.2 System response and its application
to feedforward control .......................... 120
viii
9.5.3 A floor-heating greenhouse
with ideal conditions (CUC-122) 121
Problems .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 123
10. PLANT RESPONSE TO mE ENVIRONMENT
10.1 Introduction ........................................ 124
10.2 Plant photosynthesis and respiration ...................... 124
10.3 Energy balance of a plant leaf . . . . . . . . . . . . . . . . . . . . . . . . . .. 126
10.4 Stomata resistance of plant (CUC-1S1) .................... 127
10.5 Plant growth model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 132
10.5.1 General concept of plant growth and yield models ..... 132
10.5.2 Dry matter production model (CUC-160) ............ 133
Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 138
REFERENCES .............................................. 140
APPENDIX 144
INDEX 150
ix
PREFACE
Mter plastic films were invented, covering technique became popular for crop
protection. Mulching, row covers, floating mulch and greenhouses are classified differently,
but in principle they are more or less the same technique. As far as the physical
environment for plant growth is concerned, the main sub-systems are the soil layer and the
boundary air layer above it. Covering the soil surface with film changes these environments
drastically. Air space between the cover and the soil surface is very limited in mulching. If
this space is enlarged and crops are grown under the film, the floating mulch, row cover and
plastic house systems can be utilized.
Therefore, insofar as the physical environment itself is concerned, the air space between
the cover and the soil surface is the key to the classification. The same mechanism governs
environments produced by the various covers. Therefore, in this book we will analyze all
of the different environments from mulching to greenhouses. In order to analyze the
physical environment, the relationship between plants and environment is of course another
important topic.
Stress is placed on the link between quantitative phenomena and qualitative analyses,
although not all simulation results are verified experimentally. Selection of adequate
parameter values is essential for verification of the simulations. Most phenomena involved
are non-linear and non-steady-state. For this reason, the approach which is called System
Dynamics is used and simulation models developed in a simulation language CSMP
(Continuous System Modeling Program) are fully used. Simulation languages for continuous
systems work on the same principles as analog computers and are problem-oriented. It is
very easy to understand. There are several languages, such as micro-CSMP, ACSL, SYSL,
and PCSMP, which are run on computers ranging from mainframes to IBM PCs, and each
is slightly different. The first three are available commercially. The last, PCSMP (CSMP
for IBM PCs), has been developed by the Department of Theoretical Production Ecology,
Agricultural University, Wageningen, the Netherlands. These simulation languages are much
more powerful than BASIC or FORTRAN; they can be run on IBM PCs, and they satisfy
engineers' nostalgia for analog computers.
This book was written for a computer simulation class at the graduate level at the
University of Tokyo. The author assumes that readers have some basic background in
differential equations, numerical analysis, and FORTRAN programming. He will be more
than satisfied if the digital simulation technique using CSMP described in this book becomes
widely used as a research tool as well as an educational tool in student laboratories. All
models in this book are written in micro-CSMP and are available on request (a request card
is attached to this book).
There are already some good English books for students majoring in agricultural
structures and environments. However, they are mostly for animal environments; as far as
the author knows simulation techniques have not yet been well documented in the area of
plant growth, although it is a very powerful methodology. The author started greenhouse
simulation as a graduate student, using FORTRAN on mainframes. He became acquainted
xi
with digital simulation techniques during his post-doctoral study (1968-1969) at the University
of Minnesota after having some difficulty in simulating his models using both hybrid and
analog computers. Dr. L. L. Boyd, head of the department at that time, offered the author
a chance to study there, and Dr. K. A. Jordan taught him how to use hybrid and analog
computers. The first model developed at that time was made using FORTRAN (Takakura
et al., 1971), and it has been referred to by many researchers on greenhouse environments
since then. As is indicated in Takakura and Jordan (1970), the second model was in MIMIC
(a similar simulation language to CSMP), which was only available at Minnesota. After the
author started simulation work using CSMP in Japan, he had a chance to work in the
Department of Theoretical Production Ecology (which was headed by Prof. Dr. C. T. de Wit
at that time) at Agricultural University, Wageningen, in the Netherlands in 1973, and also
had an excellent opportunity to discuss digital simulation in CSMP with other members of
his department. They cooperated with the staff of the computer science department at the
same university to develop PCSMP later.
The writing of this book began when the author visited the Department of Biological and
Agricultural Engineering, Rutgers University, in 1987. A simulation model for floor heating
greenhouses was developed with Prof. W.J. Roberts, the chairman of the department, and
his young staff members. In the summer of 1991, the author offered a one week short
course at Rutgers using the first draft of this book. All 15 attendants eagerly discussed the
contents of this book and gave many suggestions for its completion; especially helpful was
Dr. Wei Fang, National Taiwan University. Dr. Ken Jordan, now at the University of
Arizona, ran most of the models in ACSL and gave many suggestions. Nancy K. Okamura,
research fellow in our department, and Susan Schmidt, University of Tokyo Press, read the
manuscript carefully and made corrections. There are many others who contributed by
giving suggestions and preparing the manuscript. This book would not have been possible
without their help. The author would like to thank all who have contributed in many ways.
Last but not least, he would like to express his appreciation to Dr. J. M. Brewis, Kluwer
Academic Publishers, who agreed to publish of this book.
Tokyo
October 1992
Tadashi Takakura
xii