Copyright is owned by the Author of the thesis. Permission is given for
a copy to be downloaded by an individual for the purpose of research and
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A thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in
Agricultural ~conomics and Farm Management at Massey University
William Jack Sorrenson
1977
(i)
ACKNOWLEDGEMENTS
The author wishes to sincerely thank Dr A. Wright for his time, help and advice given throughout the course of this study.
Thanks are also due to Mr D.G. Bowler for his supervision of the technical aspects of water harvesting and to
Professor R.J. Townsley for his time and assistance on many occasions.
The author benefited from discussions with Dr A.N. Rae, Mr A. Chu, Mr K.I. Lowe and Mr R.E. Halford all of Massey
University, Dr P. Gander of the D.S.I.R., Palmerston North, and from helpful written communication from Mr T.D. Heiler of
Lincoln College.
The author also wishes to acknowledge the assistance and patience of his wife, Lynley, during the course of this study.
Thanks are due to staff of the Computer Centre, Massey University and to Mrs Henrickson who typed this thesis.
Also, the author wishes to gratefully acknowledge the financial assistance provided by the Economics Division, Ministry of Agriculture and Fisheries.
TABLE OF CONTENTS
ACKNOWLEDGEMENTS
iTABLE OF CONTENTS
iiLIST Of" TABLES
ivLIST OF' FIGURES
viiCHAPTER 1 INTRODUCTION
12 WATER
HARVESTING FOR IRRIGATION
43
ECONOMIC EVALUATION OF IRRIGATION SYSTEMS
194
PLANT WATER RELATIONS
395
THE SIMULATION MODEL
516
THE GRAZING SYSTEM MODEL
817
ECONOMIC EVALUATIONS OF THE CASE STUDY
117IRRIGATION SYSTEM
8
SUMMARY AND CONCLUSIONS
131APPENDIX
1A CATEGORISED LIST OF M.A.F. IRRIGATION
141ECONOMIC REPORTS
2
PASTURE GROWTH RELATIONSHIPS ANO PASTURE
144.CONSERVATION ACTIVITIES
(iii)
3
DETAILS or THE LP
MATRIX 152.4
GROSS
MARGINDETAILS
155.5
IRRIGATION AND fERTILISER COSTS
160.6
CASH fLOWS
162.BIBLIOGRAPHY 164.
TABLE
2.1
4.1
5.1
5.2
5.3
5.5
5.6
5.7
LIST OF TABLES
Depth, surface area and storage capacity of the 'No.1 Dam'
Crop factors used for pasture and maize
~. ~
Effective crop root depth and water holding capacity of a Tokomaru silt loam
~sighted yield reduction factors for maize grain in the Manawatu
Monthly catchment yield data (m.m.), 15 years simulation, non-irrigated
Dam volu~e estimates obtained from the simulation model for the 'average' year
Dam volume estimates obtained from the simulation model for the 'dry' year
Irrigation interval, days
Strategy {i) - Mean (1959/60 to 1973/74) monthly pasture production {kg OM/ha), varying deficit, net water applied in parentheses {mm)
Strategy (iv) - Mean (1959/60 to 1973/74) monthly pasture production (kg OM/ha), fixed water
application per irrigation, varying cycle length
PAGE
14
41
42
55
67
69
69
74
75
75
5.8
5.9
6.2
6.4
6.5
6.7
6.8
6.9
6.11
Strategy (iv) - Mean (1959/60 to 1973/74) monthly pasture production (kg OM/ha), fixed irrigation cycle, varying water application per irrigation
Days of maize growth
Restrictions imposed on the spelling lengths following grazing of pasture in each period
Assumed percentage of 'available feed' utilised by stock at three stocking rates
Pasture quality estimates assumed
Dry cow energy requirements
Dry cow feed demands (kg OM, non-irrigated pasture equivalents/cow/day)
Lactating cow energy requirements
Lactating cow feed demands (kg OM, non-irrigated pasture equivalents/cow/day)
Replacement stock energy requirements
Replacement stock feed demands (kg OM, non-irrigated pasture equivalents/lactating cow/day)
Animal activities - per hectare feed demands
Summary of the gross margins
Summary of the LP results
{v)
76
77
88
91
92
94
94
95
96
98
99
100
101
104
7 .1
7.2
7.3
7.5
A2.1
A2.2
A2.3
A2.4
A2.5
A2.6
A2.7
A6.1
A6.,2
A listing of the normative analyses 119
Normative evaluation results 120
A listing of the positive analyses 123
Positive evaluation results 123
Sensitivity results - Normative evaluations 124
Sensitivity results - Positive evaluations 124
'Average' year, non-irrigated simulated pasture grO\ilth 144
'Average' year, irrigated II II
'Average' year, non-irrigated pasture growth/spell relationships
'Average' year, irrigated rt ti II relationships
'Dry' year, non-irrigated
"
II flrelationships
'Dry' year, irrigated
"
II"
relationships
Pasture conservation activities
Normative evaluation cash flows
Positive evaluation cash flows
II 145
146
147
148
148
149
162
163
FIGURE
2.2
3.1
4.1
4.2
5.1
5.2
5.3
5.4
5.5
5.6
5.7
LIST OF FIGURES
Storage behavioural graph for the 'No.1 Dam'
Plan sketch of the Massey No.4 Dairy Unit water harvesting dam system
Longitudinal sketch of the Massey No.4 Dairy Unit water harvesting system
A schematic representation of the components of economic evaluation considered and their inter- relationships
Various relationships between relative evapo- transpiration rate and soil moisture tension
Relationships between ASM, Eo, soil moisture factor (P)
Diagrammatic illustration of the simulation model
Pasture growth rates 1972/73
Pasture growth rates 1973/74
Pasture growth rates; Average 1967/68 to 1972/73
Pasture growth rates; Average 1971/72 to 1972/73
Monthly rainfall means and standard deviations
Probability distributions of simulated annual pasture growth
(vii)
15
16
16
21
43
45
52
57
58
59
60
63
66
s.a
5.9
s.10
s.11
6.5
6.7
6.8
7.1
A2.1
A2.2
A3.1
Monthly rainfall and estimated evapotranspiration
Probabilities of moisture stress
Probabilities of water use
Probabilities of irrigations
Calving and dry period distributions
Calving distribution and lactation period
Feed distribution of replacement stock
Relationships between TGM, stocking rate and irrigation water
Relationships between economic response to irrigation and stocking rate
Relationships between irrigation water and time of application Stocking rate= 1.0
Relationships between irrigation water and time of application Stocking rate =
1.s
Relationships between irrigation water and time of application Stocking rats
=
2.0Present worth versus discount rate - Analyses N3B and N68
An illustration of the pasture activities, non-irrigated (P001, •••• ,P078)
An illustration of the irrigatQd pasture activities
(roo1, •••• ,I14a)
Summary of the LP matrix
71
72
72
73
93
95
97
105
106
108
109
110
121
150
151
154
