Citation
Microirrigation in Florida: systems, acreage and costs

Material Information

Title:
Microirrigation in Florida: systems, acreage and costs
Series Title:
Florida Cooperative Extension Service bulletin 276 (reprint)
Creator:
University of Florida. IFAS Task Force on Microirrigation in Florida
Florida Cooperative Extension Service
Affiliation:
University of Florida -- Florida Cooperative Extension Service -- Institute of Food and Agricultural Sciences
Place of Publication:
Gainesville, Fla.
Publisher:
Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Publication Date:
Language:
English
Physical Description:
9 p. : ill. ; 28 cm.

Subjects

Subjects / Keywords:
Agriculture ( LCSH )
Farm life ( LCSH )
Farming ( LCSH )
University of Florida. ( LCSH )
Agriculture -- Florida ( LCSH )
Farm life -- Florida ( LCSH )
Irrigation -- Florida ( LCSH )
Irrigation -- Equipment and supplies -- Florida ( LCSH )
Irrigation engineering -- Florida ( LCSH )
Microirrigation -- Florida ( LCSH )
Spatial Coverage:
North America -- United States of America -- Florida

Notes

General Note:
Reprint of: Bulletin (Florida Cooperative Extension Service) no. 276 (Jan. 1993).
Funding:
Florida Historical Agriculture and Rural Life

Record Information

Source Institution:
Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location:
Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management:
All rights reserved, Board of Trustees of the University of Florida
Resource Identifier:
27957771 ( OCLC )
AJN6469 ( NOTIS )
026330959 ( ALEPH )

Full Text





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Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
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(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida












Microirrigation in Florida: Systems, Acreage and Costs'

by IFAS Task Force on Microirrigation in Florida:2


INTRODUCTION

The term "microirrigation" is used to describe
irrigation systems which use low flow rate emitting
devices (emitters) to place water on the soil surface
very near the plants being irrigated or below the
surface directly into the plant root zone.
Microirrigation systems are extensively used in
Florida, both in commercial agriculture as well as in
landscape irrigation.

Microirrigation systems are characterized by the
use of small diameter, flexible polyethylene lateral
pipes, low flow rates per emitter, and operation at
low pressures. Normally only a portion of the crop
root zone is irrigated. Frequent, small applications
are required to keep the water content of the
irrigated root zone near field capacity. Smaller
volumes of water are typically applied with
microirrigation systems as compared to conventional
irrigation systems, thus the term "low volume
irrigation system" is sometimes used to describe a
microirrigation system.

Specific types of microirrigation systems include
drip (or trickle), microsprinkler (or microspray), line
source, and bubbler systems. To encourage
uniformity in terminology throughout the world, the
term "microirrigation" has been defined in standards
adopted by the International Standards Organization
(ISO). This same term has been accepted for use in
the United States by standards of the American


Society of Agricultural Engineers (ASAE) and in
Florida by standards of the Florida Irrigation Society
(FIS).

Chemicals are applied through most
microirrigation systems to enhance crop growth and
to prevent emitter clogging. Fertilizers can be
efficiently applied with the irrigation water to meet
the plant needs throughout the growing season.
Water conditioning and cleaning agents are normally
required as a part of a regular maintenance program
to prevent clogging of emitters due to chemical
precipitation or biological growths.

Well-designed and well-managed microirrigation
systems are very efficient in terms of both water-and
energy use. Micro systems have been shown to
increase crop yields and decrease nutrient losses from
leaching because they permit prescription applications
of water and fertilizers to be made. Water with
higher salinity levels than required by other methods
can often be used because micro systems maintain
high soil water contents with frequent irrigations, they
can be designed to avoid wetting the plant foliage,
and salt and water movement is downward away from
the plant roots.

Although the characteristics of microirrigation
systems often provide advantages, these systems are
not applicable to every Florida crop and production
system. Several crops can be irrigated more
efficiently or equally efficiently but more economically


1. This document was published January 1993 as Bulletin 276. Florida Cooperative Extension Service. For more information, contact your county
Cooperative Extension Service office.
2. A.G. Smajstrla, Agricultural Engineering Department, Chair, W.G. Boggess, Food and Resource Economics Department; BJ. Boman, Ft. Pierce
Agricultural Research & Education Center, G.A. Clark, Gulf Coast Research & Education Center, D.Z. Haman, Agricultural Engineering
Department; G.W. Knox, North Fla. Research & Education Center, SJ. Locascio, Vegetable Crops Department; T.A. Obreza, Southwest Fla.
Research & Education Center, L.R. Parsons, Citrus Research & Education Center; F.M. Rhoads, North Fla. Research & Education Center,
T. Yeager, Environmental Horticulture Department; F.S. Zazueta, Agricultural Engineering Department; Cooperative Extension Service, Institute
of Food and Agricultural Sciences, University of Florida, Gainesville.

The Institute of Food and Agricultural Sciences is an Equal Opportunity/Affirmative Action Employer authorized to provide research, educational
information and other services only to individuals and institutions that function without regard to race, color, sex, or national origin.
Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences / University of Florida / John T. Woeste, Dean


W'VERSITY OF FLORIDA LIBRARIES







Microirrigation in Florida: Systems, Acreage and Costs

with other types of irrigation systems. Other crops
cannot be economically irrigated with micro systems.
Therefore, the advantages and limitations of
microirrigation in Florida must be evaluated for each
specific crop production system. Advantages for some
production systems will be disadvantages for others.

In this bulletin, estimates of total and micro-
irrigated acreage of Florida crops are presented,
advantages and disadvantages of micro systems are
discussed, applications to specific Florida crop
production systems are discussed, and microirrigation
system costs are estimated.

CROPS AND IRRIGATED ACREAGE

Florida agricultural crops can be classified as fruit
crops (Table 1), field crops (Table 2), pasture/hay
crops (Table 3), vegetable crops (Table 4), and
ornamental/landscape plants (Table 5). Based on
irrigated acreage, 41 major crops were identified.
Also, crops with only small acreages were grouped in
categories of "Other Fruit Crops," "Other Field
Crops," and "Other Vegetable Crops," for a total of 44
crop categories. Table 6 summarizes crop acreage
from the five classes to obtain state totals.

This bulletin provides December, 1991 estimates
of crop acreage, irrigated acreage, microirrigation
acreage, potential microirrigation acreage, and the
anticipated annual rate of increase in microirrigation
acreage. Several sources were used to obtain these
data, including the Florida Agricultural Statistics
Service, IFAS research and extension specialists,
industry representatives, and IFAS publications. A
complete list of references is attached as an appendix.
Because many sources were "personal
communications" rather than published reports, a
"List of Contributors" to this document is also
appended. In that list, the contributors, their
affiliations, and their contributions are acknowledged.

Crop categories are listed in Column 1 of each
Table. Estimates of current crop acreage (Column 2)
were primarily obtained from reports of the Florida
Agricultural Statistics Service and IFAS specialists.
The irrigated acreage estimates in the next four
columns (Columns 3-6) of each Table were made by
the authors of this bulletin based on their knowledge
of the specific crop production systems and with
inputs from the other sources previously cited.
S0 1

pGZ^Lp


Page 2


ADVANTAGES AND DISADVANTAGES OF
MICROIRRIGATION

Although microirrigation systems have many
advantages, they also have disadvantages which limit
their applications in certain crop production systems.
General characteristics of micro systems are presented
here. Characteristics of specific Florida crop
production systems that would affect the use of
microirrigation are discussed by crop category in later
sections of this bulletin.

Advantages

Microirrigation systems operate at low pressure so
that smaller power units and lower energy use are
required as compared to sprinkler irrigation systems.
The flow rate per emitter is low for micro systems, so
that water supplies with limited flow rates (smaller
well sizes) can often be used. The low flow rate
advantage is lost if the entire irrigation system is
operated at once, such as when irrigation systems are
designed for freeze protection. In that case, the flow
rate requirement may be greater than the flow rate
required by conventional irrigation systems.

Well-designed and well-managed microirrigation
systems have higher water application efficiencies
than other types of irrigation systems for many crops.
The actual water savings will vary as a function of the
specific production system. Because micro systems
apply water near or directly into the crop root zone,
a greater fraction of the water pumped is placed in
the soil where it is available for crop use. This
reduces the amount which must be pumped for
irrigation and allows limited water supplies to be
used.

Prescription applications of water and fertilizers
can be made throughout the crop growing season with
microirrigation. As a result, micro systems have been
demonstrated to increase crop yields and decrease
nutrient losses due to leaching. Microirrigation
systems can usually be automated economically. The
resulting labor savings and increases in operational
efficiencies make automatic systems desirable for a
wide range of crops.

Microirrigation systems are frequently used to
apply various other agricultural chemicals such as
nematicides, herbicides, insecticides and fungicides.
The use of microirrigation systems for chemigation
can reduce application costs since conventional







Microirrigation in Florida: Systems, Acreage and Costs

with other types of irrigation systems. Other crops
cannot be economically irrigated with micro systems.
Therefore, the advantages and limitations of
microirrigation in Florida must be evaluated for each
specific crop production system. Advantages for some
production systems will be disadvantages for others.

In this bulletin, estimates of total and micro-
irrigated acreage of Florida crops are presented,
advantages and disadvantages of micro systems are
discussed, applications to specific Florida crop
production systems are discussed, and microirrigation
system costs are estimated.

CROPS AND IRRIGATED ACREAGE

Florida agricultural crops can be classified as fruit
crops (Table 1), field crops (Table 2), pasture/hay
crops (Table 3), vegetable crops (Table 4), and
ornamental/landscape plants (Table 5). Based on
irrigated acreage, 41 major crops were identified.
Also, crops with only small acreages were grouped in
categories of "Other Fruit Crops," "Other Field
Crops," and "Other Vegetable Crops," for a total of 44
crop categories. Table 6 summarizes crop acreage
from the five classes to obtain state totals.

This bulletin provides December, 1991 estimates
of crop acreage, irrigated acreage, microirrigation
acreage, potential microirrigation acreage, and the
anticipated annual rate of increase in microirrigation
acreage. Several sources were used to obtain these
data, including the Florida Agricultural Statistics
Service, IFAS research and extension specialists,
industry representatives, and IFAS publications. A
complete list of references is attached as an appendix.
Because many sources were "personal
communications" rather than published reports, a
"List of Contributors" to this document is also
appended. In that list, the contributors, their
affiliations, and their contributions are acknowledged.

Crop categories are listed in Column 1 of each
Table. Estimates of current crop acreage (Column 2)
were primarily obtained from reports of the Florida
Agricultural Statistics Service and IFAS specialists.
The irrigated acreage estimates in the next four
columns (Columns 3-6) of each Table were made by
the authors of this bulletin based on their knowledge
of the specific crop production systems and with
inputs from the other sources previously cited.
S0 1

pGZ^Lp


Page 2


ADVANTAGES AND DISADVANTAGES OF
MICROIRRIGATION

Although microirrigation systems have many
advantages, they also have disadvantages which limit
their applications in certain crop production systems.
General characteristics of micro systems are presented
here. Characteristics of specific Florida crop
production systems that would affect the use of
microirrigation are discussed by crop category in later
sections of this bulletin.

Advantages

Microirrigation systems operate at low pressure so
that smaller power units and lower energy use are
required as compared to sprinkler irrigation systems.
The flow rate per emitter is low for micro systems, so
that water supplies with limited flow rates (smaller
well sizes) can often be used. The low flow rate
advantage is lost if the entire irrigation system is
operated at once, such as when irrigation systems are
designed for freeze protection. In that case, the flow
rate requirement may be greater than the flow rate
required by conventional irrigation systems.

Well-designed and well-managed microirrigation
systems have higher water application efficiencies
than other types of irrigation systems for many crops.
The actual water savings will vary as a function of the
specific production system. Because micro systems
apply water near or directly into the crop root zone,
a greater fraction of the water pumped is placed in
the soil where it is available for crop use. This
reduces the amount which must be pumped for
irrigation and allows limited water supplies to be
used.

Prescription applications of water and fertilizers
can be made throughout the crop growing season with
microirrigation. As a result, micro systems have been
demonstrated to increase crop yields and decrease
nutrient losses due to leaching. Microirrigation
systems can usually be automated economically. The
resulting labor savings and increases in operational
efficiencies make automatic systems desirable for a
wide range of crops.

Microirrigation systems are frequently used to
apply various other agricultural chemicals such as
nematicides, herbicides, insecticides and fungicides.
The use of microirrigation systems for chemigation
can reduce application costs since conventional







Microirrigation in Florida: Systems, Acreage and Costs

application equipment such as tractors and sprayers
are not needed. The use of chemigation reduces field
traffic and compaction in the treated area.

Because they maintain high soil water contents
with frequent irrigations and they do not wet the
plant foliage, micro systems allow higher salinity water
to be used as compared to sprinkler irrigation. Also,
in contrast to seepage irrigation where soluble salts
accumulate on the soil surface, with microirrigation
salts move downward with the wetting front and do
not accumulate in the root zone.

Disadvantages

The small orifices in microirrigation emitters are
easily clogged by particulate matter, chemical
precipitates, and biological growths. Thus,
microirrigation requires that systems be regularly
flushed and that water be filtered and chemically
treated to reduce clogging problems. Some water
sources may not be suitable for microirrigation
because filtration and chemical treatment costs would
be excessive.

Microirrigation systems normally have greater
maintenance requirements than sprinkler systems.
There are usually many more components, because
each emitter covers a much smaller area than a
sprinkler. Also, emitters are typically plastic and
much more susceptible to wear and breakage than
sprinklers made from metal alloys.

Because micro systems normally irrigate only a
fraction of the crop root zone and typical Florida soils
have very low water-holding capacities, irrigations
must be scheduled frequently, sometimes more often
than daily. Maintenance requirements and the need
to manage high frequency irrigations increase labor
requirements and the quality of labor needed to use
microirrigation.

The cost of microirrigation systems can be very
high with respect to conventional systems for closely
spaced plants or crop rows. For example, the initial
cost of a microirrigation system is much lower than
the cost of a sprinkler system for widely-spaced crops
such as citrus, while the initial cost of microirrigation
for some types of ornamental nursery production
systems is $40,000 per acre. This is approximately 20
times the cost of a sprinkler irrigation system for the
same area.


Page 3


MICROIRRIGATION IN FLORIDA CROP
PRODUCTION SYSTEMS

Because there are both advantages and limitations
to their use, microirrigation systems are not
applicable to all Florida crop production systems.
The following sections of this bulletin discuss
applications and limitations of microirrigation systems
in five crop categories: fruit crops, field crops,
pasture/hay crops, vegetable crops, and
ornamental/landscape plants.

The cost of microirrigation systems vary widely,
depending on the hardware requirements for each
specific crop production system. Thus, estimated
costs of micro systems are also presented for each of
Florida's major crop production systems.

Fruit Crops

Microirrigation is adaptable to many Florida fruit
crops (Table 1). Approximately 1/3 of the entire
United States microirrigation acreage is in Florida
fruit crops. By far the largest acreage is in citrus,
although there is some micro acreage in all major
fruit crops.


There are several reasons that micro systems are
extensively used to irrigate Florida fruit crops -- the
most important is that there are many production and
economic benefits of this technology. Microirrigation
has been shown to provide a greater degree of freeze
protection and more rapid growth of young citrus
trees as compared to conventional irrigation methods.
Microirrigation also provides an economical means of
applying fertilizers with the irrigation water as needed
during the growing season.

Microirrigation systems have the advantage of
lower initial costs than permanent solid set sprinkler
systems for widely spaced tree crops. However, micro
systems require more maintenance. Water must be
filtered and chemically treated to prevent clogging.
The plastic components are more subject to breakage
than brass or steel components. Also, because they
only irrigate a fraction of the crop root zone,
irrigations must be scheduled more often than
sprinkler systems. Thus, fruit crop microirrigation
systems also require more labor and a higher quality
of labor to keep the systems operating properly.







Microirrigation in Florida: Systems, Acreage and Costs


Table 1. Fruit crops acreage and irrigation system costs
(1) (2) (3) (4) (5) (6) (7) (8)
Crop Total Acres Irrig. Micro Potentl. Micro Initial Annual
Type Acres Acres Micro Increase System Compon.
Acres (ac/yr) Cost ($/ac) Cost
($/ac)
Avocado 9,100 7,500 100 9,100 150 1,000 25
Blueberry 2,100 1,680 340 500 25 1,200 30
Citrus* 732,800 690.000 385,000 732,800 20.000 1,000 25
Grapes 580 275 275 580 25 1,200 30
Mango 3,000 2,200 200 3,000 150 1,000 25
Peach 2,000 600 300 2,000 200 1,000 25
Pecan 15,000 4,000 3,000 15,000 200 1,000 25
Other Fruit 2,700 2,700 1,800 2,700 100 1,000 25
Crops*
Subtotal 767,280 708,955 391,015 765,680 20,850 -----
Citrus includes oranges, grapefruit, lemons, limes, tangelos, tangerines, and other citrus fruit.
*Other fruit crops include apples, persimmons and chestnuts in North Florida and other tropical and subtropical fruits
in South Florida.


Microirrigation has become the system of choice
in the Florida citrus industry. Over half of the
existing acreage is in microirrigation, and growers are
replacing conventional systems with microirrigation
when system replacement is required. Almost all new
plantings use microirrigation.

For other fruit crops, the rate of conversion to
microirrigation is slower than that of citrus. Many
deciduous fruit trees such as peaches and pecans
grown in north Florida are not irrigated. Those that
are irrigated are usually not irrigated for freeze
protection, thus growers do not have the freeze
protection incentive to install micro systems in
deciduous fruit orchards.

Blueberries are often irrigated for freeze
protection of early fruit. This requires sprinkler
systems to cover the entire plant. The sprinkler
systems are then available for irrigation throughout
the growing season. Thus, microirrigation is not often
used when blueberries must be irrigated for freeze
protection.

Grapes can use microirrigation effectively in
Florida. However, there are relatively few acres of
grapes in Florida, thus the micro acreage in grapes is
expected to increase only very slowly.


The use of microirrigation is expected to increase
in avocados, mangos, and other subtropical fruit
crops. Currently the majority of acreage in these
crops is irrigated with sprinkler systems. There is
potential for microirrigation to be used in expanded
acreages of these crops and as existing sprinkler
systems wear out and are replaced.

Field Crops

Microirrigation is adaptable to few field crops
(Table 2). The primary reason is economics, and
several factors influence this. General characteristics
of field crops are given in the following paragraphs.
Exceptions to these general characteristics are then
discussed for specific crops.

The typical return per acre for field crop
production is low, while the cost of microirrigation
systems for field crops is high. The cost of
microirrigation is high because field crops are typically
grown on narrow-row spacings, thus closely spaced
laterals are required. Laterals would also need to
picked up and stored or replaced between crop
seasons because only surface lateral placement can
efficiently provide water to the crop root zone in
typical Florida deep sandy soils. Permanent buried
lateral installations such as those used in some
western states are not adaptable to use in deep fine
sands.


Page 4







Microirrigation in Florida: Systems, Acreage and Costs


Table 2. Field crops acreage and irrigation system costs
(1) (2) (3) (4) (5) (6) (7) (8)
Crop Total Acres Irrlg. Micro Potentl. Micro Initial Annual
Type Acres Acres Micro Increase System Compon.
Acres (ac/yr) Cost ($/ac) Cost
_____ ( /_____ac)
Corn 105,000 56,000 0 0 0 -
Cotton 37,000 6,000 0 0 0 -- -
Peanuts 102,000 80,000 0 0 0 -
Rice 20,000 20,000 0 0 0
Soybeans 80,000 12,000 0 0 0 -
Sugarcane 434,000 434,000 0 43,400 1,000 750 300
Tobacco 6,900 6,900 0 6,900 100 1.370 180
Wheat 65,000 6,500 0 0 0 -
Other Field 20,000 2,000 0 0 0 -
Crops
Subtotal 869,900 623,400 0 50,300 1,100 --
Other field crops include field beans, sunflower, sorghum, millet, oats and other small grains.


The typical field crop growing season is only a few
months per year, irrigation requirements are small
compared to most perennial crops, and alternative
efficient sprinkler systems can be used. Thus,
potential benefits of microirrigation in terms of water
and energy savings are also small.

Low pressure center pivot irrigation systems can
apply water for field crop production as efficiently (in
terms of water use) as microirrigation and much more
economically than microirrigation. Low pressure
center pivot systems operate at about the same
pressures as micro systems. These center pivot
systems have high water application efficiencies for
Florida humid climate conditions, especially for
irrigation at night, early morning, and late afternoon.

The initial cost of a center pivot system for field
crops would be expected to range from $350-500 per
acre as compared to $1000-1300 per acre for a micro
system. In addition, operating costs would be much
lower because center pivot systems do not require
water filtration, chemical water treatment, or annual
lateral tube replacement required by micro systems.

Within the next 10 years, microirrigation use on
field crops is expected to be limited to sugarcane and
tobacco. Currently, 90% of Florida's sugarcane
production occurs on muck soils in the Everglades
Agricultural Area (EAA), and seepage irrigation is
required to minimize soil oxidation and wind erosion


on these soils. Thus, at the present time, only an
estimated 43,400 acres of sugarcane grown on sandy
soils is expected to have potential for microirrigation.
However, this number may change if the sugar
industry is displaced from muck soil areas because of
changes in the management of surface waters in the
vicinity of the Everglades National Park.

Sugarcane micro-irrigated acreage is expected to
increase only slowly because micro systems have much
higher initial costs and maintenance costs than the
seepage irrigation systems currently used. Factors
that would increase the rate of conversion to
microirrigation are drought or water use regulations
which would limit water use permits from the water
management districts.

Tobacco is currently irrigated with sprinkler
irrigation systems, primarily gun systems. These
systems are used because they have low initial costs
and they are readily adaptable to the small field sizes
and irregular field shapes typical of the tobacco
industry. The water application efficiency with guns
is lower than that of micro systems, and the cost per
unit of water pumped is higher because of the high
pressures required to operate guns. However, the
cost of the additional pumping required plus the
additional energy needed to provide the high pressure
is much less than the cost of a micro system.


Page 5







Microirrigation in Florida: Systems, Acreage and Costs


Table 3. Pasture, hay crops acreage and irrigation system costs
(1) (2) (3) (4) (5) (6) (7) (8)
Crop Total Acres Irrlg. Micro Potentl. Micro Initial Annual
Type Acres Acres Micro Increase System Compon.
Acres (ac/yr) Cost ($/ac) Cost
S0(S/ac)
Pasture 260,000 90,000 0 0 -
Hay* 2200,000 140,000 0 0 0 -
Subtotal 2460,000 230,000 0 0 0 ------
Pasture and hay crops include grass, clover, and other forage crops.


The incentive for the use of microirrigation for
tobacco production is low because the tobacco
irrigation season is less than four months per year,
and irrigation requirements are typically only 5 to 7
inches per year. Thus, the potential water savings
with micro systems is low. For these reasons, the rate
of conversion to microirrigation is expected to be low.

The initial cost per acre for sugarcane
microirrigation systems are expected to be less than
that of tobacco systems because the sugarcane water
source is primarily surface water, while tobacco is
primarily groundwater from wells. If groundwater is
used for sugarcane, the system cost would increase
because of the additional cost of the well and
pumping system.

Both sugarcane and tobacco microirrigation
systems would be expected to use disposable thin-wall
drip-tube lateraswhich would require replacement
each year. Laterals would be required for each crop
row. This is the primary reason for the annual
component cost of $300 per acre for both systems.

In summary, microirrigation of field crops is not
expected to increase significantly in Florida because
neither economic nor water use incentives currently
exist. If significant changes occur, they will likely be
dictated by water management policy that impacts
sugarcane production in the EAA.

Pasture, Hay Crops

Approximately 260,000 acres of hay and 2.2
million acres of pasture are produced in Florida
(Table 3), but only about 1/3 of the hay and less than
10 percent of the pasture are irrigated. Neither of
these production systems is micro-irrigated because
these crops cannot economically be irrigated with
micro systems. The need to uniformly irrigate the


entire soil surface for these crops makes sprinkler or
seepage irrigation more economical than
microirrigation.

The economics of irrigation of pasture and hay
crops is not expected to change to cause
microirrigation to be used during the next 10 years.
If water shortages restrict the use of seepage
irrigation in the future, the irrigation system of choice
would be low pressure center pivot or lateral-move
systems rather than microirrigation systems.

Vegetable Crops

Almost all the Florida vegetable crops are
irrigated, yet only about five percent are micro-
irrigated using drip systems (Table 4). Most
vegetables are irrigated with sprinkler or seepage
systems. This pattern exists because both sprinkler
and seepage have been effective, economical
irrigation methods for closely-spaced crops with very
limited root systems that are characteristic of many
vegetable crops. Only the Florida strawberry and
tomato industries are exceptions to this usage pattern.

Approximately 80 percent of the Florida
strawberry acreage is drip-irrigated. This pattern has
emerged because of production benefits and water
conservation obtained from drip irrigation.
Strawberries are grown using polyethylene-mulched
beds, and drip systems permit both water and nutrient
to be efficiently applied directly into the root zone
under the mulch throughout the growing season.
Drip systems have been demonstrated to increase
production and minimize waste of both water and
nutrients.

Strawberry growers use dual irrigation systems.
Permanent solid-set sprinkler systems are also used to
provide freeze protection, crop cooling, and


Page 6







Microirrigation in Florida: Systems, Acreage and Costs


Table 4. Vegetable crops acreage and Irrigation system costs
(1) (2) (3) (4) (5) (6) (7) (8)
Crop Total Acres Irrlg. Micro Potentl. Micro Initial Annual
Type Acres Acres Micro Increase System Compon.
Acres (ac/yr) Cost ($/ac) Cost
S_($/ac)
Beans, snap 26,500 26,500 0 5.000 500 1,370 180
Cabbage 14,300 14,300 0 5,000 500 1,070 70
Carrot 9,900 9,900 0 0 0 -
Celery 8,900 8,900 0 0 0 -
Corn, Sweet 58,200 58,200 0 20,000 1,000 1,070 70
Cucumber 17,100 17,100 1,000 10,000 500 1,370 180
Eggplant 2,050 2.050 300 2,050 300 1,200 125
Escarole 4,000 4,000 0 0 0 ---
Lettuce 10,600 10,600 0 0 0 -
Pepper, 23,100 23,100 2,000 23,100 1,000 1,200 125
Green
Potato 45,500 45,500 0 45,500 500 1,070 70
Radish 29,000 29,000 0 0 0 -
Squash 13,600 13,600 0 5,000 500 1,200 125
Strawberry 5,400 5,400 4,000 5,400 100 1,370 180
Tomato 55,800 55,800 11,450 55,800 3,000 1,200 125
Watermelon 53,000 50,000 2,000 20,000 500 1,370 180
Other 44,695 40,000 2,000 8000 500 1,200 1,200
Vegetables
Subtotal 421,645 413,950 22,750 204,850 8,900 -------
*Other vegetables include cantaloupes, processing cucumbers, and other fresh and processing vegetables.


establishment of transplants. This industry is
expected to move entirely to dual drip-sprinkler
irrigation systems, but because most growers already
use these systems, few additional acres remain to be
converted.

Approximately 20 percent of the Florida tomato
acreage is drip-irrigated. Most is seepage-irrigated.
The polyethylene mulch production system described
for strawberries is also used for tomatoes. Thus, drip
irrigation provides a means of improving production
by application of both water and nutrients under the
polyethylene mulch, while conserving both water and
nutrients by efficient applications. The tomato
industry is expected to convert to drip irrigation as
growers gain field experience which documents
production benefits and as pressure to conserve water
increases.


Relatively few acres of other vegetable crops are
micro-irrigated, but this pattern is expected to change
during the next ten years for most vegetables grown
on sandy soils. Vegetables grown on polyethylene
mulch can be expected to benefit from the ability to
control both water and nutrient status under the
mulch with drip systems. Where seepage irrigation is
traditionally used, additional pressures to convert may
come from the need for water conservation.

Subsurface drip irrigation systems currently being
studied at the IFAS Gulf Coast Research and
Education Center are expected to be used to conserve
water as compared to traditional seepage irrigation
systems. These subsurface drip systems will only be
applicable to poorly drained soils in which water
tables can be established for irrigation. Conventional
drip irrigation systems will be required on deep sandy
soils.


Page 7







Microirrigation in Florida: Systems, Acreage and Costs


Table 5. Ornamental crop acreage and irrigation system costs
(1) (2) (3) (4) (5) (6) (7) (8)
Crop Total Acres Irrig. Micro Potentl. Micro Initial Annual
Type Acres Acres Micro Increase System Compon.
Acres (ac/yr) Cost ($/ac) Cost
__($/ac)
Woody Field 3,000 2,700 2,025 3,000 100 4,000 100
Wood 7,000 7,000 1,050 4,550 100 5,500 200
Container
Cut Foliage 8,000 7,800 0 0 0 -
Potted 3,825 3,825 575 3,825 75 6,500 250
Foliage
Potted 520 520 415 520 50 40,000 1,000
Flowering
Cut Flowers 4,000 4,000 160 1,000 100 10,000 1,000
Sod 65,000 30,000 0 0 0 --
Bedding 900 900 45 180 10 40,000 1,000
Subtotal 92,245 56,745 4,270 13.075 435----


Large acreages of vegetables are grown on muck
soils using seepage irrigation. Seepage irrigation is
needed to maintain a wet soil surface to prevent
oxidation and wind erosion of these muck soils. Thus,
as long as vegetables are produced on muck soils, this
fraction of the Florida vegetable industry is not
expected to be micro-irrigated.

Ornamental and Landscape Plants

Microirrigation is adaptable to many ornamental
and landscape plants (Table 5). However, system
costs are much greater than for the other crop
categories defined in this publication. The primary
reason for these high costs is that the closely-spaced
plants require an extensive network of pipelines and
emitters. Microirrigation is not adaptable to some
ornamental and landscape plants such as turf and
ornamental fern because the water application
characteristics of microirrigation are not adaptable to
these production systems.

Microirrigation system initial costs range from
$4,000 to $40,000 per acre for ornamental and
landscape plant production systems. These costs are
several times higher than the costs of micro systems
for field, vegetable, and fruit crops. These high costs
can only be supported by the high cash value of
ornamental and landscape crops, however, even on
some of these crops the higher cost microirrigation
systems cannot be economically justified.


Because of the high costs of microirrigation,
alternative highly efficient irrigation systems have
been developed for some ornamental and landscape
crops. Alternatives include ebb-flow systems for
potted plants, where potted plants are placed in an
impervious basin which is periodically flooded to
allow irrigation water to flow into the pots. Excess
water is used for irrigation of the next basin, thus
water is used without waste.

Another highly efficient irrigation method is the
traveling boom spray system which applies water
uniformly and efficiently while traveling above the
plants. This system is often used in greenhouse
production systems.

Some growers have installed impervious surfaces
in greenhouses and nurseries to route and collect
runoff and drainage for reuse. This method is highly
efficient because excess water from each irrigation is
reused on subsequent irrigations. Chemical water
treatment is typically required to prevent the spread
of disease during water reuse.

Other growers continue to use hand-watering of
plants rather than microirrigation in order to avoid
the maintenance problems of microirrigation. Micro
systems require water filtration and chemical water
treatment to prevent emitter clogging. Maintenance
costs are generally much higher for micro systems
than other irrigation methods, thus making hand-


Page 8







Page 9


Microirrigation in Florida: Systems, Acreage and Costs


and irrigated acreage by major crop


watering an economical alternative to microirrigation
in some production systems.

Most bedding and potted flowering plants are
sprinkler-irrigated or hand-watered. Some micro
systems are used on small pots, however, the cost of
microirrigation is very high (up to $40,000/acre)
because the plants are small and closely-spaced. This
high initial cost and the development of alternative
highly efficient irrigation methods limit the potential
acreage increase to only 10-20 acres per year.

Most woody ornamental field nurseries use drip
irrigation, while some use sprinkler systems. Drip
systems can be effectively used because it is not
necessary to irrigate the entire root zone of these
plants. Fertilizers can be effectively applied through
the drip systems and irrigations can be scheduled as
necessary without interfering with other nursery
operations. Because irrigation water is not applied
to the foliage, foliar-applied chemicals are more
effective since they are not washed off by irrigation
water. This industry has already largely adopted drip
irrigation, thus the increase in acreage per year is
expected to be relatively low.

Woody container plants are often sprinkler
irrigated, although micro systems are commonly used
for plants in large containers. Micro systems are
expensive, especially for small containers. The
potential exists for the use of drip irrigation on about
1/3 of this acreage. Others are expected to use
sprinkler systems with recycling of runoff water.

Potted foliage plants are often hand-watered or
irrigated with traveling boom spray systems. The
potential exists for extensive use of drip irrigation in
this production system, especially for larger


containers. Traveling boom sprays will be most
efficient on closely-spaced containers so that water
loss between containers will be minimized.

Cut flowers are primarily irrigated with seepage
irrigation systems. This trend is expected to continue
because micro systems are expensive (up to
$10,000/acre) for this production system. Also,
sprinklers cannot be used because of disease or
quality problems resulting from frequent wetting of
the foliage. When micro systems are used, the aisles
between plant beds may become dry, and quality
problems may occur due to blowing sand or dirt. This
may require the extra expense of a sprinkler system to
control sand blowing.

Microirrigation systems are not adaptable to
ornamental fern and sod production systems. These
crops have continuous lateral root development and
canopies which cover the entire soil surface. These
crops are most effectively irrigated with sprinkler and
seepage systems that distribute water uniformly over
the entire surface rather than the partial root zone
irrigation that is a characteristic of microirrigation.
Lateral water movement from micro systems is
limited by the hydraulic characteristics of typical
Florida sandy and muck soils.

Ornamental fern is grown under shade -- either
oak hammocks or shade houses. Fern is shallow-
rooted, but has an extensive lateral network of roots
in the upper foot of the soil. These plant and
production system characteristics allow sprinkler
systems to be highly efficient. Because sprinklers are
much less expensive than micro systems, and because
they are also required for freeze protection, sprinklers
are the best irrigation system alternative for
ornamental fern production.







Microirrigation in Florida: Systems, Acreage and Costs

To be effectively harvested and transplanted, sod
is grown using irrigation methods which encourage
shallow root development. This is accomplished with
either sprinkler or seepage systems, using frequent,
shallow applications with sprinklers or maintaining
high water tables with seepage. Sod cannot be
effectively irrigated with microirrigation because
micro systems are most adaptable to partial root zone
irrigation rather than the continuous shallow root
zone required in sod production systems.

IRRIGATED ACREAGE SUMMARY

Table 6 summarizes Florida crop acreage and
irrigated acreage for the five major crop classes
previously discussed. Over 4.6 million acres of
commercial agricultural crops are produced in
Florida, and approximately 2 million acres (44
percent) are irrigated. Over 418,000 acres are
irrigated with microirrigation systems, and almost 94
percent of these are in fruit crops, primarily citrus.

The potential for microirrigation in Florida is
high. Approximately 50 percent of the current 2
million acres are adaptable and may be expected to
convert to microirrigation. The rate of conversion is
estimated to be about 31,000 acres per year, with
most of this occurring in fruit and vegetable crops.

IRRIGATION SYSTEM COSTS

In Tables 1-5, microirrigation system cost
estimates for Florida crops were made in December,
1991. Costs were estimated in two categories: initial
system cost per acre (Column 7) and annual
component costs per acre (Column 8). This approach
was required because microirrigation systems require
replacement of components on an annual basis in
addition to the cost incurred for initial system
purchase.

The cost of replacement components varies widely
depending on the system design. For example, annual
component costs are low for citrus microsprinkler
systems in which main pipelines are buried and lateral
pipelines with emitters are placed under the trees and
left in place for the life of the system. In this case,
annual component costs are only the replacement
costs of damaged or worn-out components. In
contrast, annual component costs are high for
vegetable crop drip irrigation systems in which laterals
are removed and discarded each year. In this case,
annual component costs are high because lateral


Page 10


pipelines and emitters must be replaced when beds
are formed each crop year.

The sources of microirrigation system cost
'information were publications by Prevatt et al. (1992)
and Pitts et al. (1989), plus inputs from the authors
and other contributors to this bulletin, based on their
work with irrigation of Florida crops. Contributors
are acknowledged in the "List of Contributors" at the
end of this bulletin. Only the authors' best estimates
of the average microirrigation system and component
costs are shown in this bulletin. In practice, actual
individual system and component costs will vary
around that average depending on site-specific factors.

SUMMARY

Microirrigation is extensively used in many
Florida crop production systems. Forty-four major
Florida crops and crop groups were identified in this
bulletin. Crops were categorized as fruit crops, field
crp pasture & hay crops, vegetables, and
ornamentals. Estimates of both total and micro-
-.~------
irrigated acreage were presented for each crop and
category. Potential micro-irrigated acreage and rate
of conversion to microirrigation were also estimated.
Advantages and disadvantages of microirrigation were
discussed. Although microirrigation offers many
advantages for some production systems, it is not
adaptable to all Florida crops. Microirrigation system
costs were estimated for each crop adaptable to
microirrigation. Both initial system costs per acre and
annual component costs were presented.

REFERENCES

Fern. 1989. Courier-Journal. Crescent City, FL. p.
12.

Florida Agricultural Statistics Service. 1991a. Florida
Agricultural Statistics Citrus Summary, 1989-90.
Fla. Agr. Stat. Svc. Orlando, FL.

Florida Agricultural Statistics Service. 1991. Florida
Agricultural Statistics Field Crops Summary,
1990. Fla. Agr. Stat. Svc. Orlando, FL.

Florida Agricultural'Statistics Service. 1990. Florida
Agricultural Statistics Florida Vineyard and
Winery Report, 1989. Fla. Agr. Stat. Svc.
Orlando, FL.







Microirrigation in Florida: Systems, Acreage and Costs

To be effectively harvested and transplanted, sod
is grown using irrigation methods which encourage
shallow root development. This is accomplished with
either sprinkler or seepage systems, using frequent,
shallow applications with sprinklers or maintaining
high water tables with seepage. Sod cannot be
effectively irrigated with microirrigation because
micro systems are most adaptable to partial root zone
irrigation rather than the continuous shallow root
zone required in sod production systems.

IRRIGATED ACREAGE SUMMARY

Table 6 summarizes Florida crop acreage and
irrigated acreage for the five major crop classes
previously discussed. Over 4.6 million acres of
commercial agricultural crops are produced in
Florida, and approximately 2 million acres (44
percent) are irrigated. Over 418,000 acres are
irrigated with microirrigation systems, and almost 94
percent of these are in fruit crops, primarily citrus.

The potential for microirrigation in Florida is
high. Approximately 50 percent of the current 2
million acres are adaptable and may be expected to
convert to microirrigation. The rate of conversion is
estimated to be about 31,000 acres per year, with
most of this occurring in fruit and vegetable crops.

IRRIGATION SYSTEM COSTS

In Tables 1-5, microirrigation system cost
estimates for Florida crops were made in December,
1991. Costs were estimated in two categories: initial
system cost per acre (Column 7) and annual
component costs per acre (Column 8). This approach
was required because microirrigation systems require
replacement of components on an annual basis in
addition to the cost incurred for initial system
purchase.

The cost of replacement components varies widely
depending on the system design. For example, annual
component costs are low for citrus microsprinkler
systems in which main pipelines are buried and lateral
pipelines with emitters are placed under the trees and
left in place for the life of the system. In this case,
annual component costs are only the replacement
costs of damaged or worn-out components. In
contrast, annual component costs are high for
vegetable crop drip irrigation systems in which laterals
are removed and discarded each year. In this case,
annual component costs are high because lateral


Page 10


pipelines and emitters must be replaced when beds
are formed each crop year.

The sources of microirrigation system cost
'information were publications by Prevatt et al. (1992)
and Pitts et al. (1989), plus inputs from the authors
and other contributors to this bulletin, based on their
work with irrigation of Florida crops. Contributors
are acknowledged in the "List of Contributors" at the
end of this bulletin. Only the authors' best estimates
of the average microirrigation system and component
costs are shown in this bulletin. In practice, actual
individual system and component costs will vary
around that average depending on site-specific factors.

SUMMARY

Microirrigation is extensively used in many
Florida crop production systems. Forty-four major
Florida crops and crop groups were identified in this
bulletin. Crops were categorized as fruit crops, field
crp pasture & hay crops, vegetables, and
ornamentals. Estimates of both total and micro-
-.~------
irrigated acreage were presented for each crop and
category. Potential micro-irrigated acreage and rate
of conversion to microirrigation were also estimated.
Advantages and disadvantages of microirrigation were
discussed. Although microirrigation offers many
advantages for some production systems, it is not
adaptable to all Florida crops. Microirrigation system
costs were estimated for each crop adaptable to
microirrigation. Both initial system costs per acre and
annual component costs were presented.

REFERENCES

Fern. 1989. Courier-Journal. Crescent City, FL. p.
12.

Florida Agricultural Statistics Service. 1991a. Florida
Agricultural Statistics Citrus Summary, 1989-90.
Fla. Agr. Stat. Svc. Orlando, FL.

Florida Agricultural Statistics Service. 1991. Florida
Agricultural Statistics Field Crops Summary,
1990. Fla. Agr. Stat. Svc. Orlando, FL.

Florida Agricultural'Statistics Service. 1990. Florida
Agricultural Statistics Florida Vineyard and
Winery Report, 1989. Fla. Agr. Stat. Svc.
Orlando, FL.







Microirrigation in Florida: Systems, Acreage and Costs

Florida Agricultural Statistics Service. 1991. Florida
Agricultural Statistics Foliage, Floriculture and
Cut Greens. Fla. Agr. Stat. Svc. Orlando, FL.

Florida Agricultural Statistics Service. 1991. Florida
Agricultural Statistics Vegetable Summary, 1989-
90. Fla. Agr. Stat. Svc. Orlando, FL.

Gilpin-Hudson, D. and E. Hopkins. 1991. Water
Supply Needs & Sources. South Florida Water
Mgt. Dist. West Palm Beach, FL.

Irrigation Journal. 1991. 1990 Irrigation Survey.
Irrig. J. 41:23-34.

Locascio, S.J., G.A. Clark, A.A. Csizinszky, C.D.
Stanley, S.M. Olson, F. Rhoads, A.G. Smajstrla,
G. Vellidis, R.J. Edling, H.Y. Hanna, M.R. Goyal,
S. Crossman, and A.A. Navarro. 1992. Water
and Nutrient Requirements for Drip-Irrigated
Vegetables in Humid Regions. Southern
Cooperative Series Bulletin 363. University of
Florida, Gainesville, FL.

Lynne, G.D. and C.F. Kiker (Eds.) 1991.
Agricultural Land and Water Use Projections for
1995 and 2010: St. Johns River Water
Management District. IFAS Food and Resource
Economics Dept., Univ. of Fla. Gainesville, FL.

Muraro, R.P. 1991. CREC Report: Citrus in
Mexico. Citrus Industry 72(6):42-43.

Pitts, D.J. and A.G. Smajstrla. 1989. Irrigation
Systems for Crop Production in Florida:
Descriptions and Costs. Fla. Coop. Ext. Svc. Cir.
821. Univ. of Fla. Gainesville, FL.

Prevatt, J.W. G.A. Clark and C.D. Stanley. 1992. A
Comparative Cost Analysis of Vegetable
Irrigation Systems. HortTechnology, Jan., 1992.R

Smajstrla, A.G., D.S. Harrison, D.Z. Haman and F.S.
Zazueta. 1991. Irrigation in Florida. Agr. Engr.
Dept. Ext. Rpt. 91-12. Univ. of Fla. Gainesville,
FL.

Stanley, C.D., G.A. Clark, J.W. Prevatt, B.K.
Harbaugh; and A.J. Overman. 1992.
Microirrigation for Flowering Ornamental Crops
in Humid Regions. Southern Cooperative Series
Bulletin 364. University of Florida. Gainesville,
FL.


Page 11


USDA. 1991. Floriculture Crops: 1990 Summary.
United States Dept. of Agr. Publication Sp.Cr. 6-
1(91).

LIST OF CONTRIBUTORS

In addition to the authors, the individuals listed
here contributed to the data presented in this bulletin.
Names, professional affiliations, and specific sections
of this bulletin contributed to are listed. Their
contributions are gratefully acknowledged.

P.C. Andersen, IFAS North Florida Research and
Education Center, Monticello. Fruit Crops
(Deciduous Fruit).

J.E. Barrett, IFAS Environmental Horticulture Dept.,
Gainesville. Ornamental and Landscape Plants
(Potted Flowering, Cut Flowers, Bedding Plants)

J.L. Cisar, IFAS Ft. Lauderdale Research and
Education Center. Ornamental and Landscape
Plants (Turfgrass)

F.J. Coale, IFAS Everglades Research and Education
Center, Belle Glade. Field Crops (Rice).

J.H. Crane, IFAS Tropical Research and Education
Center, Homestead. Fruit Crops (Tropical
Fruits).

T.E. Crocker, IFAS Fruit Crops Dept., Gainesville.
Fruit Crops.

S.H. Futch, IFAS Multi-County Citrus Agent, Lake
Alfred. Fruit Crops (Citrus)

R.J. Henley. IFAS Central Florida Research and
Education Center, Apopka. Ornamental and
Landscape Plants (Potted Foliage, Potted
Flowering).

Chip Hinton, Florida Strawberry Growers
Association. Fruit Crops (Strawberries)

G.J. Hochmuth, IFAS Vegetable Crops Dept.,
Gainesville. Vegetable Crops.

E.D. Holcomb, IFAS Multi-County Citrus Extension
Agent, Immokalee. Fruit Crops (Citrus)

J.L. Jackson, IFAS Multi-County Citrus Extension
Agent, Tavares. Fruit Crops (Citrus)







Microirrigation in Florida: Systems, Acreage and Costs


Thomas Jones, Barron Collier Corp., Immokalee.
Vegetable Crops, Fruit Crops (Citrus).

L.B. McCarty, IFAS Environmental Horticulture
Dept., Gainesville. Ornamental and Landscape
Plants (Turf/Sod).

Thomas Mueller, Collier Enterprises, Immokalee.
Vegetable Crops, Fruit Crops (Citrus)

S.M. Olson, IFAS North Florida Research and
Education Center, Quincy. Vegetable Crops.

W.C. Oswalt. IFAS Multi-County Citrus Extension
Agent, Cocoa. Fruit Crops (Citrus).

Tony Polizos, Soil Conservation Service, Collier
County. Vegetable Crops, Fruit Crops (Citrus)

A.J. Rose. IFAS Citrus County Extension Director,
Inverness. Fruit Crops (Citrus).

R.H. Stamps. Central Florida Research and
Education Center, Apopka. Ornamental and
Landscape Plants (Cut Foliage).

C.D. Stanley, IFAS Gulf Coast Research and
Education Center, Bradenton. Vegetable Crops,
Ornamental and Landscape Plants


Page 12