This is the monthly digest of TRICKLE-L for SEPTEMBER 1995.

It was prepared from the "daily" digest mailings. It differs in
certain format details from the previous monthly digests obtained
from the trickle-l archive at listserv@unl.edu.

>How about measurement systems? For some crazy (actually not crazy) reason I
>want to read and log water levels in wells. I know the manual way is best,
>but probably not in this instance.
>Steve Jordan @ Second Foundation
>
>If cost is a concern, I am contemplating using a pressure transducer and
data logger setup from Automata, Inc. It seems to be the "best buy", but I
haven't installed one yet. Please give me a call at 941-277-1984 (in Ft.
Myers, Florida) and we can discuss the relative merits of various types of
water-level recording systems in an agricultural environment. Dale Hardin

>Anyone know of an opening for an irrigation engineer? B.S. Ag Engineering,
>EIT, Irrigation Association Drip/Micro CID. Four years design experience.
> Creative, hard-working, dependable, team player. Ten years of computer
>experience. Likes working in the field and getting hands dirty. Willing to
>relocate. Especially interested in opportunities that would involve overseas
>travel.
>
>For full resume send E-mail to Merriott@aol.com or call 407-770-2056.
>
>Thanks, Randall Merriott
>Vero Beach, Florida
>

Randall, Can we get together at my office to talk about this? I could
probably meet you in the afternoon next week on Wed or Thurs, 6 or 7. Is
that possible?

Pete Spyke.

Contact Bill Bryan at Watertec Brawley California. 619-344-8000. He needs an
engineer for his brawley operation. If you need more detail this weekend
contact me at 209 883 9507. Good luck.
Robin Franks.

unsubscribe Joseph Rajeswaran

unsubscribe trickle-l

Please unsuscribe me from your mailing list.
I tried sending sending the following message: "unsubscribe pfc-update" to
listproc@mail.gnn.com but it didn't work.

The fifth abstract I'm sending out for Trickle-L subscribers relates to some
interesting research performed in Israel. While we have discussed high
frequency drip irrigation previously on this mailing list, the following
research focuses on taking the high frequency idea one step further. Since
crop ET rates range from 0.2 to 1mm/hr (0.008 to 0.04 inch/hr), the
scientists are trying to match that minute amount and hourly rate: hence
their term "minute microirrigation" (MMI). They are basically using the
"surge flow" concept developed for furrow irrigation systems and applying it
to microirrigation irrigation.
*****************************************************************
Pulsating Microirrigation for Optimal Water Use and Control in
the Soil

Elisha Kenig, Ester Mor and Gideon Oron

Improved water use can be attained by employing minute
microirrigation (MMI) methods whereby the water application rate
is adjusted to the plants' water demand. This can be accomplished
by two main methods: (a) drip irrigation with a mean minute
emitter discharge in the range of 0.1 to 0.4 1/h (3.4 to 13.5 ounces); and
(b) intermittent application using conventional micro sprinklers or sprayers,
with a mean effective outlet flow in the range of 2 to 8 l/h (0.5 to 2
gallons), equivalent to conventional drippers, and wetting an area of 10 to
20 m2 (108 to 215 ft2). Both methods have an application rate which is lower
by an order of magnitude than that of conventional irrigation. The reduced
mean application rate is achieved by using pulsating devices at each
irrigating outlet or at the head of a cluster of laterals. Field experiments
were conducted to confirm the results of the efficiency of this approach.

Keywords: Microirrigation pulsating, Soil moisture control, Drip
irrigation

Abstract taken from paper found on pages 615 to 620 in Proceedings of 5th
International Microirrigation Congress, April 2-6, 1995, Orlando, Florida.
American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph,
Michigan 49085-9659, USA. Phone: 616-429- 0300 FAX: 616-429-3852 EMAIL:
HQ@ASAE.ORG
*****************************************************************
While their abstract is rather brief, the main text of their paper refers to
a pulsator which maintains constant water pressure within the pipe system.
Microspray delivery rates in avocado and citrus orchard experiments were 0.22
mm/hr (0.0088 inch/hr) and in sand culture greenhouse studies, surface drip
emitter delivery was 0.4mm/hr (0.016 inch/hr).

Observations in the orchard experiments concluded no runoff and 40% water
savings. The greenhouse experiment had a 47% reduction in water use and
similar yields (carnation flowers) to conventional irrigation. Soil salinity
was also lower in the greenhouse experiment compared to conventional
operation.

All this sounds good, but as usual, I have questions:

1) What exactly is a pulsator?

2) How many of these pulsators do you need per irrigation line or per hectare
or acre?

3) Was the uniformity of the drip or microspray system measured during these
bursts of water delivery and if so, how was the uniformity affected?

4) Is there anybody out there doing similar research or irrigation practice?
How are you accomplishing this?

--
Richard Mead
Trickle-L owner/manager

Pulsating micro-sprinklers were introduced in Florida several years ago for
use in citrus. I'm not sure if these are what the abstract was referring to,
but these have a small pulsator on each emitter. The ones I have seen have a
chamber that fills with water, and once it's full it releases it all at once.
One of the big selling points was that you could theoretically get just as
good a coverage with these as a regular micro-sprinkler but with a much lower
volume of water. So you could say put these in a system that had originally
been undersized and get better uniformity or design a system with these to
begin with and have a lower cost installation since you'd have smaller pipe,
valves, etc. However, many growers in Florida tend to be suspicious of
emitters that have moving parts, and in addition, the cost of these pulsating
micro-sprinklers is higher. A lot of growers also use micro-sprinklers for
frost protection and I doubt the volume would be high enough to do much good,
although I think I heard that someone did some experiments on intermittent
frost protection, which is a similar concept but I believe done with higher
volumes of water. I'd like to hear from any growers, especially in Florida,
who've used these and what their experience is. Were the maintenance
problems any greater than with regular micro-sprinklers? Anybody try using
these or another pulsing method during a freeze?

In practical terms, the design of the system must reach beyond mean E/T and
give the operater the ability to respond on demand. I think I coined the
phrase of"' High density drip" in the late 70's!!!!

Fellow Dripsters:

The Cal Poly books are not free! So Hey, Mr. Burt - Why not
save us some time and just print prices in your email?

One who Inquired and Then Bought Even Though They Cost A Bunch,

C. Storlie

dear Richard,

the "Pulsator" is brand name for a product. I will call you directly and
give you a contact name and number. if anyone else desires the information
please contact me directly at Landmark7@aol.com.
--
Landmark Irrigation
Jim Phene

unsubscribe trickle-l

Hi,
I would also like the information. Thanks.

> Date: Fri, 8 Sep 1995 18:18:01 -0500
> Reply-to: <trickle-l@unl.edu>
> From: PHLASH79@aol.com
> To: Multiple recipients of list <trickle-l@unl.edu>
> Subject: Re: Abstract #5

> dear Richard,
>
> the "Pulsator" is brand name for a product. I will call you directly and
> give you a contact name and number. if anyone else desires the information
> please contact me directly at Landmark7@aol.com.
>
> Landmark Irrigation
> Jim Phene
>
>

Best Wishes,
Taunya
--
Taunya L. Kopke (Fayetteville, AR - Zone 6b)
tkopke@ozark.org (http://cavern.uark.edu/~ozarinfo/)

The following is a response from a new member:

>1) Briefly, what is your affiliation with trickle/drip irrigation?<

A: I'm the librarian at the San Diego County Water Authority.
We are a public agency, a wholesaler of water to 23 agencies
in San Diego county. These include 2 irrigation districts
(Vista and South Bay), as well as several municipal water
districts who serve primarily agricultural areas. We are
concerned about water (& soil) quality & conservation w/regard
to our agricultural customers, and need to stay abreast of
the issues in the field, such as drip irrigation.

>11) How did you find out about our mailing list? <

A: I believe it was mentioned on another water list.
--
Kim Laru
K#u#Laru@marge.ccmail.compuserve.com

Just to make things interesting this time, I will not deliver an abstract of
the week with commentary as usual but instead discuss some stimulating
research going on which involve plant roots.

With the combined efforts of Dr. Ken Shackel (UC Davis pomologist) and a
northern California company called "DendroTech", some fascinating root
excavation* work is being performed in California almond orchards. Basically,
technicians from DendroTech hook up a fire fighting nozzle and hose to a
local water main and then blast the soil under a tree with water while
simultaneously sucking the soil/water slurry with another hose at a rate of
600 gpm (2.3 cubic meters/min). This root washing process penetrates to a
depth of 3.5 ft. (1.07 m) and a radius of 5-6 ft. (1.5 to 1.8 m). The
excavation process takes about 40 minutes per tree. The main reason I'm
mentioning this rather unique procedure is to point out what Dr. Shackel has
observed.

- Trees which were well watered all their lives had many roots, both deep and
shallow.
- Trees which were deliberately not given as much water were not well
anchored, in fact one tree actually fell during the excavation process.
- Over watering of trees did not develop proportionally more root mass.

According to Dr. Shackel, "frequently irrigated trees had surprisingly deep
and extensive root systems, while less frequently watered trees were smaller
and the root systems reflected that size."

These observations seem to confirm a growing philosophy in the drip
irrigation arena: "High Frequency". Not only is high frequency irrigation
efficient for water and nutrient application, controlling salinity and
preventing excess drainage, but it seems to create a well developed root
system for the uptake of soil water.

At our Water Management Research Laboratory (USDA-ARS), another type of root
study has begun. Plexiglas tubes have been horizontally inserted into our new
monolith lysimeters**. We will be inserting a video camera into the
transparent tubes to observe root mass of the crop growing in the lysimeters.
Upon video recording the tube exploration, the video tape will be digitally
edited and each frame of interest will be quantitatively assessed for root
length and density. The bottom line of this information is to observe and
quantify differences between roots growing in shallow saline-water table
conditions vs. roots growing without a water table using subsurface drip
irrigation in both instances. This technology will be demonstrated at our
upcoming Twin Lysimeter Open House (September 14, 1995) and pictures of this
equipment at the Open House session will be offered on our Web homepage:
(http://asset.arsusda.gov/wmrl/wmrl.html)

Does anyone know of other types of root studies, or have experiences with
root observations, especially relating to drip irrigation? If so, please
share with the Trickle-L group.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* For more information concerning this hydraulic technology, see the July '95
issue of California Farmer (pages 10, 11 and 24).

**A lysimeter is very simply a box of soil which sits on a sophisticated
scale. Crops are planted in the lysimeter and changes in weight indicate
evapotranspiration (ET) or rain fall, depending on weigh loss or gain,
respectively. Our lab has 7 lysimeters throughout the state of California,
ranging from 8 to 24 cubic meters (283 - 848 ft3) in volume. The various
crops planted in the lysimeters include: peach, grape, cotton, alfalfa,
reference grass and cantaloupe. All of our lysimeters have either surface
drip or subsurface drip irrigation systems for water delivery.

--
Richard Mead
List owner/manager

The ARS unit stationed at Auburn had what they called a rizitron (sp) that
consisted of a basement underneath a plot where plots were growing. There \
were glass/plexiglas walls on the soil mass so the root growth could be
observed. Root growth and the diurnal dehydration/hydration of the
roots was observed. I don't believe that the plots were irrigated, if
they were I would guess it wasn't by trickle irrigation.
--
Bob Edling
LSU

Additional root study work with lysimeters may have been done at the
Prosser, WA Irrigation Research and Education Center, on grapes. Dr.
Robert Evans was conducting some ET research and other researchers were
utilizing the plot for various information. This work was conducted in
the mid to late 80s and may still be ongoing.

I wonder if any of you would have some crop factors/coefficeinst for Garlic. We have not been able
to find any published to date.

Cheers
Tony M :-)
--
*****************************************************
* Tony Meissner *
* Senior Research Scientist (Soils) *
* Primary Industries, South Australia *
* PO Box 411, Loxton SA, Australia 5333 *
* Tel. 085 95 9146 *
* Fax: 085 95 9199 *
* email meissner.tony@pi.sa.gov.au *
*********************************************************

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FYI:

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Reserve October 6 and 7, 1995 for ECO-FAIR TEXAS '95, a one-of-a-kind for=
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--PART.BOUNDARY.0.375.mail02.mail.aol.com.810876913--

The following is a survey response from a new subscriber, Tim Lewis.

Welcome Tim !!

>1) Briefly, what is your affiliation with trickle/drip irrigation?<
I am a home owner who is concerned about conserving our natural resources so
I use drip and soaker systems in my yard. I also like soaker/drip irrigation
because we live in the humid mid-west where overhead watering promotes
diseases on plants so soaker/drip irrigation reduces this problem.

>2) What crops or plants do you use drip irrigation on?<
1,000 sq. ft. vegetable garden and some shrub and flower beds.

>3) If using subsurface drip irrigation, what is the average depth of
placement of the drip lateral?< na

>4) What problems have you encountered with drip irrigation?<
We have lots of lime in our water which clogs the systems easily. Sometimes
dirt or debris gets in and clogs emmiters.

>5) Fertigation is a real advantage of drip irrigation. What form of N, P and
K have you been trying and to what success?< na

>6) Have you experienced a reduction in fertilizer and/or water use?< Yes,
water usage has decreased and plant growth and health has increased even
though we experienced a near record hot summer.

>7) Do you have water quality problems? If so, how do you tackle the
situation? unplug some drippers and I understand that vinegar works too (I'll try that
next year).

>8) How frequent do you irrigate? Many times a day or just one long session
per day or several days?< I run the systems about every 3 days for 4 to 8
hours, depending on conditions and if I remember to turn it off.

>9) Do you have rodent damage? If so, how do you control the problem?< no

>10) Are you pleased with the uniformity of your system or systems? Were they
designed correctly? overhead sprinklers.

>11) How did you find out about our mailing list?< Through H.O.M.E. BBS (I
think).

I work at INIA National Research Institute of Agriculture of
Uruguay. Our department is going to work with lysimeter into a
rain out shelter, mainly in pear, peach, allium and sweet
onion.
The idea is begin to work in drip irrigation and roots growing
but until now we do not have experience in this studies.

--
Soil Water and Climate Department
NATIONAL RESEARCH INSTITUTE OF AGRICULTURE Ing.Agr. Claudio Garcia
ANDES 1365 P12 MONTEVIDEO URUGUAY cgarcia@inialb.org.uy
CP 11100 SOUTH AMERICA

In relation to garlic coeficients, Dr. Burba from Argentina
worked for more than 15 years in surface irrigation in garlic
maily red garlic. His phone number is 0054-622-70304 INTA LA
CONSULTA. He do not have e-mail.
We work in irrigation on garlic since 3 years but until now we
do not have crop coefficients. The rain is very irregular in
our country so it was not possible estimate crop consumptive.
--
Soil Water and Climate Department
NATIONAL RESEARCH INSTITUTE OF AGRICULTURE Ing.Agr. Claudio Garcia
ANDES 1365 P12 MONTEVIDEO URUGUAY cgarcia@inialb.org.uy
CP 11100 SOUTH AMERICA

1) Briefly, what is your affiliation with trickle/drip irrigation?
CSIRO research project investigating salt and water balances in vineyards.
Comparing drip irrigated vineyards with flood irrigated.
Based in the Murrumbidgee Irrigation Area in New South Wales, Australia
2) What crops or plants do you use drip irrigation on?
Drip is used on vineyards, citrus, tomatoes, cucurbits. The area under drip
irrrigation is less than 5% of horticulture. There are considerable barriers
to moving to drip.
3) If using subsurface drip irrigation, what is the average depth of
placement of the drip lateral?
Drip in perennial horticulture is surface, in vegetable crops is buried
about 150mm

4) What problems have you encountered with drip irrigation?

5) Fertigation is a real advantage of drip irrigation. What form of N, P
and K have you been trying and to what success?

6) Have you experienced a reduction in fertilizer and/or water use?

7) Do you have water quality problems? If so, how do you tackle the
situation? Filementatious algae can be a problem. Water is very turbid.

8) How frequent do you irrigate? Many times a day or just one long
session per day or several days? In peak season when ETo is 8-12mm/day
irrigation is daily otherwise every few days. Profiles need to be wetted up
before season starts, this is a heavy irrigation every day for afew days to
develop a large wetted volume

9) Do you have rodent damage? If so, how do you control the problem?
Foxes are biggest problem chewing through lines.
10) Are you pleased with the uniformity of your system or systems? Were
they designed correctly? Designs tend to be OK, although extremes of weather
may be a problem ( need large wetted volume). Management is a problem,
scheduling and irrigation times are arbitary. Drip irrigation often run too
long causing watertable rises. The 'Enviroscan" soil moisture monitoring
system is gaining acceptance and is probably the way to go.
--
Evan Christen
Irrigation and Drainage Management for Horticulture
CSIRO Division of Water Resources
Griffith Laboratory
Griffith
NSW 2680
Australia

Fax # 61 69 601600
"Errare Humanum Est" J.C. 50 B.C.

Can someone briefly describe the Environscan soil moisture
monitoring system?

Thanks,
C. Storlie

The Environscan is a soil moisture measuring instrument developed in Australia.
It works on the capacitance principle ie it measures the change in capicitance
of the soil depending on the moisture level, as there is a large difference in
the dielectric constant of soil, air and water. The Environscan measures the
change in frequency response of the soil's capitance due to its soil moisture
status. The calibration curve is supposed to be universal, but there is some
evidence that this is not so. Care has to be taken in installation as air gaps
can dramatically alter the response.

There is a similar instrument manufactured in the States. Hope this is a
simple enough explanation.

Cheers
Tony M :-)
--
*****************************************************
* Tony Meissner *
* Senior Research Scientist (Soils) *
* Primary Industries, South Australia *
* PO Box 411, Loxton SA, Australia 5333 *
* Tel. 085 95 9146 *
* Fax: 085 95 9199 *
* email meissner.tony@pi.sa.gov.au *
*********************************************************

>The Environscan is a soil moisture measuring instrument developed in
Australia. It works on the
>capacitance principle ie it measures the change in capicitance of the soil
depending on the moisture
>level, as there is a large difference in the dielectric constant of soil,
air and water. The Environscan
>measures the change in frequency response of the soil's capitance due to
its soil moisture status.
>The calibration curve is supposed to be universal, but there is some
evidence that this is not so.
>Care has to be taken in installation as air gaps can dramatically alter the
response.
>
>There is a similar instrument manufactured in the States. Hope this is a
simple enough explanation.
>
>Cheers
>Tony M :-)
>*****************************************************
>* Tony Meissner *
>* Senior Research Scientist (Soils) *
>* Primary Industries, South Australia *
>* PO Box 411, Loxton SA, Australia 5333 *
>* Tel. 085 95 9146 *
>* Fax: 085 95 9199 *
>* email meissner.tony@pi.sa.gov.au *
>*********************************************************
>
>
Tony,

Please explain why the calibration curve use for the Enviroscan is not
universal.

Could you quote me your source &/or evidence that it is not so??

Cheers Peter M.

--
Peter Moller
Irrigation Agronomist

Agrilink
P.O. Box 260
Bassendean
Western Australia 6054

Tel: 09 275 9990
Fax: 09 275 9991

> Can someone briefly describe the Environscan soil moisture
>monitoring system?
>
>Thanks,
>C. Storlie
>
>
>

If you require detailed information regarding the Enviroscan Soil Moisture
Monitoring System, contact the manufacturer:

Sentek

Ric Gatto
69 King William St
Kent Town
South Australia 5067

Tel: + 61 8 363 0839
Fax: + 61 8 362 8400

Regards Peter Moller

--
Peter Moller
Irrigation Agronomist

Agrilink
P.O. Box 260
Bassendean
Western Australia 6054

Tel: + 61 9 275 9990
Fax: + 61 9 275 9991

In a message dated 95-09-14 07:40:37 EDT, you write:

>
>

I have an irrigation management company and have been in providing irrigation
services to growers in the San Joaquine Valley of California. We currently
use ET modeling to schedule field crops and neutron probes for trees and
vines. I have used almost every technology available during the past 20
years including tensiometers, gypsum block, various ceramic cup type devices
measuring soil suction, IRTs, etc.

I have started to look at Enviroscan and the technology appears sound. The
keys to success is the frequent logging of soil moisture. The manufacture
has some really slick software from which you can analize soil moisture use
patterns. The equipment is though quite expensive.

Anyone who has practical, commericial experience?
--
Ron Brase
Crop Care Services
Fresno, California

The calibration equation used in the software of the EnviroSCAN soil moisture
monitoring system is deemed "universal" as it has been generated using
calibration data obtained from varying soil types. This data was generated by
the CSIRO and Department of Agriculture in Australia and the United States
Department of Agriculture in California. This equation is supplied as the
default equation in the software and is more than adequate for the majority of
users that are using the data for irrigations scheduling purposes. There never
will be a soil moisture sensing system that would not require a calibration
process (destructive sampling) to be performed if the user requires accurate
absolute values on their particular soil type. The software provided with the
EnviroSCAN has the ability for the user to enter their own calibration
constants/equations.
--
Rick Gatto
Sentek Pty.Ltd.
69 King William St.
Kent Town
South Australia 5067

Regarding commercial application of the enviroscan:
We have used it in vineyards with trickle and flood irrigation.
Can set refill points by assessing the point of inflection on the soil
moisture depletion curve.
Can assess depth of water extraction = root zone depth.
Can assess water use as vines come out of dormancy, extraction patterns and
root development.

Most importantly it gives a real time assesment of the irrigation practice,
depth of wetting, water past the root zone and refill. It also helps to deal
with summer rainfall, was the rain effective?, to what depth.

the cost of 32 probes + logger + software is minimal compared to capital
investment in a vineyard
With current prices the cost would be returned with a 2 - 6 % increase in
yield in a 40 ha vineyard

The main drawback is a: maximum 8 sites per logger, finding representative
sites in vineyard. however the cost of the access tube is minimal thus many
can be installed and the probes moved around. The problem of tube
installation appears to be largely solved. Soils that display a large degree
of swell/shrink could be a problem if allowed to dry down to shrinkage
limits. We have such soils but high watertables rarely allow excessive cracking.

--
Evan Christen
Irrigation and Drainage Management for Horticulture
CSIRO Division of Water Resources
Griffith Laboratory
Griffith
NSW 2680
Australia

Fax # 61 69 601600
"Errare Humanum Est" J.C. 50 B.C.

When you speak of costs, could you be more specific. Even Ball park numbers
would be helpful.

>
>The calibration equation used in the software of the EnviroSCAN soil moisture
>monitoring system is deemed "universal" as it has been generated using
....

Is that similar in function to the Troxler unit?
Steve Jordan @ Second Foundation

>In a message dated 95-09-14 07:40:37 EDT, you write:
>
>>
>>
>
>I have an irrigation management company and have been in providing irrigation
>services to growers in the San Joaquine Valley of California. We currently
>use ET modeling to schedule field crops and neutron probes for trees and
>vines. I have used almost every technology available during the past 20
>years including tensiometers, gypsum block, various ceramic cup type devices
>measuring soil suction, IRTs, etc.
>
>I have started to look at Enviroscan and the technology appears sound. The
>keys to success is the frequent logging of soil moisture. The manufacture
>has some really slick software from which you can analize soil moisture use
>patterns. The equipment is though quite expensive.
>
>Anyone who has practical, commericial experience?
>
>Ron Brase
>Crop Care Services
>Fresno, California
>
>

Dear Ron,

I provide a water management service to irrigation managers in Western
Australia to a range of horticulture crops, turf and effulent disposal
systems. I phased out the neutron probe 4 years ago and now utilise the
Enviroscan Soil Moisture Monitoring System. It provides a richer picture of
what is happening in the soil profile both in the root zone & below due to
its ability to continously log soil moisture. Irrigation agronomists
Australia wide have installed over 300 systems of the latest version (RT5)
over the last 18 months and have plenty of commerical experience
demonstrating that the economic benifits far out way the capital cost. We
have done cost analysis to compare the three year cost of a range of soil
measuring devices & find that the Enviroscan is in the same cost bracket.

My business has changed since providing a neutron probe service in 1990 with
a small group of customers limited to one region, to a business that
utilises the Enviroscan with a broad range of customers spread 1000km north
of Perth to 500km south of Perth. I utilise remote downloading & modem for
data transfer & support whilst the soil moisture content is collected every
day (60 min intervals) on site.

If you need further info please contact:

--
Peter Moller
Irrigation Agronomist
Agrilink

PO Box 260
Bassendean
Western Australia 6054

Tel: + 61 9 275 9990
Fax: + 61 9 275 9991
Email: Agrilink@iinet.net.au

Regards Peter Moller.

Sensors and automated irrigations have been previously discussed on Trickle-L
(circa April 1995). However, no mention of any particular research (i.e. in
abstract of the week format) has dealt with sensor actuated irrigation.
Presented below is abstract #6 which discusses the issue of tensiometer
actuated irrigations in apple orchards.

As stated back in April, > "Setting a clock timer is considered 'automated',
but doesn't allow for seasonal anomalies of climate. One could over irrigate
on a unseasonably cool day or under irrigate on a strange hot day". < The one
of the most effective ways to sense a need for irrigation is to monitor the
soil moisture status.
*****************************************************************
Soil Sensor Actuated Microirrigation of Apples

M. Meron, R. Assaf, B. Bravdo, R. Wallach, R. Hallel, A. Levin
and I. Dahan

A field experiment was initiated in 1992, at Matityahu Hort. Exp.
Farm, near Baram, Israel, to develop and test a soil sensor-
actuated automatic irrigation system and to optimize sensor
actuation thresholds for fruit yield and quality. Evaluation of
the effect of wetted soil volumes on water use, fertility and
vigor of apple orchards was a secondary objective. Irrigation was
applied through one or two drip laterals per row, or by one
mini- sprinkler per tree, each arrangement doubling the wetted
soil volume from the previous one. Analog output
transducer-equipped tensiometers actuated irrigation at preset
thresholds of 15, 25, and 35 kPa (.15, .25 and .35 bar) soil water tensions*,
and stopped irrigation when tension dropped to 10 kPa (.10 bar) at 0.4 m (16
in.)
depth, thus eliminating deep percolation. The control system operated as
predicted by initial simulation and the feasibility of the
concept was demonstrated.

Highest yields** were achieved at 25 kPa (.25 bar) soil water tension
actuation, applying 450-550 mm (18-22 in.) water. Lower tension thresholds of
15 kPa (.15 bar), with 650-750 mm (26-30 in.) water applied, did not raise
yields but increased fruit size and trunk growth. High thresholds of 35 kPa
(.35 bar)
with only 350 mm (14 in.) water, decreased both yield and vegetative
indicators.

Mini-sprinklers used considerably more water than drippers.*** No
recognizable differences in water use were found between single
and double drip lines per row.

More experimentation will be needed to ensure that the optimal
threshold (25 kPa or .25 bar) treatment, will maintain high yields, without
negatively effecting orchard vigor and longevity.

Keywords: Irrigation control, Automation, Soil suction, Threshold
limits, Water use efficiency

Additional information:

Soil type was stony, brown clay loam. Tensiometers were placed .3m (12 in.)
tangential to drip emitter pattern and 0.6m (24 in.) diagonally from the
center of mini-sprinkler pattern at maximum irrigation intensity. The tension
from the tensiometers were monitored by the minute. The monitoring was done
using a Campbell Scientific 21x micrologger-controller.

*Note: An increase in soil tension is associated with decreasing thickness of
hydration which surrounds the soil-particle surface...thus increasing tension
is associated with decreasing soil moisture

** 4-5.1 kg/m2 or 17.8-22.7 tons/acre
***According to my calculations, 222 mm or 8.7 in. on average.

Abstract taken from paper found on pages 486 to 491 in Proceedings of 5th
International Microirrigation Congress, April 2-6, 1995, Orlando, Florida.
American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph,
Michigan 49085-9659, USA. Phone: 616-429- 0300 FAX: 616-429-3852 EMAIL:
HQ@ASAE.ORG

--
Richard Mead
Trickle-L owner/manager
USDA-ARS-WMRL

>
>Peter, could you please send me some information on the Enviroscan Soil
>Moisture Monitoring System........

>Thank you.
>Scott Good
>
>
>Scott M Good
>6341 Wiley ST
>Hollywood, Florida, USA 33023
>
>E-mail: Scottgood@aol.com
>
>
_________________________________________

Scott,

Thanks for for enquiry. I will post detailed info to you regarding the
Enviroscan specifications and also a copy of two technical papers, one
presented at the Irrigation Assoc., of Australia's national conferance in
1994, outlining a case study of the economic benefits of irrigation
scheduling of russet burbank potatoes.This was using the Enviroscan to
collect continous soil moisture data & a water management service to provide
the grower with agronomic support.

The second paper outlines a case study of continous soil moisture monitoring
in hardwood plantations irrigated with secondary treated effluent.

Agrilink provides an integrated approach to water management in horticulture
in Western Australia. The main areas are soils, irrigation system
infrastructure & irrigation scheduling.

Soils:
a proposed irrigation development is soil mapped according to the soils
water holding capacity. Soils with the same RAW value (readily available
water) are grouped together to form a management unit. This is calcualted by
adding up the millimetres of readily available water in each textural layer
in the potential rootzone. A irrigation management plan is the outcome of
this process which directly influences irrigation system design, farm layout
(wind breaks, sheds), root stock &/or variety selection.

Irrigation system infrastructure:
the irrigation system must then be designed so as to deliver water to each
management unit as defined in the soil mapping process, independently to the
other units. This requires innnovative design which has a flexible control
system to turn each management unit on at the demand of the crop & a pump
system that can handle a range of flow rates from small to large units at
one time. The system must also be uniform in application of water across
the management unit. This is very important if regulated deficit irrigation
(RDI) is being used to control vegetative growth.

Scheduling:
Once the soils have been grouped & an irrigation system has been designed
based on the soil data then effective irrigation scheduling can occur. My
customers purchase the Enviroscan & I install it. I use this system to
collect the soil mositure data, as it is in situ which saves me &/or the
grower time & money in data collection, it provides a richer picture as it
is continous (every hour) and the software is easy to use so as to interpret
the data to understand the crop water use, stress, water logging, depth of
irrigation etc.

The benefits my customers are getting are improved efficiency with the use
of water, power, & fertilizer, improved quality (larger friut size, minimal
variation), improved yield & a more sustainable production system (reduction
in leaching of water & fertilizer).

The benefits are the result of being able to manage the soil moisture in the
rootzone with accurate info and making the right decision to irrigate based
on the actual crop's water requirements.

For further information on the Enviroscan Soil Moisture Monitoring System
contact the manufacturer:

Ric Gatto
Sentek
69 King William St
Kent Town
South Australia 5067

Tel: + 61 8 363 0839
Fax: + 61 8 362 8400

Email: 100237.1224@compuserve.com

--
Regards Peter Moller
Irrigation Agronomist

Agrilink
P.O. Box 260
Bassendean
Western Australia 6054

Tel: + 61 9 275 9990
Fax: + 61 9 275 9991

Email: agrilink@iinet.net.au

>Peter Moller
>Agrilink
>
>I have been watching with interest the discussion on Trickle-List re the
>Enviroscan soil water monitoring equipment. Where can I get more info here in
>N.S.W? What is the cost of the equipment? Is it suitable for smaller
>orchard holdings? We presently use teneiometers to monitor soil moisture and
>schedule irrigations - low initial cost but is info really sound.
>
>Looking forward to hearing from you on this.
>
>
>Regards, Ed
>
>________________________________________________________
>
>Edward Biel. | WANAKA ORCHARD
> | 'High Marlowe'
>E-mail: ebiel@tpgi.com.au | 70 Old Jerusalem Road.
> | Oakdale.
>Phone/Fax: 011 61 46 596254 | New South Wales.
> | AUSTRALIA.
>
> GROWERS OF HIGH QUALITY POME AND STONE FRUIT
>________________________________________________________
>
>

Dear Edward,

Thanks for your enquiry. Across Australia a range of crops over a range of
soil types are monitored using the Enviroscan Soil Moisture Monitoring
System. Also I have a wide range of production units in Western Australia
using the Enviroscan from 10 hectares (potatoes) through 350 hectares of
drip irrigation (effulent disposal on wooded treelot). If you contact the
manufacturer they will provide you with the contact details of the nearest
agronomist who can help to determine the system costings for your sized
production system.

For further information on the Enviroscan Soil Moisture Monitoring System
contact the manufacturer:

Ric Gatto
Sentek
69 King William St
Kent Town
South Australia 5067

Tel: + 61 8 363 0839
Fax: + 61 8 362 8400

Email: 100237.1224@compuserve.com

--
Regards Peter Moller
Irrigation Agronomist

Agrilink
P.O. Box 260
Bassendean
Western Australia 6054

Tel: + 61 9 275 9990
Fax: + 61 9 275 9991

Email: agrilink@iinet.net.au

>I am an irrigation specialist (agronomist) with Alberta Agriculture at

>Strathmore, AB, Canada, and am interested in the "Enviroscan" equipment for

>determining soil moisture. We used to use neutron probes but have pretty

>well "retired" that equipment now.
>
>I would like to know how the Enviroscan equipment works, labor(time required)

>for reading, installing tubes, etc., prices, etc. Where can one obtain these

>commercially, i.e. who manufactures them? I would like to obtain some

>literature from the manufacturer of these. Any info you can e-mail would be

>appreciated. Thanks.-------------------------------------
>Name: Dennis Alexander Roll
>E-mail: rolld@cadvision.com
>Date: 03/02/95
>Time: 23:57:11
>
>...What goes around comes around....
>-------------------------------------
>
>
>

Dear Dennis,

Thanks for enquiry. It is good to hear from someone in Canada; I was born in
Hamilton Ontario but my parents moved back to Australia when I was three
years old!!

I've got the info you have requested, but it is not all on computer, so can
you email your postal address.

For further information on the Enviroscan Soil Moisture Monitoring System
contact the manufacturer:

Ric Gatto
Sentek
69 King William St
Kent Town
South Australia 5067

Tel: + 61 8 363 0839
Fax: + 61 8 362 8400

Email: 100237.1224@compuserve.com

--
Regards Peter Moller
Irrigation Agronomist

Agrilink
P.O. Box 260
Bassendean
Western Australia 6054

Tel: + 61 9 275 9990
Fax: + 61 9 275 9991

Email: agrilink@iinet.net.au

Notice of Irrigation Association of Australia Conference 14-16 may, Adelaide Australia

AUSTRALIAN SOLUTIONS

The Irrigation Association of
Australia

is pleased to announce

IRRIGATION
AUSTRALIA
1996

conference

exhibition

When: May 14th-16th 1996

Where: Adelaide Convention Centre
Adelaide, South Australia

-----------------------------------------------------------------------

Irrigation Australia '96 Conference

Held at the same time as the Expo the Irrigation Australia '96 conference is
on the theme of "Australian Solutions".

The irrigation industry in Australia has been faced with a number of major
challenges including diminishing water supplies, competition for existing
supplies, poor quality water, ageing infrastructure and industry reform.

Irrigation Australia '96 is the chance for irrigation industry professionals
to meet with their colleagues from the region and share their experience and
knowledge learned while developing solutions.

The organising committee welcomes expressions of interest form potential
delegates, speakers and exhibitors, and from any party who would like to be
included on the mailing list for Irrigation Australia '96.

------------------------------------------------------------------------

Enquiries can be made to:

Irrigation Australia '96
The Irrigation Association of Australia
PO Box 10006
Gouger Street
ADELAIDE
SOUTH AUSTRALIA 5000

Tel: 61 8 262 6311
Fax: 61 8 302 3373
Email: "sparrow.denis@pi.sa.gov.au"

Due to the recent discussion about the Sentek EnviroScan* capacitance probe
system, I thought it would be appropriate to discuss the Water Management
Research Lab's observations with Sentek* and Troxler* capacitance probes.
Both probes use a capacitance technique known as FDR (frequency domain
reflectometry).

Let me briefly discuss how a capacitance probe works (if you're rusty in
basic electronics, get out your physics book). A capacitance sensor consists
of a pair of electrodes (circular metal rings) connected to an oscillator.
When the probe is inserted into a PVC access tube installed in the field and
activated (using radio frequencies), the soil-water-air matrix around the PVC
tube forms the dielectric of a capacitor which then completes an oscillating
circuit. Changes in soil water content cause a shift in frequency.

Our lab first experimented with the Troxler Sentry* 200 AP capacitance probe.
It is a single probe/sensor portable unit, which hooks up to a multiplexer or
directly to a reading unit. Using field and boxed soil conditions we observed
the following:

a) It is extremely critical to have good sensor-tube-soil contact for
reliable estimation of soil moisture. When the soil was repacked in a boxed
condition (~ 1 meter cube.....~35 cubic ft.), better correlations were
obtained.
b) A linear calibration equation comparing frequencies vs. true volumetric
soil moisture status gave better results than factory or derived exponential
calibration equations.
c) True zone of influence readings did not begin until the probe was 30 cm (1
ft.) below the soil surface.

The Troxler Sentry 200 AP unit did not at that time (circa mid to late 1993)
have software for continuous datalogging. Hence, it was strictly a portable
unit, similar to a neutron probe whereby it is carried from probe tube to
probe tube for raw count readings.

If you want detailed information about the Troxler* probe, contact Troxler.*
I have heard through the rumor mill that the company has updated and improved
their system.

If you want detailed information concerning our results, send for the WMRL
paper entitled "Capacitance Probe Use in Soil Moisture Measurements" (Mead,
Paltineanu, Ayars and Liu). E-mail Paula Lynch at PLYNCH@CATI.CSUFRESNO.EDU
for paper requests.

About the time we were winding down our research with the Troxler* probe, we
obtained an Sentek EnviroScan* RT5 system. The Sentek Enviroscan* RT5
system is not portable but is installed as an array of probes connected to a
self contained datalogger. Each probe can attach up to 8 sensors in 10 cm (4
in.) intervals. Our initial and eventual goal was to install these probes in
our monolith lysimeters which focus on shallow saline water table
contributions to the crop root system. While the lysimeters were being
constructed, we evaluated the Sentek* probes for measurement in different
soil textures, bulk densities and soil water salinity. The Sentek* system
uses a unique calibration setup system whereby raw readings are taken in air
(Fa) and in a water basket (Fw). Sentek* defines this initial setup as
'Universal Frequency' (UF) as [Fa-F/Fa-Fw]. It is basically a ratio of the
extremes of air and water sensor readings with an actual soil reading thrown
in the numerator.

Making a long story short, we found the following:

a) There was a positive correlation between the UF and true soil volumetric
water content in three soil types and 4 bulk densities, albeit significant
differences occurred between the soil types and densities.
b) There was some curvature in the calibration equations for clay and sandy
loam soils, but only when quadratic regressions were derived.
c) As soil salinity increased, sensor moisture values were positively skewed
(looked wetter). After salinity levels of 15.4 ECe, the skewed values
leveled off. We found that using saline water in the Fw (water basket) setup
procedure seemed to lower the skewed values.

Our studies imply that there is good volumetric soil moisture measurement
using this system, yet site specific calibrations will have to be performed
for the most precise measurements. "Wetter" than normal readings might occur
from the probes when installed in saline environments.

There is concern about shrink/swell soils (2:1 expanding clays) creating air
gaps near or cracks adjacent to the access tube. According to Sentek*, there
is a slurry recipe that involves a mixture of cement, kaolinite and water in
certain ratios that is poured into the augured hole prior to access just tube
installation. We have yet to try this technique.

If you want more detailed information about the EnviroScan* RT5 system,
contact Sentek.* If you want detailed information concerning our results,
send for the WMRL paper entitled "Evaluating the Influence of Soil Texture,
Bulk Density and Soil water salinity on a Capacitance Probe Calibration"
(Mead, Ayars and Liu). Again, contact Paula at PLYNCH@CATI.CSUFRESNO.EDU .

The obvious advantages of 'both' FDR capacitance probes are:

1) Relinquished radioactive hassles (both regulation and exposure).
2) Lack of random counting error and quick response in readings.
3) Relatively light weight.
4) Good accuracy as long as there is good soil-tube contact and relatively
low saline conditions.
5) The potential to continuously monitor a soil profile (permanent
installation).
6) Access tube installation time is equivalent to neutron probe tube
installation.

Stay tuned to Trickle-L for future discussion of TDR (Time Domain
Reflectometry) probes.
--
Richard Mead
Soil Scientist
USDA-ARS-WMRL
Trickle-L owner/manager

*The USDA-ARS does not endorse the product name, but only uses it for
descriptive terminology for the benefit of the reader.

Richard,

Thanks for the tech primer on FRD's and the references for more info.
--
Scott Good
Scottgood@aol.com

Due to the interest in EnviroSCAN I have provided the following basic
information.

PRODUCT DESCRIPTION
*******************

How does EnviroSCAN work?
-------------------------

EnviroSCAN combines state of the art electronics and software in a system that
is simple to learn and practical to use.

A solar powered, central logging facility is connected by cable to probes at
each monitoring site.
Probes can be located by cable runs up to 500 metres from the logger.

Standard length probes of 0.5 metres are used for shallow rooted crops or turf
while 1, 1.5 or 2 metre probes are used for tree crops, vines and broadacre
crops such as cotton.

In research, waste water management, environmental and mining applications
probes of longer lengths such as 5, 10 or 15 metres are used. By contrast, in
hydroponic and nursery applications, probes as short as 10 or 20cm are used.

Each probe can be fitted with multiple sensors. The sensors snap on to the
probe with slots provided every 10 centimetres allowing the user to specify the
sensor depths.

Up to 32 sensors are supported by 1 logger on 2 cable runs of up to 16 sensors
with up to 4 probes on each cable run in any configuration.

The sensors utilise electrical capacitance to measure soil moisture. The
capacitance field generated between the two metal plates of the sensor extends
beyond the PVC access tube into the surrounding soil. The capacitance field is
affected by the dielectric constant of the material the field passes through.
The dielectric of soil, regardless of whether it is sand, loam or clay, is
relatively constant ranging from 3 to 6 while air is 1 and water is 80.

Soil moisture is determined by the change in the amount of air and water in the
soil structure. This changes with rainfall, irrigation, drainage, evaporation
and crop water use.

Using capacitance the changing ratio of air and water at each soil depth can be
measured very quickly and accurately.

The sensor readings are converted to volumetric soil water content using a
default calibration equation in the software that takes into account the varying
soil types. This calibration was established using gravimetric sampling which is
the international standard used to calibrate methods such as the Neutron Probe.

Data can be logged at intervals as short as every one minute and is downloaded
to a computer for display. In sandy soils and vegetable crops it is usual to
log at 10 minute intervals while in heavy soils and tree crops and vines it is
usual to log at 15 to 30 minute intervals. Data is displayed in easy to read
graphs allowing growers to make quick decisions about when to irrigate and how
long to irrigate.

EnviroSCAN has been extensively field tested with over 500 systems installed
Australia wide.
Independent testing by CSIRO, Department of Agriculture and Research groups have
confirmed the accuracy and reliability of the information provided by
EnviroSCAN.

MARKET INFORMATION
******************

Who Uses EnviroSCAN?
--------------------

EnviroSCAN is currently in use in the following crop types:

Almonds
Apples
Apricots
Artichokes
Asparagus
Avocados
Bananas
Berries
Broccoli
Brussell Sprouts
Capsicums
Carrots
Cashews
Celery
Cherries
Citrus - Orange, Lemon, Lime, Mandarin
Cotton
Cucumber
Eggplant
Flowers
Grapes - Nursery, Table, Wine
Hops
Lettuce
Lychees
Macadamias
Mangos
Onions
Pasture
Peaches
Pears
Peas
Potatoes
Pistachio Nuts
Plums
Rockmelons
Snow Peas
Strawberries
Sugarcane
Sweetcorn
Tomatoes - Field, Hydroponic
Turf
Watermelon
Woodlots

Waste Water Applications
Mining Applications
Hydroponics and Nurseries

Growers, Grower Groups, Corporate Growers
Government Departments (CSIRO, DPI, etc)
Researchers, Consultants

EnviroSCAN is suitable for use in all common soil types from course sand to
cracking clay and will work in all soil moisture ranges from saturated to powder
dry.

DISTRIBUTION
************

The following are distributors of the EnviroSCAN and their contact details.

AUSTRALIAN DISTRIBUTORS
-----------------------

Northern Queensland
Piccone Horticultural
Ask for Marie Piccone
Phone: 071 254 955
Fax: 071 254 961

Southern Queensland
Crop Tech Research
Ask for John Hall
Phone: 071 597 433
Fax: 071 597 470

Northern Rivers
Hortech Services
Ask for Peter Broomhall
Phone: 07 204 4521
Fax: 07 886 0389

Central Northern NSW
McGregor Gourlay
Ask for Paul Castor
Phone: 067 524 122
Fax: 067 525 025

Central NSW/Hunter Valley
Hacom Pty Ltd
Ask for Warwick Harrison
Phone: 063 640 257
Fax: 063 640 268

MIA / Griffith
Quiprite Pty Ltd
Ask for Andrew McLennan
Phone: 069 623 766
Fax: 069 624 458

Northern Victoria
Soil Moisture Monitoring Svcs
Ask for Adrian Orloff
Phone: 058 219 069
Fax: 058 219 079

Southern Victoria
Irritech Management Svcs
Ask for Graham Palmer
Phone: 059 896 216
Fax: 059 896 086

Tasmania
Serve-Ag Pty Ltd
Ask for Peter Rand
Phone: 004 270 800
Fax: 004 270 801

South Australia / Sunraysia
Yandilla Park Services
Ask for Trevor Sluggett
Phone: 085 861 200
Fax: 085 851 394

Western Australia
Agrilink Technology
Ask for Peter Moller
Phone: 09 275 9990
Fax: 09 275 9991
Email: agrilink@iinet.net.au

Northern Territory
Darwin Irrigation Supplies
Ask for Brian Hood
Phone: 089 411 955
Fax: 089 811 161

CALIFORNIA - USA
----------------

Handley Irrigation
Ask for Dale Handley
Phone: 209 798 2184
Fax: 209 798 2184
E-Mail: 71242.2636@compuserve.com

Sentek is seeking distributors in other countries including Israel, South
Africa, South America, New Zealand and Europe. Distributors are typically
agronomic consultancy companies that provide an irrigation scheduling service
(usually utilising the Neutron Probe) and maintain high credibility in their
geographic area. The infrequency of data combined with the high cost of
operating the Neutron Probe are the main reasons these companies are seeking
alternate technologies to enable them to provide a service which is more
economically viable at the same time providing real time agronomically credible
data.

PRICING
*******

Pricing on the EnviroSCAN systems varies greatly dependent upon property size,
crop type, soil type, etc. For general information purposes a basic system
comprising 2 x 0.5 metre probes and 8 x sensors would cost approximately
US$6,000 whereas as an 8 x 1.5 metre probe, 32 sensor system would cost
approximately US$15,000. For a detailed quotation for your property/application
please contact your nearest distributor or Sentek.

GENERAL
*******

For further information please contact:

Manager/Product Development - Rick Gatto
Marketing/Distribution/Pricing - Nigel Robinson
Software - Gabriel Levy
Agronomy - Peter Buss

Sentek Pty Ltd, 69 King William Street, Kent Town SA 5067, Australia

Phone +61 8 363 0839
Fax +61 8 362 8400
E-Mail 100237.1224@compuserve.com.

unsubscribe

What a long strange trip its been!

I previously posted the following message. I will be in West Texas / Eastern
NM / Oklahoma during the week of Oct 2-6 and would like to interview with
those in the area who might be in need of my skills either now or in the near
future.

Will be checking messages and E-mail on a regular basis.

Thanks,
Randall Merriott
-------------------------------------------------------------

Anyone know of an opening for an irrigation engineer? B.S. Ag Engineering,
EIT, Irrigation Association Drip/Micro CID. Four years design experience.
Creative, hard-working, dependable, team player. Ten years of computer
experience. Likes working in the field and getting hands dirty. Willing to
relocate. Especially interested in opportunities that would involve overseas
travel.

For full resume send E-mail to Merriott@aol.com or call 407-770-2056.

Thanks, Randall Merriott

In a message dated 95-09-25 01:37:22 EDT, you write:

Over the past few years I have become very reliant upon neutron probe data.
Looking at the grapevines and kneading the soil is good only to a point ...
but only with accurate soil moisture data can I anticipate how the vine will
respond to changing weather conditions. Not only do I want to confirm that
field capacity has actually been reached in spring (or determine a saturated
condition if it exists), but also must manage our grapes in a fairly tight
range of high 'water deficiency' as we approach harvest. Thus I desire
fairly high volumetric accuracy over a wide range.

>How does EnviroSCAN work?
>Using capacitance the changing ratio of air and water at each soil depth can
be
>measured very quickly and accurately.
>

I have completely oriented my thinking and decision criteria around neutron
probe results ... specifically water status in terms of inches water per foot
of soil.

How accurately and repeatably can EnviroSCAN compare to neutron probe data?
Does it provide equivalent information? Through what range of moisture
does EnviroScan maintain its accuracy?

The following is abstract #7 in a series abstracts selected from the 5th
International Microirrigation Congress this past April in Florida. The
abstract is presented to stimulate interest and discussion on Trickle-L.

Success of Drip in India: An Example to the Third World

S. K. Suryawanshi

The sixties saw the rapid development of agriculture in India through the
intensive use of modern agricultural inputs such as water energy, fertilizer,
chemicals, and high-yielding crop varieties. The input-based strategy was
successful in that the agricultural production increased three-fold during
the past four decades. But predominant use of water and chemicals resulted in
a paradoxical situation in which soils in the Northern Plains turned saline,
whereas in the South, the water table went down due to excessive pumping.
Both shallow and deep water tables affected agricultural productivity to a
point of stagnation.

In the late eighties, drip irrigation gained popularity with its inherent
advantages like saving water and use in problematic soil. Various research
institutes conducted experiments on drip irrigation and made people aware of
its benefits. Some manufacturers also conducted their own studies first by
importing the materials before venturing into commercial production of drip
systems. The farming community ususally believes only after personally
observing the benefits. Today, more than a 60,700 hectare are is brought
under irrigation convering more than 30 crops. Farmers from various places
communicated their experiences of drip irrigation on various crops like
sugarcane, cotton, grapes, banana, pomegranate, vegetables, tea, ber*,
flowers, etc. The increase in yield as compared to conventional irrigation
methods is from 20 to 100 %, whereas saving in water ranges from 40% to 70%.

The results achieved by drip irrigation in a developing country like India
can show many third world countries optimum utilization of resources for
increased agricultural production.

Keywords: Drip (micro) irrigation, agriculture, farmer, water, yield

Abstract taken from paper found on pages 347 to 352 in Proceedings of 5th
International Microirrigation Congress, April 2-6, 1995, Orlando, Florida.
American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph,
Michigan 49085-9659, USA. Phone: 616-429-0300, FAX: 616-429-3852
E-mail:HQ@ASAE.ORG

* Anyone know what "ber" is??

===========================================================================
Additional information from the paper.

India needs to feed more than 1 billion people by the year 2000. An increase
of 80 million tons of food grain will be needed in less than a decade (a 50 %
increase).
There are 140 million arable hectares (346 million acres) in India with 41.2
million hectares (102 million acres) being irrigated. The 60,700 hectares
(150,000 acres) under drip quoted in the abstract represents merely 0.15% of
the irrigated area.

Other interesting factors mentioned were: In India using drip irrigation,
labor savings up to 50 - 60 % can be found, poor quality water and soils can
be used, fertilizer savings of up to 30 % are being observed.

Specific crops with noted yield increases and water savings:
Banana (52% yield increase, 45% water savings)
Grapes (23% yield increase, 48% water savings)
Sweet lime (50% yield increase, 61% water savings)
Pomegranate (98% yield increase, 45% water savings)
Sugarcane (33% yield increase, 56% water savings)
Tomato (50% yield increase, 39% water savings)
Watermelon (88% yield increase, 36% water savings)
Cotton (27% yield increase, 53% water savings)
Papaya (75% yield increase, 68% water savings)
Sweet potato (39% yield increase, 60% water savings)

If anyone has additional information about developing countries using
microirrigation irrigation, please feel free to contribute.
--
Richard Mead
Trickle-L owner/manager