msu-ceco/aec_v1 · Datasets at Hugging Face

text stringlengths 0 1.09k
Graph 3.
Readings from the tensiometers at Whittier Narrows Golf Course show how tensiometers can be used as a guide for regulating the frequency and time length of irrigation when tensiometers are not attached to automatic timing devices.
applied from September through December of 1964.
Under the completely automatic tensiometer-controlled system, only 4.5 hours or 39,150 gallons of water were applied.
This represents about a 57% reduction in water use and cost.
A similar installation was established on a Seaside bentgrass golf green at the Deauville Country Club in Tarzana, Cali.
fornia.
A sprinkler application test showed one green to have a uniformity coefficient of 88.9% and a ratio of maximum-to-minimum application of 2 to 1.
While these trials were being conducted, the green was aerified monthly from May through September, using.inch spoons, with the holes left open.
This installation was similar to that at UCLA, except that the tensiometers were installed at 2-inch and 5-inch depths at the edge of the green.
Irrigation was initiated when the shallow instrument rose to 23 eb and terminated when it dropped to 5 cb.
Corresponding readings for the deep instrument were 28 cb and 10 cb.
The termination reading for the deep instrument has since been raised to 20 cb, for it was decided that more water was being applied than necessary.
When irrigation is needed, water is applied for 10 minutes each hour and up to eight times during the night.
Information available for the first three months' operations at the Deauville Country Club shows that irrigation for 35 minutes every other night would have applied 95,400 gallons in 26.5 hours.
Under the tensiometer-controlled system, only 16 hours or 57,600 gallons of water were used.
This represents about a 40% reduction in water use, The superintendent at Deauville reported that after the first five to six weeks of automatic tensiometer-controlled irrigation, about 75 to 80% less hand watering was re-
quired on this green as compared with other nearby greens.
Tensiometers can also be beneficial without completely automatic controls, as demonstrated at the Whittier Narrows Golf Course in El Monte.
Prior to installation of the instruments at 2and 5-inch depths, irrigations were set for 15 minutes every night.
During the summer, even longer irrigations were applied.
Tensiometers were installed on June 1, 1964.
With tensiometers to schedule frequency and duration of irrigations, only 14,560 gallons of water were applied in 22.3 hours during June and July, 1964 (graph The previous schedule would have required 83,265 gallons in 151/4 hours.
This is a reduction of 83% in water use.
Often the beauty of turfgrasses used for recreational purposes is more important than savings in water and money.
However, in the trials reported here, the turf remained healthy and beautiful, and the golf greens continued in good playing condition.
Also, in many instances, deeper, more vigorous rooting resulted where tensiometers were used to determine turfgrass irrigation.
Tensiometers, therefore, can be used successfully as a guide to determine frequency and duration of irrigation for turfgrass areas-either from installations associated with manual control or from completely automatic systems.
Also, savings in both money and water are possible in varying degrees, since most turf authorities agree that overirrigation is the rule rather than the exception.
For such systems to operate successfully, however, complete irrigation management must include good distribution of water from the sprinklers with application rates not in great excess of the water infiltration capacity of the soil, a regular program of thatch control and soil aeration where needed.
Turfgrass superintendents are usually encouraged by the use of tensiometers to improve their irrigation practices.
Wayne C.
Morgan is Tur/grass Farm Advisor, Los Angeles County, and Albert W.
Marsh is Agricultural Extension Ser.
vice Irrigation and Soils Specialist, University of California, Riverside.
Information included in this report is from a paper first presented before the American Society of Agronomy, Kansas City, Missouri, November, 1964.
R ECENT FIELD EXPERIMENTS have demonstrated that certain soils in the San Joaquin Valley need to be fertilized with heavy applications of potassium to obtain maximum production.
The question of what effect these high K additions have on the nutritional status of other plant-essential elements for cotton has never been answered.
but K-induced magnesium deficiencies had been demonstrated for a number of crops by previous investigators.
A greenhouse experiment to evaluate the effect of K on the Mg status of the cotton plant, under California conditions, was conducted at Riverside.
Distinct K.
and Mg.deficiency symptoms, along with the associated plant tissue analyses, were developed.
Cotton was grown for three months in sand cultures.
Each unit consisted of a 100-liter reservoir for the nutrient solution and four 3-gallon crocks filled with sand to support the plants.
The assembly was equipped so that each sandfilled pot could be periodically irrigated with the nutrient solution.
The nutrient solutions percolated through the sand and drained back into the reservoirs.
Potassium and magnesium were added in a factorial design in amounts necessary to produce solution concentrations of 1, 10, and 50 ppm.
All other nutrients were added in amounts sufficient for plant growth.
The solution concentrations in the reservoirs were maintained by periodic additions.
After a three-month growth period, the plants were weighed, the bolls were counted, and the petioles were separated for chemical analyses.
A summary of the main effects of K and Mg nutrition on the plant weight, number of bolls, and levels of K and Mg in the petioles is shown in the table.
An increase in yield, as indicated by plant weight and boll count, occurs as the level of K in the nutrient solution is increased from 1 to 50 ppm.
For Mg, an increase in yield is observed as the concentration of the nutrient solution is increased from 1
to 10 ppm, but further increase in Mg levels did not result in increased yield.
Symptomatology and chemical analyses demonstrated that those plants grown on substrate levels of 1 and 10 ppm K were deficient in K, and those plants grown on the 1-ppm Mg substrate level were deficient in Mg.
A mutually antagonistic effect of K and Mg on the uptake of each element is indicated by the plant analysis data presented in the table.
At 50 ppm Mg in the substrate, the petiole contents of Mg drop from 1.9 to 0.3% as the K level in the substrate is increased from 1 to 50 ppm.
Similar antagonistic effects of Mg on K are indicated.
For example, at the 10-ppm level , the K content of the petioles is decreased from 2.2 to 0.9%.
Visual symptoms of plants known to be deficient in K and Mg are illustrated in the photos.
Leaf symptoms indicative of K and Mg deficiencies are sufficiently different to be distinguished from one another.
Leaves from the K-deficient plants exhibit leaf marginal chlorosis and
Progress Reports of Agricultural Research published monthly by the University of Callfornia Division of Agricultural Sciences.
William W.
Paul Manager Agricultural Publications Jerry Lester Editor Peggy Anne Visher Assistant Editor California Agriculture
Articles published herein may be republished or reprinted provided no advertisement for a commercial product is Implied or imprinted.
Please credit: University of California Division of Agricultural Sciences.
California Agriculture will be sent free upon request addressed to: Editor, California Agriculture, 207 University Hall.
2200 University Avenue, Berkeley.
California 94720.
To simplify the information in California Agriculture it is sometimes necessary to use trade names of products or equipment.
No endorsement of named products is intended nor is criticism implied of similar products which are not mentioned.
Automatic turf irrigation showing instrument area and cans set out to measure water distribution.
Evapotranspiration for Turf Measured with Automatic Irrigation Equipment
S.
J.
RICHARDS L.
V.
WEEKS
Automatic irrigation, controlled by instruments capable of detecting moisture needs of plants, has been successfully used to study evapotranspiration rates for turfgrass at Riverside.
Tests indicated that frequent, automatic sprinkling with relatively low-volume applications per irrigation might allow easy measurement of evapotranspiration.
Tensiometers, acting as hydrostats, can turn "on" irrigation water when needed, but unpredictable flow rates in soils make it necessary to use a separate timing mechanism to set the duration or amount to be applied and turn the water off.
Automatic irrigation management programs are now feasible, under many conditions, using tensiometers or other instruments responding to an energy variable of water in the soil.
However, to be accurate for evapotranspiration measurements, such procedures should account for water losses below the rooting depths in the soil.
T ENSIOMETERS measuring soil water conditions have been in use since about 1935 and the principles of automatic irrigation using a tensiometer were established as early as 1943.
Commercial development of fully automatic irrigation has progressed first in connection with systems for irrigating turf and ornamental plantings.
One such system, available for about 10 years, uses a tensiometer-type hydrostat to indicate a need for irrigation and a small electric clock motor to control the time of day or night when water is to be applied.
The duration of irrigation on each of several pipeline sections is independently controllable.
This study was conducted on a 120 220-foot turf plot located south of a large intramural field at the University's Riverside campus.
Asphalt parking and play areas occupy portions of the east and west sides.
To the south is a relatively wide expanse of trees and turf plantings.
The immediate turf area is enclosed by shrubbery borders which are watered from separate irrigation lines.
The regular sprinklers on the north half of the area were capped in July, 1961, and a separate irrigation system was installed using gear-driven rotary pop-up sprinkler heads.
The porous cup of the hydrostat was located at an average depth of 31/2 inches.
When soil suction exceeded 20 centibars at this depth, a one-hour sprinkling was started at 2 a.m.
At each irrigation, an average of 1/2 inch of water was applied automatically by meter readings.
The south half was irrigated from a semiautomatic system operating the sprinklers for a specified period each night when turned on manually.
A separate meter was installed to measure the water used under this system.
To evaluate the automated control, tensiometers were installed at five depths in two locations selected for average turf vigor.
Cans were used to measure the depth of water applied at the two instrument areas and near the hydrostat.

Graph 3.

Readings from the tensiometers at Whittier Narrows Golf Course show how tensiometers can be used as a guide for regulating the frequency and time length of irrigation when tensiometers are not attached to automatic timing devices.

applied from September through December of 1964.

Under the completely automatic tensiometer-controlled system, only 4.5 hours or 39,150 gallons of water were applied.

This represents about a 57% reduction in water use and cost.

A similar installation was established on a Seaside bentgrass golf green at the Deauville Country Club in Tarzana, Cali.

fornia.

A sprinkler application test showed one green to have a uniformity coefficient of 88.9% and a ratio of maximum-to-minimum application of 2 to 1.

While these trials were being conducted, the green was aerified monthly from May through September, using.inch spoons, with the holes left open.

This installation was similar to that at UCLA, except that the tensiometers were installed at 2-inch and 5-inch depths at the edge of the green.

Irrigation was initiated when the shallow instrument rose to 23 eb and terminated when it dropped to 5 cb.

Corresponding readings for the deep instrument were 28 cb and 10 cb.

The termination reading for the deep instrument has since been raised to 20 cb, for it was decided that more water was being applied than necessary.

When irrigation is needed, water is applied for 10 minutes each hour and up to eight times during the night.

Information available for the first three months' operations at the Deauville Country Club shows that irrigation for 35 minutes every other night would have applied 95,400 gallons in 26.5 hours.

Under the tensiometer-controlled system, only 16 hours or 57,600 gallons of water were used.

This represents about a 40% reduction in water use, The superintendent at Deauville reported that after the first five to six weeks of automatic tensiometer-controlled irrigation, about 75 to 80% less hand watering was re-

quired on this green as compared with other nearby greens.

Tensiometers can also be beneficial without completely automatic controls, as demonstrated at the Whittier Narrows Golf Course in El Monte.

Prior to installation of the instruments at 2and 5-inch depths, irrigations were set for 15 minutes every night.

During the summer, even longer irrigations were applied.

Tensiometers were installed on June 1, 1964.

With tensiometers to schedule frequency and duration of irrigations, only 14,560 gallons of water were applied in 22.3 hours during June and July, 1964 (graph The previous schedule would have required 83,265 gallons in 151/4 hours.

This is a reduction of 83% in water use.

Often the beauty of turfgrasses used for recreational purposes is more important than savings in water and money.

However, in the trials reported here, the turf remained healthy and beautiful, and the golf greens continued in good playing condition.

Also, in many instances, deeper, more vigorous rooting resulted where tensiometers were used to determine turfgrass irrigation.

Tensiometers, therefore, can be used successfully as a guide to determine frequency and duration of irrigation for turfgrass areas-either from installations associated with manual control or from completely automatic systems.

Also, savings in both money and water are possible in varying degrees, since most turf authorities agree that overirrigation is the rule rather than the exception.

For such systems to operate successfully, however, complete irrigation management must include good distribution of water from the sprinklers with application rates not in great excess of the water infiltration capacity of the soil, a regular program of thatch control and soil aeration where needed.

Turfgrass superintendents are usually encouraged by the use of tensiometers to improve their irrigation practices.

Wayne C.

Morgan is Tur/grass Farm Advisor, Los Angeles County, and Albert W.

Marsh is Agricultural Extension Ser.

vice Irrigation and Soils Specialist, University of California, Riverside.

Information included in this report is from a paper first presented before the American Society of Agronomy, Kansas City, Missouri, November, 1964.

R ECENT FIELD EXPERIMENTS have demonstrated that certain soils in the San Joaquin Valley need to be fertilized with heavy applications of potassium to obtain maximum production.

The question of what effect these high K additions have on the nutritional status of other plant-essential elements for cotton has never been answered.

but K-induced magnesium deficiencies had been demonstrated for a number of crops by previous investigators.

A greenhouse experiment to evaluate the effect of K on the Mg status of the cotton plant, under California conditions, was conducted at Riverside.

Distinct K.

and Mg.deficiency symptoms, along with the associated plant tissue analyses, were developed.

Cotton was grown for three months in sand cultures.

Each unit consisted of a 100-liter reservoir for the nutrient solution and four 3-gallon crocks filled with sand to support the plants.

The assembly was equipped so that each sandfilled pot could be periodically irrigated with the nutrient solution.

The nutrient solutions percolated through the sand and drained back into the reservoirs.

Potassium and magnesium were added in a factorial design in amounts necessary to produce solution concentrations of 1, 10, and 50 ppm.

All other nutrients were added in amounts sufficient for plant growth.

The solution concentrations in the reservoirs were maintained by periodic additions.

After a three-month growth period, the plants were weighed, the bolls were counted, and the petioles were separated for chemical analyses.

A summary of the main effects of K and Mg nutrition on the plant weight, number of bolls, and levels of K and Mg in the petioles is shown in the table.

An increase in yield, as indicated by plant weight and boll count, occurs as the level of K in the nutrient solution is increased from 1 to 50 ppm.

For Mg, an increase in yield is observed as the concentration of the nutrient solution is increased from 1

to 10 ppm, but further increase in Mg levels did not result in increased yield.

Symptomatology and chemical analyses demonstrated that those plants grown on substrate levels of 1 and 10 ppm K were deficient in K, and those plants grown on the 1-ppm Mg substrate level were deficient in Mg.

A mutually antagonistic effect of K and Mg on the uptake of each element is indicated by the plant analysis data presented in the table.

At 50 ppm Mg in the substrate, the petiole contents of Mg drop from 1.9 to 0.3% as the K level in the substrate is increased from 1 to 50 ppm.

Similar antagonistic effects of Mg on K are indicated.

For example, at the 10-ppm level , the K content of the petioles is decreased from 2.2 to 0.9%.

Visual symptoms of plants known to be deficient in K and Mg are illustrated in the photos.

Leaf symptoms indicative of K and Mg deficiencies are sufficiently different to be distinguished from one another.

Leaves from the K-deficient plants exhibit leaf marginal chlorosis and

Progress Reports of Agricultural Research published monthly by the University of Callfornia Division of Agricultural Sciences.

William W.

Paul Manager Agricultural Publications Jerry Lester Editor Peggy Anne Visher Assistant Editor California Agriculture

Articles published herein may be republished or reprinted provided no advertisement for a commercial product is Implied or imprinted.

Please credit: University of California Division of Agricultural Sciences.

California Agriculture will be sent free upon request addressed to: Editor, California Agriculture, 207 University Hall.

2200 University Avenue, Berkeley.

California 94720.

To simplify the information in California Agriculture it is sometimes necessary to use trade names of products or equipment.

No endorsement of named products is intended nor is criticism implied of similar products which are not mentioned.

Automatic turf irrigation showing instrument area and cans set out to measure water distribution.

Evapotranspiration for Turf Measured with Automatic Irrigation Equipment

S.

J.

RICHARDS L.

V.

WEEKS

Automatic irrigation, controlled by instruments capable of detecting moisture needs of plants, has been successfully used to study evapotranspiration rates for turfgrass at Riverside.

Tests indicated that frequent, automatic sprinkling with relatively low-volume applications per irrigation might allow easy measurement of evapotranspiration.

Tensiometers, acting as hydrostats, can turn "on" irrigation water when needed, but unpredictable flow rates in soils make it necessary to use a separate timing mechanism to set the duration or amount to be applied and turn the water off.

Automatic irrigation management programs are now feasible, under many conditions, using tensiometers or other instruments responding to an energy variable of water in the soil.

However, to be accurate for evapotranspiration measurements, such procedures should account for water losses below the rooting depths in the soil.

T ENSIOMETERS measuring soil water conditions have been in use since about 1935 and the principles of automatic irrigation using a tensiometer were established as early as 1943.

Commercial development of fully automatic irrigation has progressed first in connection with systems for irrigating turf and ornamental plantings.

One such system, available for about 10 years, uses a tensiometer-type hydrostat to indicate a need for irrigation and a small electric clock motor to control the time of day or night when water is to be applied.

The duration of irrigation on each of several pipeline sections is independently controllable.

This study was conducted on a 120 220-foot turf plot located south of a large intramural field at the University's Riverside campus.

Asphalt parking and play areas occupy portions of the east and west sides.

To the south is a relatively wide expanse of trees and turf plantings.

The immediate turf area is enclosed by shrubbery borders which are watered from separate irrigation lines.

The regular sprinklers on the north half of the area were capped in July, 1961, and a separate irrigation system was installed using gear-driven rotary pop-up sprinkler heads.

The porous cup of the hydrostat was located at an average depth of 31/2 inches.

When soil suction exceeded 20 centibars at this depth, a one-hour sprinkling was started at 2 a.m.

At each irrigation, an average of 1/2 inch of water was applied automatically by meter readings.

The south half was irrigated from a semiautomatic system operating the sprinklers for a specified period each night when turned on manually.

A separate meter was installed to measure the water used under this system.

To evaluate the automated control, tensiometers were installed at five depths in two locations selected for average turf vigor.

Cans were used to measure the depth of water applied at the two instrument areas and near the hydrostat.