msu-ceco/aec_v1 · Datasets at Hugging Face

text stringlengths 0 1.09k
220-440' .003 cfs ea.
550'
58' .02 cfs each furrows 2% .002 cfs ea.
110-220' .002 cfs ea.
330'
8-12' .02 cfs each slope
0-2' 2" per hour .5" per hour
Sprinkler 25' 2" per hour .5" per hour
58' 1.5" per hour .4" per hour
8-12' 1.0" per hour .3" per hour
Based on interaction of Extension professionals with Nebraska landowners and tenants, a common way to divide ownership is for the landowner to pay for and own all the permanent underground fixtures of a center pivot system.
This includes the pump, underground utilities, pipe, and dirt work required for installation.
If the lease with the tenant is terminated, the tenant will not remove any of the permanent underground infrastructure.
Keep in mind that real estate property taxes may rise, due to an increased value of the land if it is transitioned from dryland or gravity irrigation to center pivot irrigation.
Thus, the pivot should operate at a 90% timer setting when the end gun is off and slow to 77.4% when it is on to apply the 30 lbs/acre nitrogen both when the end gun is off, as well as when it is on.
The water application will be different 0.29 inches when the end gun is off and about 0.33 inches when it is on but the nitrogen rate will remain the same with the constant injection rate pump.
The concept behind this method is that the pivot will irrigate the same number of acres per hour, thus the lower cost fixed-rate injection pump will work correctly.
Causes and Prevention of Emitter Plugging In Microirrigation Systems
Microirrigation systems can deliver water and nutrients at controlled frequencies directly to the plant's root zone.
With microirrigation systems an extensive network of pipes is used to distribute water to emitters which discharge it in droplets, small streams or through mini-sprayers.
Over the last two decades, microirrigation systems continue to be used in trees and other horticultural crops because of their adaptability for both irrigation and freeze protection.
Microirrigation, properly managed, offers several potential advantages over other methods of irrigation:
Comparable water application uniformity.
Improved water use efficiency.
If scheduled properly, minimized deep percolation and runoff.
Efficient delivery of fertilizer and other chemicals trough the irrigation system.
Ability to irrigate land too steep for irrigation by other means.
The plugging of emitters is one of the most serious problems associated with microirrigation use.
Emitter plugging can severely hamper water application uniformity.
Causes of Emitter Plugging
Emitter plugging can result from physical , biological , or chemical causes.
Frequently,
plugging is caused by a combination of more than one of these factors.
Influence of the Water Source
The type of emitter plugging problems will vary with the source of the irrigation water.
Water sources can be grouped into two categories: surface or ground water.
Each of these water sources produce specific plugging characteristics.
Algal and bacterial growth are major problems associated with the use of surface water.
Whole algae cells and organic residues of algae are often small enough to pass through the filters of an irrigation system.
These algal cells can then form aggregates that plug emitters.
Residues of decomposing algae can accumulate in pipes and emitters to support the growth of slime-forming bacteria.
Surface water can also contain larger organisms such as moss, fish, snail, seeds, and other organic debris that must be adequately filtered to avoid plugging problems.
Groundwater, on the other hand, often contains high levels of minerals in solution that can precipitate and form scale.
Water from shallow wells often will produce plugging problems associated with bacteria; chemical precipitation is more common with deep wells.
Physical plugging problems are generally less severe with groundwater.
T RIALS WITH TENSIOMETERS to determine their usefulness in timing applications, as well as regulating amounts of irrigation water needed for turfgrass, were initiated by the University of California Agricultural Extension Service in Los Angeles County in 1960.
The need for modifications was soon apparent.
Subsurface installations were found necessary to avoid interference with recreational activities and cultural practices.
Such installations required protective boxes to house the instruments and moisture-proof covers for the tensiometer gauges.
These items are now available from commercial suppliers.
A thatch layer resulting in shallow rooting also interfered with the successful use of the tensiometer for determining irrigation needs.
With so many of the roots located in the thatch, grass showed severe water stress by the time tensiometers located in soil just below the thatch indicated any moisture depletion.
Data collected from several installations on golf greens indicated that mechanical aerification of the turf generally improves the
Graph 1.
Tensiometer readings for first six months after installation of the completely automatic system at UCLA.
Numbers above the readings indicate length of time sprinklers operated.
The spaces between curves are the number of days between irrigations.
ability of tensiometer readings to indicate a need for irrigation.
Trials were established on three golf greens at the Fox Hills Country Club in Culver City-all similar in age, turf condition, and management requirements.
Previous to 1962, when these trials were initiated, all greens were on a spring and fall aerification schedule with 1/2-inch diameter spoons used, followed by top dressing with a soil mix.
The greens were treated as follows: one
Tensiometers can be used successfully to determine frequency and duration of turfgrass irrigations, according to the trials reported here on three established golf greens.
Whether irrigation systems are manually controlled and merely guided by tensiometer readings, or completely automatic with tensiometers connected to a time-control system, this device-properly used-saves both time and water.
Data are also included on tensiometers buried at two depths rather than one, and special emphasis is placed on the importance of even distribution of water from the sprinklers, a thatch control program, and regular soil cultivation with a mechanical aerifier to reduce the effects of soil compaction.
green received the usual two aerifications; the second received the same plus one additional aerification in midsummer, using 1/4-inch diameter spoons, with the holes left open; and the third had the same spring and fall treatments, with two additional summer aerifications.
Tensiometers were installed at 2-inch and 5inch depths in each of the greens.
The green receiving two additional summer aerifications showed no turf stress at tensiometer readings of 50 cb , the green with one summer aerification showed a need for irrigation at about 30 cb; but the green receiving only spring and fall aerifications became hard and showed wilt symptoms before a tensiometer reading of 10 cb was reached.
The golf course superintendent was so impressed with the beneficial effects of the summer aerification, that he asked to aerify all the greens before the trials could be completed.
Therefore, the information received can be used only as an indication.
Graph 2.
Tensiometers continue to respond to varying climatic conditions as shown by frequency of applications during second six months after installation at UCLA.
The excessive lengths of irrigation during March and April were due to mechanical failure.
Uneven water distribution from inadequate sprinklers limits the use of tensiometers.
Tensiometers installed in areas receiving appreciably more or less water than other areas will not adequately reflect irrigation needs of the entire area.
Turf areas receiving low applications will show moisture stress before a tensiometer installed in a wetter area signals a need for water.
A completely automatic tensiometercontrolled irrigation system has been installed adjacent to Sproul Hall at the U.C campus, Los Angeles, on a turf area containing a mixture of bluegrass and fescue.
The soil is a clay loam, and the turf has been under a regular aerification program using 1/4-inch spoons with the holes left open.
Two tensiometers were installed in a location typical of the turf in the test area -one at a depth of 3 inches and the other at 8 inches.
A clock was attached to the control system to record the length of time the sprinklers operated.
The tensiometers were originally set to signal the controller for an irrigation when the shallow instrument reached a reading of 28 cb, or the deep instrument exceeded a reading of 12 cb.
After receiving the signals, the controller would operate the sprinklers only at a preset time during the night when the turf was not in use and the water pressure was good.
Irrigation would continue up to 15 minutes twice a night until the shallow instrument returned to a reading of cb, or until the deep instrument returned to a reading of 12 cb.
After two months, it became evident that too much water was being applied.
To corret this, the signal point of the shallow tensiometer was raised to 33 cb and the deep instrument to 24 cb.
Following a 15.minute sprinkler application test, using catchment cans in June, 1964, surface water was observed to flow into a runoff drain for over one hour after the sprinklers had stopped operating.
To
correct this, the controller was adjusted to allow the sprinklers to operate for only seven minutes, twice a night, if the tensiometers signaled that water was needed.
Graphs I and 2 show tensiometer readings from the UCLA installation and the effect of climatic conditions on the irrigation intervals.
The weather in September and October of 1963 was extremely variable, with a 2-inch rain over the three-day period of September 16 to 18, and five consecutive days of over 100 F temperatures starting September 25.
This was followed by some cool overcast periods.
The lawn had been irrigated just prior to the rain and was not irrigated again for nine days.
During the extremely hot weather that followed, there were three more irrigations in seven days.
The weather cooled during October, and only 17 irrigations were applied between that time and early April, according to the needs of the turfgrass in relation to varying climatic conditions.
The recording of more than 15 minutes of irrigation in one night is evidence that the deep tensiometers had a reading high enough to signal for more water after the first 15-minute application.
The first 15 minutes will return the shallow tensiometer to a low reading.
Drying of the soil at the lower depths indicates root activity in this lower root region.
During March of 1964, a malfunction of the controller caused excessively long irrigations to be applied.
According to the manufacturer's specifications, output for the 20 full-circle and 15 half-circle sprinklers covering the UCLA test area is 145 gallons per minute at the pressure used.
Prior to these trials, irrigations were scheduled twice a week, 15 minutes at each setting, from about November to June and three times a week from June through October.
At this frequency and duration, 10.5 hours or 91,350 gallons of water would have been

220-440' .003 cfs ea.

550'

58' .02 cfs each furrows 2% .002 cfs ea.

110-220' .002 cfs ea.

330'

8-12' .02 cfs each slope

0-2' 2" per hour .5" per hour

Sprinkler 25' 2" per hour .5" per hour

58' 1.5" per hour .4" per hour

8-12' 1.0" per hour .3" per hour

Based on interaction of Extension professionals with Nebraska landowners and tenants, a common way to divide ownership is for the landowner to pay for and own all the permanent underground fixtures of a center pivot system.

This includes the pump, underground utilities, pipe, and dirt work required for installation.

If the lease with the tenant is terminated, the tenant will not remove any of the permanent underground infrastructure.

Keep in mind that real estate property taxes may rise, due to an increased value of the land if it is transitioned from dryland or gravity irrigation to center pivot irrigation.

Thus, the pivot should operate at a 90% timer setting when the end gun is off and slow to 77.4% when it is on to apply the 30 lbs/acre nitrogen both when the end gun is off, as well as when it is on.

The water application will be different 0.29 inches when the end gun is off and about 0.33 inches when it is on but the nitrogen rate will remain the same with the constant injection rate pump.

The concept behind this method is that the pivot will irrigate the same number of acres per hour, thus the lower cost fixed-rate injection pump will work correctly.

Causes and Prevention of Emitter Plugging In Microirrigation Systems

Microirrigation systems can deliver water and nutrients at controlled frequencies directly to the plant's root zone.

With microirrigation systems an extensive network of pipes is used to distribute water to emitters which discharge it in droplets, small streams or through mini-sprayers.

Over the last two decades, microirrigation systems continue to be used in trees and other horticultural crops because of their adaptability for both irrigation and freeze protection.

Microirrigation, properly managed, offers several potential advantages over other methods of irrigation:

Comparable water application uniformity.

Improved water use efficiency.

If scheduled properly, minimized deep percolation and runoff.

Efficient delivery of fertilizer and other chemicals trough the irrigation system.

Ability to irrigate land too steep for irrigation by other means.

The plugging of emitters is one of the most serious problems associated with microirrigation use.

Emitter plugging can severely hamper water application uniformity.

Causes of Emitter Plugging

Emitter plugging can result from physical , biological , or chemical causes.

Frequently,

plugging is caused by a combination of more than one of these factors.

Influence of the Water Source

The type of emitter plugging problems will vary with the source of the irrigation water.

Water sources can be grouped into two categories: surface or ground water.

Each of these water sources produce specific plugging characteristics.

Algal and bacterial growth are major problems associated with the use of surface water.

Whole algae cells and organic residues of algae are often small enough to pass through the filters of an irrigation system.

These algal cells can then form aggregates that plug emitters.

Residues of decomposing algae can accumulate in pipes and emitters to support the growth of slime-forming bacteria.

Surface water can also contain larger organisms such as moss, fish, snail, seeds, and other organic debris that must be adequately filtered to avoid plugging problems.

Groundwater, on the other hand, often contains high levels of minerals in solution that can precipitate and form scale.

Water from shallow wells often will produce plugging problems associated with bacteria; chemical precipitation is more common with deep wells.

Physical plugging problems are generally less severe with groundwater.

T RIALS WITH TENSIOMETERS to determine their usefulness in timing applications, as well as regulating amounts of irrigation water needed for turfgrass, were initiated by the University of California Agricultural Extension Service in Los Angeles County in 1960.

The need for modifications was soon apparent.

Subsurface installations were found necessary to avoid interference with recreational activities and cultural practices.

Such installations required protective boxes to house the instruments and moisture-proof covers for the tensiometer gauges.

These items are now available from commercial suppliers.

A thatch layer resulting in shallow rooting also interfered with the successful use of the tensiometer for determining irrigation needs.

With so many of the roots located in the thatch, grass showed severe water stress by the time tensiometers located in soil just below the thatch indicated any moisture depletion.

Data collected from several installations on golf greens indicated that mechanical aerification of the turf generally improves the

Graph 1.

Tensiometer readings for first six months after installation of the completely automatic system at UCLA.

Numbers above the readings indicate length of time sprinklers operated.

The spaces between curves are the number of days between irrigations.

ability of tensiometer readings to indicate a need for irrigation.

Trials were established on three golf greens at the Fox Hills Country Club in Culver City-all similar in age, turf condition, and management requirements.

Previous to 1962, when these trials were initiated, all greens were on a spring and fall aerification schedule with 1/2-inch diameter spoons used, followed by top dressing with a soil mix.

The greens were treated as follows: one

Tensiometers can be used successfully to determine frequency and duration of turfgrass irrigations, according to the trials reported here on three established golf greens.

Whether irrigation systems are manually controlled and merely guided by tensiometer readings, or completely automatic with tensiometers connected to a time-control system, this device-properly used-saves both time and water.

Data are also included on tensiometers buried at two depths rather than one, and special emphasis is placed on the importance of even distribution of water from the sprinklers, a thatch control program, and regular soil cultivation with a mechanical aerifier to reduce the effects of soil compaction.

green received the usual two aerifications; the second received the same plus one additional aerification in midsummer, using 1/4-inch diameter spoons, with the holes left open; and the third had the same spring and fall treatments, with two additional summer aerifications.

Tensiometers were installed at 2-inch and 5inch depths in each of the greens.

The green receiving two additional summer aerifications showed no turf stress at tensiometer readings of 50 cb , the green with one summer aerification showed a need for irrigation at about 30 cb; but the green receiving only spring and fall aerifications became hard and showed wilt symptoms before a tensiometer reading of 10 cb was reached.

The golf course superintendent was so impressed with the beneficial effects of the summer aerification, that he asked to aerify all the greens before the trials could be completed.

Therefore, the information received can be used only as an indication.

Graph 2.

Tensiometers continue to respond to varying climatic conditions as shown by frequency of applications during second six months after installation at UCLA.

The excessive lengths of irrigation during March and April were due to mechanical failure.

Uneven water distribution from inadequate sprinklers limits the use of tensiometers.

Tensiometers installed in areas receiving appreciably more or less water than other areas will not adequately reflect irrigation needs of the entire area.

Turf areas receiving low applications will show moisture stress before a tensiometer installed in a wetter area signals a need for water.

A completely automatic tensiometercontrolled irrigation system has been installed adjacent to Sproul Hall at the U.C campus, Los Angeles, on a turf area containing a mixture of bluegrass and fescue.

The soil is a clay loam, and the turf has been under a regular aerification program using 1/4-inch spoons with the holes left open.

Two tensiometers were installed in a location typical of the turf in the test area -one at a depth of 3 inches and the other at 8 inches.

A clock was attached to the control system to record the length of time the sprinklers operated.

The tensiometers were originally set to signal the controller for an irrigation when the shallow instrument reached a reading of 28 cb, or the deep instrument exceeded a reading of 12 cb.

After receiving the signals, the controller would operate the sprinklers only at a preset time during the night when the turf was not in use and the water pressure was good.

Irrigation would continue up to 15 minutes twice a night until the shallow instrument returned to a reading of cb, or until the deep instrument returned to a reading of 12 cb.

After two months, it became evident that too much water was being applied.

To corret this, the signal point of the shallow tensiometer was raised to 33 cb and the deep instrument to 24 cb.

Following a 15.minute sprinkler application test, using catchment cans in June, 1964, surface water was observed to flow into a runoff drain for over one hour after the sprinklers had stopped operating.

To

correct this, the controller was adjusted to allow the sprinklers to operate for only seven minutes, twice a night, if the tensiometers signaled that water was needed.

Graphs I and 2 show tensiometer readings from the UCLA installation and the effect of climatic conditions on the irrigation intervals.

The weather in September and October of 1963 was extremely variable, with a 2-inch rain over the three-day period of September 16 to 18, and five consecutive days of over 100 F temperatures starting September 25.

This was followed by some cool overcast periods.

The lawn had been irrigated just prior to the rain and was not irrigated again for nine days.

During the extremely hot weather that followed, there were three more irrigations in seven days.

The weather cooled during October, and only 17 irrigations were applied between that time and early April, according to the needs of the turfgrass in relation to varying climatic conditions.

The recording of more than 15 minutes of irrigation in one night is evidence that the deep tensiometers had a reading high enough to signal for more water after the first 15-minute application.

The first 15 minutes will return the shallow tensiometer to a low reading.

Drying of the soil at the lower depths indicates root activity in this lower root region.

During March of 1964, a malfunction of the controller caused excessively long irrigations to be applied.

According to the manufacturer's specifications, output for the 20 full-circle and 15 half-circle sprinklers covering the UCLA test area is 145 gallons per minute at the pressure used.

Prior to these trials, irrigations were scheduled twice a week, 15 minutes at each setting, from about November to June and three times a week from June through October.

At this frequency and duration, 10.5 hours or 91,350 gallons of water would have been