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Teach123
04-01-2012, 11:15 AM
I slitseeded/overseeded my property last fall with a top-quality 80/20 KBG--Rye Mix. With this early spring the turf is gorgeous. My question is about watering. Normally, with a decently established lawn I water 1x per week for about an hour per zone (depending on rainfall). However, some of the new turf isnt established and I know those roots aren't very deep. Should I be gradually going to watering deeply..meaning water lightly to get those roots that aren't deep and then gradually decrease the frequency and increase the water volume applied? The temps are fluctuating between 80's and 60's during the day and 40's and 50"s at night.

I have an irrigation system so the watering is not the problem...

Thanks in advance for any advise.

Kiril
04-01-2012, 11:42 AM
Assuming no rain inputs.

Interval: INTz = (AWHC * RZ * MAD) / (ETo * Kl)

Runtime: RTz = [(60 * INTz * ETz) / ARze] * RTM

Smallaxe
04-01-2012, 11:53 AM
The simplest thing is to 'plug' the lawn in areas of interest... turn on your sprinkler for you 'estimated time period', and after an hour or so of shutting it off,,, pull a plug and see that the water soaked the root zone or not...

What you want is a wet root zone after irrigation, but not much beyond... Trial and error is the ONLY way to see what works in your lawn... one size does NOT fit all...

You'll be surprised about how much sense everything makes when you plug the soil for various reasons and physically look at the soil and roots ... good luck... :)

Kiril
04-01-2012, 11:59 AM
The simplest thing is to 'plug' the lawn in areas of interest... turn on your sprinkler for you 'estimated time period', and after an hour or so of shutting it off,,, pull a plug and see that the water soaked the root zone or not...

What you want is a wet root zone after irrigation, but not much beyond... Trial and error is the ONLY way to see what works in your lawn... one size does NOT fit all...

You'll be surprised about how much sense everything makes when you plug the soil for various reasons and physically look at the soil and roots ... good luck... :)

Hmmmm ..... :hammerhead:

RigglePLC
04-01-2012, 12:40 PM
So an hour per zone...does than mean an inch of water...how much exactly? Around here irrigation companies often set the sprinklers to run 15 minutes every day. Checking the soil with a screwdriver or soil probe is useful. But there are many variables: soil type, porosity, temp, wind, humidity, rain, rooting depth, drought hardiness of grass cultivar, shade, drainage faults, use of turf (athletic, park, premium home lawn) and more.

Around here, every day works fine--unless disease occurs--then I suggest 3 days per week. More minutes if hot--less if weather is cool.

Kiril
04-01-2012, 12:52 PM
Around here irrigation companies often set the sprinklers to run 15 minutes every day.

Unless you are irrigating on pure sand (i.e. a soil with almost no WHC), no reputable irrigation tech would ever water every day. That kind of scheduling is reserved for the mow and blow yahoos.

But there are many variables: soil type, porosity, temp, wind, humidity, rain, rooting depth, drought hardiness of grass cultivar, shade, drainage faults, use of turf (athletic, park, premium home lawn) and more.

Yes ... and more ... and they should all be taken into consideration.

Dave Stuart
04-01-2012, 03:39 PM
Assuming no rain inputs.

Interval: INTz = (AWHC * RZ * MAD) / (ETo * Kl)

Runtime: RTz = [(60 * INTz * ETz) / ARze] * RTM

Please listen to kiril's advice. Very important.

Teach123
04-01-2012, 05:13 PM
Riggle: An hour usually fills up a tuna can in each zone (Depending on the water pressure and wind) Usually, the water pressure is pretty solid at 4a. I know people who irrigate everyday. They don't care that they have shallow root systems. I guess if they water each day and keep it up then same result.... green lawn. I just prefer to water to about 6' and hope the turf roots start growing deep.

Also...KIRIL...Can I get those variable translated? I think I have figured out a few. Thanks!!

P.S. Much of my lawn is in FULL SUN. I don't know if this makes a difference...probably

Kiril
04-01-2012, 05:52 PM
Your basic water requirements on a per hydrozone (or valve zone) basis assuming no rain inputs, soil moisture content is at field capacity to start with and soil is homogeneous throughout root zone (both current and potential).

Interval: INTz = (AWHC * RZ * MAD) / (ETo * Kl)

INTz = Zone Interval (days)
AWHC = Soil Plant Available Water Holding Capacity (in/foot)
RZ = Root zone depth (feet)
MAD = Management allowable depletion (%)
ETo = reference evapotranspiration (in/day)
Kl = landscape/crop coefficient (%) (see WUCOLS (http://www.water.ca.gov/wateruseefficiency/docs/wucols00.pdf))

Runtime: RTz = [(60 * INTz * ETz) / ARze] * RTM

RTz = Irrigation zone runtime (mins)
INTz = Interval between irrigation events (days)
ETz = Zone adjusted ET (in/day) --> ETz = (ETo * Kl)
ARze = Zone effective application rate (in/hr) --> from catch can audit (most accurate)
RTM = Runtime multiplier (a factor of DU) --> RTM = 100/DULH


Note: Other considerations need to be made here, but this will get you started in the right direction.

Smallaxe
04-01-2012, 06:02 PM
... Also...KIRIL...Can I get those variable translated? ...

P.S. Much of my lawn is in FULL SUN. I don't know if this makes a difference...

I'm pretty sure that at least one of those variables means "FS"... :)

Smallaxe
04-01-2012, 06:14 PM
Your basic water requirements on a per hydrozone (or valve zone) basis assuming no rain inputs, soil moisture content is at field capacity to start with and soil is homogeneous throughout root zone (both current and potential).

Interval: INTz = (AWHC * RZ * MAD) / (ETo * Kl)

INTz = Zone Interval (days)
AWHC = Soil Plant Available Water Holding Capacity (in/foot)
RZ = Root zone depth (feet)
MAD = Management allowable depletion (%)
ETo = reference evapotranspiration (in/day)
Kl = landscape/crop coefficient (%) (see WUCOLS (http://www.water.ca.gov/wateruseefficiency/docs/wucols00.pdf))

Runtime: RTz = [(60 * INTz * ETz) / ARze] * RTM

RTz = Irrigation zone runtime (mins)
INTz = Interval between irrigation events (days)
ETz = Zone adjusted ET (in/day) --> ETz = (ETo * Kl)
ARze = Zone effective application rate (in/hr) --> from catch can audit (most accurate)
RTM = Runtime multiplier (a factor of DU) --> RTM = 100/DULH


Note: Other considerations need to be made here, but this will get you started in the right direction.

How long does it take to gather that data for the area around the 2 mature maples, which hardly ever gets much sun at any given time???
Then how long does it take to collect all that data for the rest the slope that recieves FS with sand at the top and clay at the bottom???

That's the front yard... now the back is a little more diversified... :)

Smallaxe
04-01-2012, 06:26 PM
One can make it as high-brow and pseudo-intellectual as one might wish to...

but I find that if the root zone in the top 3" are moist, then you're probably good for a while...

This time of year the wind has been blowing strong everyday since it thawed, but 'moisture' is NOT and issue...

2 weeks of that wind in July would have the Aspens dropping leaves already, and sandy soil lawns, w/out irrigation, would sound like walking on brown eggshell from all the burnt greenery...

I plug the ground when I'm doubtful as to whether the lawn can survive 3-5 days more w/out irrigation... I learn from physically looking at the soil, that I can believe my ignorant and incorrect eyes, much more effectively than a formula from a book or even a gov't website... :)

Kiril
04-01-2012, 07:13 PM
One can make it as high-brow and pseudo-intellectual as one might wish to...

You can either approach irrigation management as an informed professional using well established methodologies or you can be an amateurish hack without a clue. I'll leave it to the readers to decide which one applies to you.

Smallaxe
04-01-2012, 08:02 PM
I know,,, amatuerish fools believe their ignorant eyes... amatuerish fools, know what the daily weather conditions, mean to their crop... amateurish fools have grown the largest bread basket in the world and now we're promoting no-till in academic circles, w/out the slightest input from those who made it happen...

If only we HUGGG the trees, the fertility gods will feed us... :laugh:

Teach123
04-02-2012, 09:13 AM
I think there is some value in both philosophies. I think my original question referred to whether or not I should water more frequently because of the shallow roots of some of the turf. But, I took a plug from various locals throughout and it looks like I am pretty moist down to about 5" or so. It just seems odd to have to water this early....but I guess the calendar doesn't dictate...the weather does. I just want some rain!!

Smallaxe
04-02-2012, 10:20 AM
I think there is some value in both philosophies. I think my original question referred to whether or not I should water more frequently because of the shallow roots of some of the turf. But, I took a plug from various locals throughout and it looks like I am pretty moist down to about 5" or so. It just seems odd to have to water this early....but I guess the calendar doesn't dictate...the weather does. I just want some rain!!

If you have moisture 5" deep, and you want shallow roots to grow deeper, why do you want more rain sitting at the top of your turf??? Seems to me that the roots will be looking for, and finding, the moisture they want as they grow deeper...

So what kind of root mass did you find down there, and what kind of soil do you have at 5" deep??? :)

Kiril
04-02-2012, 11:11 AM
I think there is some value in both philosophies. I think my original question referred to whether or not I should water more frequently because of the shallow roots of some of the turf. But, I took a plug from various locals throughout and it looks like I am pretty moist down to about 5" or so. It just seems odd to have to water this early....but I guess the calendar doesn't dictate...the weather does. I just want some rain!!

The equations I posted tell you if you need to irrigate more frequently or not and will tell you how much you need to irrigate, providing the data you feed the equations is relatively accurate.

The only thing pulling a core tells you is rooting depth, irrigation depth and soil texture throughout the root zone, assuming you pull a deep enough core. I will use a brown probe to test irrigation depths while dialing in a system, I rarely ever pull out my coring tool for this purpose. I do pull cores while doing an audit to determine rooting depth and soil physical properties so I can get a handle on current and potential rooting depths, water holding capacity, potential restrictions to rooting, water infiltration, etc..... In cases outside of full system audits where neither of my soil moisture probes will reach the depth I need to test (> 2ft), then I will pull a core to test soil moisture, but only when dialing in a system or doing spot audits at those depths.

You could test a soil cores moisture content with an appropriate meter, estimate it using the feel method, or determine it gravimetrically, but that doesn't tell you how much you need to water. It simply tells you the current water status of the soil (accuracy varies widely depending on how you determine it). Simply "looking" at your soil to determine irrigation requirements as Axe has suggested is nothing more than wild guess work and would require you to pull cores every 1-2 days (depending on your soil) to even come close to being an adequate method. Even the feel method would provide for more accuracy than simply looking at it, and the feel method is anything but accurate.

So to continue with Axe's "look at the core" method. Once when you "think" the soil is too dry (most people think the soil is dryer than it really is) you irrigate for a short period, then you pull cores to see how deep your irrigation went ....... rinse and repeat your short irrigation cycles until you hit your target irrigation depth ...... and rinse and repeat all of the above every 1-2 days throughout the entire irrigation season. I don't know about you, but I think this is extremely labor intensive for such an inaccurate method of managing irrigation.

The methodology I posted accounts for most of the core variables required to relatively accurately determine irrigation requirements for any plant and soil during any time of the year and has been used for many decades in both Ag and landscape irrigation management. It allows you to automate your irrigation, and with the necessary fine tuning, can be an extremely accurate method of managing irrigation. It also will conserve vast amounts of water, especially if you practice deficit irrigation.

All that said, if you want to manually determine irrigation intervals then buy an appropriate soil moisture meter, which you should do in any case as it allows you to dial in a schedule. The Lincoln soil moisture meter is a relatively cheap meter and would be adequate in most cases. This will at least allow you to easily test soil moisture to some degree of accuracy to the depth you need, however it doesn't tell you how much water you need to apply or how long to run your system.

Kiril
04-02-2012, 11:13 AM
If you have moisture 5" deep, and you want shallow roots to grow deeper, why do you want more rain sitting at the top of your turf??? Seems to me that the roots will be looking for, and finding, the moisture they want as they grow deeper...

Roots do not seek out or look for moisture.

Smallaxe
04-02-2012, 11:36 AM
Roots don't grow to find water in new territories, niether do they grow to find food, they only grow becuz the magic fertility gods want them to grow for no specific reason whatsoever...

Kiril, give me chapter and verse, of some academic paper that gives a reason "Why Roots Grow"...
Then answer the question about "How long it takes to gather Accurate data", in the slpoing lawn I described... :laugh:

Kiril
04-02-2012, 11:40 AM
I am done entertaining your ignorance Axe.

Smallaxe
04-02-2012, 07:32 PM
... But, I took a plug from various locals throughout and it looks like I am pretty moist down to about 5" or so. It just seems odd to have to water this early. ...

So why do you think it is necessary to water??? :)

Teach123
04-02-2012, 10:28 PM
I don't think it is based on the cores I pulled. It just seems odd that it seems like summer already, yet the soil is still pretty moist.

Smallaxe
04-03-2012, 09:23 AM
Teach,,, We've had wind blowing day after day since the ground thawed and there is still plenty of moisture in the soil... those who have dumped fert onto the turf already are stimulating those surface roots to grow thatch, and the roots deeper in the still cool damp earth will soon be forgotten...
That is why the Ext. Offices across the Midwest indicate no ferts before May, preferably June for the 1st app...

I don't even think about irrigation until we hit 90 degrees for a couple of days in a row, IF there has been some normal rain throughout the Spring... the 1"/week rule doesn't apply this time of year... :)

Teach123
04-03-2012, 10:05 AM
I hear ya Smallaxe. I usually hit the lawn with N about the middle of May. Top growth of shoots slows root growth according to research. I;m gonna do this right. It just sucks that lawn care companies/Scotts commercials are promoting dumping everything under the sun on turf. Even my Lesco guy scoffed at me when I asked for Dimension without any type of Fert mixed in. Hell, you can't even buy Halts anymore without like 30 % N in it.

Was it you that swears by Milorganite? Or was that someone else?

Smallaxe
04-03-2012, 10:38 AM
I hear ya Smallaxe. I usually hit the lawn with N about the middle of May. Top growth of shoots slows root growth according to research. I;m gonna do this right. It just sucks that lawn care companies/Scotts commercials are promoting dumping everything under the sun on turf. Even my Lesco guy scoffed at me when I asked for Dimension without any type of Fert mixed in. Hell, you can't even buy Halts anymore without like 30 % N in it.

Was it you that swears by Milorganite? Or was that someone else?

I don't swear by anything, but I like Milorganite becuz it's higher Fe content for the $, than is Ironite and the slow release N is nice for the hot summer months and won't burn, if the drought comes...
As far as using Scotts herbicides and fertilizers, I would have people pay attention to when their CG actually becomes visible AND in which locations... I have mostly shade lawns and never have CG growing in the turf... If it appears, then I [b]need to sow more seed and get it to grow, because the CG was able to grow in a barespot... grow the grass to kill its competition, I say... :)

Teach123
04-03-2012, 10:49 AM
I agree with your crabgrass analysis. I am not a pro by any means (obviously huh?), but I will admit that I have bought into the commercial side of lawn care. I have a lush thick turf and I can bet that crabgrass would not be able to grow without a Pre-E app. To me it's just a habit. Early April comes and so does the Pre-E.

Question, if you were gonna use Milorganite as your program, how many apps per season and at what rate?

Smallaxe
04-03-2012, 11:42 AM
The Milo. calls for 1 bag per 2500 sq ft... I put it down 2 weeks before Memorial weekend, so it has time to dissolve into the turf(hopefully) by then...
I usually over seed in August and fall fertilizer in Sept/early Oct... I've never used Milo in the Fall, because I can't be sure that its breakdown procedure will be timely... :)