[Landscape Poet]

This is not for my personal use, but rather just kind of survey I am interested in of how much N each of you would say you put per K on annual basis.
I was doing some research for someone else, looking for "optimum" amount of N for St. Augustine turf. And had a hell of a time getting anything close to a straight answer from anything I would consider a reliable source. Thought it would just be interesting to see the different approaches.

So, if you would state the following

1. How much N per K your put down annually
2. What turf your location and turf type.


Thanks in advance,

Michael

 

[greendoctor]

I'll bite.

Bermuda: 9-12 lb per year
Zoysia: 4-6 per year
St Augustine: 6-9 per year
Centipede up to 4-6 per year

A 2:1 ratio of N:K is what I apply except for centipede. That gets a 1:1 ratio. Everything is applied monthly, so divide the rates by 12. If night time temperatures stay below 70, I stop feeding centipede and everything else gets a 1:1 ratio.

This is in Honolulu, Hawaii. All lawns are maintained at proper mowing heights. Bermuda and zoysia maintained at lower cutting heights are given the higher end of the rate. Centipede and st augustine maintained at the correct heights needs the lower rates to stay healthy. Less than 20 inches of rain in a 365 day growing season, so irrigation systems are mandatory. An irrigated lawn with no fertilizer becomes very pale and thin in time.

 

[RAlmaroad]

Michael:
In SC, St. Augustine is fed monthly from April(two (2) weeks after greenup)-Oct with a 2:1 ratio of N:K...(Same as Greendoctor).
Centipede is fed with a 1:1;N:K two weeks (2) weeks after greenup) on a monthly schedule until end of August.
All lawns are irrigated with 1-1.5 weeks depending on heat or rainfall. Last year it was not as hot as usual and watering cycle was shortened to a three day cycle vs. normal every other day. When heat requires more irrigation then the fertilization cycle could possible every 3.5 weeks instead of the 4 weeks. I have been guilty of fertilizing every two weeks but not as much N/K on lawns that are in bad shape.
The turf will let you know by the growth. When the mowing height on my brick gauge on their side takes longer to grow an inch above it then I up the amount of N a small amount. Most do not have this kind of time to spend but I only have a very few lawns that I maintain yearly.

 

[Landscape Poet]

Wow - 6lbs on St. Augustine seems like a large amount - interesting. I have a friend who owns a newer home on waterfront and St.Johns River mgmt group just made all the residents of that area sign a waiver stating they would not allow or use P on their lawns, along with limited the amount of N to no more than 3lbs.
Greendoctor - I am assuming that your soil is sandy like ours? Are you doing a bunch of small doses to prevent leaching or is the soil really able to hand that much? Insight into your conditions would be interesting.

Thanks for you replies guys, anybody else feel like sharing?

 

[SeedPro]

Midwest here.

3.5 to 4.5 lbs of N per year with a full program. Depends on the turf and the sun/shade situation and whether they have or do have any systemic disease issues.

.75lbs per application.

About 1lb of K per season.

I don't apply P.

 

[grassman177]

i run light N here, less than 4lbs annually. starting to not use P either as it is not needed unless doing seeding. K is changing all the time so cant answer but usually more than N. cool season grasses here. i use 40-50% CRN too. lots of iron is used plus micros twice per year

 

[ICT Bill]

Michael,
Florida state has, I believe they are still guidelines and not law, a fact sheet that was done in 2007 when Mr. (Jeb) Bush was still in office down there

http://www.flaes.org/pdf/Urban_turf_fact_sheet.pdf

 

[Grasssales2001]

Michael, Contact a local sod farm and ask how frequently they fertilize and how Much N they use annually. I think you might be suprised. Generalizations for fert applications are difficult. Each site is different. I have personally grown beautiful st. aug and centipede on @ 1# of N in three years.

 

[Landscape Poet]

Michael,
Florida state has, I believe they are still guidelines and not law, a fact sheet that was done in 2007 when Mr. (Jeb) Bush was still in office down there

http://www.flaes.org/pdf/Urban_turf_fact_sheet.pdf

Bill, I was just really interested to see what others answers would be, by region! Curiosity you know.

I do appreciate the pdf you threw up, it was in the realm of what I was looking for. As I posted above before, I have a friend that had to sign this waiver for SJ water mgmt and he asked me if his turf would be good on 3lbs of N a year and 0 P. I told him he more than likely would not see any side effects of the P because I had tested several homes in his area and the P in general in central fl is through the roof. However on the N - I had always put down 3lbs give or take a little over 4 to 5 apps last year and the turf responded well.
However with his question, it got me thinking what is the optimal level for St. Augustine. I have looked and looked and still have to find a reliable source saying this is general the optimal level for St. Augustine. I guess I am looking for a perfect answer in a not so perfect world.

I am still wonder about green doctor saying he puts down 6 to 9lb on SA. Bill or anyone else know if their soil is sandy as hell like our her in FL? If it is I can see why he calls himself the green doctor, that turf would be glowing in the night it would be so green down here I think if I threw down that much on a lawn.

So I am still interested in others and what you put down per K in your area. It is interesting learning what other areas are doing.

 

[RAlmaroad]

Michael:
St. Augustine is probably the biggest lover of Nitrogen of all turf grasses. It's habit has very large stolons, leaves and deep roots; so it needs a lot of Nitrogen. Greendoctor has a 12 month growing season, not just from March-November. Sandy soil leach water and all nutrients and minerals so they have got to be replenished. A lot of the liquid Nitrogen escapes into the air which is another reason for St. Augustine requiring nitrogen. St. Augustine will use up over half of the soluble nitrogen within two weeks of application a by the end of three weeks the rest is almost gone as test have shown. With all of these factors the amount that is required is not unusual. The sand in SC devours compost and soil. New sod will break down very fast and after three years the sod soil base is almost sand so there's not much to hold water or nutrients for available use to the plants. Part of my program is to replenish the soil with compost and top soil during the winter months. A general rule on how much is illusive.

 

[RigglePLC]

About 3.5 lbs per year on rye and blue up here in midwest. We reduced the nitrogen since the price went so high. A lot depends on grass type, temp, rainfall, ability to mow twice per week, irrigation frequency, soil type. Golf, football and baseball fields are a whole nother science. No phos. Potash in every ap.

 

[greendoctor]

I have a different problem from sandy soil. Soil that is clay subsoil from construction sites. That is what the homeowner gets when his "landscaper" brings in "topsoil". That is usually spread over coral or basaltic base coarse. What I am doing as far as the fertilizer program is concerned is getting quickly absorbed materials into the leaves and active root zone in the sod as possible. I apply monthly applications. In many cases, grass roots are only 6 inches deep, after that, they are hitting coral or rock. The few lawns I maintain that are on sandy soil get by on less intensive fertilization due to a much better root system. When discussing site conditions on another thread, another poster concurred that most customers cannot afford to have their lawns installed according to some Utopian ideal. In my case, the Utopian ideal is to remove all existing material to a depth of at least 12 inches and replace with a silica sand and peat moss mix. St augustine growing on a sandy beachfront property is very green on less than 6 lb. If it is growing on that lawn hell I described, sometimes even 9 is not enough to keep the grass healthy. RAImaroad is right about my growing season. I actually visit each property a minimum of 24 times in a year. I am constantly looking at both color and growth of the grass. For color, I emphasize micronutrients. If I need growth, more N and K.

 

[Landscape Poet]

Michael:
Part of my program is to replenish the soil with compost and top soil during the winter months. A general rule on how much is illusive.

Trying to switch my own lawn over to pure Organic this year. So I know what you are saying. The compost that I have laid so far seemed to make a instant impact and brought back color quicker than most of the neighborhood after the freeze we had down here.

 

[Landscape Poet]

For color, I emphasize micronutrients. If I need growth, more N and K.

I am not a fert guy, I am maint. However I have did most of my customers lawns this past year, I found after soil analysis, most were very deficient in certain Micro's. It is amazing as you say the color difference when the weakest link is fixed. Not to mention it seems to help aid, but not prevent, disease on some of these properties.
My biggest issue last year was the price of Tech Mag and Sulpo Mag, hard to convince some people to invest that kind of $ at first, but after seeing a neighbors results, of before and after pic, they were a little more eager. The price of Tech Mag has came down to a very large degree here though thank goodness.

Also for a little guy like me, I was not able to find a good source of B and Cu - the only option I had was a liquid which required spraying with back pack, and then of course watering in to prevent leaf burn. So again labor intensive is not cheap, another hurdle in the cost for customers. I have found a cheaper alternative for the Cu however, the initial cost of it is the downfall, it is a granular which is the mixed and then applicated.

But now I am ranting, but moral of the story, Micro's seem to give a good results in color as you have said. Fix the weakest link and all is good.

Thanks
Michael

 

[RAlmaroad]

Maybe someone can explain this: Dirt disappears/white sand appears on the coast. I can't understand why pretty sod from inland will have white sand after a few years of growth. I'm not talking right on the beach next to the ocean but inland a half mile or so. Could it be because of irrigation or sun breaking down the organic matter. At any rate, I've found that top soil (or what they sell as topsoil)cow manure and spaugnum peat most has got to be a part of my IPM. I try to use 1/2" every winter usually in January when turf is dormant. Low spots in turf are cut similar to a lid on a box and topsoil filled in under them. The spring rains settle them down to level.

 

[Marcos]

Maybe someone can explain this: Dirt disappears/white sand appears on the coast. I can't understand why pretty sod from inland will have white sand after a few years of growth. I'm not talking right on the beach next to the ocean but inland a half mile or so. Could it be because of irrigation or sun breaking down the organic matter. At any rate, I've found that top soil (or what they sell as topsoil)cow manure and spaugnum peat most has got to be a part of my IPM. I try to use 1/2" every winter usually in January when turf is dormant. Low spots in turf are cut similar to a lid on a box and topsoil filled in under them. The spring rains settle them down to level.

Wind erosion from the beaches, maybe?

 

[Marcos]

This is not for my personal use, but rather just kind of survey I am interested in of how much N each of you would say you put per K on annual basis.

Essentially our t.t.tall fescue & bluegrass customers have forced us over time to evolve toward three separate programs:

1) 3 meal applications /per season with soil test, soil amendments, and spot weed control if necessary
2) Either spring and/or fall topdressing, soil test, soil amendments, and spot weed control if necessary
3) (By far our most popular program) a marriage between #1 & #2, most often the compost happening in mid-spring, meals later in the season.

Easy-to-apply cotton seed or soybean meal (both 6% N) spread at the proper rate (15 lb / k) will yield approx 1 # N per k.....so as you can see for program #1, that's about 3# N/ year.
We'll sometimes use corn gluten meal (9% n) as fertilizer too when I can find the best local deals & spreading consistency to enable us to properly calibrate it to 10 # / k to get the same 1 # N.
Every so often we'll use alfalfa meal (3-1-3) to add some extra potash.

Compost topdressing in Ohio turf is especially marketable to those who like the concept of greatly reduced top growth to deal with every weekend if they mow it themselves.
Obviously, all of the above does a lot more than just "provide nitrogen" to the turfgrass plant a la Scotts 5 Step, etc.

But it should start with a soil test from the very get-go.
Like greendoctor posted: micros are the real key to color issues.
Address the micros 1st, then go with the minimum N requirement for the given turf species.

Why the minimum?
In this day & age of sporadic or widespread drought, watering restrictions, mulching/disposal headaches & mowing contractors getting rained out of their work for days or even weeks on-end, this business is becoming more & more about controlling /reducing top growth, isn't it, folks? :waving:

 

[greendoctor]

I am not a fert guy, I am maint. However I have did most of my customers lawns this past year, I found after soil analysis, most were very deficient in certain Micro's. It is amazing as you say the color difference when the weakest link is fixed. Not to mention it seems to help aid, but not prevent, disease on some of these properties.
My biggest issue last year was the price of Tech Mag and Sulpo Mag, hard to convince some people to invest that kind of $ at first, but after seeing a neighbors results, of before and after pic, they were a little more eager. The price of Tech Mag has came down to a very large degree here though thank goodness.

Also for a little guy like me, I was not able to find a good source of B and Cu - the only option I had was a liquid which required spraying with back pack, and then of course watering in to prevent leaf burn. So again labor intensive is not cheap, another hurdle in the cost for customers. I have found a cheaper alternative for the Cu however, the initial cost of it is the downfall, it is a granular which is the mixed and then applicated.

But now I am ranting, but moral of the story, Micro's seem to give a good results in color as you have said. Fix the weakest link and all is good.

Thanks
Michael

Micronutrients are highly efficient when applied as foliars. Yes, I dropped some money on spray equipment. However, I have made that money back many times over. I do not call myself the greendoctor to be cute. I deliver green grass and healthy, flowering shrubs where the people I refer to in quotation marks do not. My fee schedule for just fertilization starts at over $150 per acre. If someone wants to be a participant in the race to the bottom, they are welcome to take their business elsewhere. What I do is above and beyond 1% iron oxide in a bag of granules. Come to think of it, I do not own a fertilizer spreader of any kind. Everything is done through either a 7 gallon power sprayer or the 100 gallon skid sprayer. The 7 gallon power sprayer is my weapon of choice for 1-5,000 sq ft lawns.