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Fungus and fertilizer: Trying to understand

3K views 17 replies 8 participants last post by  kirk1701 
#1 ·
OK everyone with my experience in the past with Brown Patch has been "Get your N down early" so thats what I did the last two years with only minor problems with brown patch and didn't need to go the lengths I went this year and buy fungicide to treat it.

What Changed? Yea we had a lot of rain/humidity but nothing we didn't have here locally the two years prior. What did change is my fertilizer so I'm wondering and looking for suggestions before next spring. I'm wondering if it could have been the slow release N?

Last two years I used Scott's, two applications in the spring before mid April but everyone told me I needed to go to slow release so I did some research over the winter and not only is it slow release but also has Barricade for Pre-M which I must say has done wonders and I'm very pleased with the results :drinkup:

This year the Brown Patch was just about as bad as three years back when I didn't know little to nothing about lawn maintenance other then push a spreader and mow it so I had TrueGreen doing the lawn care and they seeded the lawn the fall prior.

TruGreen also used Slow release :)
Here's what I used:
(Scroll to bottom of page)
CarpetMaker® Turf Fertilizer 16-4-8 with 0.43% Barricade

I'm wondering if this was to much N, don't quiet understand the "25% slow-release nitrogen from methylene urea" or what it means?

Should I have went with the next one down on the page:
CarpetMaker® Turf Fertilizer 6-0-18 with 0.43% Barricade which has "100% slow-release nitrogen from methylene urea"?

Whats the difference between the N release? One is 25% other is 100% so I know one gets released slower then the other I just don't understand which just yet.

Hope you all understand what I'm trying to ask, LOL
Thanks.
 
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#2 ·
The fert label can be a little bit deceptive. 25 percent slow release nitrogen--seems to mean that...of the 16 percent total nitrogen and methylene urea... 4 percent is slow release and 12 percent is quick release. Some states may have different label rules.

Sometimes the salesman will say that the bag contains 50 percent poly sulfer coated urea. 8 percent of that is sulfer. But coated urea is not all slow release; some granules are not fully coated or are cracked. And of course the urea itself is only 46 percent nitrogen. Methylene urea has a few percent of the product that releases within 24 hours. Read the label carefully. Be skeptical of what the salesman says. There are some real experts on here that can explain additional complexities.
 
#3 ·
The bag with 25% slow release means just that. Of all the N in the bag, based on 50lb bag, you have 8lbs of N per bag (50 x .16 or 16%= 8, of which 2lbs are slow release N (8 x .25 or 25%)

I just take the number, in this case 16, and divide by 2 and it will give you the lbs of N per bag. The slow release portion is a % of the total N in the bag. Granted this method only works with 50lbs bags.
 
#4 ·
OK so if I'm understanding this correctly the 6-0-18 only has 6% but the whole 6% is 100% slow release?

Where as the 16-4-8 is part instant release with 25% of it being slow release but what's throwing me is your dividing in half; not 1/4???

Either way, 1/4 or 1/2 it don't seem like that would have been enough slow release to made the fungus more worse then previous years?

And going with the 6-0-18 next year I assume would be way under the amount of N necessary right?
 
#5 ·
By the way,
Lawns looking awsome, no worries, put the second app of clearys on last week and I should be good to go till fall.

I'm just looking to see if I can point the finger at the nitrogen for the reason it was worse this year then normal.
 
#6 ·
You are partially right. I divide the % N by 2 to get the total N per bag.....16/2=8lbs of N per bag. Then you take the 8lbs/4=2lbs to get the slow release N.

Just remember that the Slow release portion is a % of total N in the bag. If you have 20-20-20, you have a 10lbs of N per lb bag...(20/2=10) If 25% of it is slow release, you have 2 1/2lbs of slow release...(10 x .25= 2.5lbs).

With the 6-0-18 you can still put down 1# of N per 1000sqft, but you will use a bunch of material. 50lb bag of it contains 3# of N (6/2=3), so if you apply it at a rate of 16.6# per thousand (50/3= 16.6) you will get 1# of N per thousand.
 
#7 ·
With the 6-0-18 you can still put down 1# of N per 1000sqft, but you will use a bunch of material. 50lb bag of it contains 3# of N (6/2=3), so if you apply it at a rate of 16.6# per thousand (50/3= 16.6) you will get 1# of N per thousand.
One problem there, it's a combo product and contains 0.43% Barricade. On the advice of you guys here in another thread I didn't even go with the recomended rate, I went less because I put down mid-March and wanted the Pre-M to last 6 months in case I needed to do any reseeding come mid Sept.
 
#9 ·
Where as the 16-4-8 is part instant release with 25% of it being slow release but what's throwing me is your dividing in half; not 1/4???
Don't assume product weights here. I don't know what RBatten is doing.

Simple math kirk .... 25% of 16 is 4 -> 4% of your bagged product is slow release N

Slow Release N for your 16-4-8

a 60 lb bag has 2.4 lbs of slow release N (0.04 * 60)
a 45 lb bag has 1.8 lbs of slow release N (0.04 * 45)
a 100 lb bag has 4 lbs of slow release N (0.04 * 100)
a 13 lb bag has 0.52 lbs of slow release N (0.04 * 13)
a 50 lb bag has 2 lbs of slow release N (0.04 * 50)

TOTAL N for your 16-4-8

a 60 lb bag has 9.6 lbs of slow release N (0.16 * 60)
a 45 lb bag has 7.2 lbs of slow release N (0.16 * 45)
a 100 lb bag has 16 lbs of slow release N (0.16 * 100)
a 13 lb bag has 2.08 lbs of slow release N (0.16 * 13)
a 50 lb bag has 8 lbs of slow release N (0.16 * 50)

The above does not apply to P and K, as these are expressed as % phosphate and % potash, not on an elemental basis like N is.
 
#10 ·
I was simply trying to show him the math. Most of the bags are 50lbs, most. It is the simplest way to explain % to people.

a 60 lb bag has 9.6 lbs of slow release N (0.16 * 60)
a 45 lb bag has 7.2 lbs of slow release N (0.16 * 45)
a 100 lb bag has 16 lbs of slow release N (0.16 * 100)
a 13 lb bag has 2.08 lbs of slow release N (0.16 * 13)
a 50 lb bag has 8 lbs of slow release N (0.16 * 50)

This part of your explination is going to confuse people! Your figures are for total N not the 25% slow release in the bag.

So maybe your the one who doesn't know what he's doing.
 
#11 ·
I was simply trying to show him the math. Most of the bags are 50lbs, most. It is the simplest way to explain % to people.

a 60 lb bag has 9.6 lbs of slow release N (0.16 * 60)
a 45 lb bag has 7.2 lbs of slow release N (0.16 * 45)
a 100 lb bag has 16 lbs of slow release N (0.16 * 100)
a 13 lb bag has 2.08 lbs of slow release N (0.16 * 13)
a 50 lb bag has 8 lbs of slow release N (0.16 * 50)

This part of your explination is going to confuse people! Your figures are for total N not the 25% slow release in the bag.

So maybe your the one who doesn't know what he's doing.
You need to read my post more carefully dude. Here ... let me put it in bold for you.

Don't assume product weights here. I don't know what RBatten is doing.

Simple math kirk .... 25% of 16 is 4 -> 4% of your bagged product is slow release N

Slow Release N for your 16-4-8

a 60 lb bag has 2.4 lbs of slow release N (0.04 * 60)
a 45 lb bag has 1.8 lbs of slow release N (0.04 * 45)
a 100 lb bag has 4 lbs of slow release N (0.04 * 100)
a 13 lb bag has 0.52 lbs of slow release N (0.04 * 13)
a 50 lb bag has 2 lbs of slow release N (0.04 * 50)

TOTAL N for your 16-4-8

a 60 lb bag has 9.6 lbs of slow release N (0.16 * 60)
a 45 lb bag has 7.2 lbs of slow release N (0.16 * 45)
a 100 lb bag has 16 lbs of slow release N (0.16 * 100)
a 13 lb bag has 2.08 lbs of slow release N (0.16 * 13)
a 50 lb bag has 8 lbs of slow release N (0.16 * 50)

The above does not apply to P and K, as these are expressed as % phosphate and % potash, not on an elemental basis like N is.
 
#12 ·
TOTAL N for your 16-4-8

a 60 lb bag has 9.6 lbs of slow release N (0.16 * 60)
a 45 lb bag has 7.2 lbs of slow release N (0.16 * 45)
a 100 lb bag has 16 lbs of slow release N (0.16 * 100)
a 13 lb bag has 2.08 lbs of slow release N (0.16 * 13)
a 50 lb bag has 8 lbs of slow release N (0.16 * 50)

I read your post and understood what your were trying to convey, but you contradict yourself with the post and that leads to confusion for those that don't understand fractions, percents, and decimals.

I understand that 50%, .5, and 1/2 are all the same but some people don't. I was simply applying the KISS method. (keep it simple stupid)
 
#15 ·
Thanks Kiril
Thanks RBatten

Bottom line what I'm looking to find out is if the % of slow release was enough to last into June and July to make the brown patch worse this year then in previous years. From what I understand now; correct me if I'm wrong but I don't think it would have made much of a difference.

Kiril's explanation did help to because the bags are 40 Lb so 1.8 Lb of slow release per 1000 and me having put the product down lighter then recommended I can't see pointing the finger at the N for the reason so I'll stick with the same product come next spring. :drinkup:
 
#16 · (Edited)
I read your post and understood what your were trying to convey, but you contradict yourself with the post and that leads to confusion for those that don't understand fractions, percents, and decimals.
Oh ... now I see what you are saying. Yes ... you are correct, thanks for pointing it out. My bad.

Corrected.

TOTAL N for your 16-4-8

a 60 lb bag has 9.6 lbs total N (0.16 * 60)
a 45 lb bag has 7.2 lbs total N (0.16 * 45)
a 100 lb bag has 16 lbs total N (0.16 * 100)
a 13 lb bag has 2.08 lbs total N (0.16 * 13)
a 50 lb bag has 8 lbs total N (0.16 * 50)

I understand that 50%, .5, and 1/2 are all the same but some people don't. I was simply applying the KISS method. (keep it simple stupid)
KISS = teach someone how to take a percentage of a number. Not all fertilizer is sold in 50 lb bags. :dizzy:

Kiril's explanation did help to because the bags are 40 Lb
But according to RBatten all fertilizer is sold in 50 lb bags so you don't need to know how to take a percentage of a number. :laugh: :hammerhead:
 
#17 ·
Kirk, generally speaking methylene urea will last 10-12 weeks maximum. With only 2 lbs in the bag spread over several thou sq ft, it would not cause an issue. If it was 75% MU, then maybe. I lived south of you when I was younger and still talk to people there. I have heard it has been very hot and wet, more so than usually for June and early July. I don't think the fert had any impact on the brown patch problem, there are a number of things which can cause disease. However, for tall fescue you need to put down the vast majority of your N in the fall, will help. Very low N in the spring, just to green it up initially will be fine.
 
#18 ·
Kirk, generally speaking methylene urea will last 10-12 weeks maximum. With only 2 lbs in the bag spread over several thou sq ft, it would not cause an issue. If it was 75% MU, then maybe. I lived south of you when I was younger and still talk to people there. I have heard it has been very hot and wet, more so than usually for June and early July. I don't think the fert had any impact on the brown patch problem, there are a number of things which can cause disease. However, for tall fescue you need to put down the vast majority of your N in the fall, will help. Very low N in the spring, just to green it up initially will be fine.
Normally I do put a heavy dose on in the fall, afterall last fall I used the Scott's winter riser and we all know how loaded with N that stuff is.

God I have no idea now how my lawn survived that heavy N four times a year :laugh:

This actually might be something for me to shoot for next year, put down the 6-0-18 with 0.43% Barricade as mentioned in my original post?
 
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