Alternative to Fall Nitrogen Regimen

[mitten]

I realize the Fall Nitrogen Regimen is the best plan for fall and wintering fertilizer, but the weekly apps can come with some constraints for people who travel, have small kids that suck time/attention, don't have proper irrigation, etc. I WILL be picking up a bag of Urea on the way home to continue my Fall Nitrogen Regimen... but still curious - what is the best alternative to the Fall Nitrogen Regimen?

[turf_toes]

Watch the weather and apply only if the chance of real rain is at or nearly 100 percent. Even at that, there’s risk.

If you don’t want a showcase lawn, that’s a reasonable approach.

If you want a showcase lawn, you’ll need to figure out how to irrigate it. Some drag hoses and use orbit hose end timers.

If it were my lawn, I’d not be applying urea unless I knew I could water it in.

Others might tell you otherwise. But decades of experience suggests to me they’re wrong.

[mitten]

The warning about watering Urea in is noted. So what's the alternative if you can't make weekly apps of Urea, but still want to fertilize in the fall to winter?

[Green]

It gets kind of tricky as things start to cool down more. In my area, basic organics don't do so well after September, for example.

Unfortunately, pretty much all Fall active fertilizers for cooler soil temps are going to incorporate significant amounts of urea or ammonium sulfate. There is no way around it.

You can apply a bit more less often, as discussed above. But you probably don't want to go over the 0.50 lb of N rate every 2 weeks in most cases, if doing less frequent apps, because higher rates bring some negatives.

You can also get blended or homogeneous fertilizer products containing some slower release methylene ureas, but you still haven't escaped the need for urea, and these controlled release particles will only account for a portion of your blend. Sulfur coated urea is an option too, but studies often show catastrophic releas after significant rain events (meaning it doesn't really act that much differently from uncoated urea in many cases). Polymer coated urea exists, too, but usually is too slow for significant Fall use. It has to go down a bit earlier, similar to organics. There is also something he called humic coated urea, which is supposed to be a natural humic-based coating for the urea. I don't know much about it at this point.

If you want to try to do less apps, a blended product with organics and urea or ammonium sulfate like Screamin' Green 16-2-3 or a homogeneous particle urea/methylene urea/ammonium sulfate product like Scotts Turfbuilder or Lebanon Greenview Fairway can work. But since these are primarily urea, the same issues still exist. If you do one or two apps of these, you can get kind of close to the results of a more aggressive fast-release-only program with a bit fewer applications. As the season goes on, the faster release properties get more desirable, and eventually you'll hit the point where more fertilizer isn't a good idea anymore (pause).

[mitten]

Yeah, that's kind of what I'm looking at for those of us who can't do a Urea app every week for whatever reason. What's the next best thing. Urea every other week? Or a different type of fertilizer, such as a slow release fall fertilizer at Labor Day...

[Green]

"Organics" are pretty much out now, due to temps. I would get something that is a blend of regular urea and methylene urea (and possibly ammonium sulfate), and do 0.50 lb of N apps every 2 or 3 weeks until the end of your period. Scotts Green Max is a good one. But be aware, it's still mostly fast release urea and ammonium sulfate, so it's not going to be substantially different from using regular 46-0-0. But that fraction of slow release will bridge the gaps somewhat.

[Green]

Another potential option if doing higher rate 46-0-0 urea apps less often (e.g. 0.50 to 0.65 lb of N per thousand square ft), and this is not necessarily 100% scientific/foolproof, is to apply humic acid at the same time. It's supposed to bind up the N and keep it from leaving the soil. I wouldn't go so far as to say it replaces slow release N, but it can help keep the Nitrogen losses from being too high. More along the lines of a chelating or stabilizing effect, I believe, but I've just recently begun to look into this and havent gotten very in my research, so don't hold me to 100% accuracy at this point. I'm definitely going to learn more about the effects, though.

[andy10917]

I wrote the Fall Nitrogen Regimens thread based on my research (and fiddling around with variations) over 8-10 years. What I learned and found most effective is what is on the first few postings in the thread - the rest is questions answered and fine-tuning performed.

The reason for the "every week at lower application rates" is a safety consideration - the incidence of accidental overlaps and overapplication was lower with the every-week program, since a single overlap accident didn't cause Nitrogen burn, and the probability of multiple accidents in the same exact location for two weeks in a row was almost zero. Going ahead with double the application rate at half the number of applications works almost as well as the documented regimen, but upped the likelihood of accidental damage to some degree (exact likelihood not quantified).

So, what does all that mean? It means that if you want the best results at the lowest likelihood of damage, the best regimen I found is the one that is documented. All of the alternative approaches either didn't create the same results, or increased the opportunity for damage. If you believe that you are a perfectionist that never makes a mistake, then feel free to double the rate at half the number of applications. I write my suggested regimens for the person that has average skills and isn't a dice-roller - I don't want to read "I screwed up, please help" postings in an area where the damage can be permanent. There is no free-lunch shortcut that I've found that is both completely safe and effective. I have not found the Humic Acid idea to work - the Fall Nitrogen Regimens approach is a game of timing, and the timing doesn't align with how Humic Acid works well-enough to recommend it.

One other seemingly intuitive idea that doesn't work as well as I expected is the use of slow-release Urea. It's nearly impossible to calculate how much slowly-released Nitrogen has been released at any specific time, and when to make the next application safely - which leads to more dice-rolling. You can stick with the bag-rate, but you won't get as much Urea stored in the grass roots in the limited time-period where the Fall Nitrogen Regimen is in-play.

Bottom line, what is documented leads to the most effective results I found in 8 years of experimentation, and you either choose to do it, or choose to do something else of your own design. I'm sticking with the regimen that is both safe and effective, even though it takes a bit of extra work...

[Green]

Thanks, Andy. Wonderful explanation of the "why" behind the every week you've found to works so well. Now I'd like to offer a complementary counterpoint.

Personally, I like your approach, and I've done it as written with beautiful results for a couple of years. It works. I don't think there is anything that could give better visual results (and I've tried the other methods, too).

I'm still in experimental mode after 10 years to find the best compromise for me. Maybe not to the extent of ityer people. I'm willing to sacrifice 10-20% of the result quality for tradeoff gains in other areas...less mowing, less frequent apps, less leaching potential (especially after irrigation is shut down), etc. So what I've settled on is your approach (especially as soil temps get colder) plus more use of enhanced efficiency fertilizers and slow release methylene ureas earlier in the season (e.g August and September). I'm not a fan of going over 0.50 lb N application rates with any urea or ammonium sulfate fertilizer, though...even slow release...I didn't like the results as much at higher rates.

One thing I've found that helps with accuracy of applying smaller amounts of N more accurately (and larger amounts, too) is a battery powered handheld spreader. Especially in tighter spaces, but I will use it in areas up to 3,000 square feet at a time. The advantages are that I can see what's coming out better to reduce skips or overlaps, and can fine-tune the setting so just enough fertilizer comes out, and alter it on the fly easily if needed. It's something I mostly started using a bit last year, and used more heavily this year.

I hope the above also helps someone decide the pros and cons of various methods. Ultimately, you either stick with established methods that work and produce predictable top level results, or adapt them and find what fits your own lawn, soil, goals, and time constraints. But there will usually be a slight sacrifice in results if you can't get out there quite as often, as Andy stated above. Know this going in!

[Green]

Anyway, if it helps someone, great. Here is my current non-aggressive "Fall" program iteration. Feel free to borrow ideas and modify. This allows me to get about 3 lbs of N down a year, with some flexibility by modifying when things are applied or eliminating or adding an extra application if needed.

-Start of "Fall": August once temps start to decrease at night and grass responds with recovery from Summer: 0.50 lb of N (70% slow release from organics and methylene urea)

-"Early Fall": about a month later - September once grass is fully recovered and growing vigorously: 0.50 lb of N (50% urea/AMS and 50% slow release from sulfur coated urea and organics)

-About two weeks later: 0.50 lb of N (same as previous)

-"Real Fall" (probably October by now; roughly another two weeks): 0.333-0.50 lb of N from 46-0-0 urea

-Optional if needed 1-2 weeks later: 0.25-0.50 lb of N from urea and/or AMS.

-Pause

-3-5 weeks later: Final Winterizing app. Urea/AMS mixture at reduced application rate (~0.50 lb fast release N again), plus a touch of high-activity methylene urea to help sustain greening early next Spring).

[mitten]

Green and Andy, thanks for your well thought out responses. Obviously the Fall Nitrogen Regimen is the top standard, and I've gotten great results with it in years past. Now that I have young kids timing everything is so much more difficult so it's really puts a damper on my ability to follow the strict regimen. Ideas like doubling the Urea dose so you can do fewer applications is exactly what I was looking for. Of course there are tradeoffs, like potential damage for example. But since I can't find time to do an app every week I'm not sure what the alternative would be.

[YEM]

But since I can't find time to do an app every week I'm not sure what the alternative would be.

Can you manage weekly apps on a smaller portion of your lawn? Spread quickly & run sprinklers off the hose in that area for a while? Might be a compromise to hit the spot you care most about.

[turf_toes]

If I recall, he indicated he travels and irrigation would be an issue. If he cannot water, I’d not suggest weekly applications of urea.

But if he can’t be around to water in the urea, he ought not be around to apply it either.

[mitten]

Not a bad idea with doing a section at a time. My yard is only 5000 sq feet. Alternatively if I did the double dose every other week, I could perhaps remove a slight chance of mistakes by making 2 passes at a lower does rather than 1, since the actual spreading doesn't taking a lot of time.

[mitten]

So just to confirm, the Fall Nitrogen Regimen you drop 1 lb of Urea per 1000 sq ft every week... So the riskier approach is 2lb of Urea per 1000 sq ft every other week. So I'll drop 10 lb on my 5000 sq ft lawn. Please check my math! haha. I think this is also the "bag rate" on the Lesco packaging.

[Green]

I've been thinking. A potential (or likely) reason why slow release Nitrogen (e.g. methylene urea or urea triazone) does not work as well as expected as a stand-in for an aggressive Fall N regimen is due to soil temps. Once we get into October, the micro herd is already slowing down. Urea is of course an organic molecule that requires microbial degradation to form plant-available Nitrogen, and it's well-documented that not only do the microbes slow down in the Fall, but so does the activity of the actual urease enzyme. What that means is that so-called "fast release" urea is no longer as much of a fast release source. It takes longer than it would in warm or hot weather to become plant available. In fact, my experience shows it takes about a week to start working after being watered in, and can feed for 2 weeks.

Now, if you start adding even more Carbon bonds on top of the fundamental ones (which is what slow release urea molecules have), it should take even longer to break down into usable N, because even more microbial degradation steps are needed. (And the experiments and observations do back this up.) This all adds up to a response that is just too slow in many cases. As such, I do not use or advise the use of slow release in October as a stand-in for an aggressive program. You might be able to get one such application down, but that likely won't provide enough plant response for a discerning lawn hobbyist, because it just isn't enough Fall N in many cases. I have no qualms about using slow release or controlled release N sources in August and September. But not in the last leg of the Fall N season. In fact, my final Fall app (and I'm no longer doing an aggressive weekly approach, but rather a less frequent application program) is going to contain not just urea, but also some ammonium sulfate (which is truly immediately plant available in cooler conditions). I try not to use too much AMS due to the effects on soil pH, but I save it for when I need or want that true fast release effect when soil temps have dipped below 50F or so.

[flyin-lowe]

I have a large yard I treat so the weekly route is not an option. What works for me is waiting until soil temps get in the low 50's and apply 2 lbs of urea per 1000 square feet when a rain is forecasted. If you can't do the weekly program this might be your best bet. I have had good luck with this.

[Green]

Flyin-low:

Definitely makes sense. The urea conversion slows in those temps around 50F, so it acts as more of a slower release N at that point. That's why you're able to use your higher rate (1 lb of N) without consequences as long as the weather cooperates and you apply very evenly. The downside of course is that often, soil temps won't hit 50 until you're almost in the pause period. At that point, fertilizing with anything but tiny amounts of foliar N (e.g. FAS rates) is probably not the greatest idea. But you know better than anyone as to when your pause period should start.