Should i even use synthetic fertilizers and if so how?

A place to discuss organic lawn care products and practices
Deadlawn
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Re: Should i even use synthetic fertilizers and if so how?

Post by Deadlawn »

JeffR84 wrote:
Wed Apr 14, 2021 10:06 pm
I’m saying the sulfur in the product won’t affect pH. Sulfur levels and pH aren’t directly linked. Elemental sulfur can lower pH by being converted to Sulfuric acid overtime by the microbes in the soil, but it’s not the same is sulfate sulfur.

pH is a measurement of the amount of hydrogen ions in the soil. Synthetic fertilizers that contain ammonium sulfate and to a lesser extent urea can acidify the soil because the ammonium releases hydrogen ions into the soil. But that’s a very negligible effect and any synthetic fertilizer is going to have that affect.
Aha! So that's why synthetics acidify. Chemistry was never my strong point, but I'm learning!

Note - I corrected my original post to reflect this.
Last edited by Deadlawn on Sun Apr 18, 2021 2:19 pm, edited 1 time in total.
Tier 1 - I just want something green. Perennial "weeds" that stay green year round are welcome.

tneicna
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Re: Should i even use synthetic fertilizers and if so how?

Post by tneicna »

Ph.D biochemist here.

The biggest difference between synthetics and organics is that the use of organic fertilizer significantly increased in the relative abundance of Burkholderiales, Myxococcales, Streptomycetales, Nitrospirales, Ktedonobacterales, Acidobacteriales, Gemmatimonadales, Solibacterales, etc. It does this because the organics contain a % of those, where all the synthetic ones do not.

What does this mean exactly? It improves soil quality by altering the microbial composition and recruiting beneficial bacteria into the rhizosphere.

The synthetics have none of those benefits.

The potential benefits of organic fertilizers have been documented in countless studies in which investigators observed a raise in soil microbial activities, which in turn improved crop growth and restrained pests and diseases. This *does* affect turfgrasses as well.

Ahmad R, Jilani G, Arshad M, Zahir ZA, Khalid A. Bio-conversion of organic wastes for their recycling in agriculture: an overview of perspectives and prospects. Ann Microbiol. 2007; 57:471–479.

Sun QR, Xu Y, Xiang L, Wang GS, Shen X, Chen XS, et al. Effects of a mixture of bacterial manureand biochar on soil environment and physiological characteristics of Mals huupehens seedlings. Chin Agric Sci Bull. 2017; 33:52–59

Hu HQ, Xiao RL, Xiang ZX, Huang Y, Luo W, Qin Z, et al. Effects of different ecological manage-ment on the soil microbial biomass and microbial population of tea plantation in hilly red soil region. Chin J Soil Sci. 2010; 41:1355–1359

corneliani
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Re: Should i even use synthetic fertilizers and if so how?

Post by corneliani »

Thanks for that succinct explanation @tneicna. Appease my curiosity and thirst for knowledge a bit, if you don't mind: Since the addition of organics encourages the growth of these microorganisms/bacteria, which in turn create the nutrients req'd by the turf, can't the same be said for the root cycling of a plant (understanding that roots are the driver of said ecosystem) that is aided in growth by synthetics? Albeit there are headwinds from synthetics on microbial life through the addition of salts and chlorides, etc, but in the end, isn't it just different ways to get to the same place? Or does one considerably outpace the other (??). Curious to hear your thoughts, and if you have a personal preference.

Personally I can see the value of synthetic NPK as a means for directly feeding the turf. I don't think it should be vilified but instead looked at for what it is: a tool in the toolbox to be used when/as needed to achieve our desired goals. Since we push our turf (not to mention ag as a whole) beyond what nature itself can produce on its own it only makes sense that the soil becomes depleted of nutrients that otherwise would be created & released naturally. I like the idea of "feeding the soil" as a way to encourage microbial life and its ecosystem, but that has its time & place just the same as a synthetic product does. In the end, synthetics are nothing more than "extracted" natural elements that humans have learned to mine, whether out of the air or ground. It's nothing short of amazing to see what humankind has been able to accomplish by deciphering the code of 'what things are made of' and reassembling things to their own liking, repercussions be damned. :)

tneicna
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Re: Should i even use synthetic fertilizers and if so how?

Post by tneicna »

Here are a few issues that I've always had with 'synthetic' turfgrass ferts.

- Explosive growth (due to fast-acting Urea present as a %)
- The explosive growth requires more cutting
- Soluble Salts.
- The evolutionary biology of turfgrasses doesn't really support huge amounts of N/P/K/etc. (Hence excessive thatch accumulation, turf diseases, etc)
- Leeching of high % of N/P/K (your soil is not a closed ecosystem). Do you want to throw money away if you have crappy soil? At least try and improve the soil chemistry overall.
- Harmful Thatch accumulation

The longer version about Thatch - In my opinion is the greatest problems with some turfs (Zoysia, Cool Season Grasses, some Bermudas?)

The formation of a thatch layer on turfgrasses (especially golf greens) is accelerated when organic matter production exceeds the degradation rate (Beard, 1973). This means that when you feed a turf synthetic with %/% of fast/slow release Nitrogen, the organic matter production surges (more cutting required)

Now, with that being said, the thatch layer is more or less highly organic matter that accumulates between the soil and green turfgrass; it consists of dead and living stolon, rhizome, root, crown, leaf sheath, and blade tissues (Engel, 1954; Roberts and Bredakis, 1960). A mat layer is generally below the thatch layer, where soil or sand is intermingled (depending on your turf maintenance/topsoil) with thatch as a result of earthworm activity or cultural practices, such as core aeration and topdressing (McCarty, 2005). A thatch layer is often desirable to increase resilience and wear tolerance of the turfgrass surface, reduce surface hardness, and moderate soil temperature extremes (Beard, 1973). However, an excessive thatch or mat layer is undesirable in turfgrass because it leads to decreased saturated hydraulic conductivity (SHC), decreased movement of oxygen through the thatch or mat zone, low oxygen levels within the thatch/mat layer during wet periods, and increased water retention (Carrow, 2003; Hartwiger, 2004; McCarty et al., 2007).

More negative physical and biological effects on the soil profile relating to Excessive Thatch; increased localized dry spots (Cornman, 1952), reduced tolerance to cold temperatures (White, 1962; Thompson, 1967), increased disease and insect problems (Musser, 1960; Mascaro, 1961; Thompson, 1967; Sprague, 1970), and reduced pesticide effectiveness (Cornman, 1952; Latham, 1955; Musser, 1960).

The rate of microbial decomposition of thatch is partially dependent on the lignin content of organic matter. Lignin degradation can act as the rate-limiting step in organic matter decomposition (Taylor et al., 1989). Sinsabaugh et al. (1993) conducted a plant litter decomposition study and reported a close relationship between lignocellulose-degrading enzymes and plant litter mass loss.

Lima et al. (2009) performed a study showing increases in lignin content in the soil when using organic ferts (See "Effects of organic and inorganic amendments on soil organic matter properties" Lima et al (2009))

Li et al (2020) performed a comparison of synthetic/organic (30-year application) fertilizers and noted with a synthetic application, increased microbial biomass (161%) and amino sugar production (19.7%), but did not alter lignin phenol and SOC concentrations despite the increased plant input.

Comparatively, long term organic (manure) applications increased the concentration of SOC (30.8–70.9%), as well as that of amino sugars (82.9–107%) and lignin (96.8–212%) in soil.

"Differential accumulation of microbial necromass and plant lignin in synthetic versus organic fertilizer-amended soil" Li et al (2020)

The tl;dr: Organic applications are better for your soil health/turfgrass than Synthetics in the long run.
Last edited by tneicna on Wed May 19, 2021 2:12 pm, edited 3 times in total.

corneliani
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Re: Should i even use synthetic fertilizers and if so how?

Post by corneliani »

This may be the most cited post on TLF & I love it !!!

I can totally agree with your objections for synthetics btw, they're overapplied and borderline environmentally irresponsible at times. I'm learning myself that less is more as far as NPK goes.

The thatch issue may be more turf-specific but the detriments of excessive thatch is not debatable. I wish my unirrigated TifTuf would build up some thatch in my red GA clay though, but it just won't do it, even at 6#N/1000/yr! Hence I can't relate to that problem.. yet. Maybe if I finally pull the trigger with my bluemuda plans I'd have to be more mindful of it (?).

Those last few citations seem interesting, esp the 30-yr study. That's what I was wondering about in my previous post, curious if long-term they even out. Your position is that you come out ahead with organics, and being so cited definitely gives you some credence in my eyes :)

Thanks for engaging me on this, btw! :thumbup:

tneicna
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Re: Should i even use synthetic fertilizers and if so how?

Post by tneicna »

corneliani wrote:
Sun Apr 18, 2021 4:55 pm
This may be the most cited post on TLF & I love it !!!

I can totally agree with your objections for synthetics btw, they're overapplied and borderline environmentally irresponsible at times. I'm learning myself that less is more as far as NPK goes.

The thatch issue may be more turf-specific but the detriments of excessive thatch is not debatable. I wish my unirrigated TifTuf would build up some thatch in my red GA clay though, but it just won't do it, even at 6#N/1000/yr! Hence I can't relate to that problem.. yet. Maybe if I finally pull the trigger with my bluemuda plans I'd have to be more mindful of it (?).

Those last few citations seem interesting, esp the 30-yr study. That's what I was wondering about in my previous post, curious if long-term they even out. Your position is that you come out ahead with organics, and being so cited definitely gives you some credence in my eyes :)

Thanks for engaging me on this, btw! :thumbup:
If you want to generate a lot of thatch, apply liquid gibberellic acid at a high rate combined with liquid N.

Chocolate Lab
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Re: Should i even use synthetic fertilizers and if so how?

Post by Chocolate Lab »

Some great posts in this thread!

@behrygood1982 You should check out Howard Garrett's radio show, the Dirt Doctor. He's from out your way in Pittsburg, TX and is on 660 am Sunday mornings (and of course podcasted). He says the worst things for your soil are the high nitrogen chemical salt fertilizers -- surprisingly (at least to me) even worse than herbicides or pesticides. I've always followed his recommendations and they've always worked great for me, going back to before I even had a lawn and just grew some vegetables.

I have heard some of the cover crop farming experts like Gabe Brown say that if you're starting out with really horrible, depleted soil, you might have to start out with chemical inputs just to get things started.

My only problem is finding a local source of the organic ferts I like. My folks pick me up some from Colorado when they're out there, but the only things I'm aware of in Texas or Oklahoma are much more expensive.

mjh648
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Re: Should i even use synthetic fertilizers and if so how?

Post by mjh648 »

@Chocolate Lab Microlife too expensive for you? What's the cost comparison with this Colorado organic stuff?

Chocolate Lab
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Re: Should i even use synthetic fertilizers and if so how?

Post by Chocolate Lab »

mjh648 wrote:
Tue May 18, 2021 10:21 am
@Chocolate Lab Microlife too expensive for you? What's the cost comparison with this Colorado organic stuff?
I'd never even heard of that until I just searched it, LOL. Looks like it's not available within 50 miles of me. Looks like great stuff, but how much does it cost?

The Colorado stuff is Richlawn Organic 100, which is basically pelletized chicken litter. It's like $9.59 for 40 lbs. But they don't sell outside Colorado, not even in New Mexico towns not far from the border. (Or at least not last time I checked.)

mjh648
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Re: Should i even use synthetic fertilizers and if so how?

Post by mjh648 »

Not sure exactly where you are but there are retailers in DFW, houston, Austin, and north of San Antonio.

tneicna
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Re: Should i even use synthetic fertilizers and if so how?

Post by tneicna »

Soluble Salts in the synthetic ferts, over time, will probably negatively alter soil chemistry.

Leeching of N because the turf can't absorb is more or less you throwing money down the drain. Even slow-release technologies still have problems with this (PCU, SFU) since they are affected by countless things (temp, moisture, % of microorganisms in the soil, etc)

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