Jobryant's Soil Test (July 2018)

[jobryant]

Also new to the forum, thanks for your help! Sorry for my double-post... Still figuring out how to post this

Here is my soil test from Logan Labs. I followed all your instructions but if I missed anything please let me know. I'm looking for your 'best approach'. I'd like a lush, full, green lawn.

- I'm located in Phoenix, AZ and I believe my grass is a hybrid Bermuda. I mow to a height of 1-1.5" every 7 days. All the grass gets full sun. No chronic diseases that I know of. At the beginning of summer (before I had done my research...) I added too much fertilizer and my grass suffered from some fertilizer burn. I was hoping the grass would fill in better but it has been very slow. I'm currently getting some spurge in the bare spots of the lawns, which I plan on spraying for.
- On the report, 'Front' is my front yard, which is approximately 1,700 sq ft of grass. I am currently watering the front yard 1.5" per week (15 minutes, six days per week).
- 'Back' is my backyard, which is approximately 600 sq ft of grass. This grass has become very thin and is bare in many spots. I'm currently watering this grass about 3" per week, hoping it will fill in better (30 minutes, six days per week).
- In case it's relevant, I plan on overseeding with Rye in October to maintain a green lawn through winter.

Test Results:
https://postimg.cc/image/4l7hn4jdd/

Pictures of Front Yard:
https://postimg.cc/image/e5r4a265d/
https://postimg.cc/image/sc6v5bjld/

Picture of Back Yard:
https://postimg.cc/image/84tfd1gz5/

[andy10917]

In all the years I've been doing test interpretations (a lot!), I don't know if I've ever seen one quite like this...

You have Calcareous soil. Big time. Calcareous soil is when there is so much Calcium that is in the soil that not all of it can be in solution in the soil. There is the stuff that is in solution and then the stuff waiting to be in solution. And when a standard soil test is run, ALL of it gets picked up - distorting the results.

Now, once in a while the Magnesium is part of the calcareous situation. Your's has that too.

But I've never seen one that has the Calcium, Magnesium and Potassium all off the scale. Guess whose results show that?

The end result is an extreme pH of 8.5. This isn't getting easier.

I could give you some general advice, or you could call Logan and ask if they still have your samples to run an Ammonium Acetate test (they probably do!) - it will cost more $$$$, but the distortion will be far less, and I'll be able to be more specific.

Let me know which way you want to go!

[jobryant]

Thanks, Andy. That's funny, glad I can keep things interesting!

I'll have them do the Ammonium Acetate test. They have a 7.0 and an 8.2 test. Which would you like?

[andy10917]

Use the 8.2 test

[jobryant]

Here is the 8.2 Ammonium Acetate year. Thanks again for your input!

https://postimg.cc/image/gfs8lu28x/

[andy10917]

Well, now - doesn't that sing a different tune!!

[jobryant]

Well, now - doesn't that sing a different tune!!

Glad it clears it up a little. I’m looking forward to seeing what to think it needs!

[andy10917]

First of all, I would determine what kind of grass I have (posting pix is not very good for doing that) - the mowing height and care is different for different grasses. Get someone that knows what they're doing to do it, not just a neighbor.

The revised TEC numbers and OM% show a soil that's a medium loam with very poor organic matter numbers. If you can't come up with lots of leaves to mulch in, then you'll need to supplement as much as the budget will allow of compost or peat moss (I prefer peat moss for soil like your's). Use whatever free OM you can find and apply.

The Ammonium Acetate test did paint a different picture - not necessarily better - but different. It's saying that if we eliminate the portion of the cations that can't get into solution, that Calcium is eliminated at a higher rate and the Magnesium is the most dominant (by ratio) nutrient in this picture. That's MORE unusual data.

It's also very unusual to see Potassium at those numbers and base saturation numbers.

Let's start with a plan that won't hurt any particular grass and will help overall until you get the grass type identified...

Let's add Nitrogen and Phosphorus - both are clearly needed. Get a good Starter Fertilizer and apply it at bag rate, monthly while the grass is growing. If you don't understand bag rate, then purchase the Starter Fertilizer and post the NPK numbers.

The Iron numbers are abysmal, but wouldn't be available at your pH even if they were plentiful. If color is important to you, read the article on Iron and FAS (Ferrous Ammonium Sulfate) and do the applications as needed (probably every three weeks if the grass is growing well).

In the micro's, Boron and Zinc could use work - do you want to address those this year?

Get going with that info. Get and post the grass type, and repeat the soil test (as Ammonium Acetate) next year (May?). Then we'll see how things are doing, and consider trying to displace some of the Magnesium with Calcium - it won't change the pH but will make the soil a bit easier to work.

[jobryant]

Thanks, Andy. I can't wait to post pics next year!

I will use peat moss and add Nitrogen and Phosphorus. I will try some Bottled Iron Product without chelates, due to my high pH. Addressing the micros next year is fine with me too.

A couple of follow-up questions:
1. I got my grass checked and it is Midiron Bermuda. What are your thoughts on the mowing height and care for this?
2. In 6-8 weeks (mid-October) I'm planning to scalp my Bermuda and overseed with Perennial Rye Grass, to have green grass through the winter. With that in mind, should I start all this treatment now, or is there any part of it that should wait until after I have planted the RGS? Would any of your guidance change?

[andy10917]

1. I got my grass checked and it is Midiron Bermuda. What are your thoughts on the mowing height and care for this?

Sorry! I'm no Bermuda expert, and this isn't a soils question. Maybe one of the Suthenas will chime in and help me! Otherwise, repost your question in the Warm-Season forum.

2. In 6-8 weeks (mid-October) I'm planning to scalp my Bermuda and overseed with Perennial Rye Grass, to have green grass through the winter. With that in mind, should I start all this treatment now, or is there any part of it that should wait until after I have planted the RGS? Would any of your guidance change?

Nothing changes - go for it.

[jobryant]

Thanks, Andy!

[zachhorn]

Midiron Bermuda is a hybrid Bermuda common in the AZ area. Like other hybrid Bermudas, it will tolerate low mowing very well 3/4”-1.5”. That said, you will have a hard time mowing much lower than 1.5” with a rotary mower without scalping the ground (unless you have a perfectly flat/level lawn with no dips/holes. I have Tiway419 Bermuda in central Texas - supposedly Tiffany can be mowed a bit lower than Midiron (a lot of golf courses in your area use Tiffway for this reason) but we are talking maybe 1/4” difference in optimal height between the two. That said, I maintain my Tiffway at 1.5” with a Honda rotary mower and it looks amazing. At that height, hybrid Bermuda’s love to grow nice and think (the shorter mowing height encourages more outward growth/density). However, to maintain that height it requires mowing 2x per week (I cut when it reaches 2” down to 1.5”, taking no more than 1/3 of the blade off at a time) Bermuda can get very “leggy” when it gets too tall, and cutting more than 1/3 of the blade can leave the brown parts of the lower leaves/stems exposed - which makes the yard look brown until it greens back up. In the summer months it grows like crazy... as in 1/2” every 3-4 days at that height... hence the 2x weekly mowing schedule... in the heat... ugh. But so worth it...(oh and mulch your clippings - do not bag).

Also, I have calcareous soil as well with a Ph of ~8.3... Andy turned me on to FAS treatments this year and let me tell you - it’s amazing. Yes, it is a massive pain in the a**, especially since the guidance is not to apply it when temperatures are above 85 (I’m sure you are worse, but for me that means applying it in the dark at 11:00 at night and rinsing the grass off in the morning before it gets hot again). However, it’s all worth it as I have the best looking lawn in the neighborhood (haven’t shared my FAS “secret” with the neighbors yet... that one is for me

Hope that helps.

[jobryant]

Thanks, zachhorn. I also use a rotary mower and like you said, I can only get to about 1.5". I've been thinking about getting a reel mower but I'm afraid I'd need to start mowing more than once per week. Wish I could but my life gets a little too busy (hence the delay in my reply )

Glad to hear you've had good results with the FAS treatments. I'm definitely going to be starting those soon! I too would like the best lawn in the neighborhood haha.

[jobryant]

Let's add Nitrogen and Phosphorus - both are clearly needed. Get a good Starter Fertilizer and apply it at bag rate, monthly while the grass is growing. If you don't understand bag rate, then purchase the Starter Fertilizer and post the NPK numbers.

Hey Andy, could I ask you a clarifying question to something you recommended? You suggested using starter fertilizer to add Nitrogen and Phosphorus to my soil. I've found a bunch of different starters with different NPK's (Scott's 24-25-4, Sta-Green 18-24-6, Arizona's Best 6-20-20). I'm guessing higher N and P numbers are better but is there a certain NPK ratio that I should find? Also, do you recommend applying this starter fertilizer once per month?

[andy10917]

You have a surplus of Potassium, so the third number (K of NPK) should be very low or absent. "4" is low enough, and even "6" is OK. "20" is not.