When is there too much thatch?

[Scott44]

I have some observations on thatch. I guess I've never had too much even though I thought I did. I started spray and rolling my plots 3 years, broadcasting my brassicas into the last years rye.
I also did a sorghum plot last year with this method because I couldn't get the tractor back there because it was too wet.
I wanted to plant a sorghum mix here but it was too wet so I tried the throw and roll method. This is what I started with.


What it looked like after rolling.





I stuck a trail cam up to check the plot,





A month after planting.



2 months



What it turned out to be.



The only thing is I didn't have enough to do a throw and roll this spring so I hit it once with the disc and the broadcast and disced it in. This year I tried a different mix to try and leave more thatch for next year's throw and roll/mow.

Starting this spring.









A week ago, I hope I have enough thatch for next year.

 

[Scott44]

Another plot that I thought I had way to much thatch was last years brassica plot. I've been doing Paul's cereal grain brassica rotation and rolling down the rye for my brassicas. Thought I had way too much rye but it worked out to be my best brassica plot ever.

The rye I started with,







Pretty spotty at first.



But finally filled in.



Also rolling the rye I get some volunteer rye.

 

[Scott44]

What is everyone's thoughts on how much is too much thatch? What do you use any why? I tried a couple plots this year without spraying to see how it works.

 

[MarkDarvin]

The only terminal level of thatch I could see is if you begin to fail to germinate your next crop, or if you get mold or pest issues. Even if those things happen, I wouldn't break out the tillage equipment, I'd just plant a crop of low carbon forage to let the soil catch back up.

 

[dgallow]

How much thatch is too much residue? Look at the ground near your feet is the soil covered at all times with both past residue and healthy growing plants?

Here is a series of questions which need to be evaluated frequently:

What is the decay rate in your area?
Pattern of rainfall?
Rainfall zone?
Soil drainage class?
Innate soil fertility?
Times of highest water evaporation/transpiration rates?
Period of slowest plant growth?
Level of field biological activity and decay organisms?
Is germination slow or rapid under good growing conditions?
Height of the next canopy grown?

When you consider all of those factors interact, then it is about impossible to give general recommendation. Through experience you will gain the knowledge you need!

The first question to answer:
Is your soil covered by residue and growing vegetation 365 days per year? You start there and then continually evaluate nuances in the future.

Saturated soil and the thatch load in the pic on 6/18/25 would worry me if the summer mix had significant portions of beans or cow pea. Sorghums, millets and flowers seem to handle excess water okay. Can tell it rained in the pic but can't tell how fast water infiltrated. Under conditions of heavy thatch over poorly drained soil germination issues are common and weed issues tend to rise...especially in spring.

Plant pest issues may rise in the first couple years of this type of management....that is normal....as insect predator species lag behind plant pest species. In a few years when the soil becomes healthy and the forage diverse/healthy, then predators keep the pests in check.

 

[Scott44]

How much thatch is too much residue? Look at the ground near your feet is the soil covered at all times with both past residue and healthy growing plants?

Here is a series of questions which need to be evaluated frequently:

What is the decay rate in your area?
Pattern of rainfall?
Rainfall zone?
Soil drainage class?
Innate soil fertility?
Times of highest water evaporation/transpiration rates?
Period of slowest plant growth?
Level of field biological activity and decay organisms?
Is germination slow or rapid under good growing conditions?
Height of the next canopy grown?

When you consider all of those factors interact, then it is about impossible to give general recommendation. Through experience you will gain the knowledge you need!

The first question to answer:
Is your soil covered by residue and growing vegetation 365 days per year? You start there and then continually evaluate nuances in the future.

Saturated soil and the thatch load in the pic on 6/18/25 would worry me if the summer mix had significant portions of beans or cow pea. Sorghums, millets and flowers seem to handle excess water okay. Can tell it rained in the pic but can't tell how fast water infiltrated. Under conditions of heavy thatch over poorly drained soil germination issues are common and weed issues tend to rise...especially in spring.

Plant pest issues may rise in the first couple years of this type of management....that is normal....as insect predator species lag behind plant pest species. In a few years when the soil becomes healthy and the forage diverse/healthy, then predators keep the pests in check.

THanks!

 

[Fish]

Nice job, Scott44!

 

[Jason Broom]

I don't know if you answered your questions, but based on the results you're getting, I would say you do not yet have too much thatch.

 

[Smallplot]

Depending on planting techniques, a very small amount my be too much. And with very healthy soils, you may never have enough because thatch can be rapidly digested. Also we need to look at what type of plants make up the layer of thatch. High cellulose plants will take longer to break down while some plants contain so much water that as the plants dry down they become a small fraction of mass they were at termination.

I love drilling brassica mix into winter rye thatch. Always have good luck with that.