# Glyphosate and soil fertility



## Alowan (May 25, 2021)

Reading up on glyphosate after seeing slower test germination after application left me wondering. Can the accumulation of glyphosate in the soil rescue the fertility? From what I Can read some places say you can seed and sod shortly after applying while others state a grace period of 10+ days.

Seeding to test germination (very unscientific as There are many variables) led me to think There might be a slower germination after applying.

Found this study in Nature (https://www.nature.com/articles/s41598-019-56195-3) that suggest this could be the case. And since glyho has a semilong halflife (half-life of glyphosate in soil ranges between 2 and 197 days) I Was wondering if anyone had any experience or idea if this could be a germination problem for seed?

Also making me think if it could effect the new planted seed or plants close to the lawn area afterwards? (The product statement says it is inactive)..

This is not to start a glypho is good/bad fight I am just curious About its effect on the soil.


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## g-man (Jun 15, 2017)

From Zac Reicher:



> Glyphosate has no soil activity and will therefore not affect seedlings when seeded even the same day of application.


https://turf.purdue.edu/renovating-turf-how-long-should-i-wait-to-seed-after-a-glyphosate-roundup-application/#:~:text=Glyphosate%20has%20no%20soil%20activity,to%20the%20distant%20plant%20parts.

I've done gly the day after seeding without any issues.


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## LeeB (Jul 1, 2019)

If you look at the concentration they used, it's about 18 oz of roundup concentrate mixed with 12 gallons of soil. That's like dumping half a bottle of the purple concentrate into one bag of soil. Then mixing it so it's coating all the soil particles in contact with the seeds.

Suffice to say this is really unrealistic and would only represent years of extremely heavy-handed agricultural application rates. You using it one time is not going to cause an issue. The excess glyphosate will adsorb to the very top layer of the soil, but if you till then the seed will be exposed to fresh underlying soil. Sort of like if you spray painted the dirt, after a light tilling it the color would be all mixed in and leave virtually no trace. You'd have to spray paint and till the dirt a dozen times in a row before you'd see the accumulation.

The bad press about glyphosate is really overblown IMO, if you're a homeowner using it according to label directions and take basic safety precautions like not getting it on your skin, you will be fine and it won't hurt your soil. It is still a very useful chemical for the time being. The concerns are found with very heavy commercial or agricultural usage (multiple applications per year for decades) only.


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