Barren Earth? We're working on it.

[ladyapple27]

Dr. Bill Hanlin, our local agricultural extension agent, wrote an article in this week's local paper about a growing problem: herbicide residue in manure used as fertlizer. Broad leaf herbicides are widely used on pastures and silage crops. Because these chemicals don't break down quickly in the environment, residue collects in the systems of animals fed food from treated fields. The residue is deposited in manure, where it continues to act on plants. Some farmers and gardeners are reporting damaged crops due to the residue in manure. Hanlin suggests testing manure in a small area, or checking the provenance of manure before using it. Some crops are more susceptible than others. I'll see if Mr. Hanlin has a file of the article that he'd like to share.

If we keep on carelessly using chemicals that remain in the environment years after use, we're going to make the Earth barren. Anybody remember DDT and the food chain? Will we ever learn?

BTW, the residue isn't removed by composting the manure. 

Comments

[wherrymotor.livejournal.com]

Do send a link if you can? I just spent a few hours with the chemistry of Roundup and similiar. Are you referring to any such? On first blush, they look likely not to persist.

[ladyapple27.livejournal.com]

http://www.uri.edu/ce/factsheets/sheets/herbicides.html
This is the best article that I've found foe a general overview of how different classes of herbicides work.

I believe that Mr. Hanlin is referring to selective systemic herbicides, not a non-selective systemic like Roundup. Roundup is glyphosate, specifically isopropylamine salt. Glyphosate comes in other formulations. Roundup is widely believed to be quickly broken down in the soil. If you must use a herbicide, it is probably your safest bet. I'll post on the safest and most effective ways to use it later in the week.

Other herbicides like Dicamba are quite active in the soil and may travel in the soil. When ingested by animals, 2,4-D isn't broken down; instead it's excreted in its original form. Some of the preemergent herbicides linger in the soil for long periods of time. Everything depends on what class of chemicals you use and how well you understand them.

I have other posts planned on all aspects of using herbicides. Right now, I'm getting imput from specialists to make sure that the planned posts are clear, accurate, and up to date.

[wherrymotor.livejournal.com]

You are most diligent and caring!
Right, that was my impression of Roundup and other glyphosates - that they interfere with synthesis of 4 essential aromatic amino acids - that we animals get from plants anyhow. The outcome is fewer plants, but no other effects.
'Looking forward to the rest!