Glyphosate Residues/Crop Damage

Last spring (2010) I burned-down and plowed-up two additional acres of pasture, installed irrigation and planted it this year in tomatoes. I planted winter greens there last fall and there were areas of obvious glyphosate damage, effecting about a third of the plot. These areas are where I had severe wild bermuda that required several passes with glyphosate, mixed strong. I had hoped it would be okay by this spring, but it's still in the soil, which is almost pure sand with virtually no organic matter.

I know now - too late! - that glyphosate doesn't break-down in sand with no organic matter to allow microbial activity. The other 2/3rds of the plot was all bahia grass, which only required a single pass with normal concentrations and no sign of crop damage there. We've still got plenty of tomatoes though (unless I run-out of irrigation water in my pond, which is going down fast.)

We are in drought here, which doesn't help, and I read somewhere that glyphosate clings to the sand grains and doesn't wash-out easily, even with hard rain or irrigation. I don't know how long it will take for this to straighten itself out. Several year ago, I accidentally tipped over a 2-1/2 gal jug of Roundup on a grassy area and nothing grows there to this day!

I read that organic matter would take care of it. I really have no desire to spend the rest of the year hauling cow manure in sufficient quantity - and I know from past experience that it will quickly leach-out this lousy pine tree sand.

This may be a dumb question - but is there anything resistant to glyphosate, (they don't sell weed seeds LOL), that I can plant as a cover and till it in to provide a little organic material to overcome the chemical residues. My only manure access is around the hay rings in my neighbor's pasture - hard to collect. Or should I just write-off that area and break some new pasture - being more careful with the Roundup next time! :-)

Any comments will be appreciated,

Jack

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Permalink Reply by Greg on May 6, 2011 at 11:04pm

I think there are a lot of GMO's out there that are resistant to glyphosate. I know of Monsanto GMO corn and I think now sugar beets. And also some resistant alfalfa and Roundup ready soybeans.

Although I do know that some farmers using such crops have said it has to be a specific Roundup used on a specific crop. I would check with Monsanto.

Also, I would check to see if you you used the the Roundup with Residual benefits, versus the usual glysophate that disapates.

I hope this helps.

Greg

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Permalink Reply by Jack Ellis on May 7, 2011 at 5:27am

Thanks, Greg - it sure does help. I use a 41% product from Tractor Supply called "Big and Tough" and the label specifically states "no residual activity in soil." It should be qualified with "some soils", "if used at 2% strength" or etc.

I've heard of RU-Ready cultivars but I know nothing about them or how to buy some seed. The soy beans would be perfect. I wonder, though, if their resistance extends to stubborn concentrations in the soil - which is a different matter than simply spraying emerging weed foliage. I sure would like to give it a try, if I can just find a way to buy a bag of that soy bean seed. In my past experience a lot of that stuff is tightly controlled by big growers and the dealers won't give us the time of day.

I sure wish y'all would send some of that rain down our way! Every day I watch dark clouds pass overhead on the south wind, laden with moisture from the Gulf, but not a drop for us.

Jack

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Permalink Reply by Jim Blair on May 8, 2011 at 3:48pm

Another thought if you can't get something get get some bales of old hay, straw or other fodder and till into soil. I have even used grass clipping to ad organic matter to the soil.

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Permalink Reply by Jack Ellis on May 9, 2011 at 7:34am

Great idea, Jim! Bales of hay are readily-available here - although this year - worst drought since the 1930's - it's in pretty short supply. What I should do is load-up the urine and feces soaked hay around my neighbors feeding rings. I've done that before, but I'm not that ambitious anymore (at 75). :-)

Jack

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Permalink Reply by Devlin Reynolds on May 27, 2011 at 9:11am

Jack,

Aa crazy as it sounds they do sell weed seeds. They even specifically sell glyphosate resistant weed seeds. I worked a lot in the west and your best bet would be kochia seeds. Just make sure you don't let it go to seed itself and I would pre soak the seeds to make sure you don't introduce a new weed seed into your soil. Kochia is used in UT and kther places for hay, but mostly an annual weed in row crop and non-crop situations. You can mow it several times during the growing season to keep it down and then till it in late season. Kochia does self thin after so if you let the plants get too big right away you won;t have as many plants and many of the seeds may stay dormant. Other options ate mearestail, Russian thistle and pigweed.

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Permalink Reply by Bill Fleming on May 27, 2011 at 10:38am

Interesting.

In all the research I've read never heard of glyphosate resides on sandy soil that cause damage lasting more than ten days. In fact damage decreases rapidly after three days.

I would suspect some contaminate in the most likely Chinese made glyphosate is the real cause of your problem.

IMO just a good tillage and irrigation if possible would be the best way to remedy the situation.

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Permalink Reply by Greig Sayre on May 27, 2011 at 3:01pm

Glyphosate is adsorbed onto clay particles to the extent that it is inactivated. Got any clay sitting around? Lime should also work against any glyphosate soil activity. Glyphosate is not absorbed readily by root tissue. I think that the suggeation that a contaminant may be at work in the soil is plausable.

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Permalink Reply by Jack Ellis on May 27, 2011 at 8:03pm

Well, the glyphosate was a cheap-off brand of 41% from Tractor Supply. I never thought of a foreign contaminant, but there's something very wierd going on. It's been a full year now and the soil still won't grow anything except severly stunted and deformed plants - not even weeds! The whole field was treated (new land from pasture) in the spring of 2009, and only about 1/3rd is affected - and these are areas where I had well-established wild bermuda which I treated several times with strong concentrations to kill the stubborn bermuda. The rest of the field was bahia and simply sprayed once with a normal 2% solution. All of that's okay - the damage is just where the bermuda was. I mixed it, I think, at about 10% on the bermuda - three times before it finally died. Frankly, I think I just used way too much. It won't happen again - in fact, I've switched to carfentrazone and clethodim and have quit using glyphosate on crop areas. More expensive, but a lot safer!

There's absolutely no question that it's being absorbed by the roots. The field is presently in pinto beans, which is the third crop to go in there - all the same damage (okra followed by turnips followed by these pinto beans). I'll try lime but I don't have ready access to clay. I've got the poisoned areas staked-off, so I know where they are, and I'll just plant around them when I plant the winter brassicas in August. I've still got 2/3 of the field - it will look bad with patches of bare ground, but that's just a mental thing. :-)

A lot of the problem is this sandy soil with no organic matter. I read where a hawaiian sugar cane field, also sand, was accidentally treated with an overly strong application of Roundup 22 years ago and still will not grow a crop! In my extensive internet research, I have read several such horror stories - from reliable sources - where too much glyphosate ruined sandy soil for years!

I never should have applied so much - but I was under the impression that gly has little or no soil activity. Wrong! It must be used sparingly in sandy soil. The possibility of a foreign contaminant that Bill suggests certainly exists - but nothing I can do now except write-off of that soil I guess. I have plenty of land - it's just having to look at those dead patches which remind me every day of my screw-up! That bothers me more than a little ruined soil, to be honest. If one more guy asks me "what happened there?" I'm gonna punch him in the nose! LOL

Jack

edit - PS - Ive tilled deeply several times , plowed with a middle buster and ran the sprinklers for hours and hours on end - all to no avail. More and more, I'm thinking about what Bill said about cheap chinese glyphosate. If I want to fork over some bucks, I could get it lab tested but it would just satisfy my curiosity and not solve the problem. Thanks to y'all for the input. JME

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Permalink Reply by Douglas W Speed, Sr on June 25, 2011 at 8:20am

Jack, Treat the soil with a combination of Quantum Growth Light and VSC. The microorganisms will restore the soil's health plus provide additional benefits. Visit the web site www.douglasspeed.com for additional information or call 1-866-680-2565.