Renovating Weedy Crop Land into Pasture

[Stocker Steve]

I purchased 120 acres from the FSA this week. It is about 2/3 tillable and has not been farmed for 3 years. (FSA foreclosed when it was in corn and refused to rent it because they were planning to sell. FSA was unable to resell until now they did not understand what the actual market value is...) The abandoned corn fields are rough, and about 75% bluegrass/timothy and 25% weeds. Most of the weeds are Canada thistle.

I plan to renovate into alfalfa/white clover/meadow brome & alfalfa/red clover/reed canary mixes but I am concerned about all the weed seed out there. Is there a significant reduction in weed germination with a year of Round up Ready cropping, or should I just seed it down in the spring and plan to do a lot of clipping for the next couple years?

 

[msscamp]

You might check into Cimarron weed killer. I have no personal experience with it but, from what I've read on the manufacturer's website, it will kill Canadian Thistle, Bindweed, Sandburs, and a couple of other tough to kill weeds without harming the grass, alfalfa, or clover. I believe it also has a pretty good residual, but I'm not certain about that - it's been a few months since I read up on it.

 

[Stocker Steve]

I will look into this chemical for next summer. Do you have any experience wether burning off the pasture residual can reduce spring weed germination?

 

[LonghornRanch]

Call your county extension office, a smart guy with alot of letters after his name will come out and tell you MORE than you want to know.

 

[ENNOT]

Burning canadian thistle hasn't work real well for us. You might try to spray it out before you plant and use a proven chemical. I realize once you have the alfalfa/clover planted, it's hard to spray, so if it pencils out, try to spray before you plant. Then once established, it should choke most of the weeds out. It just depends how bad the weeds are I guess.

 

[msscamp]

I will look into this chemical for next summer. Do you have any experience wether burning off the pasture residual can reduce spring weed germination?

We have a real problem with Sandburrs, and we had the pastures flamed this past spring because of that. It reduced the Sandburrs dramatically - did not eradicate them - but did not seem to have any effect on the other weeds.

 

[cowtrek]

Roundup of course has no soil activity-- it is bound up to the soil particles as soon as it hits the ground, so it will have no effect on the weed seed bank you have in the soil now. IF you were going to crop it you'd have to rent it to somebody who'd hit it with soil-applied herbicides that hopefully will have efficacy on the weed seed you're trying to eradicate. It's highly unlikely you'd find someone willing to rent the ground on a short term lease like that and spend the extra money on soil-applied herbicides (or extra roundup trips since it's going to be a mess anyway) and they might apply something with a long soil residual that won't be too friendly to the grasses and legumes you plan to plant later on. The other option would be to crop it yourself and choose the crop based on the best herbicide selection you can find to take out the weed seed bank. Neither of these is a very good plan IMHO.

The good thing about this situation is that, not having been cropped for a few years, any soil residuals from things like Trifluralin or Command or a good number of other long-lived soil herbicides should be gone. Carryover from some of these herbicides can really frustrate trying to get a good stand of forages established. That's why I'd be extra-careful in cropping it if you choose that route to make sure that nothing too 'hot' is put on the field that might take out the seed bank but then have a long carryover that would sicken or kill the legumes or grasses seeded later on.

I'd say your best bet would be to either 1) forego any production on it for a year and just keep it burned down with Roundup and other foliar herbicides as needed to kill sprouting annuals and perennials and established perennials, but this probably won't take out the entire seedbank by a longshot since most weed seed can lay dormant for a LONG time and doesn't necessarily sprout the first year (or the second or the third....) OR 2) put a few head on it to make use of the timothy and other grasses you said were out there while you focus on wicking the weeds or hitting them with more selective herbicides aimed specifically at the weeds you have, again watch about stuff like Grazon that might give you fits down the road when seeding legumes later on. That's what we're doing in converting our old cotton farm into pastureland. That way you're at least getting SOME production out of the place while you clean things up a bit, then later completely moldboard plow it to bury as many weed seed as deeply as you possibly can, disk it a couple times and then seed the grasses and legumes you intend to establish. Either way you'll probably have to deal with at least part of the seedbank because you just can't get it all no matter what you do. If the land is rough you'll probably do well moldboard plowing it as deep as you can to bury as much of the seedbank as deeply as you can. The old timers did this a lot and it can really reduce the amount of seed close enough to the surface to germinate. It'll give you a lot of loose soil to work with in disking it down for a seedbed for your grasses and legumes too and smooth the land out nicely for you to get a good start. Depending on where you are and the soil/climate and topography you might have to be careful and get something established pretty quickly afterwards, but it just might be your best bet. Just realize no matter what you do you're going to have to fight some weeds that get through even if you do EVERYTHING to get rid of them beforehand. Good luck! OL JR

 

[msscamp]

Burning canadian thistle hasn't work real well for us. You might try to spray it out before you plant and use a proven chemical. I realize once you have the alfalfa/clover planted, it's hard to spray, so if it pencils out, try to spray before you plant. Then once established, it should choke most of the weeds out. It just depends how bad the weeds are I guess.

To the best of my knowledge, my experience, and from everything I've read - nothing chokes out Canadian Thistle. It is a noxious weed and it does the choking out. Generally speaking, pre-emergent weed killers don't have any effect on Canadian Thistle, and it doesn't start growing until after the crops do (at least in my area). Another problem is that all of the proven weed killers that will kill it also kills/knocks the heck out of the clover and alfalfa. We've had good results with careful spot spraying, but it's a major pain in the butt and extremely time consuming.

 

[msscamp]

Roundup of course has no soil activity-- it is bound up to the soil particles as soon as it hits the ground, so it will have no effect on the weed seed bank you have in the soil now.

Perhaps I'm misunderstanding what you're saying, but with some weed seed, Round-Up will kill them if they are on the surface. I'm not sure how wide spread this is, but I do know it will prevent some from germinating. If one tills the soil, then one is bringing new weed seed to the surface and you're right.

 

[Bluestem]

Herbicides are a good short term fix. Round-up is the least harmful to your soil. I would do a good soil test. Canadian thistle likes soil with high iron, low calcium and magnesium levels and low levels of organic matter.

 

[cowtrek]

Roundup of course has no soil activity-- it is bound up to the soil particles as soon as it hits the ground, so it will have no effect on the weed seed bank you have in the soil now.

Perhaps I'm misunderstanding what you're saying, but with some weed seed, Round-Up will kill them if they are on the surface. I'm not sure how wide spread this is, but I do know it will prevent some from germinating. If one tills the soil, then one is bringing new weed seed to the surface and you're right.

Well, anything is POSSIBLE I guess but that certainly isn't what RU is really supposed to be used for. It might kill some seed that it comes into direct contact with (sprayed onto) but if this was a viable alternative I'm sure the guys at the big M would be thrilled to death to add it to the labeled uses LOL

Yep moldboarding will bring up some seed from down deep but if you're burying the fresh seed bank on the surface and bringing up some old seed of which maybe only 10-20% may be viable I'd say that's a good swap, especially in taking out the established perennial's root systems in the deal. Most herbicides that have efficacy on perennials work much better on younger or newly sprouted perennials and annuals alike, simply because they have smaller reserves and are growing faster as seedlings. That's why you can usually get by with lower herbicide rates on annuals and germinated perennials versus resprouting perennials. OL JR

 

[Dap]

Cimarron is a great product and inexpensive, but it kills clover and alfalfa.

Canada thistle can be controlled, but you have to be persistant. I have a few trouble spots, and usually it takes an early summer plus a fall application. I usually use either Cimarron+2,4-d, or 2,4-d+Banvel. Still can take 2 or 3 years to knock it out.

 

[Stocker Steve]

Roundup of course has no soil activity-- it is bound up to the soil particles as soon as it hits the ground, so it will have no effect on the weed seed bank you have in the soil now.
The good thing about this situation is that, not having been cropped for a few years, any soil residuals from things like Trifluralin or Command or a good number of other long-lived soil herbicides should be gone. Carryover from some of these herbicides can really frustrate trying to get a good stand of forages established. That's why I'd be extra-careful in cropping it if you choose that route to make sure that nothing too 'hot' is put on the field that might take out the seed bank but then have a long carryover that would sicken or kill the legumes or grasses seeded later on.
I'd say 2) put a few head on it to make use of the timothy and other grasses you said were out there while you focus on wicking the weeds or hitting them with more selective herbicides aimed specifically at the weeds you have, again watch about stuff like Grazon that might give you fits down the road when seeding legumes later on. That's what we're doing in converting our old cotton farm into pastureland. That way you're at least getting SOME production out of the place while you clean things up a bit, then later completely moldboard plow it to bury as many weed seed as deeply as you possibly can, disk it a couple times and then seed the grasses and legumes you intend to establish. Either way you'll probably have to deal with at least part of the seedbank because you just can't get it all no matter what you do. If the land is rough you'll probably do well moldboard plowing it as deep as you can to bury as much of the seedbank as deeply as you can. The old timers did this a lot and it can really reduce the amount of seed close enough to the surface to germinate. It'll give you a lot of loose soil to work with in disking it down for a seedbed for your grasses and legumes too and smooth the land out

Good ideas. I'm thinking about grazing this spring, burning it down this summer, and then planting this fall.Do you have any tips on fall forage stand establishment?

 

[msscamp]

Roundup of course has no soil activity-- it is bound up to the soil particles as soon as it hits the ground, so it will have no effect on the weed seed bank you have in the soil now.

Perhaps I'm misunderstanding what you're saying, but with some weed seed, Round-Up will kill them if they are on the surface. I'm not sure how wide spread this is, but I do know it will prevent some from germinating. If one tills the soil, then one is bringing new weed seed to the surface and you're right.

Well, anything is POSSIBLE I guess but that certainly isn't what RU is really supposed to be used for. It might kill some seed that it comes into direct contact with (sprayed onto) but if this was a viable alternative I'm sure the guys at the big M would be thrilled to death to add it to the labeled uses LOL

Hence the statement about "I'm not sure how widespread it is.". I know it will kill some weed seed, so consider it an added advantage.

Yep moldboarding will bring up some seed from down deep but if you're burying the fresh seed bank on the surface and bringing up some old seed of which maybe only 10-20% may be viable I'd say that's a good swap, especially in taking out the established perennial's root systems in the deal. Most herbicides that have efficacy on perennials work much better on younger or newly sprouted perennials and annuals alike, simply because they have smaller reserves and are growing faster as seedlings. That's why you can usually get by with lower herbicide rates on annuals and germinated perennials versus resprouting perennials. OL JR

Um, 'moldboarding' (I think the term is mowboarding, but I may have the spelling wrong on that) has been outlawed in a lot of states - I know it has in Wyoming - due to the loss of topsoil that results. I was talking about regular discing/working the ground prior to planting a crop the following spring which, I'm sure you're aware, has a major impact on the amount of Canadian Thistle, and Bindweed - just to name a few - that then sprout.

 

[Bluestem]

Deep plowing (moldboarding) disrupts the soil structure. Burying what little organic matter and soil life you have left. It'll sit you back years. Discing two or three inches max will work.

 

[msscamp]

Deep plowing (moldboarding) disrupts the soil structure. Burying what little organic matter and soil life you have left. It'll sit you back years. Discing two or three inches max will work.

I apologize for my previous statement about 'mowboarding' vs 'moldboarding'. It has always been referred to as 'mowboarding' (at least phonetically) in my part of the country.

 

[preston39]

stocker...,

Depends on your plans for use. Concluding that you plan pasturing the acreage. I would have soil tested. Lime and ferterlize as necessary. Pasture and clip...clip and pasture. Especially if hills or rolling land. Some weeds will come back anyway and must be clipped. You will be surprised how rapidly the weeds will diminish over time while you are getting a value. Each to his own. We avoid chemicals like the plague...where there are alternative methods.

 

[Stocker Steve]

Thanks for the tips. I have pulled soil samples but have no results yet. We have fairly heavy clay soil, and the majority thinking here is you need to plow crop land at least every third year. In my case I am trying to convert poorly managed crop land to a high production legume grass mix - - and I need to minimize the establishment cost, avoid any chemical residual, and minimize future clipping required. A couple years of Round up Ready crops could certainly do that but I am not that patient.

We fall plowed one field this week that was a little low so it would dry out next spring. I re walked the other big field - - and I have never seen such a dense stand of quack grass. There was not a lot of Canada thistle in this area. I think the quack choked it out! I am planning to burn it off this spring to remove the thatch, continuously graze it this summer to weaken the quack stand, spray it with Round up, till it, and then fall seed to alfalfa, festolium, and brome. Any other suggestions?

 

[NorCalFarms]

I would probably plow it, but we hay all of our irrigated pasture at times so I want it smooth. If it is only to be grazing land and you don't need it super flat or smooth I would graze off all the stubble and then no till grass in to it. Less cost to establish for sure, not plowing it. Temporary electric fence off any parts that don't get a good stand and replant. By planting straight grass you can then spray all the 2,4-D, Dicamba, MCPA etc you want on it to clean it up all while still getting some grazing return off of it. After a year or two (or whenever the weeds seem to be under control) then go in and drill the legumes into it. I would only roundup the place if there is some grass weeds in it that you can't spray out of the desired grasses.