Can't really explain why the oats did so poorly??  For the legumes, the berseem clover winter killed so I understand that being lower.  Not sure why the red clover didn't do better?  I don't see how/why both did worse than no cover crop???  This was only one plot and clearly not scientific obviously, but, I hope it is worth sharing and discussing.

Any thoughts/comments?

1)  You are looking at one set of numbers from one plot with no replication.  How much does field variability factor in?  Lots I'd say.  It would be interesting to have a statitician look at the standard deviation to show where the real significant differences are.  (Maybe Greg Roth or his assistane Mark Antle could help with that?)

2) You seem to be using 100% of the poultry nitrogen being available.  Is that a realistic number? 

3) Looking at the N numbers, if you use 75 lb N from poultry litter, then 80 lb N coming from Crimson Clover.  That seems in line with what we expect. 

4) How much growth was on the oats?  Would that have an effect of the amount of N tie-up (as someone else suggested could be a cause) ?

5) How much growth did you have on that hairy vetch?  In light of the yield of the "no cover", I would have expect more from the hairy vetch.  How did it over-winter?  What was the size when you killed it?

6) I have to wonder what your numbers would look like if you had no-tilled those cover crops into fields harvested as corn silage.  I think I always see a yield response to planting corn into wheat stubble versus planting into corn stubble. In a year like this one, hopefully you would not have a lot of excess N in the soil after harvest, so your numbers would give a true(er) indication of what you would be getting from the manure and cover crops.

7) If you do this again, you should have a strip of "no manure, no cover", just for comparison. Enough for a yield check.  

I've read about Berseem clover years ago, and I remember that winter-kill could be a problem with it.  So we never got on that band-wagon. I've been impressed with the crimson clover we used so far.  I had some farmers plant some hairy vetch this fall for the first time.  We'll see how it works.  we'll evaluate next summer and then decide whether to push more clover, or vetch, or ????

Interesting results.
Just put some outs out this fall for cover after seed corn and potatoes. They're up and looking pretty good now. Don't get much nutrient out of them(I don't think) but I like the way it leaves the ground for no tilling corn next year.

I have to agree with you - I like the how the soil is mellowed when planting into fall-seeded oats cover crop. Most times we don't let them get too big.  If they do, they get harvested.  Oats allowed to grow to boot stage, then harvested, makes a very nice seedbed.

I did one year of hairy vetch back when we grew wheat and the corn loved it. Wish I could find a way to get it to grow through standing soybeans then have it as the cover when soys are harvested.......................ever had any experience with that?

Is aerial seeding an option for you?

Do the clovers fix N like the vetch?

Yes.  Research shows it is not quite as much.  However, I have to wonder.... if you get a better stand, does that make up for some of the difference?  So far, I am seeing better stands in clovers(Crimson) than in hairy vetch.  However, it is too early to make a definitive statement on that.

Maritn, so many questions, so few answers

Majority of test area was one soil type the northern end of the field ,where oats were, is a less productive soil and may be (probably is) part of the reason the oats didn't do as well?  The N from poultry was calculated using 75% available given fall/winter application on a cover crop with the manure analysis of 60#N/ton.  Obviously this wouldn't hold true on the wheat fallow section or the oats and that may be reflected in the lower yeilds although the wheat fallow didn't seem to be affected nearly as much as the oats??  Oats winter killed at around 15-18" tall.  Nitrogen certainly could have been tied up in the decay of the residue, I just wouldn't have expected such a dramatic result.  We would have preferred to do "experiment" with no manure applied or commercial fertilizer, but, our producer wasn't going that far.  We aren't impressed with the berseem and really haven't pushed its use either.  It just doesn't get enough growth or cover before winter.  The crimson is still my first choice based on what we've seen, but, I can't complain about the red clover at all.  Some have mixed the two this past year.  I'm still nervous with the vetch, but, I will say that stuff makes one heck of a carpet if planted early enough!!  The residue breaks down quicker than the clover which is probably good for the N release but, when things got drier, the clover residue would hold more moisture.  I'm curious to see if we have any long term issues with the vetch as some have indicated.

1) The more I think about it,  the more I see the value in having that check plot with no poultry manure.  It would really have shown how much "available" N (or should I say "utilizable N?)  you were getting.

2) Why mix red clover with crimson clover?  The only reason I could see is if seed supply is limited.  If you take your numbers at face value - and that is questionable at this point - you got a 38 bu/ac yield response from using crimson clover versus using red clover.  Even if the red clover was free - and the drilling was free- I could still afford to buy the crimson clover.   (of course,  I really don't think there is that much difference between the red clover and the crimson, but that is what your plot shows.)

I couldn't agree more in regards to the no manure checks.  I was a little disapointed but I understand why he added the manure.

 Mixture of crimson and red was mostly due to costs, but, I still like the idea of some diversity.  Granted, they aren't that much different,but, I like these producer to think diversity in cover crops and this is a real good start.