Monday, February 2, 2015

Grazing Winter-Killed Sorghum-Sudangrass, What I'll Do Differently Next Time

Looking west, the Sun is out, and a cold front is rolling in

Looking south, the Sun is behind the clouds, everything's trampled on the ground, and there's no bare soil
I've more or less finished grazing the field of winter-killed sorghum-sudangrass and there are a few things that I think I'd do differently next time.  

I originally planned to plant sorghum-sudangrass in this field right after harvesting the wheat so that I could cut it for hay, but for various reasons didn't actually get it planted until July 22, so I decided to treat it as a cover crop that I would let grow to maturity so I could then graze it after it had been winter-killed.

I ended up dividing this field up into four paddocks and kept track of how many days of grazing and how many cattle I had on each part of the field, and after a quick calculation it turns out that I was able to get the equivalent of about 35 bales of hay (1300 lb. round bales) from this 23 acre field.   

If I was in the hay business or was only interested in producing the maximum amount of grazing possible, that would be a pretty disappointing amount of hay or grazing.   But in the long run, I'd like to increase the organic matter levels in my cropland, so right now it's going to be a tradeoff between maximum forage production for the cattle and also leaving enough crop residue laying on the surface to feed all the soil critters ('soil critters' is a highly technical term that is used to collectively describe all the various bacteria, microbes, and itty-bitty bugs that are present in a healthy soil).

If I'd given them a smaller area to graze at a time and had forced the cattle to really clean everything up before I moved them I probably would have gotten more forage off of this field.  But, I would have also ended up with more bare soil and less trampled organic material laying on the ground.  Ideally, I'd like to be able to produce more hay or forage while also leaving even more organic material laying on the surface as possible which might be a little more difficult. 

Planting sorghum-sudangrass, letting it winter-kill, then grazing it instead of feeding hay is relatively simple, and actually works, but I think the basic idea can be improved to give me both  more grazing or hay and more soil-building potential. 

The next time I plant sorghum-sudangrass in a situation like this I think I'd be better off if I planted it immediately after wheat harvest in mid-June instead of waiting until mid-July, and I'd also fertilize it with a moderate amount of nitrogen (~30 lb./acre).  After about 45-60 days of growth, depending on how much hay I had stored, I'd either bale it for hay or I'd graze it, I might fertilize it again, and then I'd let it grow until it either winter-killed so that I could graze it over winter or until it had grown tall enough to graze it once again in late summer before planting something like wheat in early fall (something like a simple mixture of wheat, clover, and turnips might be even better).  

With that sort of management, I should be able to easily get at least 45 bales of hay, plus a similar amount of grazing either in late summer or over the winter after it has winter-killed.  Grazing the sorghum-sudangrass a couple of times over the summer instead of baling hay would probably be the best option for soil building, plus having something like wheat pasture to graze in the winter would be a better overall system for wintering cattle than grazing winter-killed sorghum-sudangrass. 

I do have a pretty good idea that if I'd planted wheat in September after grazing the sorghum-sudangrass that I'd have a decent amount of wheat pasture right now, and I'd also have the option to either graze it until May before planting something like grain sorghum or I could take the cows off of it in a few weeks and harvest it for grain.  After grazing this field of winter-killed sorghum-sudangrass, my options are more limited to planting something like grain sorghum this spring.   

Of course after writing all that, there's always something to be said about keeping things as simple and low-input as possible, and drilling that sorghum-sudangrass into some wheat stubble, then grazing it after it winter-killed was a pretty simple and low-input way to feed cattle.

Will Rich plant a complicated mixture of exotic cover crops next summer? Will Rich keep things as simple as possible?  Stay tuned for more edge-of-the-seat tales of adventure about planting cover crops this summer and find out.


  1. I'm learning things all the time when it comes to cattle and grazing. It seems like such a simple thing but like everything, once you get into them they can be a simple or as complex as you want to make them.

    Living here in the timbered river valleys of southeast Iowa, I never seem to tire of your pictures showing a horizon that seems impossibly far away. If I ever get filthy rich, I wouldn't mind owning a house somewhere out there where all I can see if flat farm fields and sky for as far as I can see. Someone can farm it for me, I'll just sit on the porch and stare at the horizon.

    1. "...they can be a simple or as complex as you want to make them..."

      That pretty much sums it up, grazing cattle is an inexact science that can be all the way from an extremely low-input task to an overwhelmingly complicated high-input operation, and maximum profit doesn't always come from the higher input side of the equation.

      There's a point somewhere between those extremes where maximum profit, minimum input, and highest quality of life all meet that I'm always trying to find, and every year that point seems to be in a different place.

      Until I started taking these photos, I noticed almost everything around me, but I didn't really notice how blue the sky was or how the sun played with the clouds or how green the trees were when they leafed out. If the drought comes back this summer, I'll see if I can take some photos that show what a severe drought feels like, 100 degree days for months on end might or might not change your mind.