I've been interested in cover crops for a while, first planting them in my garden at least fifteen years ago. I originally started out with a 'deer food plot mix' that I planted in the fall which was a mixture of winter wheat, winter rye, oats, crimson clover, ladino clover (white clover), alfalfa, and Austrian winter peas. Planting that cover crop mixture improved my garden almost overnight, based on how the garden and cover crops grew and looked afterwards.
Because of my garden experiences with those 'deer food plot mixes', I've always had it in the back of my head that if cover crops worked in a garden, then they would also work in a field, but I've never really tried to scale up the idea for a number of reasons, mainly drought and the cost.
While I've been pondering cover crops over the years, I've read and re-read everything I could find online from people like Gabe Brown, Ray Archuleta, David Brandt, and Gail
Fuller, who all speak a lot about the benefits of cover-cropping (it's
easier for you to search for more info about them than it would be for
me to list a bunch of links, so start google-izing them if you're
interested, but I'll dig up some links if anyone asks).
At the same time, I also happened to find the Sweet Bay Farm blog,
which is a blog written about planting cover crops to improve the soils
on a farm in Maryland. I tend to be skeptical whenever I'm listening
to an 'expert' talk about anything, but reading this blog and about her
results made me start thinking even more seriously about cover cropping
some of my cropland. Experts might tend to stretch the truth at times, but 'ordinary people' usually don't, so I tend to be more likely to believe the results from people that aren't self-proclaimed experts.
Over the years, I've planted both pearl millet and sorghum-sudangrass (or haygrazer) as hay crops on the farm, which would have been technically sort of, but not really a cover crop experiment. But, last summer I planted a simple mixture of pearl
millet, sorghum-sudangrass, and grain sorghum as a hay crop. This mixture
was about as simple as one could be since it was only three different warm-season grasses, but it grew slightly better than the
sorghum-sudangrass that I planted at the same time (which was sort of
surprising). That got me to thinking that if I had added in something like cowpeas, buckwheat, or sunflowers and grazed it instead of baling it, I'd have really seen some soil building results.
Since most agriculture is regional (what works in Iowa might not work in Texas), I re-read everything I could find and decided that Gail Fuller in KS was farming in an area pretty similar to mine and I read about a cocktail he has been planting after wheat harvest that looked like it might work for me.
Basically, it's a combination of different warm season grasses (millet, sorghum, etc), warm season broadleaves (soybeans, alfalfa, etc), cool season grasses (winter wheat, oats, etc.), and cool season broadleaves (winter peas, canola, etc.) with about 3-5 lb. of sunflowers (the black oilseed kind, not the eating kind) thrown into the mix, and it's all planted at the same time right after the wheat is harvested. The idea is that the warm season plants will frost-kill in the fall, allowing the cool season plants to start growing, then cattle can graze the field over the winter. In a good year, there is also the possibility of harvesting the sunflowers in early fall as a cash crop. So, you can get the benefits of a cover crop, grazing, and a possible grain harvest.
Since it's difficult to double-crop grain sorghum after wheat and get a harvest for a number of reasons, if it's feasible I would much rather plant a cocktail like this, graze it over the winter, and then plant grain sorghum the following spring. It would be less risky, there would be no need to bale hay or feed it, and if it goes right, a sunflower harvest would be a bonus (it might be a trick finding somewhere to sell them though).
With this all in mind, I'm going to plant a mixture of grain sorghum, sorghum-sudangrass, soybeans, black-eye peas, winter wheat, maybe some oats, crimson clover, turnips, and sunflowers in a test plot. Since this is a test, and I'm using what I have on hand (okra would be a substitute for something like sunn hemp, etc.), I'm also going to throw in some okra seed, flax seed, dill seed, and whatever other seeds I can come up with.
I'm thinking that I'll plant at a rate of about 8 lb. of grain sorghum, 8 lb. of sorghum-sudangrass, 10 lb. of soybeans, 10 lb. of black-eye peas, 60 lb. wheat, 3 lb. crimson clover, 1 lb. turnips, and 5 lb. of sunflowers per acre. That sounds like a lot of seed, but since I'm only planting a small garden spot (2000 sq.ft.), I'll only need about a twentieth of those amounts to plant the entire area.
For a true trial of the whole idea, I'll have to wait to plant my mixture until a time that's closer to wheat harvest, but I thought if I posted this now it might help me remember to actually do it, while giving other people some ideas of their own.
I'm also thinking about and/or planning to plant a simple cover crop mixture of grain sorghum and sunflowers in an area of a wheat field that has poor drainage as a combination dove food plot, 'wet spot' dryer-upper, and cover crop, but that's a topic for another day.