No doubt the neighbors stared curiously as I tromped all over the future fruit orchard yesterday, running handfuls of soil through my fingers. The dirt has a nice sandy-loamy feel, but after so many years of neglect, it’s got to be jonesing for some nutrients.
That’s where cover crops come in.
Cover crops–also known by the tantalizing name of green manure–are planted, grown until just before going to seed, then plowed into the soil to improve productivity. There are lots of options, and my first choice was crimson clover because it fixes nitrogen, has a strong root system, and likes to be sown in the fall.
When I say fixing nitrogen, I’m not talking about the latest drug craze. This a pretty amazing process where bacteria that live on the roots of legumes (like clover) take nitrogen from the atmosphere (which isn’t terribly useful to plants) and convert it into a form that helps the plant grow. In exchange for all that nitrogen, the plant provides sugary meals to the bacteria. And when the plant dies, the fixed nitrogen is released into the soil, like a giant dose of fertilizer. Believe it or not, these tiny things can fix 75-125 pounds of nitrogen per acre.
I ordered a couple of pounds of crimson clover seed back in October when we first bid on the land, but it was too late to plant by the time we closed on the property in November. Clover needs a good four weeks to get established before the first frost, so now we’re shopping around for a spring-planted crop.
We might do buckwheat instead, a beautiful flowering broadleaf (below) that grows quickly and loosens soil. The recommended May planting date is perfect, since it would give us plenty of time to fence and till the property first. But I’ve read that buckwheat isn’t terribly drought-tolerant, so it might not make the cut. I have a rule in the garden – if it doesn’t feed me, I don’t feed it. Non-food-producing plants have to survive on what little rain falls in a Georgia summer. Harsh, I know, but we have to save every drop of water down here. I’ll chat with friends who used buckwheat last year to find out just how hardy it is.
That brings us to door number three: peanuts
. Peanuts are also legumes that fix nitrogen — to the tune of 150 to 170 pounds per acre — but with the added bonus of being a food source. And they’re harvested in October, which will give all that biomass time to decompose before our November tree planting. This sounds like a great option to me (speaking as a peanut butter junkie), so I’m puzzled by the lack of online documentation about using peanuts as cover crops. Maybe it’s the much higher pricetag. A 50-pound bag of buckwheat seed costs about $16, whereas half a pound of peanut seed will run you $14.50
What are your experiences with cover crops? Any suggestions?