Cover crops / soil fertility

I'm in SW Missouri and just got some soil test back. Very Very low in available Phosphorus (10lb/ac I think, don't have it in front of me).

Anyway I was reading about buckwheat and that it "fixes" phosphorus. But I'm rather ignorant in these matters. does this mean it adds phosphorus to the soil, or makes more available in the soil?

I'm trying to get my soil to some balance and add organic matter. Prefer to use organic/natural as opposed to chem fertilizers.

Thanks,

Don

All Nitrogen and mineral "fixing" means the plant draws or creates those elements to it from sources inaccessible to most of your garden. For instance if the plant has very deep roots it can draw up minerals more shallow rooted plants can't get to and then contains it. When the plant dies down (or is slashed and composted in place) the elements are released into the topsoil and thus become available to all plants/soil life.
Apart from buckwheat, some other good phosphorous plants are caraway, clover, dandelions, fennel, lupines, marigolds, mustards, rapeseed and yarrow.

thank you Saskia.

My question is, at these levels, is there enough to grow healthy cover crops?

I don't know about the numbers at all.
I'm reasoning if a soil that is low in Phosphor lies bare, the weeds that will show up will be the ones that fix Phosphor, because that is the way nature works, it always tries to restore balance.
So if your cover crop doesn't grow well, let the weeds grow a bit. Then compost them in place and sow or plant your cover crop in that. The soil will already be more balanced and the cover should be doing better by that time. If necessary repeat, and of course keep adding organic matter, compost, manure, etc..
Good luck with it!

How densely and expansive would it be planted?
You'd be able to draw up quite a lot of phosphorus and have it available for the next in rotation, if it were planted densely. Great erosion control green crop too.

"Buckwheat can also increase phosphorus and micronutrient availability in the root zone for the following cash crop in a rotation."

LivingWind wrote:
How densely and expansive would it be planted?
You'd be able to draw up quite a lot of phosphorus and have it available for the next in rotation, if it were planted densely. Great erosion control green crop too.

"Buckwheat can also increase phosphorus and micronutrient availability in the root zone for the following cash crop in a rotation."

not sure. I'm new enough I've no idea. I've got plenty of time. Not living out there yet but thought I'd get started buliding the soil.

its basically a mix of weeds. some ol fescue, sprouts etc.  I eventually want to put an apple orchard out there but it may be a few years.

Likely will be broadcast spread.

pcdreams wrote:
not sure. I'm new enough I've no idea. I've got plenty of time. Not living out there yet but thought I'd get started buliding the soil.

I suggest you try it at different densities and keep records of how dense where, so for the next round/spot you will know which density works best for you soil.

saskia wrote:
I suggest you try it at different densities and keep records of how dense where, so for the next round/spot you will know which density works best for you soil.

when we talk about different densities, are we talking about lbs/acre of seed or ?

pcdreams wrote:
when we talk about different densities, are we talking about lbs/acre of seed or ?

Yes, that's it. And you go as scientific as you want with it, but yes, that's the general idea.
The most basic form is: You sow a minimum of three different densities, one a lot denser than is generally recommended, one following more or less the recommendation for your area, and one that is a lot lower than that.
But if you want to measure everything and do 10 or 50 different densities, no one is going to stop you and your results will be a lot more precise.

Actually you use a similar method if you want to find out ideal planting distances for any crop that is not broadcast: You sow/plant the whole bed going from too dense to too wide and make note of the smallest spacing that gives you the ideal result. You do this once for every crop and then always apply this distance, as it is the optimal one for your garden. You might want to repeat the trial every 10 years or so if you do a lot of soil improvement...