Taiji
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Location: Gardening in western U.P. of MI. 46+ N. lat. elev 1540. zone 3

How Long do the Nutrients Last?

I am starting to create some new beds for gardening in a new location. Was wondering if I plant some green manure crops (buckwheat, rye, whatever) and turn them in a couple of months from now with some leaves, maybe some peat, etc. will those nutrients still be good and available to the plants say, maybe 4 or 5 months from now next spring?

I realize you need to wait to plant things in freshly amended soil for a few weeks before the nutrients are available, but how about waiting a really long time? Would like to get a head start now if possible. Will the goodies still be available to the plants or should I just wait til next spring to do these things? Thx. :)

imafan26
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Re: How Long do the Nutrients Last?

I don't know about all of the nutrients but in general nutrients are bound or in solution. The bound nutrients will be released slower depending on what they are bound to and things like pH and presence of other elements which effect their release.

Nitrogen is not a long lasting element. It is one of the reasons that most soil tests do not directly give you nitrogen results unless you ask for it. Nitrogen is volatile and is constantly coming and going and the rate is dependent on a lot of different factors.
https://www.nature.com/scitable/knowledg ... n-15644632

To answer your question. Adding green manure will add biomass and nutrients. They will still be there a few months later, but like most organic fertilizers, all of it will not be available to plants immediately, some will be bound, and some would have been lost through leaching. The only way I know to tell how much is left would be to get a soil test. Even soil tests will tell you the total of the elements in the soil, not just what is available and some of it will be bound and unavailable.
Happy gardening in Hawaii. Gardens are where people grow.

Taiji
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Joined: Fri Oct 05, 2012 7:19 am
Location: Gardening in western U.P. of MI. 46+ N. lat. elev 1540. zone 3

Re: How Long do the Nutrients Last?

Thanks, that is good advice. I've never had a soil test anywhere I've lived, but probably should do that.

I am planting some buckwheat as I create each new bed just for fun. To my delight it has sprouted after about 5 days. It might have time to flower before frost if I'm lucky! We don't have any real farm stores around here, so I went to a health store and bought some buckwheat groats. Didn't know if they would sprout or not, but they're doing well!

Once it gets hit and dies I'll probably seed over it with a cool weather rye. Hopefully that will help prevent some of the leaching you mentioned, and add some more biomass.

imafan26
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Location: hawaii, zone 12a 587 ft elev.

Re: How Long do the Nutrients Last?

I do the same thing. Bulk buckwheat at the healthfood store is cheaper than buying seed. Buckwheat grows very fast. It goes from seed to flower in about 6 weeks. It adds biomass to the soil, but it is not a legume, so no nitrogen fixing. It does attract beneficial insects when it flowers. It should be tilled in when it first flowers to benefit the soil the most and because for me buckwheat can become a weed if it is allowed to go to seed.
Happy gardening in Hawaii. Gardens are where people grow.

Taiji
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Posts: 885
Joined: Fri Oct 05, 2012 7:19 am
Location: Gardening in western U.P. of MI. 46+ N. lat. elev 1540. zone 3

Re: How Long do the Nutrients Last?

It is because of you mentioning buckwheat in a previous thread that I am trying it. I googled it then and thought the flowers were so great! I like the weed smothering aspect of it too. I don't have a weed problem where I am now, but I can see that I will have in this new location.

The lady in the health store said that the buckwheat groats would not sprout, but I suspected they would. Just a heads up for someone else, be sure to get raw groats, not toasted!

I was able to find some yellow clover seed today too, to plant as a cover crop, but no one here seems to have white or red. I guess it'll be ok?

I don't think my buckwheat will make it to the seeding stage before frost, but I think I'm safe from it becoming a weed here anyway since it is so arid.

imafan26
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Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

Re: How Long do the Nutrients Last?

To overwinter, you might consider winter rye. It will hold the soil and you can till it in before you plant your crop. All of the cover crops seed fairly easily so that is one of the reasons why you till it in when the flowers start to appear. Winter rye can be mowed.
For the legume, I usually plant cowpeas with a cowpea inoculant. If I let it grow instead of tilling it in, it will produce beans and eventually the dried beans will give me black eyed peas to plant or eat. The residues get chopped up and returned to the soil. Allowing the beans to form, though negates the nitrogen fixation benefit since by then the energy has been transferred from the roots to the beans pods.
Happy gardening in Hawaii. Gardens are where people grow.

Taiji
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Posts: 885
Joined: Fri Oct 05, 2012 7:19 am
Location: Gardening in western U.P. of MI. 46+ N. lat. elev 1540. zone 3

Re: How Long do the Nutrients Last?

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I am so lovin the buckwheat I planted! Thanks for the heads up Imafan. Seeds from the health store. It made it to flowering stage before frost. Still no frost forecast for at least the next 7 to 10 days.

After the buckwheat gets hit by frost, I will plant winter or annual rye in those beds. In the top foto the half of the bed in the foreground is doing better than the other half of the bed as you can see. I think I covered the seed with too much earth in that sparse area.

If you see this post, was wondering when you talk about cowpeas, is that the same as black-eyed peas? I see those in the health store bins too.

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