75% topsoil
15% aged manure/sand
10% compost

Al

Thanks Al.
As the organic material breaks down there will be settlement of the mix in the bed. Would I use the same percentage of the above material to top off the raised bed each year or just top it off with more organic material and no topsoil?

Thanks

The reason I was so heavy on the inorganic fraction was specifically so you could avoid the shrinkage. I would mulch well each year with either the compost or the manure & let soil organisms incorporated the good stuff, which they will - handily. Keeping 2-3" of the organic material you described on top of the soil should yield a very productive soil very quickly.

Use the actual level of soil in your beds as your guide. If you don't think there is a large enough mineral fraction, just add more topsoil or sand/manure until you're satisfied, then turn to all organic mulch.

Al

Thanks Al I appreciate your knowledge and input here and on the other boards.

My pleasure, Joe. Best luck to you!

Al

Al,

You mention on the soil forum that adding pine bark fines to the mix that you previously recommended for my raised bed(75% topsoil, 15% aged manure/sand,10% compost )would be helpful.
Today I mixed the above materials according to the percentages you prescribed and the mix seems a bit heavy.
Since I can get the pine bark fines at a reasonable bulk rate, I thought I'd add some. Can you help me out again and recommend an amount to add to the formula? Or would it be better to change the formula all together to incorporate the pine bark fines?

Thanks again

What about the mix makes you feel it's heavy? Remember, you have the entire earth below acting as a giant wick. ;-) You can add as much bark as you want, which will be helpful in subsequent years more than in the immediate. All you'll sacrifice for the additional bark is a small increase in N immobility, which you'll compensate for by adding a little high-N fertilizer (like the commonly found 27-3-3 or 27-0-3 [depending on where you live] granular slow release) like you would use on turf.

Al

Al,

In my novice, inexperienced eye I somehow envisioned the mix being lighter in texture. Don't know why really.

As a learning experience, how will the bark be helpful in later years?

How does the following formula sound to you?

Would more pine bark fines be better?

50% topsoil
25% pine bark fines
15% manure/sand
10% compost

Thanks
Joe

As the cellulose in the bark is consumed by soil organisms, all that will be left are a few biocompounds, mainly lignin and suberin, which will add structure to the soil and a steady supply of nutrients as it breaks down slowly. There are other benefits associated with the breakdown of organic matter as well - organic acids that promote soil life and compounds that bind soil particles together in aggregate form, so it helps the structure of the soil, and as it ages it does so w/o tying up N.

I'm not being snotty when I say you can do whatever you want & be successful. The main considerations are: The greater the fraction of pine bark and other OM, the greater the (soil) shrinkage factor and the greater the degree of N immobilization (tie-up), which as noted you can remedy with the addition of a high-N slow release fertilizer such as those you might apply to your lawn in spring if you're into that. 27-3-3 or 27-0-3 are common examples, but I've seen formulations like 33-0-4 and such, as well. I'd incorporate the slow release right into the soil when I filled the beds. Be careful - a little goes a long way.

Alternately, you could mix and regularly sprinkle a solution of MG 30-10-10 on the soil surface when light coloration of foliage tells you of a probable N deficiency.

Al

night blooming cerius
{{gwi:3238}}

Thanks Al.

I think I have a better idea of what's going on now.

I'm wondering if using alfalfa meal would be sufficient for the added nitrogen?

Nice cereus pic!!

Thanks again.

Thanks.

It (AM) would probably work fine in a raised bed.

Al