which would you choose?? pic added!

[Collector]

Help me decide which ammendments would be best to put on my garden space. I have access to 2 different types of compost.
1. Three way mix, Horse manure, sawdust, and maybe 10% sand
2. Staight horse manure/straw.
Both are well rotted, around two years old.
I can get as much as I want for free from my work place. Do you think I should get one kind over another or some of each?

 

[CountryGirl]

Hi Collector,

I would think it depends on what you want to plant. The three way mix would be good for root crops (easier to extract from the soil) such as carrots, turnips, beets, etc. But either one sounds like a winner. You get compost for the garden and it's FREE!

 

[vfem]

I say take it all!

I don't know your soil type, so I don't know what you are lacking or if you need the sand at all. So its really up to you... your soil could benefit from either.

 

[Collector]

We have fairly decent topsoil, but it is clay based. And there are a couple spot that are pretty thin on topsoil over hard clay. Also DW wants to amend her perennial beds.

 

[hoodat]

Sand is a good amendment for clay soil but only if it's coarse sand. Fine sand may actually make the problem worse.
The straw would break down faster than the sawdust .

 

[Ridgerunner]

Eastern Washington can be pretty dry, so what I consider two year old well rotted might be a bit different for you. If it has been moist enough to decompose, you have a tremendous resource to amend your soils. If it has been too dry to decompose, you might need to compost it a bit. Digits may be able to speak to that better than I can.

I agree with Hoodat. Fine sand may make the problem worse, but coarse sand with large irregular shaped grains may help. I don't think the coarse sand helps much until you get a certain amount in there, but I don't think it hurts anything at all. I'll go throughy a bunch of blather down below to explain that, if you are interested. I'm going to ignore the benefits of the organic matter in there and talk just about sand and clay. Organic matter is a tremendous benefit to either sandy or clayey soils.

I am a retired civil engineer. Soils were not a point of strength from my practice, but I did study soils a lot many decades ago in school and did run into some applications for foundations. I've searched extension websites on using sand as a soils amendment for growing things and found nothing consistent or very helpful that I trust. I can address it more from a soils particle aspect than on the possible chemical interactions.

One benefit you would get from sand is that the large, irregular shaped grains can create some open pore space in the soils where they come together. With fine sand, you do not get that pore space. It will mix with the even smaller grains of clay and fill in any pore space there.

The clay particles are much smaller than the sand particles. If you mix a little coarse sand with clay, the tiny clay particles will fill in between the sand particles, so you have not done a lot of good. But once you get enough sand so that the particles are touching each other and the clay particles cannot fill in all the void space created, you get pore space for water to travel through. That is when you really benefit.

As with most things, it is a little more complicated. Another aspect is that clay particles are charged to where they really bond tightly with each other where the sand tends to be more chemically inert. When you mix wet pure clay, you pack those tiny clay particles tightly together and break down any existing bonds, so that when it dries and re-establishes those bonds it sets up hard as brick. If there is enough coarse sand in the mix, the inert sand particles interfere with the chemical bond between the clay particles.

I know that to make many kinds of bricks, you add sand to the clay. Although you may get some abrasive resistance from the sand, the main purpose of the sand is not to make the bricks harder. The main purpose of the sand it to keep the bricks from shrinking.

If anyone is still with me, if that sand is a fine sugar sand or play sand, I would not use it. If it is a coarse construction-type sand, I would use it.

 

[thistlebloom]

So was the sand deliberately added to the manure mix, or was it there as a result of cleaning sandy pens?
I just wonder because you may not know what type of sand it is (unless you have access to the pens it came from ) or know the person who mixed it. If it was me I'd go for the manure/straw first, then if you have room for more get the M/sawdust/sand mix. Sawdust will take longer to decompose, oh, Hoodat already said that!

 

[Collector]

here are a couple pics of the 3-way mix

The first pic is of a handful of the compost.
It is really wet now because of melting snow and the snowing and raining it has been doing daily.
The second pic is just a close up of the pile after I unloaded it in the garden.
The sand is from the pit that the stuff is in, It is sand we screen and sell to local paving companies.
So far I have hauled 2 pickup loads home, it equels about 2.5 yards. I am hoping to haul about 6 yards of each compost.
I hope these pics are OK I took them with a I-phone.

 

[hoodat]

Clay soil can be be very complicated problem. As Ridgerunner said, besides the physical properies you have the complication of an electrical charge binding the particles together. It's like a giant storage battery. Clay particles are also flat plates rather than irregular particles. That's why they pack so tightly together.
Of course you have to work with what you have and one good thing is that if you can solve the drainage problem clay soil is usually rich in minerals.

 

[April Manier]

Can you get a mixture? I would be careful about the sand. Too much in the wrong climate could make your soil too dry. It looks lovely.