Amending Soil - Reducing Heaviness of Red Clay-ish Soil

[mattie g]

One of my garden plots was clay and sandstone. Construction and landscaping of the house stripped off the upper soil layer and after forty some years of it being a weed fields the was still only two inches of topsoil over the clay/rock some of the clay veins were was blue gray just like modeling clay.

I mixed in about six inches of half composted hardwood chips (lots of nitrogen was added to quick compost it) and I planted a heavy cover crop of winter rye after the first season. That was five years ago I think. Now the soil is like coffee grounds with clay marbles mixed in and I can till it when it is fairly wet. I mulch heavily with fall leaves covered with grass clippings which helps a little but the wood chips realy changed the soil. I did it all without a tiller, but that really would have helped break up the clods.

Wood has calcium which interacts with acidic clay particles, and lignin which breaks down into humic substances which also coats clay particles and keeps them from sticking to each other. The wood and nitrogen feed soil fungus which exude various chemicals that also help the soil structure at a microscopic level.

For soil conditioning wood chips are ultra concentrated compared to compost from soft vegetation, and soft vegetation doesn't have the high concentration of lignin which is the hard part of wood. The down side is that it might take a year to adjust the nutrient balance.

I've been using hardwood mulch the last couple years, then digging it into the ground in the fall. Perhaps I was doing something positive to start the amendment process without even knowing it...

[TheWaterbug]

I saw the banner ad for soildirect.com at the bottom of this forum, and I'm considering trying an order for later this fall, after my pumpkin harvest. I can get 10 cu yards of compost, delivered, for $458 in my area, which is $1.70/cu ft.

That's way less than what I've been paying for bagged soil (typically $2 - $3 per ft) and it includes delivery, which is worth a lot in time, trouble, and the absence of injuries to me.

The key questions are whether they'll deliver down the horse trail into my garden, as opposed to dumping in on the street, and the quality of the soil. They sell samples for $10, but I have no idea how large the samples are. I have an email in to them with some questions, so I'll update the forum if they come back with answers and/or if I get samples.

They also offer "forest blend mulch" and "amended topsoil (flower vegetable mix)" for $471 or $510 for 10 cu yards, but if the compost is good I'd rather have that.

So I'm taking one for the team

Soildirect (finally) answered my email, and samples are shipped by USPS in an Ziploc freezer bag in a USPS flat-rate box. $10 is a lot of money for less than a shovelful of dirt!!! Well, I suppose they have to pay a buck or two for postage.

Anyway, I'm curious, so I bought one sample each of the 3 varieties listed above, and I'll report back with findings when I get them.

On a related note, I broke open those 2 bages of 3 cu ft. Kellogg's Organic Garden Soil for Flowers and Vegetables and the "N'Rich Compost" to compare. They look absolutely identical. The usage directions on the bag are identical. I wouldn't be at all surprised if they are actually the same product in two different bags, just to get more shelf space.

The texture is also very, very similar to that of the free municipal stuff. If I'm feeling up to it I may get a few bags of the free stuff on Friday afternoon and takes pictures of the three, side by side by side.