April 2016
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Building Soil

When we began the transformation of our property, the soil was in very poor condition. If we were going to be successful at creating a food forest, we needed better soil.

Much of our property consists of about an inch of top soil on top of hard, dry clay. Before our street was developed around 1979, it was a big farm. The soil might have been depleted from years of conventional farming practices.

More likely, the top soil simply has been washed away with water run-off. The area where we wanted to develop the food forest is gently sloped. The hard clay doesn’t absorb water very well, so it just runs down the hill to a ditch along the road, carrying top soil with it.

Step one was to stop the run-off, which we have done with the swales. Now that water is held on our property instead of running off, we could begin the process of building up the soil again. This is an on-going process that began 18 months ago and will continue perpetually as the food forest is developed.

Multiple Ways to Build Soil

When we first dug the swale, the bottom of it was hard clay so we had a lot of work to do. What we needed was biomass, biomass, and more biomass! Whenever I find a fallen stick in the yard, it goes in the swale. Rotting wood holds moisture, creating a friendly environment for the growth of fungi. Fungi growth is very important in developing healthy soil.

When I clean the chicken coop, the pine shavings go into the swale. The chicken manure also goes into the swale. Periodically I rake up old material from the chicken run and that goes in the swale too. It is usually full of uneaten sunflower seeds too.

The sunflower seeds sprout and growth right out of the swale. When they start to die, I chop and drop them right in the swale to break down.

During the summer, I bag grass clippings with a mower. Most of these get processed by the chickens and later added to the berms as compost. Some of the clippings get put directly on the berm if they are fairly seed free.

I’ve been sheet mulching the grassy areas adjacent to the swales with cardboard or newspaper, covered with grass clippings, leaves, wood chips or any other biomass I have available. I have a chipper/shredder that I use to process all of our summer and fall prunings into mulch. The cardboard smothers the grass and a thick layer of material on top begins to break down slowly.

In the fall, I collect all the chopped leaves I can get. When I run out, I even get some from my neighbor’s yard. Another option is to drive around with a truck or trailer in suburban neighborhoods and look for the brown paper bags full of leaves. Leaves are safe but I wouldn’t take their grass clippings because they’re probably loaded with chemicals.

Recently I was lucky enough to get two big truckloads of free wood chips. I’ve been using the chips to sheet mulch much larger areas a lot faster than I normally could. I’m really sold on the wood chips.

Before Sheet Mulching with Wood Chips

Before Sheet Mulching with Wood Chips

After Sheet Mulching with Wood Chips

After Sheet Mulching with Wood Chips

Comfrey is a big part of soil building in the berm. It sends a deep tap root down to mine nutrients and bring them to the leaves, which are subsequently chopped and dropped to break down on the surface.

I’m planting honey locust trees along the high side of the swales. They will drop their leaves every fall. They will be pruned to control their size and that material will be chipped. I’m also planting a variety of other trees like random apples, cherries, and paw paws in the area between the swales. All of these will add to the fall leaf drop.

Nothing leaves the area. If I see some undesirable grasses, they are chopped and dropped, then sheet mulched to smother them. Sunflowers and comfrey are chopped and dropped. Some plants like wildflowers are allowed to go to seed for the next season.

What a Difference a Year Makes

Since we dug the two swales a year apart, it is interesting to see the progress the first swale has made compared to the freshly dug lower swale. After experiencing a full year cycle, the first swale has a significant build-up of organic material. A year ago, the bottom of the swale was hard clay. Now it has about 3-4 inches of rich soil in the bottom.

The soil in the bottom of the swale is loaded with earthworms. When I pull back the cardboard under the sheet mulch, it is also full of earthworms. When you see a lot of earthworm activity, good things are happening. If the progress after just one year is this good, I can’t wait to see how it progresses as the food forest evolves over a period of years.

Before the Swales

Before the Swales

Panoramic View of Swales and Fruit Trees

Panoramic View of Swales and Fruit Trees

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