Notes from the meeting of November 7th

At this meeting, we got a hot compost pile started. We are layering leaves, manure, and coffee grounds in an eight by eight foot wire mesh bin. We also added a little blood meal. Sufficient nitrogen causes a compost pile to heat up. However, the manure we are using may not have enough nitrogen in it; the manure pile had not heated up. And we did not have enough blood meal and coffee grounds to heat up the pile by themselves.  If, by next week, the pile shows no signs of heating, we will add some more nitrogen.

We had some lawn care companies dump leaves. In fact, we got too many leaves (if that can be possible.) And the truck drivers dumped leaves right on top of our sheet mulch garden beds, where it may prove difficult to rake them up without raking up the sheet mulch. These leaves will be hot composted, since we do not know where they came from or what they might contain. We have already picked out some trash. A hot compost pile will break down almost all chemicals, and kill pathogens. The only common contaminants which a hot compost pile can’t get rid of are heavy metals and certain extremely long lasting herbicides. Heavy metals should not be a problem in leaves. People don’t spray herbicides on their trees. By the time the leaves land on the lawn, there should be very little herbicide present on the surface, and even less would end up in raked leaves. To insure that this reasoning is correct, we will be testing all finished compost before adding it to the garden beds. Compost can be tested simply for quality by planting a few radishes or other inexpensive seeds in it.
We got our first set of professional soil tests back. The cheap home soil test had rather inaccurate results. We will not need to add any nutrients to the soil except nitrogen, since we actually have overabundant levels of many nutrients. The pH is 7.8, which has an advantage. It will bind with any heavy metals which might be present, keeping them from being taken up by plants. The only common heavy metal for which this will not work is arsenic. In a few weeks we should have our heavy metal soil test results back. The high nutrient levels may have been caused by a chemical fertilizer overdose by the previous owner.

Notes from the meeting of October 11th

We got some soil nutrient testing done in the past week. We will have to wait about two week for the lead test to come back. The pH is neutral; this is good, especially if we have lead in the soil, since a neutral or alkaline soil ties up lead. The phosphorus and potassium are medium, and the nitrogen is low. However, the air is full of nitrogen, and most soils are full of locked up potassium, so we shouldn’t have to buy any. Phosphorus can be applied cheaply as manure or phosphate rock, though phosphate rock tends to be tied up in alkaline soils. Chemical fertilizers are expensive because the nutrients in them have been made available and soluble by energy intensive processing. Because of this they burn soil life and organic matter, and most of them wash away before they can be captured by plants. In contrast,  nutrients in a natural soil are insoluble, until they are made soluble by the action of plants and their fungal and bacterial allies— right in the root zone, a little at a time. If we do need to add trace minerals, they can be added as granite dust, which also contains potassium, or as seaweed.

Hopefully, our lead testing will not turn up any problems. However, since our soil has chunks of concrete, brick, etc. in it, testing is a prudent course of action. Most lead contaminated soils can be made safe by adding large amounts of phosphorus (to turn soil lead into unavailable minerals) adding organic matter (to bind with lead) keeping the pH up, and mulching heavily (to keep from coming in contact with lead in soil and dust.) All of these are things we would be doing anyway. If the lead was really high, in addition to the steps above, we would only grow fruiting crops like tomatoes, squash, and apples, since plants don’t accumulate lead in their fruits.

At the meeting we finished our first hugelkulture. At previous meetings we had dug a  broad, shallow hole about a foot deep, and filled it with sticks and branches. At this meeting we continued adding wood until the pile was about three feet above ground. We then added coffee grounds and manure to the top, and shook the pile so that they would migrate down and fill voids. The manure will add nitrogen to help rot down the largely carbonaceous wood, and helps hold water.  Then we piled on the soil from the hole, and covered it with cardboard and wood chips, to prevent erosion and weed growth. The only step remaining is to place the rocks from the hole on top of the pile. These will trap heat, creating a better microclimate, and will help with water retention. In Colorado, much of our snowfall disappears as water vapor without melting. Rocks trap enough heat to melt the snow into the mulch, and then help to hold that water in.

We also put up some wire to contain leaves, and laid down cardboard so our next pile of manure  will not be infiltrated by bindweed.

The horses which use the field are “scuffing” through our sheet mulch. To prevent this, we will be putting up a simple temporary fence to keep them out. This should be fairly easy, since they don’t WANT to get in; they are just running around the field.

We saw lots of snakes, especially hiding under our tarp. This is good, they will eat voles and mice.