Friday, October 28, 2011

The Human Plow



In good farm fashion I rose early for the day's work. I took the truck to the compost facility for my last load, stopped only by this freight train on my return. 

This time I shoveled the compost right into the waiting tractor's shovel, which was then dumped where it was needed, saving me a lot of back ache, but tearing up the sod pretty well.

Enormous amounts of rain had fallen in the region since mid August. Puddles formed in the tire tracks.

Which Is why we trenched the lower, wetter part of the plot in order to raise the height of the beds at this end. Water collected in the trench, even as we pumped it out. Fortunately our beds are well above the water line.

You can see here what a mess the tractor made of the lawn.

But the water is an indicator of other possible problems which we hope do not bear out. Namely, high soil acidity due to constantly saturated soil. In anticipation of this I spread 40 pounds of lime onto the site pre-compost. Forty pounds may not be enough to elevate our pH to appropriate levels, but will have to do for now.

Soil limed, compost spread, now I am set to make the beds.

 But not before I jump on the ol' wheel horse one last time to till it all in.

Each bed is roughly twenty inches wide, set to accommodate two rows of garlic planted eight inches apart. Despite the wet soil, I cross-contoured the rows so that they hold water and soil in place.

I had hoped to have the soil test results before this day, but ESAC did not come through until two days later. As it turns out, our soil has a very low pH of 5. This has all kinds of implications, the most important being how acidity affects soil bound minerals like iron, aluminum, and magnesium. I've all kinds of books on soil sitting on my shelf, unread, until now never needing to fully understand the chemistry of soil. Soil particles are charged positively or negatively. Compost is useful because it binds certain metals. Lime raises the pH, but not all limes are created equal. Aluminum is abundant and toxic to plants, but is locked up at neutral pH. Zinc is a trace mineral necessary for growth, but too much is a bad thing. Cadmium is related to zinc on the periodic table, is a byproduct of smelting, is found in phospate fertilizers. 

The likelihood of finding perfect soil is slim, and I will do the best that I can with what has been given. I've added three inches of compost to the top soil, added lime with more to come. Our lead was only twice background and way lower than even the most stringent residential standards. Mercury was at background levels. Arsenic was extremely low. Our Cadmium levels were twice what my bagged Farfard compost tested at three years ago, but little information exists on standards for soil cadmium. Chromium was lower than the bagged compost. Copper was low and zinc appears high (62) until you compare it to Canadian agricultural standards (200ppm). 

Here's a head ringer: Commercial fertilizers may be responsible for a large portion of the heavy metals in your yard or agricultural field. Whether it is from bagged and dried sewage sludge like Milorganite, straight up bagged synthetic N-P-K, or micro-nutrient fertilizers, you may be adding cadmium, lead, zinc, copper, chromium, arsenic, and what else to your yard or field every year. Even liming can have industrial waste-product origins. Did you know that burnt tires are a source of zinc for micro-nutrient fertilizers? Check out this lengthy EPA report. I am all for reporting on bag or box what extra components are built into our fertilizers. I use "organic" fertilizers, but even those are not excluded from the problem. Many mineral fertilizers are the by-products of industrial or mining processes. And many toxic metals are mined along with those nutritive minerals. Oy.



2 comments:

  1. Wow, interesting.

    It was only after reading Elizabeth's book (Garbage Land) that I realized that our sludge (ex sewage) is labeled as an organic fertilizer, but its origin is not on the bag. So everything that is flushed into our sewage system, including chemicals, paints, thinners, drugs, blablabla, lands up in the sludge.

    Yum.

    That's some hard work you signed up for. Looking forward to the garlic.

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  2. I meant to post on Milorganite this summer and it never happened. I should!

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