Sunday, October 25, 2009

Living with manure

Every year we harvest 75,000 pounds of alfalfa from our fields. That’s 1,776 pounds of potassium, 222 pounds of phosphorous, and 1,110 pounds of calcium. Alfalfa replaces the nitrogen in the soil by fixing it from the air with the bacteria that cluster around its roots, roots that sink themselves up to twelve feet into the dirt. The roots of the alfalfa also sequester carbon dioxide, taking it from the air and holding it underground until the next time the soil is tilled or the alfalfa plant is killed. So growing alfalfa is good for our sheep and good for global warming, but is it good for our soil?

We thought of alfalfa as a self sufficient wonder crop until it occurred to us that whenever we tested our soil, it always needed fertilizer. And every time we spread fertilizer, the cost went up. We also noticed that every year we harvested less alfalfa from our fields – they just didn’t produce as well as they had 10 or 20 years ago.

We began reading about sustainable agriculture. Obviously, the way we were making hay was not sustainable. Last year, Dave spread manure on a sparse, weedy section of hayfield. This year, we could see exactly where he had driven the manure spreader – a patch of deep green, weedless alfalfa towered over the rest of the crop. The manure had made an incredible difference.

Manure differs from fertilizer in several ways. It’s nutrients are released into the soil slowly as it decomposes. It contains vegetable matter which adds to the top, organic layer of soil and keeps the soil more porous so water can seep into instead of run off. So now, we look for extra manure to add to our fields.

Today, Dave is cleaning the barn. He uses the skidsteer to scrape manure and straw off the floor and to dump the mixture into the manure spreader. He combines the manure with compost from our one year old compost pile and spreads the results on the west hayfield.

It’s a wet day. I tracked manure into the house when I walked back from the barnyard this afternoon. But no matter how much I complain about the mess, I don’t complain about manure. When we first started farming, I couldn’t even pronounce the word manure properly - it’s pronounced manúr with a soft “u” like in “yer”, not with a long “u” like in “unicycle and it has only two syllables, not three – and now I can’t live without it.

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