Woman and lass, I have familiarity with and experience in using a variety of manures in the garden: horse, goat, rabbit and chicken.
Now that you are properly awed, let us discuss how to best use manures; more to the point, how this gardener uses manures. After all, every garden or farm constitutes an experiment of one.
Manure is a wonderful resource if you can get your hands on it, in a manner of speaking. It typically contains bedding materials, straw or wood chips, as well as animal waste. This combination equals gardener gold: a mix of carbons – the bedding – plus nitrogen from the waste.
It is best to use aged manure, because fresh animal waste can burn plants, either damaging or killing them.
Having said that, farmers have used fresh manures on fields for centuries, but with great care; in the fall when they can be safely spread on fields or by selecting less-hot manures with lower nitrogen content, such as goat or rabbit.
Fresh chicken manure is hot, hot, hot. I strongly advise against using it unless first composted or aged. With chicken manure, there is also the danger of overdoing potassium levels, so it pays to conduct soil tests before applying in bulk.
The best information about manures can be found in old gardening or farming texts written before the widespread use of chemical fertilizers. Peter Henderson’s “Gardening for Profit,” published in 1887, is a wonderful addition to any gardener’s bookshelf. He devotes an entire chapter to manures, beginning with these lines:
“The quantity, quality, and proper application of manures is of the utmost importance in all gardening operations, and few have any conception of the immense quantity necessary to produce the heavy crops seen in our market gardens. Of stable or barn-yard manure, from 50 to 100 tons per acre is used, and prepared, for at least six months previously, by thoroughly turning and breaking up to prevent its heating unduly.”
Henderson notes the importance of maintaining a fenced and covered “manure yard” in the low part of the garden.
“The manure of horses is most valued, as we consider it, weight for weight, worth about one-fourth more than that of cows or hogs; on stiff soils it is of much benefit as a pulverizer,” he says.
He recommends breweries’ refuse-hops for top dressing or mulching, saying: “From my experience with this fertilizer, I consider it to be of nearly double the value of that of stable manure. It requires to be composted in the same manner as other manures; it heats rapidly, and must be either spread regularly over the hog yard, or else turned once in two weeks to prevent ‘fire-fang’ from violent heating.”
Horn or whalebone shavings and scrapings added one ton to 15 tons of manure is helpful, he notes. This is interesting information, though few of us in Western North Carolina will likely have access to either. And in the author’s day, pounded-to-powder guano (seabird and bat droppings) replaced stable manures at the rate of 1,000 to 1,200 pounds per acre.
Wood ashes were in wide use, brought to New York by the boat load, then sold from 15 to 20 cents per bushel. “Some of our gardeners have been using them instead of bone dust or guano as an addition to stable manure, harrowing them in after plowing at the rate of from 150 to 200 bushels per acre; a lesser quantity (say one half) of unleached ashes would answer the same purpose,” Henderson says.
He recommends green manuring, growing crops such as rye to plow under as soil fertilizer. “A crop that may be easily grown in a few weeks, and then turned under, may furnish to the soil as much fertilizing matter as eight or ten tons of manure; and the process may often be repeated two or three times in one year,” he says.
Ideally, the gardener systematically alternates the use of various manures. “I am convinced (this practice) is of quite as much importance to the production of uniform crops of first quality, as is the alternation of varieties of the different kind of vegetables,” Henderson says.
Quintin Ellison is editor of The Sylva Herald.