Authored by Dr. Frank Gouin
There are more horses in Anne Arundel County than in any other county in the U.S.A. Some of that horse manure is occupying precious landfill space or being dumped near streams thus contributing the Bay pollution problems. Anne Arundel County also has an abundance of restaurants contributing tons of organic waste, rich in nitrogen, into landfills. Like yard debris neither of these organic wastes should be occupying landfill space when they can easily be converted into compost. Landfills are costly to construct, maintain nearly impossible to locate.
In the early 80' the Bay Gardener was involved in writing the state law that prohibited the dumping of yard debris into landfill and established yard debris composting facilities. One such facility is located near Upper Marlboro just a mile from the Anne Arundel Co. line, near the intersection of Rt. #4 and Rt. 301. It is operated by Maryland Environmental Services and one of the locations that manufactures LeafGro. .
The Anne Arundel County Council and the County Executive have approved the composting of horse manure and restaurant waste on farms with no less than 5 acres and no more than 10 acres in size. The legislation has established strict standards that limit the area for compost to 25% of total acreage. The legislation does not allow the composting of dead animals or waste from processing facilities. It also limits proximity of composting pads to adjacent properties and occupied dwellings and streams. The composting must be done on a non-porous pad and the facility must be managed by an operator certified in the science of composting. Also considered in the legislation are road access to the facility and the location must be pre-approved.
The Maryland Department of Agriculture is responsible for certifying managers of composting facilities. To be certified, one must participate in a training program and pass a rigorous written exam. The Maryland Department of the Environment is responsible for inspecting and assuring that the facilities are properly managed and sanitary conditions are maintained. Since the Bay Gardener was first in the nation to establish a commercial composting training program, he prepared many of the questions that are included in the certification exam. Managers must be knowledgeable in the biological processes, monitoring equipment, standards and management procedures. Most of the current composting facilities in Maryland have been operating for the past 30 years without creating problems and producing such compost products as LeafGro, Orgro, Veterans Compost, etc. Many municipalities compost their own yard debris, following standards established, within their jurisdictions without creating odors and make it available to their residence at a minimal charge. Near exit 1 on the Baltimore Beltway, there is a composting facility that processes 180 to 200 tons of Baltimore sewage sludge per day without creating an odor problem and produces a composts called Orgro.
It is important to understand that composting is an exact science. It requires blending the proper amount of feed stocks, horse manure in this program with restaurant waste. The amount of carbon and nitrogen in each are determined by established laboratory testing methods . After these two materials are blended properly in the correct amounts and placed in wind-rows, moisture levels are maintained between 50% and 60% and oxygen levels are maintained above 5%. Temperatures within the piles will average between 140 oF and 160 oF within 24 to 36 hours. When oxygen levels drop below 5% the wind-rows are turned with specialized equipment to introduce more oxygen into the mixture. Some composting facilities draw air, using fans, through the composting piles to maintain oxygen at the proper level. Only when the temperatures within the piles achieve those near ambient air is the compost ready. The process will generally require 80 to 100 days depending on the time of year and the volume being composted. The resulting compost has a rich earthy smell.
The microorganisms that digest the carbon in the horse manure, while using the nitrogen from the restaurant waste are the same microbes that are found in garden soils. The same process occurs on the forest floor, but science has discovered that under ideal conditions, those same microorganisms will gladly work over-time. The only by-products of composting are water vapor, heat and carbon dioxide. There are no toxic gasses released during the composting process.
Gardening has become the most popular hobby in the U.S.A.. The ornamental horticulture industries are the second largest agricultural income producing industry, second to poultry in Maryland. All of the plants in pots are grown in soil-less blends containing1/3 to ½ by volume compost. With more people demanding organically grown food, the need for compost far exceeds the supply. Compost is not only a great soil amendment, but it is also a good source of slow release nutrients.
The Bay Gardener has spent more than 30 years conducting research on using compost made from sewage sludge, animal manures, yard debris, crab waste, and garbage. He has also been involved in developing composting methods for yard debris, lobster and herring waste, paper-mill sludge. Composting is the ultimate in recycling and it can be done safely and efficiently. Although composting is an old agricultural practice, today’s composting technology is as different as the Model A Ford is to today’s hybrid cars.