A Dairyman’s Recipe for Making Stable, Quality Compost
By Hugh Lovel
The initial mix of materials should be about 30 to 1 carbon to nitrogen, so manures and fresh, green materials will need a fair bit of other material that is low in nitrogen. Mixing in wood waste is a common practice. This can mean a 200 to 1 ratio for something like sawdust all the way to a 60 to one ratio for shredded leaves, twigs and small branches. Straw, which may be especially valuable for its silica content, may run something like 20 or 25 to one carbon to nitrogen.
Soil, which is an absolutely essential part of the mix for the formation of stable clay/humus complexes, needs to be at least 10% of the initial mix. Fine, siliceous rock powder (quarry fines, depending on fineness) can be substituted for up to half of the soil if the rest of the soil contains roughly 40 % clay or more. When clay is not available and has to be imported it may be more efficient to use a super-clay like Zeolite and cut the rate in half. Where Bentonite would have a TEC of 30 or so and Montmorillionites could be 60 or 80, Zeolite would have a TEC of 200 as a result of its honeycomb structure and extremely high surface area.
To ensure healthy, balanced and thorough humification processes a complete set of organic process patterns should be added, either homoeopathically via a water borne application of Biodynamic Soil Activator#* or in a higher homeopathic dilution such as patterns incorporated into other products such as AEM [activated effective microbes], or as a radionic application (if such is available). This is important, and any doubt about the value of this step can be investigated by comparing compost made using these patterns with compost made without them. In many respects the processes that occur are more important than the materials.
Also, pH should be adjusted insofar as possible to 7.0 to minimize nitrification (too much acidity) or volatilization as ammonia (too much alkalinity). Small amounts of builder’s lime (hydrated lime) at no more than 2.5 kg/ton of the mix, can be especially good if the mix is acidic at the start. If phosphorous deficiency is an issue, up to 50 kg/ton of soft rock phosphate can be added in the place of some of the soil. If sulphur deficiency is an issue gypsum can be used at a similar rate. If the compost is too alkaline, elemental sulphur can be added up to 2 kg/ton of initial mix. Because elemental sulphur takes a while to oxidize and lower the pH, be careful to add only enough for a final pH of 7.0. Also a highly beneficial additive is sea minerals at a rate of about a litre per ton of raw mix.
The compost yard should be well drained with a soil surface rather than concrete, and windrows or piles should be covered when not being turned. Where there is run-off there should be a dense, vegetative border, such as a vigorous grass, vetiver, sugar cane, cat-tail reeds, or other verge grasses to filter out nutrients and tie them up in growth which can be harvested and utilized as compost material for the future. This will prevent losses which might otherwise create environmental problems.
Compost turners are rapid and efficient for making quick compost (humification in 16 weeks), but they also are good for the initial mixing and the high heat, rapid digestion phase of static piles. Once this phase is finished and at 50% moisture the windrows or piles can be covered and left to mature with no further turning.
Other machinery such as excavators, loaders, PTO driven manure spreaders, gravel screening equipment, and probably other devices—even a crew with pitchforks—anything that can do a good job of mixing and getting moisture levels right would be suitable on a small scale where compost turners aren’t cost efficient.
Some believe that only fungal organisms build the complex carbon structures found in humus, and thus they say humification can only occur in static piles where the fungal mycelia are undisturbed for long periods. However, it has been found that Actinomycetes, which thrive in turned piles and create the desirable clean smell of healthy compost, are also humus builders even though they may not build much large molecule humus. What we need to keep in mind is that humic acids range from around 2,000 molecular weight units to more than 10,000 with the smaller molecules being more readily available for plant growth.
Turned windrows should be re-turned whenever moisture levels go below 50%, carbon dioxide levels go above 15% or temperature goes above 65C. If water is an issue, this is a good use for effluent water. Initially this means turning just about every day for the first two weeks, but as the moisture, aeration and temperature stabilize the windrow or pile slows down. This is where humification and the tying up of loose nutrients in and on large carbon molecules occurs. Screening out of coarse materials may be needed at the final stages, but when the compost is fine like crumbly soil, the original forms are virtually all gone and it smells fresh and feels greasy when rubbed between finger and thumb, it is ready to use.
Ideally, before spreading, any trace elements shown to be deficient by soil tests should be blended in before spreading.
Except when being turned, all piles should be covered. Heavy black plastic, as is used for covering a silage pit, is quite good, though not especially durable. Canvas or other more durable materials that shed rain as well as retaining moisture may be used, though plastic is good for static piles that may remain undisturbed for up to a year before spreading.
Compost testing should show nitrate or ammonium levels below 1000 ppm maximum for well-humified compost. If industrial animal confinement manures are used the final compost should be tested for heavy metals (arsenic, cadmium, mercury, etc.) to see these do not build up on pastures with long-term use. For example, meat chicken feed is usually laced with a trace of arsenic for faster growth of the birds, but repeated applications of compost made with this input could result in arsenic toxicity. If chemicals or organic synthesis are suspected, a 0.1% solution of hydrogen peroxide [derived from diluting concentrated industrial hydrogen peroxide] may be used to stimulate microbial breakdown of toxins in the composting process.
These guidelines apply to every dairy farm whether or not they are presently making compost. Sooner or later ALL dairy farms should be recycling their waste stream. If they don’t there will come a time when this is mandated by law for environmental reasons. I would suggest it is better to get into composting ahead of the heavy hand of the law–besides it can mean big savings in fertiliser.