Agricultural Composting FAQs

Question: How big does my agricultural compost system need to be?
Answer: The size of the system depends on the volume of material that you will be composting. In general, we design each composting bin to hold 3 to 6 weeks worth of raw material. For initial planning purposes, a typical 6 to 8 horse farm will have a compost system that measures 10-feet wide by 25-feet long. The actual size will vary to match your specific preferences.

Question: Where should I put my agricultural compost system?
Answer: You should locate your compost system where it is most convenient, ideally within 25 to 50 feet of your barn. Because it eliminates problems with odors and flies, we locate it close to the barn for chore-efficiency. It needs to be near electricity, unless operated by solar power and should also be located near a source of water.

Question: How does the aeration system work?
Answer: All O2Compost systems deliver air to the base, generally with either a slatted floor for smaller systems or aeration trenches for larger systems. Pipes on-grade can also be used for free standing piles and block bay systems. Oxygen is delivered to the pile using an electric blower that is operated by a timer, both of which are included in all of our training programs.

Question: How much does it cost to construct an O2Compost system?
Answer: We have a compost system for every budget. The cost of the system depends on four factors: 1) size; 2) configuration; 3) building materials, and 4) who builds it. For planning purposes, your agricultural compost system will cost about the same as a small barn or outbuilding. For an actual cost estimate contact us; we would be happy to talk with you about your specific needs and preferences.

Question: What is the return on my investment (ROI) for an agricultural compost system?
Answer: The ROI for an O2Compost system typically ranges between 6 months and 2 years. By eliminating the expense of manure disposal, the ROI can be very fast. An Intrinsic ROI is also realized by: 1) saving you time; 2) improving your horses’ health (fewer vet calls); 3) improving pasture quality (less fertilizer and herbicides); and 4) improving surface and ground water quality.

Question: Can I start composting with an ASP system and then graduate to a permanent system when I’ve saved enough money?
Answer: Yes. This is a very smart approach that will enable you to accurately determine your volumes and will provide training immediately. You can then construct a larger composting system when money and labor are more readily available.

Question: How does an O2Compost system improve the value of my farm?
Answer: There are many answers to this question, including:

• It improves the aesthetics of the barn and surrounding area
• It improves pasture quality
• It solves a universal problem that can serve as a sales feature to a prospective buyer
• It can create a new profit center that can be passed along to the next owner
• It improves neighbor relationships
• It epitomizes the Sustainable Farm ethic

Question: How long does the composting process take with the O2Compost system?
Answer: The active phase of composting takes approximately 30 days, followed by the curing phase, which takes an additional 30 to 60 days. Compost can be applied to pastures after approximately 45 days and can be sold for use in gardens after about 90 days.

Question: How much volume do you lose in the composting process?
Answer: You can expect to lose between 25% and 40% of your volume, depending on the type and amount of bedding material used in the stalls.

Question: Your website recommends using a “wood pellet” type bedding. Why is this?
Answer: With wood pellets, or other fine-textured bedding, you will end up with less wood fiber in the compost mix. When converting from shavings to wood pellets, you will immediately see a 60-70% reduction in waste volume. This saves a great deal of time when mucking out stalls and it reduces the size of the agricultural compost system you will need to build.

Question: Can the O2Compost System be run on Solar Power?
Answer: Yes! We are very pleased to now offer a complete solar package. The size of the solar kit will be matched to the size of your compost system and to your area of the country.

Question: How much power does the system use and how noisy is the blower?
Answer: The amount of power is roughly equivalent to running a 60-watt light bulb for 12 hours a day. The blower is quiet, much like a pool pump in your back yard. The noise can be further muffled with a “dog house” cover, and the noise will not startle or annoy your horses in any way.

Question: Does my agricultural compost system need to have a roof cover?
Answer: A roof is not required, but we recommend using a cover of some sort to help maintain the right moisture content of the mix. There are many options of how to cover the system, including a simple tarp cover; a sliding lid; a shed or truss roof; or a hoop-house cover.

Question: Does the O2Compost system work in cold weather?
Answer: Yes it does. With a nursery grade soil heat cable, we are able to thaw out frozen manure in about three days, thereby allowing the biology of the system to supply sufficient heat to keep the process alive throughout the active phase of composting. Severe freezing conditions are some of the most challenging, but we have successfully managed this in the coldest parts of the USA and Canada.

Question: Does the O2Compost system work in hot, arid climates?
Answer: Yes, provided that we include a tight-fitting impervious cover immediately over the top of the pile to retain moisture in the mix. If the mix becomes dry (less than 40% moisture content), the biologic process will stop and the pile will need to be remixed with water. We have several very successful projects in Arizona where daytime temperatures often exceed 110ºF.

Question: Can food scrap waste from the kitchen and/or landscape waste also be composted?
Answer: Absolutely. Aerated composting is perfectly suited to every form of organic waste material, provided that a homogenous blend of materials is prepared for composting (no layers).

Question: What does the finished compost look and smell like?
Answer: The specific look and texture of the finished compost depends on what materials are being composted. However, in all cases the finished compost is rich, dark brown or black in color, and the texture will be soil-like after completing the curing process. With horse manure composting, there will be some residual lumps and chunks but testing has proven them to be high in Nitrogen - we think of these as “raisins in our Raisin Bran”. The finished compost will have a pleasant, earthy smell.

Question: What is the best use for finished compost?
Answer: Most of our clients use their compost as a nutrient supplement on their pastures, flowerbeds, and vegetable gardens. Because the finished compost is free of parasites, pathogens and weed seeds, it is completely safe to spread on pastures where animals are presently grazing. Even those who initially planned to sell their compost often end up keeping it for themselves when they see what a positive impact it has on their property.

Question: If I choose to sell it, how much money should I ask for it?
Answer: This depends on the availability of good compost in your area; however, it is not unrealistic to expect to earn $20 to $40 per cubic yard if sold on a bulk basis. If sold in bags, this amount can be considerably more but keep in mind that a bagged product should be screened or shredded and it takes time and effort to put your compost in the bags and distribute it to prospective buyers.

Question: Can horse manure compost be used as stall bedding?
Answer: Yes, in fact many people are using their horse manure compost as a way to offset the cost of bedding. Ideally, it would be screened first to remove any residual lumps and bumps, but as discussed above, these contain a higher proportion of Nitrogen and can be used around your garden plants. The finer screened material is free of parasites, pathogens and fly larvae, quite absorbent, and has a pleasant odor. Using horse manure compost as bedding is strongly recommended by equine veterinarian Dr. Karen Hayes in her book “How to be the Perfect Horse Keeper”.

Question: How long does it take to get started with an O2Compost system?
Answer: When we have received payment for the O2Compost system of your choice, we will have the component parts shipped to you within 2 to 3 business days. Once you have received the design drawings, we are available to answer your construction-related questions. When you are finished with the construction phase, we will be available to help you through the start-up process to ensure your success with composting. We are available to help you - on your schedule.

Question: What do we do next?
Answer: Our next step is to contact us so we can learn more about your specific needs and preferences. It will take about a half hour and together we will determine if an O2Compost system will work on your farm. If you have any other questions about the O2Compost systems, please send them to us at or fill out our contact form.