In-house composting in high-rise, caged layer facilities
Composting inside high-rise, caged-layer facilities can reduce fly populations by generating temperatures above the lethal limit for fly larvae. This method of fly control has led to reduced pesticide use, and generated a product (compost) which is more marketable than fresh manure. Refinements in the technique have allowed for more precise carbon rate and turning frequency recommendations for different seasonal climates and bird ages. Atmospheric ammonia (a major consideration for bird and worker health) was shown to vary within high rise buildings and over time. Initial laboratory evaluations of physical and chemical controls show promise to reduce atmospheric ammonia.
1. Determine the effects of carbon rate and turning frequency on in-house composting and fly control for pullet manure;
2. Determine the effects of material moisture content on in-house composting and fly control;
3. Evaluate commercially-available amendments to reduce ammonia production during in-house composting;
4. Evaluate the economic feasibility of in-house composting relative to traditional poultry manure management practices (land application of manure, traditional outdoor composting procedures);
5. Disseminate research results to poultry producers and assisting professionals in Utah, the Western SARE Region, and the United States.
Objective 1: Two in-house composting trials were completed to evaluate the effect of carbon rate and turning frequency on composting success (indicated by the ability to achieve target temperatures ¡Ý43o C, the lethal limit for fly larvae). Trials indicated that initial carbon rates of 1.9 kg/m2 are adequate to achieve the target temperature as long as material was turned at least once every three days during early stages of composting. Critical volumes of 0.18 m3/m windrow were required to consistently achieve temperatures ¡Ý43o C on the day of turning. These data are presented in the Miner et al. (2001) paper. Two additional trials were recently completed evaluating the effects of turning frequency (3 or 6 days/week) and carbon rate (1x or 2x standard rates) on composting with young bird (pullet) manure. Preliminary results indicate that increased turning frequency could be used to accelerate pullet manure drying and increase compost temperatures, but that doubling the rate of carbon was less effective.
Objective 2: Two recently completed trials on composting with young bird (pullet) manure showed that higher turning frequencies accelerated manure drying and increase composting temperatures. Correlation relationships between peak composting temperature and compost moisture content are being developed. Two additional trials are planned to meet objective 2 during the 2002 summer season where more precise control of material moisture content can be achieved.
Objective 3: Initial efforts were focused on documenting the spatial and temporal variability of atmospheric ammonia inside high-rise facilities during composting. Atmospheric ammonia levels were shown to vary spatially within the buildings, with higher concentrations found near the center of the building away from ventilation fans. Concentrations frequently exceed 25 ppm NH3 (the upper limit for long term exposure of facility workers or birds) in the manure storage area. However, atmospheric ammonia concentrations were approximately 50% lower in the cage area. Over time, atmospheric ammonia varied considerably, with spikes occurring immediately after a compost turning event and lasting for < 60 minutes. Over time as manure accumulated and compost volumes increased, basal atmospheric ammonia levels increased.
Laboratory trials simulating in-house composting were used to initially evaluate chemical amendments to reduce ammonia volatilization. Among amendments evaluated, aluminum sulfate reduced ammonia volatilization by over 80%, calcium chloride by 65%, magnesium chloride by 70%, and gypsum by 15%. Initial trials to develop the protocols to measure the impact of chemical amendments on ammonia loss within buildings took place in 2001. Evaluation of the chemical amendments to reduce ammonia loss is currently ongoing. These data are presented in the Miller et al. (2001) paper.
Objective 4: A complete evaluation of the economic feasibility of in-house composting compared to traditional manure handling practices is scheduled for 2002. Some economic data has already been provided by the producer-cooperators. They report that the cost savings associated with reduced pesticide use to control flies nearly equals the cost of composting (capital and equipment maintenance costs, labor costs). In addition, the compost is a more marketable product than fresh manure. More farmers and homeowners are willing to accept and/or pay for in-house produced compost. The in-house composting process and product has reduced complaints lodged to local health departments about fly problems.
Objective 5: To date, results have been disseminated through three professional articles (Journal of Applied Poultry Research, Compost Science and Utilization, and American Society of Agricultural Engineers), two professional meetings and abstracts, and several individual consultations with poultry producers throughout the U.S. Contacts have also been received and information provided to producers in several Midwestern U.S. states, and several European countries. At least three additional research manuscripts are planned before the end of this project. We are also considering enhancing the information dissemination aspect of this project by developing an in-house composting manual for egg producers.
Impacts and Contributions/Outcomes
All livestock producers are under increasing pressure to manage manure properly. In addition, many poultry facilities are located in areas with increasing urban encroachment. In-house composting offers benefits of reduced pesticide use to control flies, reduced fly problems, increased manure marketability, and reduced manure volume and moisture content. Adoption of in-house composting by the egg industry has been rapid. At the beginning of this research only one egg producer in Utah (Shepherd Egg Farm) was practicing in-house composting. Now, three out of the four egg producers in Utah are composting indoors, and the fourth facility is composting outdoors. In addition, egg producers in Idaho and Arizona have begun in-house composing. Widespread adoption of in-house composting process is taken as an indication of the impact of this work.
Utah County Extension Agent
Utah State University Extension
51 S University Avenue #206
Provo, UT 84601
Office Phone: 8013708469
Utah State University
2300 Old Main Hill
Logan, UT 84322-2300
Office Phone: 4357972232