Tag: vegetative buffers

Posted on

Efficacy of Vegetative Environmental Buffers to Mitigate Emissions from Tunnel-Ventilated Poultry Houses

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

The proceedings, “Mitigating Air Emissions from Animal Feeding Operations”, with expanded versions of these summaries can be purchased through the Midwest Plan Service.

This Technology is Applicable To:

Species: Poultry (Broiler and Turkey)
Use Area: Animal Housing
Technology Category: Environmental Barriers
Air Mitigated Pollutants: Dust, Ammonia, Odor

System Summary

Emissions of dust, gases and odor from poultry facilities pose major challenges for the poultry industry worldwide. Cost-effective technologies to abate emissions from modern tunnel-ventilated poultry houses are limited. In 2002 a three-row planting of trees was installed opposite two, 1.2 meter (4 ft) diameter tunnel fans to evaluate vegetative environmental buffers (VEB) as a means of mitigating emissions from the poultry house. The first row, 9.1 meters (30 ft) from the fans was 4.8 meter (16 ft) high bald cypress, followed by 4.3 meter (14 ft) high Leyland cypress and the outer most row of 2.4 meter (8 ft) high Eastern red cedar. Over the next six years the efficacy of these trees to reduce total dust, ammonia and odor was determined. Measurements were taken at 1.2 meter (4 ft) height on 47 days during peak fan operation with market-age broilers. The relative change in concentration across this 6.7 meter (22 ft) wide vegetative buffer found the VEB significantly reduced total dust, ammonia and odor by 56%, 54% and 26%, respectively. Meteorological conditions and the type of crop next to the VEB appeared to influence the efficacy of vegetation to reduce odor. Dust and ammonia concentration was influenced by these factors to a lesser degree. This suggests the use of trees as vegetative filters may offer a long-term, cost-effective means of partially abating emissions from houses. The local poultry industry trade association for the Delmarva Peninsula has hired a coordinator to implement tree plantings around farms to help abate emissions and to be proactive in addressing increasing neighbor-relations concerns.

Applicability and Mitigating Mechanism

  • Certain plants have the ability to absorb ammonia and capture particulates
  • Vegetation also acts as a sink for chemical constituents of odor
  • A properly designed windbreak aids in dispersion and dilutions of odors as well as reducing wind speed
  • A VEB planting has multiple goals; abate emissions, improve neighbor-relations, and provide shade and shelter of the house

Limitations

  • Growers need technical assistance on the proper design, implementation and care of VEB that is tailored to the unique features of each operation
  • Retrofitting a farm with VEB to capture emissions from all fans is difficult.
  • Species of tree and proper implementation influences time required for VEB to become effective in reducing emissions
  • VEB is a practical and multi-purpose BMP to partially abate emissions.

 

Cost

Average cost for implementing a VEB on an existing broiler farm is ~$5,500. Cost range from $1,500 for a limited one-row planting to provide a visual screen of the farm, and up to $12,000 for multi-row plantings around the outside perimeter of the poultry houses. There is limited information on design and efficacy of VEB plantings between houses. Locally, cost-share programs have provided support to cover most of the costs associated with implementing this program. Plantings to address neighbor-relations have been a driving factor in VEB establishment. An estimated 1/3 of all poultry farms have established VEB on the Delmarva Peninsula. A VEB is also a requirement for a new house loan from one of the major lending institutions.

Authors

George Malone1, Gary VanWicklen1, Stephan Collier1
1University of Delaware
Point of Contact:
George Malone, malone@udel.edu

The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.

Posted on

The Use of Vegetative Environmental Buffers For Livestock and Poultry Odor Mitigation

Reprinted, with permission, from the proceedings of: Mitigating Air Emissions From Animal Feeding Operations Conference.

The proceedings, “Mitigating Air Emissions from Animal Feeding Operations”, with expanded versions of these summaries can be purchased through the Midwest Plan Service.

This Technology is Applicable To:

Species: Poultry, Dairy, Beef, Swine
Use Area: Animal Housing and Manure Storage
Technology Category: Vegetative Buffers
Air Mitigated Pollutants: Particulate Matter, Odor, Ammonia

System Summary

Vegetative Environmental Buffers (VEBs) – linear arrangements of trees and shrubs planted near and around livestock/poultry production sites – have been shown to incrementally mitigate odors, particulates, and ammonia through a complex of dynamics. Among the most important dynamics are: 1) enhancement of vertical atmospheric mixing through forced mechanical turbulence – leading to enhanced dilution/dispersion of odor; 2) odor filtration through particulate interception and retention – odor largely travels by way of particulates; capturing particulates also captures odors; 3) odor/particulate fallout due to gravitational forces enhanced by reduced wind speeds; 4) adsorption and absorption of ammonia onto and into the plant – this is due to a chemical affinity that ammonia has to the waxy coating on tree leaves; 5) softening socio-psychological responses to odor due to improved site aesthetics and creating “out of sight, out of mind” dynamics; and 6) improved producer/community relations by using highly visible odor management technology.

Applicability and Mitigating Mechanism

  • As air moves across vegetative surfaces, leaves and other aerial plant surfaces can remove odors, dust, gas, and microbial constituents of airstreams.
  • VEBs can mitigate odors/ particulates from all livestock/poultry species;
  • VEBs are size neutral technology and can be used to mitigate odors/particulates from all sources of odor: buildings, manure storage, and land application.
  • Trees/shrubs are among the most efficient natural filtering structures in a landscape.

Limitations

  • Mitigation effectiveness is highly site specific and will vary considerably from farm to farm.
  • VEBs often require considerable land area and may take up to five years to become physically effective.
  • Care in VEB design must be taken to avoid causing snow deposition, ventilation, and on-farm visibility problems.
  • At best, odor/particulate mitigation will be “incremental” and therefore should be always used with other odor management strategies.

Cost

Costs for VEB systems are highly variable and are site/design specific – but for midsized producers (and larger) VEBs likely amount to just a few cents per animal produced. There are three main categories of expenses associated with VEBs: 1) Site prep costs, 2) tree establishment costs, and 3) long term maintenance costs. It should be noted that the majority (usually in the range of 40-70%) of the total cost is “upfront” and is tied to the cost of the initial planting stock (e.g. older, larger nursery stock can be considerably more expensive than bare-root seedlings but such an investment may “buy time” in VEB establishment). Long term maintenance costs vary depending upon the overall health of the VEB. It should be recognized that there are expenditures that occur regularly throughout the life of a VEB and maintenance is an annual process, however as a VEB system matures the annual maintenance requirements will likely decrease over time.

Authors

John C. Tyndall11Department of Natural Resource Ecology and Management
Point of Contact:
John C. Tyndall, jtyndall@iastate.edu

The information provided here was developed for the conference Mitigating Air Emissions From Animal Feeding Operations Conference held in May 2008. To obtain updates, readers are encouraged to contact the author.

Proudly powered by WordPress