Lab-Scale Assessment of Gaseous Emissions from Laying-Hen Manure Storage as Affected by Physical and Environmental Factors

Thumbnail Image
Li, Hong
Xin, Hongwei
Major Professor
Committee Member
Journal Title
Journal ISSN
Volume Title
Research Projects
Organizational Units
Journal Issue
Is Version Of
Agricultural and Biosystems Engineering

Manure-belt (MB) and high-rise (HR) laying-hen houses are the two predominant housing types in the U.S. Compared with HR houses, MB houses have better indoor air quality and lower aerial emissions as a result of frequent (every 1 to 4 d) manure removal from the hen houses into separate manure storage. However, emissions from on-farm manure storage are integral parts of the whole-farm emissions and need to be quantified. This series of lab-scale studies assesses emission rates (ER) of ammonia (NH3) and greenhouse gases (CH4, CO2, and N2O) from stored laying-hen manure as affected by the following physical and environmental factors: air exchange rate (10 or 20 air changes per hour, or ACH), manure stacking configuration expressed as surface area to stack volume ratio (SVR at 2.5, 5, 10, or 20 m-1), air temperature (constant at 25°C or diurnal cyclic from 21°C to 32°C), manure moisture content (MC, 50% or 77%), and periodic addition of new manure to the existing stack. Results of the studies showed the following: (1) air exchange rate of 10 or 20 ACH had no apparent effects on the gaseous emissions; (2) SVR significantly affected emissions, with larger SVR leading to higher NH3 and CO2 ERs but lower CH4 ER on per kg manure basis; (3) emissions were positively related to air temperature; and (4) laying-hen manure with 77% MC had higher emissions than that with 50% MC. At the storage condition of 25°C air temperature, 20 ACH, every 2 d addition of 120 kg (5 cm thick layer) manure at 75% MC (equivalent to 2 d manure production of 682 laying hens) to the flat base area of 2.8 m2, the daily gaseous ERs per hen were 0.06 to 0.22 g NH3, 1.6 to 4.8 g CO2, and 7.4 to 32 mg CH4 (0.18 to 0.8 g CO2e). N2O concentrations from the stored manure were below the detection limit (0.03 ppm) of the measurement instrument; hence, N2O emission was omitted from the presentation.


This article is from Transactions of the ASABE 53, no. 2 (2010): 593–604.

Fri Jan 01 00:00:00 UTC 2010