A modular approach for quantification of nitrogen flows and losses along dairy manure management chains of different complexity

Manure management and composting methods may greatly affect compost characteristics. An experiment was conducted to characterize 23 on-farm and 6 industrial composts in Québec (Canada). Cluster analysis identified two major groups characterized by their chemical composition, source materials, management intensity and degree of decomposition. Electrical conductivity, total N and K, water-soluble NH4+, PO4, K, Al and organic C, and a cress test were the best chemical and biological parameters for grouping composts. These groups were strongly associated with bedding rate, turning frequency, composting duration, profile windrow appearance, material aggregation and odor. When restricted to dairy manure composts, no clear relationship could be established by cluster analysis between material grouping and their farm management. Statistical analysis on single chemical parameters of dairy manure composts, however, identified five farm management factors: type and amount of bedding, system of manure handling and storage, compost windrow turning, composting length and milk production intensity. These factors affected one or several major parameters: pH, dry matter, electrical conductivity, total and water-soluble C, N, P and K, and humic components characteristics. This study demonstrated the importance of leaching losses in the on-farm composting operations in humid cold regions and the need for more environmentally sustainable composting methods. Key words: Farm manure management, composting, chemical composition

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Components of Dairy Manure Management Systems

Journal of Dairy Science ◽

10.3168/jds.s0022-0302(94)77147-2 ◽

1994 ◽

Vol 77 (7) ◽

pp. 2008-2030 ◽

Cited By ~ 127

Author(s):

H.H. Van Horn ◽

A.C. Wilkie ◽

W.J. Powers ◽

R.A. Nordstedt

Keyword(s):

Dairy Manure ◽

Management Systems ◽

Manure Management

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Greenhouse-gas emissions from stockpiled and composted dairy-manure residues and consideration of associated emission factors

Animal Production Science ◽

10.1071/an16009 ◽

2016 ◽

Vol 56 (9) ◽

pp. 1432 ◽

Cited By ~ 3

Author(s):

J. Biala ◽

N. Lovrick ◽

D. Rowlings ◽

P. Grace

Keyword(s):

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Emission Factors ◽

Dairy Manure ◽

Manure Management ◽

N2o Emissions ◽

Emission Rates ◽

Low Carbon ◽

Gas Emissions ◽

Chicken Litter

Emissions from stockpiled pond sludge and yard scrapings were compared with composted dairy-manure residues blended with shredded vegetation residues and chicken litter over a 5-month period at a farm in Victoria (Australia). Results showed that methane emissions occurred primarily during the first 30–60 days of stockpiling and composting, with daily emission rates being highest for stockpiled pond sludge. Cumulated methane (CH4) emissions per tonne wet feedstock were highest for stockpiling of pond sludge (969 g CH4/t), followed by composting (682 g CH4/t) and stockpiling of yard scrapings (120 g CH4/t). Sizeable nitrous oxide (N2O) fluxes were observed only when temperatures inside the compost windrow fell below ~45−50°C. Cumulated N2O emissions were highest for composting (159 g N2O/t), followed by stockpiling of pond sludge (103 g N2O/t) and yard scrapings (45 g N2O/t). Adding chicken litter and lime to dairy-manure residues resulted in a very low carbon-to-nitrogen ratio (13 : 1) of the composting mix, and would have brought about significant N2O losses during composting. These field observations suggested that decisions at composting operations, as in many other businesses, are driven more by practical and economic considerations rather than efforts to minimise greenhouse-gas emissions. Total greenhouse-gas emissions (CH4 + N2O), expressed as CO2-e per tonne wet feedstock, were highest for composting (64.4 kg), followed by those for stockpiling of pond sludge (54.5 kg) and yard scraping (16.3 kg). This meant that emissions for composting and stockpiling of pond sludge exceeded the new Australian default emission factors for ‘waste composting’ (49 kg). This paper proposes to express greenhouse-gas emissions from secondary manure-management systems (e.g. composting) also as emissions per tonne wet feedstock, so as to align them with the approach taken for ‘waste composting’ and to facilitate the development of emission-reduction methodologies for improved manure management at the farm level.

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