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Project title

Life cycle analysis of emissions management for Irish livestock production systems

Primary Funding Agency

Environmental Protection Agency

Co-Funding Organisation(s)

n/a

Lead Organisation

University College Dublin (UCD)

Lead Applicant

Nicholas Holden

Project Abstract

Actions to moderate the major emission contributors of enteric fermentation fertiliser and manure management on farms should not simply move the emissions elsewhere in the system but actually reduce them. Life cycle assessment methodology was used to provide an objective framework for estimating emissions and to evaluate emission management scenarios with respect to kg CO2 eq. emitted per unit of energy corrected milk (ECM) (dairy system) and live weight (suckler beef and sheep systems) produced to the farm gate. European Union agri-environmental schemes aim to reduce the environmental impact of agricultural production but the schemes were developed before consideration of greenhouse gas emissions (GHG) from agriculture. Nevertheless these schemes were assessed for dairy and beef systems to ascertain whether reductions in GHG emissions could be attained. An average dairy unit was defined from national census data and emissions were compartmentalised to calculate a total emission of 1.50 kg CO2 eq kg-1 (energy corrected milk) yr-1. Of the total emissions 49% was enteric fermentation 21% fertiliser 13% concentrate feed 11% dung management and 5% electricity and diesel consumption. Scenario testing indicated that more efficient cows with extensive management could reduce emissions by 14-18% elimination of non-milking animals could reduce emissions by 14-26% and a combination of both could reduce emissions by 28-33%. It was concluded that the evolution of the Irish dairy sector driven by the Common Agricultural Policy (CAP) should result in reduced GHG emissions. To evaluate these results a case study involving ten functioning farms (five functioning conventionally and five within an agri-environmental scheme) was carried out. The agri-environmental scheme farms operate extensive systems from 40 to 120 milking cows producing between 3032 to 5946 kg (ECM) per cow per lactation. The cows are fed on grazed grass conserved silage and concentrates. Supplementation ranged between 250 to 620 kg cow-1 yr-1. The conventional (more intensive) farms had between 30 and 77 milking cows producing 4736 to 6944 kg (ECM) per cow per lactation. Supplementation ranged from 400 to 1000 kg cow-1 yr-1. The emissions from each dairy unit were estimated using published emissions factors and possible error was evaluated by using ranges of values for each factor. Emissions were calculated to range from 0.92 to 1.51 kg ECM-1 yr-1 and 5924 to 8323 kg CO2 equivalent ha-1. On average total emissions from conventional farms were around 18% (p = 0.01) greater than the agri-environmental scheme farms and emissions per hectare (total area required) were 17% greater (p = 0.02) but there was no significant difference (p = 0.335) in terms of emission per unit of energy corrected milk produced.

Grant Approved

�63,950.00

Research Hub

Climate Change

Research Theme

Greenhouse Gas Emissions, Sinks, and Management Systems

Start Date

02/09/2002

Initial Projected Completion Date

n/a