Global warming potential of Swiss arable and forage production systems

Transcription

1 Federal Department of Economic Affairs DEA Agroscope Reckenholz-Tänikon Research Station ART Global warming potential of Swiss arable and forage production systems Thomas Nemecek Agroscope Reckenholz-Tänikon Research Station ART Zurich, Switzerland anic agriculture and climate change, Clermont-Ferrand 17 April 28 Overview LCA methodology Impacts of organic and integrated farming on global warming: Farming system experiments - DOC - Burgrain Arable crops Forage production systems Conclusions 2 1

2 Life cycle assessment (LCA): characteristics Life cycle assessment: from cradle to grave (or farm gate) Environmental management tool: Process optimisation ( hot spots ) Choice of the best option (comparative LCA) Comprehensive assessment of environ. impacts: Energy demand, global warming, ozone formation, eutrophication, acidification, ecotoxicity, human toxicity, biodiversity, soil quality Potential environmental impacts assessed by models Environmental impacts related to functional units: 1 ha*year for function land management 1 kg dry matter of main products for productive function 1 currency unit for the financial function 3 System description Resources Infrastructure: Buildings Machinery Field production (Catch crops) Field work processes: Soil cultivation Fertilisation Sowing Chemical plant protection Mechanical treatment Harvest Transport Animal production system Animal excrements Manure storage Product treatment: Grain drying Potato grading System boundary Inputs: Seed Fertilisers (min. & org.) Pesticides Energy carriers (Irrigation water) Products: Silage maize Sugar beets Fodder beets Beetroot Carrots Cabbage Wheat Barley Rye Oats Grain maize CCM Faba beans Soya beans Protein peas Sunflowers Rape seed Potatoes Direct and indirect emissions Co-Product: Straw 4 2

3 DOC farming systems Contribution of GHG g CO2-eq/kg DM Other N2O CH4 CO2 (fossil) 1 5 Bio-dynamic Bio-organic Conv. mixed D D1 D2 O1 O2 C1 C2 M2 Conv. min. fert. 1 5 Source: FAL report 58 (25) 5 DOC farming systems Contribution of inputs and processes Bio-dynamic Bio-organic Conv. mixed fert. Conv. min. fert. D D1 D2 O1 O2 C1 C2 M g CO2-eq/kg DM P: Seed P: Pesticides P: Fertilisers & nutrient losses P: Energy carriers M: Transport M: Harvest M: Maintenance M: Plant protection M: Fertilisation M: Sowing M: Soil cultivation Source: FAL report 58 (25) 6 3

4 Burgrain farming systems Contribution of GHG g CO2-eq/kg DM Other N2O CH4 CO2 (fossil) Source: FAL report 58 (25) Food crop Feed crop Mean Burgrain farming systems Contribution of inputs and processes Cash crop Feed crop Mean kg CO2-eq/kg DM P: Seed P: Pesticides P: Fertiliser and nutrient losses P: Grain drying M: Transport M: Harvest M: Maintenance M: Plant protection M: Fertilisation M: Sowing M: Soil cultivation Source: FAL report 58 (25) 8 4

5 GWP organic relative to IP intensive product 6% 4% 2% % -2% anic arable crops: Need for improvement per ha per CHF -4% -6% winter wheat winter rye winter barley spring barley grain maize silage maize potatoes faba beans soya beans protein peas rape seed carrots cabbage Source: FAL report 58 (25) 9 anic forage production: Slightly lower GWP 5 Farming system Intensity 7 kg CO 2 -eq./(ha a) g CO 2 -eq./mj NEL per MJ NEL Others N 2 O CH 4 CO 2 (fossil) 1 14 IP int cut int cut b IP fa int cut fa int cut c IP int pasture int pasture d IP int cut. IP fa int cut. 2/3Int + 1/3Ext 3/4Int + 1/4Ext e IP low int cut IP ext cut IP ext pasture NEL: net energy for milk production fa int = fairly intensive Source: FAL report 58 (25) 1 5

6 Conclusions (1) anic farming system as a whole: lower global warming potential (GWP) Less nitrous oxide (no mineral N fertilisers, lower N inputs) Less carbon dioxide (no mineral N fertilisers) Advantages bigger per ha (25-37%) than per kg (6-2%), due to lower organic yields Higher GWP for several organic products from arable crops 11 Conclusions (2) Options to reduce GWP in organic farming: Increase yields Use the machinery efficiently Implement minimum tillage techniques Reduce nitrogen losses contributing directly (N 2 O) or indirectly (NH 3, NO 3, NO x ) to the GWP Methodical aspects: Consider farming systems as a whole Life cycle perspective is crucial Do not focus only on global warming 12 6