Impact of cultivation strategies and regional climate on greenhouse gas emissions from grass/clover silage

Abstract

More than half the annual dry matter intake (DMI) of feed by dairy cows can be roughage. Its production and storage constitute a significant part of the life cycle greenhouse gas (GHG) emissions from milk production. This study estimated and analysed the impact of grass/clover silage production practices in five climatically different dairy production regions in Sweden on emitted GHG. GHG emissions calculated by the life cycle assessment method were 0.46–0.54 and 0.48–0.63 kg carbon dioxide equivalents per kg silage DMI for normal and higher silage nutrient quality, respectively. Crop cultivation for higher nutrient quality through an extra cut and increased nitrogen fertilisation rates increased GHG emissions by up to 16%. Varying the yield level by +/–20% decreased (11%)/increased (15%) GHG emissions per kg DMI. Improved management practices can reduce GHG emissions feed production, but accurate estimates of yield levels and feed losses are needed to reduce uncertainties.

Keywords:

• Carbon footprint
• dairy production
• mitigation option