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RESEARCH ARTICLE

Can arable forage production be intensified sustainably? A case study from northern Germany

Antje Herrmann A B , Sandra Claus A , Ralf Loges A , Christof Kluß A and Friedhelm Taube A
+ Author Affiliations
- Author Affiliations

A Institute of Crop Science and Plant Breeding, Grass and Forage Science/Organic Agriculture, Kiel University, Hermann-Rodewald-Str. 9, D-24118 Kiel, Germany.

B Corresponding author. Email: aherrmann@gfo.uni-kiel.de

Crop and Pasture Science 65(6) 538-549 https://doi.org/10.1071/CP13362
Submitted: 30 October 2013  Accepted: 22 March 2014   Published: 13 May 2014

Abstract

Greenhouse gas emissions (GHG) resulting from forage production contribute a major share to ‘livestock’s long shadow’. A 2-year field experiment was conducted at two sites in northern Germany to quantify and evaluate the carbon footprint of arable forage cropping systems (continuous silage maize, maize–wheat–grass rotation, perennial ryegrass ley) as affected by N-fertiliser type and N amount. Total GHG emissions showed a linear increase with N application, with mineral-N supply resulting in a steeper slope. Product carbon footprint (PCF) ranged between –66 and 119 kg CO2eq/(GJ net energy lactation) and revealed a quadratic or linear response to fertiliser N input, depending on the cropping system and site. Thus, exploitation of yield potential while mitigating PCF was not feasible for all tested cropping systems. When taking credits or debts for carbon sequestration into account, perennial ryegrass was characterised by a lower PCF than continuous maize or the maize-based rotation, at the N input required for achieving maximum energy yield, whereas similar or higher PCF was found when grassland was assumed to have achieved soil carbon equilibrium. The data indicate potential for sustainable intensification when cropping systems and crop management are adapted to increase resource-use efficiency.

Additional keywords: carbon footprint, forage cropping system, N fertilisation, N fertiliser type, perennial ryegrass, silage maize.


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