**1. Introduction**

Due to the adverse impacts of the conventional arable production system on the environment, alternative production systems are required to maintain the multifunctional landscape of producing food, fodder, and energy. Agroforestry is one such alternative where crops and trees are integrated, in one field to produce a diversity of food, fodder, and bioenergy products and to mitigate and adapt to climate change. The Food and Agriculture Organization of the United Nations (FAO) have recognized the benefits of agroforestry systems to provide environmental, economic, and social benefits. FAO defines agroforestry systems to "include both traditional and modern land-use systems where trees are managed together with crops and/or animal production systems in agricultural settings" [1]. The term agroforestry thereby covers a range of production systems from natural grassland systems to intensively managed systems and so, the extent of agroforestry systems is di fficult to estimate [2]. In spite of being common practice in tropical countries, the extent of agroforestry in Europe is rather limited [3] due to the intensification of farming systems, lack of integration of forest tress and agricultural land, and the absence of current adequate policies to promote agroforestry practices. Intensive farming has improved production with use of external inputs but has created many environmental concerns including loss of soil fertility and soil degradation [4]. In contrast, agroforestry with woody components can improve resource use in the aboveground and belowground to achieve ecological intensification.

Agroforestry is increasingly recognized as productive and environmentally friendly practice due to multifunctional roles in agronomic productivity and environmental performance of agroforestry systems. This calls for a quantitative assessment of environmental footprint in agroforestry systems. Life cycle assessment (LCA) is a robust tool for quantitative assessment of environmental footprint by taking account of the managemen<sup>t</sup> inputs for comparison between production systems. Due to the diversity of agroforestry systems in Europe, environmental footprint of a specific agroforestry system under a particular environment can be very di fferent depending on the inputs and the managemen<sup>t</sup> intensity. In order to investigate the diverse agroforestry production systems in the study, Denmark was identified to represent Atlantic environmental zone and Italy was identified to represent Mediterranean environmental zone, representing two diverse environmental zones, for assessment of environmental footprints under di fferent socioeconomic contexts.

Agroforestry systems in each country were identified as potential alternative production practice for comparison to the conventional arable crop production system. In Denmark, agriculture constitutes 72.6% of the land cover covering an area of 2,625,093 ha, while forestry covered only 9.5% in 2016 [5]. The integration of short rotation woody crops like willow and poplar into the arable fields (agroforestry) can contribute to microclimate e ffects like reduction of wind speed, reduced erosion [6], and mitigate nutrient leaching for protection of water quality [7] for sustainable production of food, fodder, and bioenergy.

In Italy, olive is one of the priority crops. Olive trees constitute the second most widespread crop, covering an area of 1,165,562 ha. It is the sixth most widespread crop in terms of production in Italy ranking third after Spain and Greece, the biggest producers of olives on a worldwide scale. Italy's share in global production was 10.9% (2,092,175 tonnes) in 2016 [8]. Olive orchards integrated with cereals are common agroforestry systems in the Mediterranean area to improve nutrient cycling and erosion control [9]. Hence, agroforestry systems play a significant role in production of olives and assessment of environmental footprint for comparison among the di fferent managemen<sup>t</sup> systems is necessary to identify the gaps in managemen<sup>t</sup> for improvement.

LCA can be used to quantify the di fferent environmental impacts of the olive production system to identify the managemen<sup>t</sup> gaps in a production system [10–12]. LCA studies show that mineral fertilization contributes most to environmental impacts [13,14]. Irrigation also contributes considerably [12] for production of olive and irrigation is necessary for olive cultivation in the Mediterranean environmental zone. In Denmark, organic crop production and conventional production systems have carbon footprints of 2920 and 4474 kg CO2-eq ha−<sup>1</sup> yr<sup>−</sup>1, respectively [15] whereas such carbon footprint assessments are lacking in Danish agroforestry systems.

The objective of the study was to carry out comparative LCA of four agroforestry systems with olive production in Italy and two production systems, specifically one agroforestry and one conventional wheat production system, in Denmark. Comparisons of environmental footprints were carried out among the production systems within the country and between Italy and Denmark.
