Ecological Indicators 73 (2017) 247–253 Contents lists available at ScienceDirect Ecological Indicators j o ur na l ho me page: www.elsevier.com/locate/ecolind Could energy flow in agro-ecosystems be used as a “tool” for crop and farming system replacement? Marios C. Michos a , George C. Menexes b , Kiriaki L. Kalburtji a , Constantinos A. Tsatsarelis c , Christos D. Anagnostopoulos a , Andreas P. Mamolos a,∗ a School of Agriculture, Laboratory of Ecology and Environmental Protection, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece b School of Agriculture, Laboratory of Agronomy, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece c School of Agriculture, Laboratory of Agricultural Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece a r t i c l e i n f o Article history: Received 12 April 2016 Received in revised form 30 August 2016 Accepted 28 September 2016 Keywords: Agro-environmental indicators Crop replacement Energy budget Organic farming Production coefficients a b s t r a c t Energy flow in orchards can be used to determine first the best management practices and second the possibility of using those which have best environmental advantages. Conventional and organic peach and kiwi orchards were selected in order to (a) determine energy flow of the farming systems, and (b) reveal the importance of energy inputs in crop and farming system replacement. Fifteen farms (four conventional and three organic kiwi orchards; four conventional and four organic peach orchards) were selected with proportional stratified random sampling during the years 2010–2013. The Hierarchical Cluster Analysis (HCA) method was applied using nine production coefficients’ variables (fertilizers, fungicides, insecticides, weed control, diesel, labor, irrigation, branches shoring, and machinery) and revealed three groups of the studied orchards. The highest contributors in cluster formation were weed control, branches shoring, labor, and machinery. The effect of the production coefficients on the group- ing of the studied orchards reveals their importance for these crops and farming systems. Most of the production coefficients showed their lowest values in organic kiwi orchards (Group 3), so it could be said that they can play a key role in the replacement of the peaches, and conventional kiwi orchards. It seems that production coefficients can be used as a “tool” for decision makers who are seeking for crops and farming systems with low energy inputs and best environmental advantages in order to use them in crop replacement in agro-ecosystems. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Continuous demand in increasing food production resulted in intensification of agriculture, a threat to the environment worldwide. Intensification resulted in growing concern about biodiversity conservation and its role in functional biosphere main- tenance (Tilman et al., 2002). The risk of detrimental environmental effects could be reduced by using less intensive farming practices (Tilman et al., 2002; Müller et al., 2006; Dantsis et al., 2010). Integrated and organic farming, low intensity farming systems, may contribute in diminishing energy inputs per ha (Michos et al., 2012; Zafiriou et al., 2012). The latter will minimize environmen- tal problems such as greenhouse gas emissions (Litskas et al., Abbreviations: KC, kiwi conventional orchards; KO, kiwi organic orchards; PC, peach conventional orchards; PO, peach organic orchards. ∗ Corresponding author. E-mail address: mamolos@agro.auth.gr (A.P. Mamolos). 2011; Zafiriou et al., 2012) and confine the degradation of natu- ral resources (Alonso and Guzmán, 2010). An environmental and an energy analysis of an agro-ecosystem could be combined to lead to the best management practices (Kaltsas et al., 2007; Franzese et al., 2009; Michos et al., 2012). Energy resources are linked to the development of agriculture, which uses relatively small amounts of energy (IPCC, 2014). How- ever, energy use in food production is often a large percentage of energy consumption in developed countries (Pimentel et al., 2002). Farming practices determine to a large extent the amount of energy inputs used in crops. The knowledge of energy use in crops is essential in developing sustainable production systems (Ziesemer, 2007). Although there are studies exploring the mul- tifaceted sources and uses of energy inputs at farms (Venturi and Venturi, 2003; Meisterling et al., 2009; Kremen and Miles, 2012), there is still a lack in research due to the different farm production systems all over the world. Several methods, including Life Cycle Assessment (LCA), have been widely used in bioenergy assessment studies (Schweinle et al., http://dx.doi.org/10.1016/j.ecolind.2016.09.050 1470-160X/© 2016 Elsevier Ltd. All rights reserved.