Contents lists available at ScienceDirect Soil & Tillage Research journal homepage: www.elsevier.com/locate/still Effect of land use, time since deforestation and management on organic C and N in soil textural fractions Alexandros Eleftheriadis a, ⁎ , Francisco Lafuente b , Maria-Belén Turrión b,c a Area of Soil Science, Irrigation and Drainage, Landscape Architecture Dpt., Technological Educational Institute of Eastern Macedonia and Thrace, 66100 Drama, Greece b Area of Soil Science and Soil Chemistry, E.T.S. Ingenierías Agrarias, University of Valladolid, Avda. de Madrid 57, 34004 Palencia, Spain c Sustainable Forest Management Research Institute, University of Valladolid-INIA, Avda. Madrid 44, 34071 Palencia, Spain ARTICLE INFO Keywords: Soil organic carbon Soil nitrogen Land use change Particulate organic matter ABSTRACT Deforestation and subsequent cultivation practices often result in loss of soil organic matter, in a degree de- pending on time since deforestation and soil and crop management. A land in North Greece was studied in order to check the influence of land use and management on soil organic C (SOC) and N. Cultivated soils with three dates since deforestation (25, 34 and 72 years) were compared to adjacent undisturbed forest soils. Two man- agement systems were used in the cultivated soils: not irrigated wheat with superficial ploughing and irrigated cotton crop with deeper ploughing alternated with wheat every two years. Soil samples were separated in textural size fractions and organic C and N were analysed. In terms of land use, the most distinctive differences between agricultural and forest plots were found in coarse particulate organic matter (2.8 g kg -1 soil in agri- cultural land vs 14.8 g kg -1 soil in forest sites), and in the fine sand fraction SOC (8.6 g kg -1 soil in agricultural land vs 40.6 g kg -1 soil in forest sites), and N (1 g kg -1 soil in agricultural land vs 2.4 g kg -1 soil in forest sites), with minimal differences in the clay fraction (15.5 g kg -1 soil in agricultural land vs 21.2 g kg -1 soil in forest sites for SOC, and 2.2 g kg -1 soil in agricultural land vs 2.4 g kg -1 soil in forest sites for N). Time as a factor was significant for all the studied properties regarding the first years following deforestation. Management practices had an effect on SOC and, more pronounced, on N, with the wheat plots showing higher contents. Clay particles present the most stable behavior in terms of SOC (especially regarding time and management as factors) and N (especially regarding land use and time as factors) protection and maintenance. 1. Introduction Deforestation is a practice adopted worldwide, aiming to obtain new land for agricultural purposes, increasing CO 2 release from soil to atmosphere (Eleftheriadis and Turrión, 2014; Kucuker et al., 2015; Gómez-Acata et al., 2016; de Oliveira Marques et al., 2017) and often leads to a depletion of the soil organic carbon (SOC) and N stocks when followed by intense agricultural practices (Ashagrie et al., 2007; Caravaca et al., 2004; Ratnayake et al., 2011), due to reduced input of biomass and enhanced decomposition after physical disturbance (Poeplau and Don, 2013). Yang et al. (2004) reported that land use changes, especially conversion of forest to cropland, can alter C and N pools and N availability for plant uptake. Hajabbasi et al. (1997) re- ported in their study that deforestation and subsequently tillage prac- tices resulted to a 50% decrease in SOC and total N and a decrease in aggregate size, overall resulting to a decrease in soil quality and pro- ductivity of natural soils. Losses between 24 and 52% have been reviewed by Smith et al. (2016). Sigstad et al. (2002) found that soil C after 15 years since deforestation with continuous cultivation is almost completely worn out. Soil tillage involves disturbance of the upper soil layers resulting to the breakdown of soil aggregates, thus influencing C stability in the soil (Paustian et al., 2000). This depletion in SOC content is primarily due to accelerated decomposition rates caused by soil tillage, which enhances aeration and physical contact to decomposer organisms (Zinn et al., 2002). Grasslands and generally uncultivated soils have often higher C and N contents than cultivated arable soils, due to the higher in- corporation of SOC, the absence of soil tillage and reduced exposure to erosion (Hassink, 1997). Changes in management practices are re- flected by the SOC and N status (von Lutzow et al., 2002). The buildup of SOC and N is determined by the amount and quality of the input of organic residues and their decomposition rate (Hassink, 1994). Wright and Hons (2004) concluded that soil management strategies play sig- nificant roles in SOC and N sequestration. Tillage systems that minimize https://doi.org/10.1016/j.still.2018.05.012 Received 10 January 2018; Received in revised form 14 May 2018; Accepted 23 May 2018 ⁎ Corresponding author. E-mail addresses: info@filyraplants.gr, alexelef@in.gr (A. Eleftheriadis). Abbreviations: SOC, soil organic C; cPOM, coarse particulate organic matter Soil & Tillage Research 183 (2018) 1–7 0167-1987/ © 2018 Elsevier B.V. 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