Impacts of land-use intensity on soil organic carbon content, soil structure and water-holding capacity M. A C  IN -C ARRERA 1 , M. J OS  E MARQUES 2,3 , P. C ARRAL 2 , A. M.  ALVAREZ 2 , C. L  OPEZ 1 , B. MART  IN -L  OPEZ 1 & J. A. G ONZ  ALEZ 1 1 Social-ecological Systems Lab, Department of Ecology, c/Darwin, 2. Universidad Aut  onoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain, 2 Department of Geology and Geochemistry, c/Francisco Toma ´s y Valiente, 7. Universidad Aut  onoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain, and 3 DesertNet-International, Hamburg University, Hamburg, Germany Abstract The impact of land-use intensity is evaluated through changes in the soil properties in different areas of the traditional central Spanish landscape. Soil organic carbon (SOC) content, bulk density, aggregate stability and water-holding capacity (WHC) in the topsoil of active and abandoned vineyards, livestock routes (LR) and young Quercus afforested areas were analysed. These different types of land use can be interpreted as having a gradient of progressively less impact on soil functions or conservation. As soil use intensity declines, there is an increase in SOC content (from 0.2 to 0.6%), WHC (from 0.2 to 0.3 g H 2 O per g soil) and aggregate stability (from 4 to 33 drop impacts). Soils beneath vines have lost their upper horizon (15 cm depth) because of centuries-old tillage management of vineyards. Except for an increase in bulk density (from 1.2 to 1.4 g/cm 3 ), there were no differences in soil characteristics 4 yr after the abandonment of vine management. LR can be considered sustainable uses of land, which preserve or improve soil characteristics, as there were no significant differences between topsoil from LR and that from a 40-yr-old Quercus afforested area. SOC content, one of the main indicators for soil conservation, is considered very low in every case analysed, even in the more conservative uses of land. These data can be useful in understanding the slow rate of recovery of soils, even after long-term cessation of agricultural land use. Keywords: Livestock routes, abandoned lands, vineyards, soil organic carbon, soil structure, agricultural policies Introduction The current situation of degraded agricultural soils in southern Europe is due in part to the variety of agricultural policies implemented in the last 30 yr that have gone through different stages. The first objective of European policies was ‘to increase productivity, by promoting technical progress and ensuring the optimum use of the factors of production, in particular labour’ (Treaty of Rome, 1957). In the nineties, policies focused on the creation of set-aside payments to withdraw land from production; as a consequence, between 10 and 20% of agricultural lands in the Euro-Mediterranean countries were abandoned (Grove & Rackham, 1996). The last ‘single farm payments’ were subject to conditions relating to environment, food safety and animal welfare standards (reforms since 2004– 2005). Currently, there is a new proposal to reform the Common Agricultural Policy with three main goals: viable food production, sustainable management of ecosystems and balanced territorial development. To develop this new vision of improving the management of agro-ecosystems, farmers should be involved in preserving environmental landscapes, and policy makers must base their decisions on scientific knowledge. Quantitative information, from both observations and modelling, is needed. Particularly, local data on the current state of soil conservation would provide the information needed to understand how different soil properties change over time and under different land uses, compared with their unaltered original conditions. As a consequence of these European agricultural policies, countries with semi-arid climates are currently a mosaic of abandoned and used lands, whose detailed conservation Correspondence: M. Jos  e Marques. E-mail: mariajose.marques@uam.es Received September 2012; accepted after revision March 2013 © 2013 The Authors. Journal compilation © 2013 British Society of Soil Science 547 Soil Use and Management, December 2013, 29, 547–556 doi: 10.1111/sum.12064 Soil Use and Management