Short-term effects of land management change linked to cover crop on soil organic carbon in Mediterranean olive grove hillsides

Manuel González-Rosado; Beatriz Lozano-García; Jesús Aguilera-Huertas; Luis Parras-Alcántara

doi:10.1016/j.scitotenv.2020.140683

Short-term effects of land management change linked to cover crop on soil organic carbon in Mediterranean olive grove hillsides

Sci Total Environ. 2020 Nov 20:744:140683. doi: 10.1016/j.scitotenv.2020.140683. Epub 2020 Jul 5.

Authors

Manuel González-Rosado¹, Beatriz Lozano-García¹, Jesús Aguilera-Huertas¹, Luis Parras-Alcántara²

Affiliations

¹ SUMAS Research Group, Department of Agricultural Chemistry and Soil Science, Faculty of Science, Agrifood Campus of International Excellence - ceiA3, University of Cordoba, 14071 Cordoba, Spain.
² SUMAS Research Group, Department of Agricultural Chemistry and Soil Science, Faculty of Science, Agrifood Campus of International Excellence - ceiA3, University of Cordoba, 14071 Cordoba, Spain. Electronic address: luis.parras@uco.es.

PMID: 32721665
DOI: 10.1016/j.scitotenv.2020.140683

Abstract

The spatial distribution of soil organic carbon (SOC) is essential to estimate the SOC reserves. Therefore, the soils ability to store organic carbon is a key factor for climate regulation and for other soil functions. The soil management and the topographic position play an important role in SOC variation, especially when the landscape is not uniform (Mediterranean areas). Many researches have explored the SOC distribution according to topographic position in hillsides for long-term, but very few studies have focused on the short term. Therefore, it is necessary to know, the changes that taking place in the soil due to land management change (LMC) in these irregular surfaces for sustainable agricultural production and its implications on climate change regulation. This study aims to assess the influence of topographic position and LMC on SOC stock (SOC-S) in Mediterranean olive groves (OG) soils in short term (2 years). In this line, three experimental plots were selected in three topographical position (summit - S, backslope - B and toeslope - T). In these plots, the land management was modified from conventional tillage (CT) to no tillage (NT) with application of pruned olive branch chippings branches and vegetation cover (spontaneous vegetation) in the OG streets. The studied soils did not show important changes due to LMC in their physical properties for short term, in addition, these soils were characterized by low organic matter content (<1.2%). LMC caused a SOC reduction in surface, and a SOC increase in the Bw horizon. The N concentrations showed a similar trend to SOC and the C:N ratios were highly variable (4.37: C horizon-NT-S; 13.45 Bw/C horizon -CT-B). Normally, the SOC-S concentrations decreasing in depth. LMC for two years showed soil carbonization (S and T position) and decarbonization (B position) processes. The SOC-S increased 1.88 Mg ha^-1 y^-1 and 0.47 Mg ha^-1 y^-1 for S and T topographic position respectively, however the SOC-S decreased in B position 5.27 Mg ha^-1 y^-1. Therefore, LMC has a positive effect on soil carbon reserves in S and T position, conversely in B position, this effect was negative.

Keywords: Cambisol; Carbonization; Decarbonization; Mediterranean areas; Topographical position; Traditional olive grove.