Changes in the soil inorganic carbon dynamics in the tilled layer of a semi-arid Mediterranean soil due to irrigation and a change in crop

Uncertainties in the calculation of pedogenic carbonates

authored by
Isabel S. De Soto, Pierre Barré, Kazem Zamanian, Henar Urmeneta, Rodrigo Antón, Alberto Enrique, Iñigo Virto
Abstract

Soil inorganic carbon (SIC) accounts for more than one-third of the total soil carbon pool, but the effect of agricultural management on carbonates dynamics in Mediterranean semi-arid calcareous soils has largely been ignored and remains unclear. However, SIC plays a key role in physical, chemical and, biological properties of soils, which in turn can affect plant growth and productivity. Based on a 7-year field experiment in a paired irrigated and non-irrigated trial, with two different crops (maize and wheat), we investigated the effects of the land use change (from non-irrigated wheat to irrigated maize) on the SIC dynamics in the topsoil (0–30 cm) of a carbonate-rich soil in Navarre, northern Spain. The results obtained using the accepted equation for determining carbonate type showed that during the 7-year study period, irrigation application and the crop change modified the carbonate typology (lithogenic and pedogenic) in a very short period, without affecting the total SIC content. The main drivers of pedogenic carbonate formation in this case appear to be the water volume and the type of organic matter entering the soil (from C3 plants or C4 plants). However, the equation seems to be strongly dependent on the type of soil organic carbon, which can introduce uncertainties when used to determine the proportion of pedogenic carbonates in soils experiencing a crop change from C3 to C4 plants.

Organisation(s)
Institute of Earth System Sciences
External Organisation(s)
Public University of Navarre
École normale supérieure (Paris)
Type
Article
Journal
CATENA
Volume
246
No. of pages
11
ISSN
0341-8162
Publication date
11.2024
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Earth-Surface Processes
Sustainable Development Goals
SDG 2 - Zero Hunger, SDG 15 - Life on Land
Electronic version(s)
https://doi.org/10.1016/j.catena.2024.108362 (Access: Open)