Language:
English
In:
Science of the Total Environment, 01 December 2015, Vol.536, pp.1045-1051
Description:
To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1016/j.scitotenv.2015.07.064 Byline: Martin Wiesmeier [wiesmeier@wzw.tum.de] (a,*), Rico Hubner (b), Ingrid Kogel-Knabner (a,c) Keywords Soil organic carbon; Climate change; Net primary productivity; Soil C input Highlights * C stocks in agricultural soils may be largely affected by climate change. * It is assumed that C stocks would increase due to an assumed increase of NPP. * However, crop statistics indicate stagnating yields of major crops since the 1990s. * Concurrently stagnating C inputs would lead to C decreases in the long-term. * Indications for declining agricultural C stocks were already found. Abstract The carbon (C) balance of agricultural soils may be largely affected by climate change. Increasing temperatures are discussed to cause a loss of soil organic carbon (SOC) due to enhanced decomposition of soil organic matter, which has a high intrinsic temperature sensitivity. On the other hand, several modeling studies assumed that potential SOC losses would be compensated or even outperformed by an increased C input by crop residues into agricultural soils. This assumption was based on a predicted general increase of net primary productivity (NPP) as a result of the CO.sub.2 fertilization effect and prolonged growing seasons. However, it is questionable if the crop C input into agricultural soils can be derived from NPP predictions of vegetation models. The C input in European croplands is largely controlled by the agricultural management and was strongly related to the development of crop yields in the last decades. Thus, a glance at past yield development will probably be more instructive for future estimations of the C input than previous modeling approaches based on NPP predictions. An analysis of European yield statistics indicated that yields of wheat, barley and maize are stagnating in Central and Northern Europe since the 1990s. The stagnation of crop yields can probably be related to a fundamental change of the agricultural management and to climate change effects. It is assumed that the soil C input is concurrently stagnating which would necessarily lead to a decrease of agricultural SOC stocks in the long-term given a constant temperature increase. Remarkably, for almost all European countries that are faced with yield stagnation indications for agricultural SOC decreases were already found. Potentially adverse effects of yield stagnation on the C balance of croplands call for an interdisciplinary investigation of its causes and a comprehensive monitoring of SOC stocks in agricultural soils of Europe. Author Affiliation: (a) Lehrstuhl fur Bodenkunde, Department fur Okologie und Okosystemmanagement, Wissenschaftszentrum Weihenstephan fur Ernahrung, Landnutzung und Umwelt, Technische Universitat Munchen, 85350 Freising-Weihenstephan, Germany (b) Lehrstuhl fur Strategie und Management der Landschaftsentwicklung, Department fur Okologie und Okosystemmanagement, Wissenschaftszentrum Weihenstephan fur Ernahrung, Landnutzung und Umwelt, Technische Universitat Munchen, 85350 Freising-Weihenstephan, Germany (c) Institute for Advanced Study, Technische Universitat Munchen, Lichtenbergstr. 2a, 85748 Garching, Germany * Corresponding author. Article History: Received 23 April 2015; Revised 12 July 2015; Accepted 13 July 2015 (miscellaneous) Editor: D. Barcelo
Keywords:
Soil Organic Carbon ; Climate Change ; Net Primary Productivity ; Soil C Input ; Environmental Sciences ; Biology ; Public Health
ISSN:
0048-9697
E-ISSN:
1879-1026
DOI:
10.1016/j.scitotenv.2015.07.064
URL:
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