Estimating organic carbon in the soils of Europe for policy support

Abstract

The estimation of soil carbon content is of pressing concern for soil protection and in mitigation strategies for global warming. This paper describes the methodology developed and the results obtained in a study aimed at estimating organic carbon contents (%) in topsoils across Europe. The information presented in map form provides policy-makers with estimates of current topsoil organic carbon contents for developing strategies for soil protection at regional level. Such baseline data are also of importance in global change modelling and may be used to estimate regional differences in soil organic carbon (SOC) stocks and projected changes therein, as required for example under the Kyoto Protocol to the United Nations Framework Convention on Climate Change, after having taken into account regional differences in bulk density.The study uses a novel approach combining a rule-based system with detailed thematic spatial data layers to arrive at a much-improved result over either method, using advanced methods for spatial data processing. The rule-based system is provided by the pedo-transfer rules, which were developed for use with the European Soil Database. The strong effects of vegetation and land use on SOC have been taken into account in the calculations, and the influence of temperature on organic carbon contents has been considered in the form of a heuristic function. Processing of all thematic data was performed on harmonized spatial data layers in raster format with a 1 km  1 km grid spacing. This resolution is regarded as appropriate for planning effective soil protection measures at the European level. The approach is thought to be transferable to other regions of the world that are facing similar questions, provided adequate data are available for these regions. However, there will always be an element of uncertainty in estimating or determining the spatial distribution of organic carbon contents of soils.

Carbon Inputs from Miscanthus Displace Older Soil Organic Carbon Without Inducing Priming

“…In light of climate change likely to increase global temperatures, the temperature sensitivity of soil C decomposition is a major issue; globally, soils contain an estimated 2300 Gt C [27]. In upland mineral soils alone, predicted losses due to a climate change related increase in decomposition are ∼40 Gt C by 2100 [28], meaning a substantial addition of CO 2 to the atmosphere, on top of those already occurring, further contributing to climate change. Consequently, there is a potential for soil C sequestration under bioenergy crops like Miscanthus to play a key role in mitigating some of these losses, but the effects of temperature on decomposition rates (and therefore CO 2 emissions) must also be taken into account.…”

Effects of permanent grass versus tillage on aggregation and organic matter dynamics in a poorly developed vineyard soil

“…The topsoil of the studied vineyard was rather vulnerable to aggregate breakdown in both 264 treatments (Figure 3), as often observed in hilly areas of the Mediterranean, where OC contents as 265 low as 20 g kg -1 are not unusual (Jones et al 2005) due to erosion (García-Ruiz et al 2013;Novara 266 et al 2015) and poor soil development (Novara et al 2015). Moreover, deep tillage before vine 267 planting could have also contributed to reducing OC contents due to the combined effects of (i) 268 mixing of deep horizons with the topsoil, as often happens after severe disturbances (e.g., Stanchi et 269 al.…”

How much green for the buck? Estimating additional and windfall effects of French agro-environmental schemes by DID-matching

“…As many farmers choose both measures 08 and 09 along with measure 0301, 29 the impact of each AES is estimated separately. 30 Results are presented in table 3. All DID estimators suggest that participants in AES 0301, chosen with or without AES 08 and 09 (rows 1 and 2), have increased their area planted with cover crops, whereas participants in AES 08 and 09 only (without AES 0301) have not.…”

“…29 Half the beneficiaries of AES 0301 have also chosen AES 09. 30 This does not need to be done for other AES, as the outcomes considered are not likely to be influenced by more than one AE measure.…”