Can animal manure be used to increase soil organic carbon stocks in the Mediterranean as a mitigation climate change strategy?

TL;DR

This study evaluates whether using animal manure can effectively increase soil organic carbon stocks in Mediterranean agricultural soils, highlighting its potential and limitations for climate change mitigation.

Contribution

It provides a simulation-based assessment of manure application effects on SOC in Catalonia, Spain, revealing partial success and the need for combined strategies.

Findings

Manure application can partially increase SOC stocks.

Transporting manure alone is insufficient for full policy goals.

Additional strategies are necessary for effective SOC enhancement.

Abstract

Soil organic carbon (SOC) plays an important role on improving soil conditions and soil functions. Increasing land use changes have induced an important decline of SOC content at global scale. Increasing SOC in agricultural soils has been proposed as a strategy to mitigate climate change. Animal manure has the characteristic of enriching SOC, when applied to crop fields, while, in parallel, it could constitute a natural fertilizer for the crops. In this paper, a simulation is performed using the area of Catalonia, Spain as a case study for the characteristic low SOC in the Mediterranean, to examine whether animal manure can improve substantially the SOC of agricultural fields, when applied as organic fertilizers. Our results show that the policy goals of the 4x1000 strategy can be achieved only partially by using manure transported to the fields. This implies that the proposed approach needs to be combined with other strategies.