The Positive Effects of Soil Organic Carbon on European Cereal Yields Level Off at 1.4%

Sammanfattning

IntroductionIncreasing soil organic carbon (SOC) in croplands is a natural climate mitigation effort that can also enhance crop yields. However, there is a lack of comprehensive field studies examining the impact of SOC on crop yields across wide climatic, soil, and farming gradients. Furthermore, it is largely unknown how water retention, soil microbial diversity, and nutrient availability modulate the SOC-crop yield relationship.Materials and MethodsWe conducted an observational study across 127 cereal fields along a 3000 km north-south gradient in Europe, measured topsoil (0-20 cm) organic C content, and collected data on climate, soil properties, crop yield and farming practices. Additionally, we explored the relationship between crop yield, particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) contents at three soil depths (0-20, 20-40 and 40-60 cm) in a subset of sites.ResultsRelative yield increases levelled off at 1.4% SOC, indicating an optimal SOC content for cereals along a European gradient. The quadratic relationship between SOC and cereal yield was conspicuous even after controlling for large differences in climate, soil and farming practices across countries. The relationship varied significantly across soil depths and C fractions. MAOC dominated the SOC pool, and was significantly related to relative yield up to an optimal level that varied with soil depth. Soil microbial diversity and nutrient availability emerged as main drivers of the SOC-yield relationship, while water retention did not exhibit a notable influence.ConclusionsOur study demonstrates that SOC is as a key determinant of cereal yield along a European gradient, and identifying this threshold can inform soil management strategies for improved carbon capture based on initial SOC levels. Nevertheless, the complex SOC-yield relationship highlights the necessity for tailored soil management strategies that consider specific site conditions to optimize C storage and crop yield.

Nyckelord

cereal production; soil mechanisms; soil organic carbon fractions; sustainable agriculture

Publicerad i

Journal of Sustainable Agriculture and Environment
2024, volym: 3, nummer: 4, artikelnummer: e70017
Utgivare: WILEY

SLU författare

• Hallin, Sara

  • Institutionen för skoglig mykologi och växtpatologi, Sveriges lantbruksuniversitet
    

• Saghai, Aurélien

  • Institutionen för skoglig mykologi och växtpatologi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Jordbruksvetenskap
Miljö- och naturvårdsvetenskap

Publikationens identifierare

• DOI: https://doi.org/10.1002/sae2.70017

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/139710