Organic and inorganic carbon storage in Dutch agricultural systems

Soil carbon is critical for feeding the global population and for mitigating climate change, yet agricultural intensification is leading to significant losses. Despite the need to stop agricultural soil carbon depletion and promote its restoration, uncertainties persist regarding agricultural practices that can enhance carbon accumulation across different pedological conditions.

Although soil carbon encompasses both inorganic and organic components, most research has focused on the effect of agricultural management on organic carbon due to its sensitivity to soil disturbances and role in soil functioning. However, there is growing evidence showing that agricultural activities can cause irrevocable losses of inorganic carbon, which may be detrimental for soil health and contribute to climate change. It is therefore crucial to study the response of both inorganic and organic carbon to agricultural management.

However, agricultural management includes a variety of practices that can be combined in different ways. This constitutes an obstacle in understanding how agricultural intensity impact soil organic carbon and in defining practices that promote its retention. This project investigates how soil agricultural management influences soil carbon storage across diverse pedological conditions.

Briefly, a total of 956 grasslands and arable soil samples from a wide range of agricultural management and pedological conditions were collected in the Netherlands. Detailed information on agricultural management was gathered using questionnaires to define management intensity and organic and inorganic carbon content were determined. In addition, explanatory variables such as aluminum and iron oxides content, pH, nutrient availability, soil texture, microbial biomass and environmental parameters such as air temperature, soil temperature and soil moisture were measured.

Here, we will show how agricultural management intensity affects soil organic and inorganic carbon content in grassland and arable fields in the Netherlands. Moreover, we will identify agricultural practices which can help promote soil carbon storage and how this varies with pedological conditions. These findings will improve our understanding of how agricultural management and soil proprieties interact to determine soil carbon storage, thus helping to develop targeted management practices to stop soil carbon depletion and promote restoration.