CENTURY agroecosystem dynamic model

CENTURY is a process-based model designed to simulate Carbon (C), Nitrogen (N), Phosphorous (P) and Sulphur (S) dynamics in natural or cultivated systems, using a monthly time step. The model was originally developed in the late ’80s by Colorado State University and it is, currently, one of the most widely used soil biogeochemistry models. 

In the JRC.D.3 model framework, CENTURY is running at a resolution of 1 km2 in the agricultural soils of the EU, incorporating the most recently available pan-European datasets. The main purpose is to quantify the current soil organic carbon (SOC) stock and its change under different scenarios, although many ecosystem outputs (eg. soil respiration, plant productivity, etc.) can also be retrieved.    

A major benefit of CENTURY is that it can incorporate the effects of policy scenarios based on land-use changes and support practices. The impact of the Good Agricultural and Environmental Condition (GAEC) requirements of the Common Agricultural Policy (CAP) and the EU’s guidelines for soil protection can be assessed under land management and support practices.

CENTURY is a typical soil organic carbon (SOC) compartment model based on first order decay: the soil organic matter sub-model includes three SOC pools (active, slow and passive), along with two fresh residue pools (structural and metabolic), each with a different turnover rate. Soil temperature and moisture, soil texture and cultivation practices have different effects on these rates. The model is also able to simulate the water balance, using a weekly time step, and a suite of simple plant growth models are included to simulate C, N, P and S dynamics of crops, grasses and trees.

In our model framework, CENTURY is running at a resolution of 1 km2 in the agricultural soils of the EU, incorporating the most recently available pan-European datasets. The model can also be implemented with the soil erosion component. A daily time-step version of the model (DayCent) is recently running using the same JRC-D.3 model framework inputs.   

The CENTURY model was spin-up through a series of management sequences encompassing the main agricultural technological stages of the last 2,000 years, until the actual management representing the business as usual scenario. A validation against the Land Use and Coverage Area frame Survey (LUCAS) soil samples was performed to test the model accuracy of the present SOC stock estimations.

Key input to CENTURY are: 

• spatial distribution of the agricultural land use categories (arable, pasture, rice, permanent crops) (Source: Corine Land Cover 1990-2000-2006-2012)
• soil texture, pH, bulk density, layers definition and depth, hydraulic properties (source: European Soil Database v.2 and LUCAS-derived spatial layers)
• actual gridded climate (Source: European Climate Assessment & Dataset,  E-OBS gridded weather dataset)
• climate projections (Source: Coordinated Regional Climate Downscaling Experiment (CORDEX) climatic projections)
• crop area distribution at NUT2 level, livestock density at NUT2, NUT3 level (source: EUROSTAT)
• crop distribution, fertilizer consumption, irrigation, livestock density (Source: FAO)
• soil erosion map (Source: Revised Universal Soil Loss Equation, RUSLE2015 (optional))