MODELLING CARBON FLOWS IN CROP AND SOIL
This presentation is the property of its rightful owner.
Sponsored Links
1 / 11

MODELLING CARBON FLOWS IN CROP AND SOIL PowerPoint PPT Presentation


  • 72 Views
  • Uploaded on
  • Presentation posted in: General

MODELLING CARBON FLOWS IN CROP AND SOIL. Krisztina R. Végh. Carbon and Nitrogen flows and storage. Eckersten, 1994). Carbon flows in the CoupModel. Organic residues: surface litter, rhizodeposition: 900-3000 kg C/ha. C/N:20-80. C/N:10-30. Dissolved organics. (Jansson, 2004).

Download Presentation

MODELLING CARBON FLOWS IN CROP AND SOIL

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Modelling carbon flows in crop and soil

MODELLING CARBON FLOWS IN CROP AND SOIL

Krisztina R. Végh


Modelling carbon flows in crop and soil

Carbon and Nitrogen flows and storage

Eckersten, 1994)


Modelling carbon flows in crop and soil

Carbon flows in the CoupModel

Organic residues: surface litter,

rhizodeposition: 900-3000 kg C/ha

C/N:20-80

C/N:10-30

Dissolved organics

(Jansson, 2004)


Modelling carbon flows in crop and soil

C input: crop growth

  • Logistic growth:

  • Water use efficiency

  • Light use efficiency

3 approaches for the simulation of plant growth :

the potential growth is a function of time

growth is estimated from WUE and simulated transpiration

light use efficiency is used to estimate potential growth rate, limited by unfavorable temperature, water and N conditions.


Modelling carbon flows in crop and soil

Allocation of assimilated C to the different plant parts

Plant biomass is divided into compartments of carbon (CLeaf, CStem, CRoot, Cgrain Cmobile)


Modelling carbon flows in crop and soil

Different response functions of C allocation to roots from above ground mass

shoot mass, water stress, leaf C:N

Options:linear function

exponential

independent

Original parameters

doubled:


Modelling carbon flows in crop and soil

Decomposition and mineralization – Soil organismsm are implicit

The decomposition is substrate controlled and calculated as a first order rate process:

When soil organisms are implicit, the soil profile includes maximum of three carbon pools with specific decomposition rates kl, kf, kh.

The relative amounts of decomposition products

The three rate constants are affected by response functions for soil moisture (f) and temperature (fT).

Efficiency parameter fe determines the fraction of Cthat is not released from the soil as CO2


Modelling carbon flows in crop and soil

Organic carbon pools and carbon flows in the soil

Estimated consumption rate of microbes with their efficiency explicitly taken into account + respiration of microbial biomass

subpools

fraction of microbes located in the different pools


Modelling carbon flows in crop and soil

Decomposition :

Substrate dependence,

CN ratio

Scons: substrate half rate concentration

Decomposition :

Substrate dependence,

Carbon contentration


Modelling carbon flows in crop and soil

The affects of parameters TemQ10 and TemQ10Bas affect the response function

Q10 temp. response function with a threshold value


Modelling carbon flows in crop and soil

Conclusions

Simulation models help to understand the mechanistic relationships between SOC and soil – plant interactions

C flows and OC pools are similarly conceptualized in several models. Simple switches to obtional pools, the possibility of the use of different allocation functions and several abiotic response functions help to describe the processes that interact simultaneously to control C dynamics in crop and soil.


  • Login