John Deere has confirmed it will start using selective catalyst reduction, urea-based exhaust gas treatment technology to help its larger tractors meet tighter emissions regulations from 2014.

Deere has been using the single fuel exhaust gas recirculation (EGR) system to meet Stage 3B regulations, but in order to comply with Stage 4 emissions levels it has said it will have to bolt on urea after-treatment.

The EGR system and diesel particulate filters will operate in a similar fashion to current Stage 3B power plants, but the SCR system will help reduce nitrogen oxide emissions by the 80% required by Stage 4.

Deere says combining the two technologies means less Adblue is needed and its tractors can be fitted with smaller exhaust fluid tanks than those relying purely on SCR technology. It also means DEF/Adblue filter services will be required less frequently.

The Integrated Emissions Control System will start to be used from 2014 on tractors larger than 174hp and it is expected to creep into smaller machines about two years later.

EGR (Exhaust Gas Recirculation)

A system that reduces nitrogen oxide emissions by sending some of the exhaust gasses back to the engine cylinder to be burnt again. Filters also take out some of harmful deposits.

SCR (Selective Catalyst Reduction)

A system that uses a urea-in-solution to clean up exhaust gasses

Adblue

Brand name for one of the urea solutions used in SCR systems

DEF – Diesel Exhaust Fluid

General term for urea liquids such as Adblue used in SCR systems

Stage 3B

Current European emissions standards for agricultural vehicles manufactured up to 2014

Stage 4

European emissions standards or agricultural vehicles manufactured from 2014

Interim tier 4

US equivalent of Stage 3 B

Final Tier 4

US equivalent of Stage 4