The Ministry of Ecology and Environment has officially approved the release of the national environmental protection standard "Technical Requirements for Pollutant Emission Control of Non-Road Diesel Mobile Machinery (Release Draft)". This standard specifies the technical requirements for the emission control of pollutants from the fourth-stage non-road diesel mobile machinery and the diesel engines it is equipped with. The standard points out that from December 1, 2022, all production, import and sales of non-road mobile machinery below 560 kW (including 560 kW) and the diesel engines installed should meet the requirements of this standard. The implementation time of the fourth phase of the non-road mobile machinery above 560 kilowatts and the diesel engines installed therein will be announced separately.

In February 2018, the "Technical Requirements for Pollutant Emission Control of Non-Road Diesel Mobile Machinery (Consultation)" issued by the former Ministry of Environmental Protection officially started the "National Four" emission upgrade work. It should be noted that upgrading the emission standards of agricultural machinery is not as simple as changing an engine. Different from the previous National 1 to National 3 standards that directly require diesel engines to meet the standards, this National 4 upgrade directly affects the overall agricultural machinery. In short, a tractor that is only installed with a diesel engine of the National IV standard does not necessarily pass the audit. Only when the finished product discharges up to the standard, and has complete testing and monitoring equipment, and fully meets the standard requirements, can it officially go on the road. Therefore, the National IV emission upgrade is not only an upgrade of the engine, but also an upgrade of the entire system, which is an overall improvement of the product.