California Air Resources Board

In 2022, California’s agricultural industry consisted of over 68,400 farms and ranches, providing over 400 different commodities, making agriculture one of the State’s most diverse industries.  Over a third of the country’s vegetables and nearly three-quarters of the country’s fruits and nuts are grown in California.  Producers, custom operators, first processors, and rental companies own and operate approximately 118,500 pieces of off-road, diesel-fueled, mobile agricultural equipment statewide.  Even with increasingly more stringent emission standards on engine manufacturers, emissions from these vehicles and equipment are a significant source of air pollution.  In 2020, emissions from off-road agricultural equipment account for approximately 8% of the oxides of nitrogen (NOx) and 5% of the particulate matter (PM) emissions from mobile sources statewide, and in the San Joaquin Valley, it accounts for approximately 22% of the NOx emissions and 17% of the PM emissions from mobile sources.  Reducing these emissions is necessary to meet federal ozone and particulate matter air quality standards, particularly in the San Joaquin Valley where the agricultural sector is a vibrant and critical part to the local and state economy, but also contributes to the poor air quality.

In October 2013, the Board approved the State Implementation Plan Credit from Mobile Agricultural Equipment Regulation, which provides the administrative mechanism for emission reductions resulting from mobile agricultural equipment incentive projects funded by the Carl Moyer Program to be eligible for SIP credit in the San Joaquin Valley.  This regulation complements the San Joaquin Valley Air Pollution Control District's Rule 9610 that will ensure emission reductions achieved through local, State, and federal voluntary incentive programs from mobile agricultural equipment projects are eligible for SIP credit.  

In October 2018, the Board adopted the San Joaquin Valley Supplement to the 2016 State Strategy for the State Implementation Plan (Valley State SIP Strategy) describing measures and emission reductions necessary to attain health-based federal air quality standards for PM 2.5 in the San Joaquin Valley.  The Valley State SIP Strategy includes measures that will rely on the deployment of the cleanest technologies in the mobile agricultural equipment sector through a combination of incentives and regulation.  CARB is working to gain a better understanding of the agricultural sector and how mobile agricultural equipment is used in California through efforts such as surveys of agricultural producers, first processors, and custom operators to update the mobile source emissions inventory.