China's first citrus orchard carbon sink group standard was released

Recently, the Fujian Provincial Agricultural Society issued the group standard of "Technical Regulations for Carbon Sequestration Measurement and Monitoring of Citrus Orchards". Jointly drafted by the Institute of Resources, Environment and Soil Fertilizer of the Fujian Academy of Agricultural Sciences and the Fuzhou Municipal Bureau of Agriculture and Rural Affairs, the regulation is the first group standard for the measurement and monitoring of carbon sinks in citrus orchards in China.

Orchard carbon sequestration refers to the processes, activities, and mechanisms by which fruit trees absorb carbon dioxide from the atmosphere and fix it in the vegetation and soil of fruit trees through photosynthesis. Citrus is the world's largest producing fruit, and citrus orchards have great potential for carbon sequestration. At present, there is no carbon sink measurement and monitoring standard applicable to orchard ecosystems in China.

The existing national, industry and local standards are only applicable to the design of forestry carbon sequestration projects, the measurement and monitoring of carbon sequestration, and the accounting of soil carbon sequestration in farmland. As an agro-type perennial vegetation, orchard ecosystems are significantly different from forests. Classical standing tree biomass models and survey methods in forestry cannot be accurately used to estimate the biomass of fruit tree vegetation, and the appropriate carbon measurement parameters between the two are also very different.

Earlier, the Ministry of Agriculture and Rural Affairs and the National Development and Reform Commission issued the "Implementation Plan for Agricultural and Rural Carbon Emission Reduction and Sequestration", proposing to improve the standard system for agricultural and rural carbon emission reduction and sequestration, and improve the monitoring indicators, key parameters and accounting methods for agricultural and rural carbon emission reduction and sequestration.

In this context, Fujian Province has started the drafting of carbon sink measurement and monitoring standards for citrus orchard ecosystems.

As one of the drafting units, the Institute of Resources, Environment and Soil and Fertilizer of Fujian Academy of Agricultural Sciences has long been committed to the research, training and application of carbon measurement and low-carbon agricultural technology, and has undertaken projects such as "Research and Demonstration of Carbon Sequestration and Sink Enhancement Technology of Fruit (Tea) Orchard Complex System in Southeast Hilly and Mountainous Areas" and "Research on Carbon Sequestration and Carbon Balance of Southern Orchard Ecosystem".

According to the composition and operation characteristics of the carbon pool of the orchard ecosystem, the drafting unit summarized and formulated the technical regulations for the measurement and monitoring methods of carbon sinks suitable for citrus orchard ecosystems on the basis of relevant scientific research results and under the guidance of relevant national standards and industry standards. The procedure systematically established a technical standard system for orchard carbon sink measurement and monitoring from the aspects of orchard ecosystem carbon sink measurement terminology, measurement principles, quadrat setting and survey sampling methods, fruit tree biomass model construction, soil organic carbon storage accounting, monitoring cycle and carbon sink change calculation.

According to the regulations, the orchard carbon pool includes three carbon pools: aboveground and belowground biomass of fruit trees, litter and soil organic matter. Orchard carbon sink refers to the change of carbon storage in orchard ecosystems over a certain period of time, minus the greenhouse gas emissions generated during orchard planting and management within the ecosystem boundary. Greenhouse gas emissions, including nitrogen dioxide emissions from the application of fertilizers, and carbon dioxide emissions from energy consumption such as mechanical fuel and electricity used during crop management for pruning, picking, ploughing, irrigation, and transporting fertilizers.

The release of the group standard will promote orchard business activities with the main purpose of increasing sinks, form a set of scientific, reasonable, systematic and practical orchard carbon sink methodology, and provide a scientific basis for orchard carbon sinks to enter the carbon trading market.