Carbon farming is a set of agricultural methods that aim to store carbon in the soil, crop roots, wood and leaves. The technical term for this is carbon sequestration. The overall goal of carbon farming is to create a net loss of carbon from the atmosphere. This is done by increasing the rate at which carbon is sequestered into soil and plant material. One option is to increase the soil's organic matter content. This can also aid plant growth, improve soil water retention capacity and reduce fertilizer use. Sustainable forest management is another tool that is used in carbon farming. Carbon farming is one component of climate-smart agriculture. It is also one way to remove carbon dioxide from the atmosphere.

Agricultural methods for carbon farming include adjusting how tillage and livestock grazing is done, using organic mulch or compost, working with biochar and terra preta, and changing the crop types. Methods used in forestry include reforestation and bamboo farming. As of 2016, variants of carbon farming reached hundreds of millions of hectares globally, of the nearly 5 billion hectares (1.2×10¹⁰ acres) of world farmland.

Carbon farming tends to be more expensive than conventional agricultural practices. Depending on the region, carbon farmings costs US$3-130 per tonne of carbon dioxide sequestered. Some countries provide subsidies to farmers to use carbon farming methods. While the implementation of carbon farming methods can reduce/sequester emissions, it is important to also consider the effects of land use changes with respect to the conversion of forests to agricultural production.

The overall aim of carbon farming is to store carbon in the soil, crop roots, wood and leaves. It is one of several methods for carbon sequestration. It can be achieved by modification of agricultural practices because soil can act as an effective carbon sink and thus offset carbon dioxide emissions.

Agricultural sequestration practices may have positive effects on soil, air, and water quality, be beneficial to wildlife, and expand food production. On degraded croplands, an increase of one ton of soil carbon pool may increase crop yield by 20 to 40 kilograms per hectare of wheat, 10 to 20 kg/ha for maize, and 0.5 to 1 kg/ha for cowpeas.

Compared to natural vegetation, cropland soils are depleted in soil organic carbon (SOC). When a soil is converted from natural land or semi natural land, such as forests, woodlands, grasslands, steppes and savannas, the SOC content in the soil reduces by about 30–40%. The loss of carbon through agricultural practices can eventually lead to the loss of soil suitable for agriculture. The carbon loss from the soil is due to the removal of plant material containing carbon, via harvesting. When land use changes, soil carbon either increases or decreases. This change continues until the soil reaches a new equilibrium. Deviations from this equilibrium can also be affected by varying climate. The decrease can be counteracted by increasing carbon input. This can be done via several strategies, e.g. leaving harvest residues on the field, using manure or rotating perennial crops. Perennial crops have a larger below ground biomass fraction, which increases the SOC content. Globally, soils are estimated to contain >8,580 gigatons of organic carbon, about ten times the amount in the atmosphere and much more than in vegetation.

In part, soil carbon is thought to accumulate when decaying organic matter was physically mixed with soil. Small roots die and decay while the plant is alive, depositing carbon below the surface. More recently, the role of living plants has been emphasized where carbon is released as plants grow. Soils can contain up to 5% carbon by weight, including decomposing plant and animal matter and biochar.

About half of soil carbon is found within deep soils. About 90% of this is stabilized by mineral–organic associations.