Table 3.
Methodology used to estimate changes in soil C stocks for cropland remaining cropland, including agricultural land use and management activities on mineral soils
| GRA country | Tier | Land management activities | Reference |
|---|---|---|---|
| Australia | |||
| The Full Carbon Accounting Model (FullCAM) | Tier 3 | Crop type and rotation (including pasture leys) | Richards (2001) |
| Stubble management, including burning practices | |||
| Tillage techniques | |||
| Fertilizer application and irrigation | |||
| Application of green manures (particularly legume crops) | |||
| Soil ameliorants (application of manure, compost or biochar) | |||
| Changes in land use from grassland | |||
| Crop‐specific coefficients sourced from the literature combined with ABS agricultural commodities statistics | Tier 2 | Changes in the area of perennial woody crops | |
| Canada | |||
| Process model (CENTURY) based on the National Soil Database of the Canadian Soil Information System | Tier 3 | Change in mixture of crop type (increase in perennial crops and increase in annual crops) | McConkey et al. (2014) |
| Change in tillage practices | |||
| Change in area of summer fallow | |||
| Land use, tillage, type and amount of input | |||
| Crop residue, farmyard manure and presence or absence of vegetative cover | |||
| Perennial and organic management systems | |||
| Denmark | |||
| Average SOC calculated annually per soil type and region based on process‐based model (C‐TOOL) using data on temperature and estimated C input from crop residues and manure using national databases | Tier 3 | Crop type and crop yield | Taghizadeh‐Toosi and Olesen (2016) |
| Cover crops | |||
| Residue management | |||
| Manure application | |||
| Grassland management | |||
| France | |||
| The IPCC Guidelines and OMINEA database | Tier 1 | Land use | CITEPA (2019) |
| Tillage | |||
| Type and amount of input | |||
| Japan | |||
| Average carbon stock changes in each year by land‐use subcategory (rice fields, upland fields, orchards and pastural land) calculated by the Roth C model by the mineral soil area of each prefecture obtained from statistical material, map data and questionnaire survey | Tier 2 | Carbon input from crop residue | Shirato and Taniyama (2003) |
| Farmyard manure | |||
| Presence or absence of vegetative cover | |||
| Lithuania | |||
| National statistics for woody crops and available data of arable land certified as organic in FAOSTAT and ecological agricultural land statistics. | Tier 2 | Crop type (perennial crops, certified organic crops, other crops) | Statistics Lithuania (2018) |
| Amount of input | |||
| Norway | |||
| Reference stock and stock change factors estimated by the Introductory Carbon Balance Model (ICBM) in a study where CO2 emissions were estimated for Norwegian cropland | Tier 2 | Crop rotations | Borgen et al. (2012) |
| Carbon inputs | |||
| Tillage | |||
| Spain | |||
| SOC values calculated by use and province, together with the reference values of the management factors provided by the IPCC Guidelines | Tier 1 | Land use | Rovira et al. (2007) |
| Crop rotations | |||
| Amount of input | |||
| Tillage | |||
| United Kingdom | |||
| Review UK relevant literature on the effects of cropland management practices on soil carbon stocks to model UK‐specific emission factors (methodology developed in Defra project SP1113) | Tier 1 | Manure | Moxley et al. (2014) |
| Residue inputs | |||
| Crop type (perennial, cropland, set‐aside) | |||
| Tier 2 | Tillage | ||
| United States | |||
| Published literature to determine the impact of management practices on SOC storage. Activity data based on the historical land use/management patterns recorded in the 2012 NRI (USDA, 2018) | Tier 2 | Tillage | Ogle, Breidt, Eve, and Paustian (2003); Ogle, Breidt, and Paustian (2006) |
| Cropping rotations | |||
| Intensification | |||
| Land‐use change between cultivated and uncultivated conditions | |||
Abbreviation: ABS, Australian Bureau of Statistics; GRA, Global Research Alliance of Agricultural Greenhouse Gases.