The World Reference Base for Soil Resources ( eng. World Reference Base for Soil Resources ) is an international standard for the taxonomic hierarchy of soils adopted by the . The base was developed in the framework of international cooperation coordinated by the ( ISRIC ) under the auspices of IUSS and the FAO (Land and Water Resources Division). This base replaces the previous .
The global abstract database borrows modern concepts of soil classification, including the , the legend of the soil map of the world (FAO, 1988), the French pedological repository ( French Référentiel Pédologique ) and Russian concepts. The classification is based on as an expression of soil formation . The main difference from the US Department of Agriculture’s soil classification is that the soil climate is not part of the system, with the exception that the climate influences soil profile formation. Diagnostic criteria match existing systems as much as possible, correlating with national and previous international systems.
The purpose of the World Reference Base is the interconnection of national and local systems. The level of detail corresponds to the USDA taxonomic soil classification subgroups without soil climate information. The second edition did not have sufficient detail for large-scale mapping (larger than 1: 200 000), but this aspect of the database was improved in the third edition [1] [2] .
Key
Simplified key for identification of 32 abstract soil groups [1] . In order to correctly determine the soil profile, it is necessary to follow a number of detailed procedures described in the report on the World Reference Database .
| one. | Soils with a powerful humus horizon | (HS) |
| 2 | Soils, strongly modified by man | |
| Soils of long and intensive use in agriculture | (AT) | |
| Soils with high artifact content | (TC) | |
| 3 | Soils with restricted root growth due to close permafrost or stony occurrence | |
| Soils under the influence of permafrost | (CR) | |
| Thin or very stony soils | (LP) | |
| four. | Soils under the influence of water | |
| Alternating wet conditions abounding with swelling clay | (VR) | |
| Floodplaces , marches | (FL) | |
| Alkaline soil | Salts (SN) | |
| Salt-rich due to evaporation | Salt Flats (SC) | |
| Groundwater affected soils | (GL) | |
| five. | Soils whose properties are determined by the chemistry of Fe / Al | |
| Allophans or Al-humus soils | (AN) | |
| Chelyuviation and helluviation | Podzols (PZ) | |
| Fe accumulation in hydromorphic conditions | (PT) | |
| Low clay, P fixation, highly structured | (NT) | |
| The predominance of kaolinite and sesquioxides | (FR) | |
| 6 | Soils with stagnant water | |
| Sharp textural heterogeneity | (PL) | |
| Structural or moderate textural heterogeneity | (ST) | |
| 7 | The accumulation of organic matter in high content | |
| Typical Mollik | Chernozems (CH) | |
| Transition to arid climate | Chestnut (KS) | |
| Transition to a more humid climate | (PH) | |
| eight. | Accumulation of less soluble salts or non-saline substances | |
| Gypsum | (GY) | |
| Silica | (DU) | |
| Calcium carbonate | CL] | |
| 9. | Soil enriched with clay | |
| Whitish language | (AB) | |
| Unsaturated, highly active clay | (AL) | |
| Unsaturated, low active clay | (AC) | |
| Highly saturated, highly active clay | (LV) | |
| Highly saturated, low active clay | (LX) | |
| ten. | Relatively young soils or poorly developed soils | |
| With a dark sour upper horizon | (UM) | |
| Sandy soil | (AR) | |
| Moderately developed soils | (CM) | |
| Underdeveloped soils | (RG) |
Notes
- 2 1 2 World Reference Base for Soil Resources 2014, Update 2015. International soil maps and soils for soil maps . - 3rd. - Rome: FAO, 2015. - ISBN 978-92-5-108370-3 .
- ↑ Schad, P. Presenting the 3rd edition of the WRB // Geophysical Research Abstracts. - 2014. - Vol. sixteen.