# Cation Exchange Capacity (CEC) (0-5cm) (`CECSOL_M_sl1_1km_ll`) — EDIS AI Agent Dataset View

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## 1. Dataset Metadata
- **Raster Name**: Cation Exchange Capacity (CEC) (0-5cm)
- **Slug**: `CECSOL_M_sl1_1km_ll`
- **Units**: `cmol(c)/kg`
- **Spatial Extent**: UL(83.9991672, -180.0) to LR(-56.0008328, 180.0)
- **Summary**: Cation Exchange Capacity (CEC) represents the soil’s ability to retain and exchange positively charged ions (cations) such as calcium (Ca²⁺), magnesium (Mg²⁺), potassium (K⁺), sodium (Na⁺), and hydrogen (H⁺).
- **Included in Flagship Map Package**: `Global_ISO9223_2020_2024_LE_V4` (`GET https://secure.engineeringdirector.com/api/bundles/Global_ISO9223_2020_2024_LE_V4/point_query`)


# CECSOL_M_sl1_1km_ll.tif — Technical Specification and Citation

## Parameter Name
- **CECSOL**  
- **Definition:** Cation Exchange Capacity of Soil

## Description
Cation Exchange Capacity (CEC) represents the soil’s ability to retain and exchange positively charged ions (cations) such as calcium (Ca²⁺), magnesium (Mg²⁺), potassium (K⁺), sodium (Na⁺), and hydrogen (H⁺).

CEC is strongly influenced by:
- Clay mineral content
- Organic matter
- Soil texture
- Soil chemistry

Higher CEC values generally indicate greater nutrient retention capacity and increased electrochemical activity within the soil matrix.

## Units
- **cmol(c)/kg**  
  - Centimoles of positive charge per kilogram of soil

## Depth Level
- **sl1 (Soil Layer 1)**  
- Depth interval: **0–5 cm**

## Data Source
- **ISRIC SoilGrids**
- Based on:
  - WoSIS (World Soil Information Service)  
  - Machine learning models (e.g., Random Forest)

## Spatial Characteristics
- **Coverage:** Global (typically excludes Antarctica)  
- **Resolution:** 1 km  
- **Coordinate System:** WGS84 (EPSG:4326)  
- **Grid Type:** Latitude/Longitude (ll)

## File Naming Convention
`CECSOL_M_sl1_1km_ll.tif`

### Components
- **CECSOL** = Variable (Cation Exchange Capacity)  
- **M** = Mean prediction (also available: Q05, Q95 for uncertainty)  
- **sl1** = Depth layer (0–5 cm)  
- **1km** = Spatial resolution  
- **ll** = Geographic coordinate grid (latitude/longitude)  

## ISRIC Metadata Alignment
- **Variable Name:** Cation Exchange Capacity of Soil  
- **Attribute Title:** CEC of soil (cmol(c)/kg) at depth 0.00 m  
- **Units:** cmol(c)/kg  
- **Range Domain:** 0 to 233

## Typical Value Range

| CEC Value (cmol(c)/kg) | Interpretation |
|------|--------------|
| 0–5 | Very low nutrient retention |
| 5–15 | Sandy to moderately weathered soils |
| 15–30 | Moderate fertility soils |
| 30–50 | Clay-rich or organic-rich soils |
| 50–100 | Organic or highly active clay soils |
| >100 | Extreme organic, volcanic, or highly active clay systems |

## Important Clarification
- **0–5 cm = depth interval (sl1)**  
- Values represent:
  - Soil electrochemical exchange capacity
  - Not electrical conductivity directly
- Higher CEC often correlates with:
  - Increased clay content
  - Greater moisture retention
  - Lower soil resistivity

## Recommended Citation

### Primary Scientific Citation
> Poggio, L., de Sousa, L.M., Batjes, N.H., et al. (2021).  
> *SoilGrids 2.0: producing soil information for the globe with quantified spatial uncertainty*.  
> **SOIL**, 7, 217–240.  
> https://doi.org/10.5194/soil-7-217-2021  

### Data Citation
> ISRIC – World Soil Information (2020).  
> *SoilGrids250m: Global gridded soil information*.  
> https://soilgrids.org  

### Example Usage Citation
> Soil cation exchange capacity data (CECSOL, 0–5 cm) obtained from ISRIC SoilGrids (1 km resolution).

## Notes for Advanced Use
- High CEC soils generally exhibit:
  - Greater nutrient retention  
  - Increased clay activity  
  - Higher moisture retention  
  - Lower permeability  
- Elevated CEC may contribute to:
  - Reduced oxygen diffusion  
  - Lower soil resistivity  
  - Enhanced electrochemical corrosion environments  
- Critical for:
  - Soil resistivity modeling  
  - Corrosion and MIC analysis  
  - Agricultural fertility assessment  
  - Geochemical and hydrologic interpretation  

---

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