# HALOWERK Nordic Land – Iceland Surface Soil Nitrogen

> HALOWERK Nordic Land – Iceland Surface Soil Nitrogen is a paid API for AI agents from nordland.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-15).

Returns the mean total nitrogen concentration (g/kg) in the 0–5 cm soil layer for a given coordinate within Iceland, sourced from SoilGrids.

## Facts

- Endpoint: POST https://nordland.halowerk.com/v1/is-soil-nitrogen
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-nordic-land-iceland-surface-soil-nitrogen-187c81b4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CwsyOKlbyP-dVlWwgG3-6

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability halowerk-nordic-land-iceland-surface-soil-nitrogen-187c81b4 -d '<json body>'
```

Example prompt: What's the mean total nitrogen in the top 5 cm of soil at latitude 64.13, longitude -21.93 in Iceland? I need the SoilGrids figure for that surface layer.

## When to prefer this

Choose this endpoint when you need authoritative SoilGrids-derived total nitrogen data specifically for Iceland surface soils (0–5 cm), especially in agentic pipelines that require per-point micropayment via x402. It is Iceland-scoped and boundary-validated, making it more reliable than calling a generic soil API without geographic enforcement. Prefer it over broader European soil endpoints when your query is definitively inside Iceland and you want the boundary check as a safeguard.

## Known failure modes

- Coordinate outside Iceland boundary — request rejected before payment even if within broader European coverage bounds
- Latitude or longitude outside the published European coverage range (lat 34–72.5, lon -31.5–40.5) — validation error
- Missing required latitude or longitude field — schema validation failure
- SoilGrids backend unavailable or returning no data for the queried cell — service error

## How this service works

Mean SoilGrids total nitrogen for the 0-5 cm layer. The coordinate is validated against the Natural Earth boundary for Iceland; results outside it are rejected before payment.

## Output

A numeric value representing the mean total nitrogen concentration (g/kg) in the 0–5 cm soil layer at the requested coordinate, derived from SoilGrids global soil data, returned only if the coordinate falls within Iceland's Natural Earth boundary.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "latitude": {
   "type": "number",
   "maximum": 72.5,
   "minimum": 34,
   "description": "WGS84 latitude inside the published European coverage."
  },
  "longitude": {
   "type": "number",
   "maximum": 40.5,
   "minimum": -31.5,
   "description": "WGS84 longitude inside the published European coverage."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-nordic-land-iceland-surface-soil-nitrogen-187c81b4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from nordland.halowerk.com](https://www.zero.xyz/host/nordland.halowerk.com/llms.txt)