# HALOWERK Southern Land – Portugal Soil Total Nitrogen (0-5 cm)

> HALOWERK Southern Land – Portugal Soil Total Nitrogen (0-5 cm) is a paid API for AI agents from suedland.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-15).

Returns the mean SoilGrids total nitrogen content for the 0-5 cm soil layer at a given coordinate within Portugal, validated against Natural Earth boundaries.

## Facts

- Endpoint: POST https://suedland.halowerk.com/v1/pt-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-southern-land-portugal-soil-total-nitrogen-0-5-cm-55dfc7d0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BgxPe-2zTmxQO-XGiM_Xm

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-southern-land-portugal-soil-total-nitrogen-0-5-cm-55dfc7d0 -d '<json body>'
```

Example prompt: What's the mean total nitrogen in the top 5 cm of soil at latitude 38.72, longitude -9.14 in Portugal?

## When to prefer this

Use this endpoint when you need topsoil nitrogen data specifically for a point location within Portugal and want automatic boundary validation to avoid out-of-scope queries. Prefer this over generic SoilGrids API access when you need a simple, pay-per-call lookup with built-in geographic filtering for Portuguese territory.

## Known failure modes

- Coordinate outside Portugal boundary — request rejected before payment is processed
- Latitude or longitude outside the published European coverage range (lat 34–72.5, lon -31.5–40.5)
- Invalid or missing coordinate parameters in request body
- Service unavailable or upstream SoilGrids data unreachable

## How this service works

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

## Output

A numeric value representing the mean SoilGrids total nitrogen content (cg/kg or equivalent unit) for the 0-5 cm soil layer at the queried coordinate. Returns an error or rejection if the coordinate falls outside the Natural Earth boundary for Portugal.

## 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-southern-land-portugal-soil-total-nitrogen-0-5-cm-55dfc7d0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from suedland.halowerk.com](https://www.zero.xyz/host/suedland.halowerk.com/llms.txt)