# HALOWERK Baltic Land – Poland Soil Nitrogen (0-5 cm)

> HALOWERK Baltic Land – Poland Soil Nitrogen (0-5 cm) is a paid API for AI agents from baltikum.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 topsoil layer at a given WGS84 coordinate within Poland.

## Facts

- Endpoint: POST https://baltikum.halowerk.com/v1/pl-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-baltic-land-poland-soil-nitrogen-0-5-cm-79ea8edd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NsrmHvB-mFA190Yfw-_Wl

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-baltic-land-poland-soil-nitrogen-0-5-cm-79ea8edd -d '<json body>'
```

Example prompt: What's the mean total nitrogen in the top 5 cm of soil at latitude 52.23, longitude 21.01 in Poland?

## When to prefer this

Choose this endpoint when you need point-level SoilGrids total nitrogen data specifically for locations within Poland and want coordinate boundary validation built in before payment. It is ideal for agricultural analysis, environmental monitoring, or land-use planning workflows focused on Poland. Prefer this over generic SoilGrids API calls if you want pay-per-query pricing with automatic Poland-boundary enforcement and consistent topsoil (0-5 cm) depth standardization.

## Known failure modes

- Coordinate outside Poland boundary — request rejected before payment, error indicating invalid location
- Latitude or longitude out of the European coverage range (lat 34–72.5, lon -31.5–40.5) — validation error
- Missing required latitude or longitude — schema validation failure
- SoilGrids data unavailable for remote or edge-boundary locations — null or error response
- Network timeout or service unavailability — HTTP 5xx 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 Poland; results outside it are rejected before payment.

## Output

A numeric value representing the mean SoilGrids total nitrogen content (in g/kg or cg/kg) for the 0-5 cm topsoil layer at the queried coordinate. The response is only returned for coordinates that pass validation against the Natural Earth boundary of Poland; out-of-boundary coordinates are rejected before any charge is applied.

## 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-baltic-land-poland-soil-nitrogen-0-5-cm-79ea8edd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from baltikum.halowerk.com](https://www.zero.xyz/host/baltikum.halowerk.com/llms.txt)