What you'd ask before you trusted a zone map.

Agronomists and crop consultants who put their name on a zone map. It's built for someone who has to stand behind the lines in front of a grower.

One honest limit worth knowing: the satellite crop-vigor reading can't tell a crop from weeds. A slough full of cattails or a weedy headland can read as the best ground in the field. The boundary editor lets you cut that ground out before you draw zones. Picking the right seasons and cleaning up the boundary is still your call, and it's the call that matters most.

A membership and a field boundary. No boundary file? Draw one on the map instead. TerraZoner runs in the browser, so there's nothing to install, and the satellite imagery is included — nothing to set up.

Any modern desktop browser — Chrome, Edge, Firefox — on a laptop or desktop. A full-size screen is the comfortable way to work, and large tablets are fine too. A phone is good for opening an exported map in the field, not for building zones.

KML, KMZ, or a zipped shapefile with the .shp, .shx, .dbf and .prj files together — one field per file. Boundaries out of John Deere Operations Center, Climate FieldView, SMS, or Trimble load fine, and a UTM, StatePlane or NAD83 projection converts on load from the .prj.

No file? Draw the boundary on the map. The boundary editor can cut a hole, clip an edge, extend a line, or split a field, and the cleaned-up boundary exports as shapefile, GeoJSON or KML.

A few minutes once the boundary is in. The imagery pulls on its own, then whichever zone method you pick runs. Terrain methods take a little longer, because the elevation has to load first.

Yes — same tool, renamed in early 2026. A PowerZoner login carries over as-is. TerraZoner 3 is the current release, and TerraZoner 2 is still there for members who prefer it; the Members menu opens either one.

The Academy has free video lessons, two manuals cover every screen, and support is answered by a real person.

Composite Zones is the standard route: you pick the seasons, the classification method, and how many zones you want. Use it when a field has fewer than four usable seasons, or when you want a particular method behind the lines. Performance Zones is one click, grades the field on the same scale as every other field, and needs four or more usable seasons.

Terrain refinement builds on either one — it splits a poor zone into wetter and drier ground and shows you the split before anything changes. Landscape Response reads the whole field's position, high ground against low ground against slope, lined up with how each part has performed; it needs elevation loaded but doesn't need Performance Zones run first. A drawer holds two more methods: zones built from an uploaded EC survey, and blending any two layers at a weight you set. The Features page has a table that walks through the choice.

Up to seven, and only as many as the field actually reaches. A uniform field can honestly come back with one or two — that's the tool telling you the field doesn't need zoning. Any map, whatever method built it, can be merged down to the count a grower's controller needs.

Performance Zones grades every field on the same fixed scale. If the field performs alike, it lands almost entirely in one near-average band instead of being split into five, and the result says so in plain words: "Most of this field performs alike. Only small areas stand apart from the field average." It's a straight answer you can hand a grower. Composite Zones has no such check — it draws the count you ask for whether or not the field has the spread to justify it, which is why Performance Zones is the better starting point once a field has four or more usable seasons.

EVI2, by default, in both apps. The classic reading, NDVI, tops out once a crop gets thick, so the best acres in a canola or corn field can all read the same. EVI2 keeps telling those acres apart. NDVI (classic) is still one click away, and a project built on it before reopens exactly as it was.

Sentinel-2, 10 meter pixels, seasons back to 2015, worldwide — open data from the European Space Agency's Copernicus programme. Each season's value is the greenest clear look the satellite got that summer, with cloud, haze and snow screened out first. With ten-plus seasons on file, one odd season can't drag the lines on its own.

Three things. Performance Zones grades on the same fixed scale every time, so a field that performs alike can say so instead of always finding a way to sell you a map. Every line traces back to something you can explain — the years of imagery, the shape of the ground, or this week's scene. And terrain work splits the wet low spot from the dry knoll that a plain imagery map lumps together.

On top of that: one flat membership, no per-acre charge, and exports that open in whatever software the grower already runs.

From the elevation. It models where water collects and drains across the field, including a low spot that sits inside higher ground and gets missed by eye. That work runs on the device you're using — the elevation data never leaves the browser.

No — it's included with every membership. Search satellite scenes for a field by date range and cloud limit, look at either crop-vigor reading, classify a scene into zones, or run a damage estimate. Same login, no second bill. More on the In-Season page.

Tag a clear image from before the event and a clear one from after. Every acre gets a severity call, from total loss down to no apparent loss, plus a "not assessable" class where cloud hid the ground that day. Flood and hail acres count from moderate loss up; drought counts only at severe stress, since it's a stress signal, not confirmed loss.

The PDF report carries the owner, the legal land location, the preparer, a damage map with the estimated acres on the cover, before and after images side by side, and the acres in each severity class.

The acres are an estimate built from satellite imagery. The adjuster makes the call, no insurer is bound by the numbers, and TerraZoner carries no liability if the field count comes back different. Treat it as documentation that supports the conversation, not a replacement for a field inspection.

Not where public LiDAR already covers the field. In the US (USGS 3DEP) or Canada (NRCan HRDEM), it loads on its own. Where it doesn't — or anywhere outside those two countries — upload RTK-quality elevation points as a zipped point shapefile.

Coverage isn't wall to wall, so check the live map on Data & Coverage before you count on it.

Composite Zones and Performance Zones work anywhere there's imagery, elevation or not. For the terrain methods — refinement and Landscape Response — upload RTK-quality points and the same tools run on that data instead.

One flat annual price per plan, with the full feature set on every plan — no per-acre fees, nothing held back for a higher tier. The plans differ only by seats: Individual is one account; Team, Corporate and Enterprise add seats for firms where each agronomist carries their own clients. The numbers are on the Pricing page.

GIS4AG is a Canadian company, so the price is set in Canadian dollars. What that comes to in US dollars moves with the day's exchange rate.

No. Run as many fields and seasons as the work calls for — no per-acre charge, no usage tier. An Individual membership is meant for one lead operator and the support staff working the same client files; agronomists who each carry their own clients need a seat each, which is what the Team, Corporate and Enterprise plans are for. We only step in if an account is plainly being shared beyond that, automated, or resold.

There's no trial.

If TerraZoner doesn't deliver and we can't make it right, full refund within 30 days.

If the terrain methods are the reason you're buying, check the coverage map before you sign up.

The membership renews annually. Cancel any time before the renewal date from the My Account page.

A two-page PDF report, a KML for Google Earth with every zone in its map colour and its name, acres and average on click, shapefile (.shp/.shx/.dbf/.prj), GeoTIFF, and a KMZ picture of the map. Prescriptions cover up to six products, with acres shown beside each rate. Soil sampling points export as KML. A full project backup saves and reopens the whole field.

All of it opens in John Deere Operations Center, Climate FieldView, Trimble, SMS, QGIS, ArcGIS — anything that reads a shapefile. There's no viewer app; the exports travel on their own.

Boundaries, projects and zone maps stay in the browser and in the files exported from it. Terrain work runs on the device too — elevation never leaves it. The only things fetched remotely are public lookups made on your behalf: satellite imagery, rainfall, public soil and crop data, and the elevation tiles.

Fetched imagery is cached in the browser for speed. Nothing sits on a TerraZoner server.

The operator does. Full commercial rights to use, distribute or sell the zones, maps, prescriptions and reports, on any basis.

Keep the imagery credit when sharing or selling outputs. TerraZoner credits Copernicus with the imagery years and adds Planet Insights Platform for imagery processed through Planet. Copy the applicable credit from the app or PDF report.

Through Stripe. Card details go to Stripe, never to us.

Name, email, and login. Passwords are encrypted. No card numbers, no field data, no zone outputs.

No. The only outside service that sees anything is Stripe, and only for payment.