Crop targets and growing advice

1. Open the sensor's settings page. Press “Choose a crop” in the notice on the sensor's page (it is there while no crop is set), press “Settings” at the top of the sensor's page, or use the cog in the location's list of sensors. Opening the settings page explains the ways in.
2. In the “Device Settings” card, find “Crop”, just below “Location”. The line under it reads “Sets the growing targets this soil sensor's readings are judged against.”
3. Open the list and pick the crop, for example Tomato, Cucumber or Strawberry. Crop names follow the language you use CropWatch in.
4. Press “Update Device”. The button stays grey until something on the card has changed.
5. A bar reads “Device settings updated.” Press “Back To Device Detail”; the targets card is now on the sensor's page.

To take the crop off, choose “No crop” at the top of the list and press “Update Device”. The targets card, the target lines and the advice card leave the sensor's page. The readings themselves are not touched.

Changing to a different crop changes the targets card and the chart lines straight away, for past readings as well as new ones. The advice card catches up with the next overnight report.

Choosing the crop counts as editing the sensor, so it needs the same level as renaming it: Owner, Admin or Manager. Everyone who can see the sensor sees its targets and its advice. Disabled people cannot see the sensor at all.

CropWatch sets the targets; you only choose the crop. Each crop's values were gathered from published growing guidance and research, such as Japan's Ministry of Agriculture, Forestry and Fisheries, prefectural agricultural research centres, the FAO and university extension services, and each value is stored with the source it came from. Everyone who picks the same crop gets the same numbers, and there is no screen for changing them.

A crop can have targets for these readings:

• Soil: soil temperature, soil moisture, soil EC and soil pH, each with one target for the whole day.
• Air: air temperature and air humidity, each with a day target and a night target.
• Daytime only: CO₂ and VPD.
• Light: a daily light goal (DLI), and the light level above which more light adds little (light saturation).

Each target is a best range, and some also have stress limits: the levels past which the crop starts to suffer damage. Where the research gave no reliable number, the value is left blank rather than guessed.

• Soil moisture assumes a loam soil. Soils that hold much more water, such as volcanic ash soils, read well above the range even when watering is right. On such a field, treat the soil moisture status as a guide.
• EC often comes from a lab soil test. A lab mixes the soil with five parts water (a 1:5 extract), which gives a different number from a probe in the ground. When the crop only has the lab value, the target shows with “(lab test, 1:5)” after it, and its status is a guide only.
• Targets describe established plants in active growth. Growth stage, variety and rootstock change what is right, so weigh the numbers against your own experience.

Sunrise and sunset come from the latitude and longitude of the location the sensor belongs to. Without them CropWatch falls back to fixed hours, and the line under the targets card's title says so and asks you to set the location's position. With no position:

• Day and night targets switch at 06:00 and 16:00, whatever the season.
• The daily light goal is spread over 06:00 to 16:00 instead of the real day.
• The “DLI Today” card says the day is assumed to end at 16:00 (“day assumed to end”), and pointing at that line explains that the location has no coordinates.
• The daily advice uses fixed sunrise and sunset times too.

Set the position once in the location's settings, as described in Location settings. Every sensor at that location uses it.

The card sits directly under the “Above & below ground” panel and has four columns:

• “Reading”: which reading the row is about.
• “Now”: the newest value, in your units (°F if you chose Fahrenheit).
• “Target”: the crop's best range, for example 20 to 25 %. A target with only one end shows as “≥ 20 %” or “≤ 900 ppm”.
• “Status”: where the reading sits, on the seven-step scale described below.

Rows appear only for readings the sensor sends, in this order: Soil Moisture, Soil Temperature, EC, pH, Air Temperature, Air Humidity, VPD and CO₂. A soil probe on its own shows the soil rows; a soil sensor that also measures the air adds the rest. VPD is worked out from air temperature and humidity.

A dash in the Target column means the crop has no value for that reading. A dash in the Status column means there is nothing to judge against, or the crop only has a limit that the reading has not passed. For example, a crop with only an upper limit for night humidity shows a dash until the humidity goes over the limit, then “Very high”.

A reading outside its target range is graded by how far off it is, measured from the nearest end of the range as a share of that end. With a soil moisture target of 20 to 25 %, 10 % below the low end is 2 points (18 %) and 10 % above the high end is 2.5 points (27.5 %).

On that 20 to 25 % target, 19 % reads “Slightly low”, 17 % “Low” and 14 % “Very low”. On the high side, 27 % reads “Slightly high”, 30 % “High” and 32 % “Very high”. A reading past one of the crop's stress limits is always “Very low” or “Very high”, however close to the range it is.

Light targets appear on soil sensors with a light sensor. They start from the crop's daily light goal in mol/m²/day, its DLI (PPFD and DLI explains the units), and use sunrise and sunset at the location's position.

The PPFD gauge is titled with the crop, for example “Tomato PPFD”. Its target covers the current clock hour only and is labelled “Target” followed by the hour, such as 10:00 to 11:00. CropWatch spreads the daily goal over the day by the sun's height at your location, so a midday hour gets a larger share than the hour after sunrise. The hour's target is its share of the goal, given as the light level the hour needs on average. If the crop's goal has no upper end, the hour's upper end is the crop's light saturation level. At night the label reads “Target (night)” and no band is drawn.

The “DLI Today” card adds up today's light so far and shows:

• The daily goal, as “Target for Tomato:” and the range. While the sun is up, it adds how much light should have fallen by now (“expected by now”).
• At the top right during the day: “Still needed” (light the day still needs), “Room left” (light that still fits inside the goal) or “Over target”, with “Falling short”, “On track”, “Target reached” or “Above target” beside it.
• How much of the day's light is left and the time of sunset, and once 15 % of the day's light has fallen, where today ends at its current pace (“At today's pace”).
• After sunset, a final “Status:” of “Very low”, “Slightly low”, “Low”, “Good”, “High” or “Very high”.
• “Daily history”: one bar for each of the last 7 full days (days without readings are left out).

A soil sensor with a crop gets a daily report in a card titled “Growing advice”, with a light bulb beside the title, just above the “History” table. The line under the title reads “Daily AI report for” and a date: the day the report covers, which is the day before it was written.

The chip at the top right sums up that day:

• “Looking good” (green): everything that could be judged was within or close to its target. The card says no change is needed.
• “Needs attention” (amber): at least one reading was off by more than a small margin, or the sensor's readings looked wrong.
• “Outside safe limits” (red): at least one reading was past one of the crop's stress limits for 60 minutes or more in total.
• “Not enough data” (grey): nothing could be judged, usually because the sensor sent readings for less than three quarters of the day's hours.

The card first appears after the overnight run that follows your choice of crop, so look for it the next morning.

Once a day, shortly after midnight Japan time, CropWatch reports on the previous day, midnight to midnight, for every soil sensor that has a crop. The card always shows the newest report, and a report does not change during the day. Today's conditions appear in tomorrow's report; for right now, read the targets card.

Three things go into a report: this sensor's readings for that day (nothing from other sensors), the crop's targets, and sunrise and sunset at the location's position. For the report, daytime starts one hour after sunrise, because a greenhouse takes about an hour to warm up, and ends at sunset.

A fixed set of rules does the judging and works out every number, verdict and recommended action. The AI only words the “AI summary”, and its wording is checked before it is saved: text that adds a number, leaves out an action, or names a chemical or a dose is thrown out and fixed wording is used instead. The AI is never given your sensor's name, your location's name or your notes, and it runs on CropWatch's own computer, so your readings are not sent to an outside AI service.

Each reading gets one verdict for the day:

• Within target: at least 90 % of the day's readings were inside the range.
• Close to target: off by no more than a small margin, such as 1 °C for temperature or 5 % for humidity.
• Needs attention: further off than that.
• Outside safe limits: past a stress limit for 60 minutes or more in total.
• Not assessed: the readings covered less than 75 % of the day's hours.

Press “Print” at the top right of the card. Your browser's print window opens with just this card: both panels open, the Print button left off, and light colours even if you use CropWatch in dark mode. Long reports run onto extra pages.

To keep a copy as a file, choose Save as PDF in the print window. The file name starts with “Growing advice” and the report's date.

• It does not change anything. No heater, vent, valve or relay is switched by it, and no setting is changed.
• It does not warn you. Nothing is sent by email or notification. For a warning when a reading goes out of range, set up an alert rule.
• It does not name products or doses. For EC and pH it tells you to have the soil tested and talk to your extension adviser before changing fertilizer or adding anything to the soil.
• It does not keep a history in the app. Only the newest report is shown.
• It does not see your field. It knows one sensor's readings at one spot, and nothing about plant health, pests or the work done that day.

• There is no Growing advice card: the sensor needs a crop, and the first report arrives after the next overnight run. If it is still missing a day after you chose the crop, contact support.
• The advice talks about yesterday: each report covers one finished day. The date under the title is that day.
• Soil moisture always reads “Very high”, but the plants look fine: the crop's moisture target assumes a loam soil. Soils that hold more water, such as volcanic ash soils, read above it when watering is right.
• The VPD, PPFD and DLI panels say “Awaiting sensor data”: they need a sensor that measures air and light. On a soil probe without those, they stay that way.
• The line under the targets card mentions 06:00 and 16:00: the location has no position, so sunrise and sunset are assumed. See Location settings.
• Can I change a crop's targets?: no. They are the same for everyone who picks that crop. If a value looks wrong for your area or variety, tell support.
• My crop is not in the list: leave the sensor on “No crop” and tell support which crop you grow. Only CropWatch can add crops to the list.