🌿 Vegetation index (NDVI) chart
If you need to see vegetation index changes on the field, the NDVI chart will be of much help. In the web app, open the 'Weather' tab and select a field. If you haven't already done so, add a crop and planting date to your field. After that, the app will build the vegetation index chart for the selected period.
On this chart, you can see how the NDVI index changed in the field over time. The chart's purple curve shows average NDVI values for a field for different days. The upper and lower borders of the light-purple area indicate the maximum and minimum NDVI values that were registered on the field on a particular day.
If you want to see the field's NDVI map for a particular day, hover the mouse over the purple point that corresponds to the day you want to check. You'll see the 'Show on map' tooltip. Click it, and a new window will open with the field's NDVI map for the day you selected.
What are growing degree-days?
A growing degree-day (GDD) is a measure of heat that a plant accumulates over a certain period of time. It's important to know this data to understand when a plant will enter the next growth stage.
To see the GDD chart, open the 'Weather' tab in the web app and select a field. If you haven't already done so, add a crop and planting date to your field. After that, the app will build the growing degree-day chart for the selected period.
How we calculate growing degree-days
The chart starts from the planting date you specified for the field. If you don't specify the crop and planting date, you'll see the error 'No data available'.
To calculate growing degree-days, we use the following formula:
Add the maximum and minimum temperatures for the day.
Divide the sum by two to get the average temperature.
Subtract the plant's base temperature. The base temperature is the minimum threshold below which plant development stops. Base temperatures may vary for different crops in different countries.
📌 Growth stages and notes about field operations
Growing degree-days make it possible to predict plant growth stages. This info is crucial for planning fieldwork, such as fertilizer and pesticide application and harvesting. Using the GDD chart, you can track when a field enters a new growth stage and add notes about field operations.
You can mark growth stages and add notes in the web app. Open the 'Weather' tab and select a field. Remember to add a crop and planting date to use the feature.
To add notes about field operations or growth stages, hover your mouse over the chart. A green '+' icon will appear on the lower axis. Click it and select either 'Note' or 'Growth stage' depending on the kind of data you want to add. Fill in the data in the window that opens. After you click 'Save', the note about the field operation or growth stage will be added to the chart.
💧 Accumulated precipitation chart
The accumulated precipitation chart makes it possible to measure the moisture in the soil. Use this information to predict yield and calculate fertilizer rates more accurately.
📈 For what period can I build all these kinds of charts?
You can check vegetation index, growing degree-days, and accumulated precipitation charts from 2016 on. To do that, create seasons for the years for which you want to see this data and log crops and planting dates. The charts will be available for each individual season.