Calculation of the Normalized Difference Vegetation Index (NDVI), which is available on-the-fly, comes first. In addition, NDVI is often used around the world to monitor drought, forecast agricultural production, assist in forecasting fire zones and desert offensive maps. Farming apps, like Crop Monitoring, integrate NDVI to facilitate crop scouting and give precision to fertilizer application and irrigation, among other field treatment activities, at specific growth stages. NDVI is preferable for global vegetation monitoring since it helps to compensate for changes in lighting conditions, surface slope, exposure, and other external factors.
NDVI is calculated in accordance with the formula:
NIR - reflection in the near-infrared spectrum
RED - reflection in the red range of the spectrum
According to this formula, the density of vegetation (NDVI) at a certain point of the image is equal to the difference in the intensities of reflected light in the red and infrared range divided by the sum of these intensities.
This index defines values from -1.0 to 1.0, basically representing greens, where negative values are mainly formed from clouds, water and snow, and values close to zero are primarily formed from rocks and bare soil. Very small values (0.1 or less) of the NDVI function correspond to empty areas of rocks, sand or snow. Moderate values (from 0.2 to 0.3) represent shrubs and meadows, while large values (from 0.6 to 0.8) indicate temperate and tropical forests. Crop Monitoring successfully utilizes this scale to show farmers which parts of their fields have dense, moderate, or sparse vegetation at any given moment.
Put simply, NDVI is a measure of the state of plant health based on how the plant reflects light at certain frequencies (some waves are absorbed and others are reflected).
Chlorophyll (a health indicator) strongly absorbs visible light, and the cellular structure of the leaves strongly reflect near-infrared light. When the plant becomes dehydrated, sick, afflicted with disease, etc., the spongy layer deteriorates, and the plant absorbs more of the near-infrared light, rather than reflecting it. Thus, observing how NIR changes compared to red light provides an accurate indication of the presence of chlorophyll, which correlates with plant health.
Crop Monitoring is a perfect tool for tracking the health of the crops in the field with the help of the NDVI measured on-the-fly. All you need to do is add your fields to the system, customize the NDVI settings and start receiving the notifications.
Crop Monitoring tracks changes in the NDVI for individual fields throughout the season. This enables you to refer to the historical field’s productivity for up to 5 past years. You can monitor both the crop rotation patterns and the current vegetation rates. With the help of the user-friendly charts, the app visualizes different types of data, including the vegetation indices, temperature, precipitation rate, growth stages, historical weather, among others. Another important feature, based on calculating the NDVI rates, zoning allows you to identify high productivity zones, as well as discover the weak points in the field that require special treatment. Each zone, at every growth stage, needs a different amount of fertilizer and irrigation treatment (the latter is also decided based on the precipitation rates), both of which can be manually adjusted in the app to a great degree of accuracy. Precision agriculture, based on NDVI, doesn’t end there, however! Crop Monitoring updates scouting by using NDVI to find problem areas in the field and sending scouts directly to the exact location, thus saving time and resources. Users also get notified every time an abnormal change of the NDVI value has been detected, allowing farmers, traders, and insurers to make well-informed agricultural decisions in a timely manner.
Torrington, WY, USA / no NDVI 42.0140° N 104.2435° W
Torrington, WY, USA / with NDVI 42.0140° N 104.2435° W
Entre Rios, Argentina / no NDVI 32.0082° S 60.2895° W
Entre Rios, Argentina / with NDVI 32.0082° S 60.2895° W