Remote sensing for agricultural production areas

Monitoring agricultural production areas using remote sensing resources has proven to be an effective tool for monitoring production and planning management activities. With technology capable of analyzing images received by satellite, it is possible to obtain rapid monitoring.

The study is possible because the NIR (Near Infrared) radiation band is very precise in capturing the vigor of plants, differentiating between vigorous plants (which reflect more NIR) and weaker plants (which absorb radiation). Therefore, NIR images obtained by state-of-the-art satellites are treated by an equation called NDVI (Normalized Difference Vegetation Index), which transforms the different NIR readings into color tones, having a high correlation with the leaf area index (LAI). ) and plant vigor.

In the end, maps are created that describe the distribution of plant vigor in the field, which allow “in season” monitoring of the evolution of agricultural production fields, in order to identify areas that deserve more attention.

Among the benefits, we can mention the rapid detection of failures in irrigation or in mechanized operations, such as fertilization, soil preparation or phytotoxicity due to agrochemicals; patches of soil with low productivity, areas with laminar erosion, limestone deposits; identification of low-vigor reboles caused by nematodes or soil-borne pathogens; areas with lower than expected vigor, possible deficiencies in irrigation equipment, regions with greater production potential, among others.

In the image below, shades of red and yellow can be seen on a part of the edge of the pivot, in this case it is the highest area of ​​the land and pressure was identified below the minimum required at the tip of the equipment, which causes non-uniformity and application of water below what is necessary For plants, the area affected by this equipment was 2,1ha.

Example 1 – Seed corn 60 days after planting, image obtained on 25-05-15. Source: Geosys

In the sequence below, you can clearly see the Irriger/Farmers Edge mark left by the position of the old pivots where the soil was already corrected and less vigorous plants that were inserted into the pivot. It should be noted that many of these differences are not noticeable to the naked eye and cause differences in productivity.

Example 2 – Response in plant vigor with changing pivot positions, image obtained on 04/07/15. Source: Irriger/Farmers Edge partnership

Below you can see an area of ​​low vigor in the ring-shaped pivot that is attributed to a clogged emitter or mounted with inadequate flow. This diagnosis can be made before visible symptoms are presented in the field, as the image with NDVI treatment is very accurate to detect differences in the vegetative vigor of plants.

Example 3 – Ring formed by a clogged or inadequate emitter, image obtained on 03/08/15. Source: Irriger/Farmers Edge partnership