Optimizing yields and minimizing environmental impact through precise resource management is the promise of precision agriculture. Among the tools of this cutting-edge agriculture, you have probably heard of modulation rate maps or intra-field modulation.

Modulation aims to optimize the use of resources by maximizing crops potential. This approach, which is part of precision agriculture, is also an effective way to secure inputs and control operating costs.

Adjusting agricultural input applications

Even the same field can present differences, such as soil composition, topography, biotic or abiotic stress experienced by crops. Therefore, resources need can vary from one area to another. Modulation consists of adjusting amount of resources (fertilizer, pesticides, irrigation water, etc.) according to these needs. Farmer increases dose in areas where needs are high and reduces it when needs are lower. Modulation relies on the use of field data and precision technologies.

How does a modulation rate map work?

A modulation map is a cartographic representation of intra-field resources needs. This map is mainly based on field data.

To generate an intra-field modulation map, data must first be collected. Several techniques exist, including drone. As the drone flies over the field, it takes photos that are then analyzed by image processing software to generate modulation maps. These maps can also be created from satellite data using NDVI (Normalized difference vegetative index). This is one of the indices used by SKYFLD®. Another possibility is to use georeferenced soil analyses, collecting representative samples in different areas. Combine harvesters equipped with sensors can also be used to create yield maps.  

For example, with SKYFLD® you can generate a map based on NDVI with a single click. However, you can also choose to combine multiple types of maps (yield, soil, NDVI).

What can be modulated in precision farming?

Modulation in agriculture can be applied to:

• fertilizers, a single field often has a heterogeneous distribution of its nutrients. Nitrogen fertilization reflects vegetative state of the crop. One of the most used data is the vegetation index, or NDVI. Using onboard sensors, satellites measure plant covers reflectance at regular intervals.
• seeds, to obtain a uniform emergence. Modulation is based on yield maps, soil analysis, and vegetation index map.
• growth regulators (PGRs). By combining satellite images (NDVI measurement) with soil and/or yield data, it is possible to visualize intra-field heterogeneity. This allows farmers to adjust their resources.
• pesticides, by using pests or diseases data.
• Water irrigation, especially in dry areas.

Modulate resources with GPS...but not only!

Once modulation map is exported from the web platform, it is transmitted to the tractor terminal via a USB key or a cloud. To modulate your resources, you obviously need an equipment able to manage that. Your machine must be able to determine its position in real time and transcript properly provided data (fertilization, sowing, growth regulators, etc.). Please note that your implement must be able to process georeferenced information.

Manual modulation is less simple, but possible.

Machine (spreader, sprayer, etc.) used to modulate resources, must be adapted, or equipped accordingly. In some cases, purchasing a license and terminal unlocking options may be necessary to manage these maps.