Precision farming service puts ‘boots on the ground’

A new service aims to make the benefits of precision farming readily accessible without growers having to master all its complexities.

FieldSense uses satellite mapping of soil and crop variability across fields, says ProCam regional technical manager, Nigel Scott, who has been integral in developing and testing the new service.

This is then used to derive variable rate input applications tailored to these variations, rather than relying on a blanket approach. The goal is to improve economic crop output across the field and bringing environmental gains.

Accessed via a web browser, the FieldSense system is based on a collaborative approach between the agronomist and grower – rather than farmers having to do everything themselves, says Mr Scott.

Working together

“It will be the ProCam agronomist who makes sense of the satellite images, drawing on their boots on the ground experience of the field and ground-truthing any anomalies that the images might reveal.”

This can be combined with the farmer’s own knowledge of the field as necessary. Growers can also pick only those parts of the package relevant to their farm and machinery – or begin by trying the system over a small area.

“Once maps have been interpreted, the agronomist will produce variable rate files for downloading directly to the tractor that is controlling the drill or fertiliser applicator. It is precision agronomy through partnership.”

The first phase of the launch is focusing on four key areas for combinable cropping: grid-based soil sampling; variable rate seeding; variable rate nitrogen (N), phosphate (P), potash (K) and lime applications; and yield mapping input.

Mapping

Fields are mapped into various sized grids – one hectare squares for soil sampling, 24m grids for variable rate fertiliser spreading, and 6m grids for variable rate drilling, or the most appropriate grid size for the width of machine.

“The variable rate drilling package in FieldSense uses historical NDVI satellite maps that are available that show the variations in crop biomass that have occurred in that field over multiple years,” , says ProCam regional technical manager Harry James.

“From these, the agronomist will create a variable seed rate plan – to drill more seed in historically lower biomass grid squares and less seed where less is needed – with the aim of achieving a uniform, optimum tiller density over the field.

“In one test, we’ve found that almost double the seed rate was needed in poorer areas of a field to bring tiller numbers back up towards the better areas. Without this knowledge, poorer areas would have been drilled at sub-optimal density, risking sub-optimal yield.”

Crop nutrition

For soil sampling, the location of samples in each hectare is recorded by GPS and shared back to the FieldSense platform. Maps are then used to create variable rate spreading files to correct nutrient deficiencies, and for liming if required.

Variable rate nitrogen application, on the other hand, uses satellite measurements to create a normalised difference vegetation index of the growing crop. Nitrogen is then applied accordingly.

These are taken every 5-7 days on a 10m x 10m grid or every 3-5 days on a 3m x 3m grid. The aim is to use variable rate nitrogen to produce the optimum green area index (GAI) over the whole field.

Farm-testing in oilseed rape where GAI in March was found to vary from a near optimum of 3.0 to just 1.0, showed that by varying N dose between 60 to 90 kg/ha, crop uniformity was corrected by early June.

In fields where yield mapping is carried out on the combine harvester, yield data can also be uploaded into FieldSense to guide future agronomic decisions.