Sensing your soil's potential

Wednesday, August 15, 2018

Image detection systems could enable producers to reduce chemical usage by up to 90 per cent

By: Kate Ayers
Staff Writer
Better Farming

Producers could use sensor-based precision herbicide applications as another tool to fight hard-to-control weeds in their fields.

Such systems recognize "objects within a digital image and differentiate the crop plants from the weeds based on (parameters) of the object in the image" like size and location, said Mark Siemens, an associate professor in the department of agricultural and biosystems engineering at the University of Arizona.

In terms of location, for example, "all of the crop plants should be in the crop row and anything outside that row would be a weed."

    Blue River Technology photo

John Deere's See & Spray technology, developed by Blue River Technology, is one such tool.

This system identifies and sprays individual plants in milliseconds.

Each row has its own intelligence – equipped with cameras, sensors and nozzles – and uses "computer vision" to see every plant, Danny Jefferies, an integrated solutions data and agronomy support consultant with Huron Tractor, said to Better Farming.

This tech overcomes one of the early obstacles of weed detection technology: the "identification of crop plants versus weed plants … because they are both green," said Siemens.

Rather, the See & Spray system uses libraries of plant images to distinguish subtle differences between crops and weeds.

The machine gathers data on thousands of plants as it moves through the field and is always learning in the process, Jefferies said.

In addition, the See & Spray technology is equipped with a second set of cameras, allowing the machine to double check its work as it operates.

Another interesting feature of this system is that producers can set a safe zone around plants, enabling growers to choose how close the spray gets to the crop.

This machine improves the efficacy of weed control in the field.

"Because we are not applying (herbicide) to the crop, we can implement additional chemistries that could not be previously used," offering farmers increased options to fight resistant weeds, said Jefferies. For example, farmers will not be limited to only using glyphosate on glyphosate-resistant crops for weed control.

Since the robotic nozzles do not spray unless weeds are detected, growers can avoid excess chemical usage and reduce the volume of a typical broadcast application by up to 90 per cent, he said. Growers still achieve similar results to those from conventional sprayers, he added.

The See & Spray technology develops a map of the field showing plant stand, areas of highest weed pressure and weed species present to enable farmers to better manage the field in the future, Jefferies said.

The machine is "basically an inkjet printer, (with the) ability to put grass herbicides only on grasses, broadleaf herbicides only on broadleaf weeds, and mixes of chemistries on resistant weeds," Jefferies added.

This technology is currently only available for use in cotton and lettuce crops. However, Blue River aims to release a product for all row crops in 2019 or 2020, its website said.

In addition to weed control, the company wants to apply similar technology to the precise application of fertilizer, fungicide and growth regulator in the longer term, Jefferies said. BF