Remote sensing creates maps of fields to guide P.E.I. farmers

UPEI researchers are using remote sensing tools, including electroconductivity detection, to create specialized maps for farmers to help them better understand their fields and manage them more effectively.

'It's about hopefully saving some money as well as maximizing the yield potential of that field'

Hassan Afzaal measures the the soil electroconductivity in a field in Central Bedeque, P.E.I. The device sends electromagnetic signals into the soil that are then recorded on the logger. (Kirk Pennell/CBC)

UPEI researchers are using remote sensing tools to scan Island fields, and create specialized maps to help farmers manage their crops more effectively. 

"It maps the soil through a combination of the electroconductivity, as well as other remote sensing methods," said Ryan Barrett, research and agronomy specialist with the P.E.I. Potato Board, a partner in the research. 

"Even the slope, the elevation of the land, and puts that all together to then create a map of different zones."

The maps show stronger sections of the fields, as well as weaker ones that may need more fertilizer or lime, or have compacted soil that is limiting root growth. (Evan MacDonald/SWAT Maps)

"The green zones could be the wetter parts of the field, or maybe the heavier soil. The red parts could be the tops of the hills, the knolls, the parts that may be a little sandy." 

"It's really trying to show that we can have a lot of variation, even within one small field."

Make better decisions

Barrett said the information from the maps then allows farmers to make better decisions. 

"The reason to do this mapping is then we can manage that field in a site-specific way," Barrett said.

"Rather than the same fertilizer rate over the whole field, or the same tillage over the whole field, or the same seed spacing over the whole field, we can manage that variably within the field." 

Ryan Barrett of the PEI Potato Board Barrett says the information from the maps allows farmers to make better decisions. (Kirk Pennell/CBC)

The project is also looking at whether potatoes should be planted farther apart in the poorer sections, or closer together in the better parts of the field.

"Normally you would space potatoes at 15 inches between plants, but in the green areas of a field, you may say, OK that's the best area of the field, we can put more plants in that area," Barrett said. 

"We can tighten that spacing up, and maybe we could go to 13 inches."

The scans can also highlight better parts of the field, where potatoes can be planted closer together, making the most of the soil's potential. (Kirk Pennell/CBC)

"The red areas, with sandier soil, or it doesn't have as many nutrients, we need to space those out a little bit, and give those plants a little bit more room to grow, a little bit more access to nutrients," Barrett said. 

"The goal is that we would increase the productivity of the whole field by doing this sort of site-specific management."

Barrett said the maps can also guide decisions on other applications such as lime, or manure. 

"It's about hopefully saving some money, as well as maximizing the yield potential of that field." 

'Huge potential'

Barrett said the researchers are also using the remote sensing tools to look at soil compaction.

"Soil compaction is a challenge in almost all agricultural systems where traffic on the soil, and tillage, can over time cause the layers of the soil to become a little bit more compacted," Barrett said.

"So we're trying to detect whether a field is compacted, and then also the depth of that compaction."

Researchers are also doing work on soil compaction, using a tool to break up the subsoil in this strip of field, to see what impact that has on yield the following year. (Kirk Pennell/CBC)

 Hassan Afzaal started working on the project in 2017 as a graduate student. 

He now works as a research assistant in the Precision Agriculture Lab in UPEI's School of Sustainable Design Engineering, headed by Dr. Aitazaz Farooque.

Afzaal looks at the data being collected by the electroconductivity detector in a field in Central Bedeque. It is measuring soil texture differences and moisture differences, and compaction. (Kirk Pennell/CBC)

"We started this project to establish some basic theories regarding soil electroconductivity, and different soil variables such as soil moisture, soil nutrients and soil micro-nutrients," Afzaal said.

"We found that the soil electroconductivity has a huge potential in determining different soil characteristics."

Environmental benefits as well as savings

Evan MacDonald works as a precision agronomist with a company based in Saskatchewan that produces soil, water and topography maps.

He is also doing a PhD at UPEI looking at variable rate spacing of potatoes.

"Last year, we found that the cost to do this type of an analysis on the fields, the soil sampling and the conductivity scans, were more than paid for by the little bump in yield that a farmer might get," MacDonald said. "Whether that's additional production, or reducing inputs a little bit."

The researchers also use a drone to assess how the crop is doing. (Kirk Pennell/CBC)

"There might be actually parts of a field that may need a little bit more fertilizer, if they're a better producing area. But on some of these weaker parts of fields, we can actually afford to back off a little bit," MacDonald said.

"In a lot of cases, you can reduce your nutrient inputs 10, 20 30 percent without a significant hit on yield."

MacDonald said the remote sensing tools and maps also offer other benefits.

The researchers say their work is showing that soil electroconductivity has a huge potential in determining different soil characteristics. (Kirk Pennell/CBC)

"The side benefit of of precision agriculture, outside of just profitability for the farmer, is the environmental impacts," MacDonald said. "If we can reduce the amount of nutrients going on that aren't being taken up by the crop, that's a big environmental benefit."

MacDonald said there has already been a big uptake in the technology, with more than 6,000 hectares, or 15,000 acres, around P.E.I., that have already been mapped.


Nancy Russell has been a reporter with CBC since 1987, in Whitehorse, Winnipeg, Toronto and Charlottetown. When not on the job, she spends her time on the water or in the gym rowing, or walking her dog.