VIDEO: University team collects crop research, field data using flux towers

A “weather station on steroids” is how Henrique Carvalho describes the flux towers he and his research team have positioned in six fields across Manitoba.

Carvalho, assistant professor in the University of Manitoba’s department of soil science, wants the data they provide to help growers better manage their fields.

The technique Carvalho and his team use to do that is called “eddy covariance,” which measures H2O and CO2 concentrations alongside fluctuations in vertical wind speed, measurements that can be taken at a frequency of at least 10 times per second.

Essentially, sensors in the towers measure how plants respond to their environment and vice versa.

The goal is to build a long-term dataset to help predict how crops may perform under certain growing conditions — for example, water use efficiency and how drought can affect photosynthesis and ultimately, yields.

The type of information growers entering a dry year could use to better manage their fields and conserve water for crops.

Macro vs. micro

The flux towers constantly capture data – day and night, 365 days a year – even in the bitter cold of winter.

When spring rolls in, work kicks into high gear.

Of particular focus for Carvalho and his students’ work in micrometeorology is measuring what’s happening on the ground.

Each crop creates its own microclimate, and as plants take up water and carbon dioxide to grow, what’s happening on the ground becomes increasingly important to measure.

Two instruments in particular atop the flux tower are at the core of collecting that data: a sonic anemometer that measures wind speed and velocity and an infrared gas analyzer that measures carbon dioxide and water vapour.

The way crops interact with the atmosphere to take up carbon through photosynthesis and use water through evapotranspiration (how water moves from ground into the atmosphere) is very unique to each crop.

What’s happening at the macro-meteorological scale — the general climate — impacts what’s happening on the ground level.

However, Carvalho said that while we’re all subject to regional climates, responses are local.

“That is essentially the reason why we make those measurements in different fields … because each field is going to respond to those macro changes differently,” said Carvalho.

For example, a warming climate could lead to longer growing seasons and a longer frost-free period.

This could change the biological activity of a plant for photosynthesis and evapotranspiration.

He said it’s no guarantee that crops will have the ability to take advantage of a longer growing season or have available water.

“This is just one example … but there are many others of how the macro influences the local scale,” said Carvalho.

He hopes that the datasets he’s collecting now can be used to help develop new plant growth and yield models in the future.

“This kind of information is what is used to essentially ground-truth calibrate those kinds of models,” said Carvalho.

The project, funded by the Natural Sciences and Engineering Research Council of Canada via the LEAP program, has collecrted about a year’s worth of data. The project is funded at least until 2028.

Carvalho’s goal is to continue collecting these measurements for as long as possible.

He used an analogy of buying a new car to describe the merits of gathering long-term, in-field datasets these flux towers can provide.

“The moment you take your car out of the dealer, it loses value” said Carvalho.

“I know this increases in value.“