Eureka!

Mapping Dirt

A soil-typing device invented by a UB professor could help farmers increase yields and decrease pollution

a plowed field with fresh sprouted vegetables

By Grove Potter

A farm field can have a variety of soil types. Some soils, for example, hold water longer than others, which affects how much and how frequently they should be irrigated and fertilized.

A detailed map of those differences can thus be a huge help to a farmer. But mapping soil types has traditionally been a laborious, time-consuming process. Boring test holes, again and again, up and down an entire field. ... It can take days.

So Erasmus Oware, assistant professor in the Department of Geology, used some technology to come up with a better way. His device, a roughly 3-foot-long probe weighing just under 9 pounds, emits an electric wave into the ground to measure the soil’s electrical conductivity; an embedded GPS then logs the precise location. Because different soil types have different conductivity, the result is a precise map of the boundaries between the various soil types.

With the boundaries demarcated, a farmer can then test a spot in each soil area the old-fashioned way, by boring and measuring the water-holding capacity. Using this process, it takes about 20 minutes to map one acre, an area that would take about 20 hours using conventional methods.

“It’s faster, and you get a higher-resolution soil map,” says Oware. “We are collecting a lot of data points, many more than with traditional soil sampling.” It’s also convenient. The apparatus is snugged into a car-rooftop carrier that is dragged behind an ATV, back and forth over every square yard of the field.

Erasmus Oware in his lab, showing the soil-zapping device he created.

Erasmus Oware in his lab, showing the soil-zapping device he created. Photo: Douglas Levere

The map results generally are not a surprise to the farmers, Oware says; they know from experience which areas of their fields produce differently. But the detailed maps give them much more accuracy—a major plus not just for farmers but for the planet as well.

“If you over-irrigate a farm, the water will either create runoff and wash the fertilizer into nearby surface water bodies, or it will induce drainage whereby the fertilizer drains beyond the root zone and will contaminate groundwater resources,” says Oware. “On the other hand, under-irrigation will create water stress of the plant, affecting plant quality and yield.” Getting a precise handle on irrigation, he continues, saves water, reduces the amount of fertilizer used and saves energy.

Created in collaboration with Darcy Telenko of the Cornell Cooperative Extension, the invention won an $84,840 grant from the New York Farm Viability Institute, which was augmented with support from UB’s College of Arts and Sciences. The money was used to purchase equipment and help pay for UB students to do fieldwork on three Western New York farms during the summer.

Next up for Oware: refining the device and seeking a patent, and devising a valve system to make it easier for farmers to vary the amount of water sent to different parts of the terrain. In the meantime, he and his students will be back in the fields in April, just before planting season.