MobiLab gives three-hour result in the field

Waiting three or four days for laboratory soil results can rain on your parade if you were hoping to get out in the field to apply some nutrients before the next rainfall.

Quick-answer, in-field soil labs are one answer to this dilemma.

There are dozens of these test kits available with varying levels of accuracy and response time. Some measure only nitrogen, while other are capable of analyzing a whole range of elements.

Whatever the time lapse or range of measured elements, farmers seem to be in agreement that a mobile in-field lab is more useful than having to wait days for conventional lab results.

One of these kits is produced by Metos Pessl.

Guy Ash, agro-meteorologist for Metos Pessl says the Pessl MobiLab allows farmers to take a soil sample and process it on the spot. Three hours later, the farmer has enough information on soil-bound nutrients to make crop management decisions.

“It’s a whole set of tools, not just a device to measure a single nutrient,” says Ash.

The Metos MobiLab is almost a complete soil test lab:

• Measures nitrate, ammonia, sodium and chlorine.
• From plant sap, it measures potassium, sulfate, calcium, and magnesium.
• Future functions include copper, iron, zinc, aluminum and boron.

The Metos website says MobiLab is based on capillary electrophoresis. It yields quick results of soil NO3 and NH4. It also analyzes nutrients from plant sap and other sources. The data can be logged to GPS co-ordinates.

The system integrates soil nutrient analyses into a single microfluidic chip. After the soil samples are extracted, the sample preparation can be carried out in the field.

Scientists know that significant nutrients are charged molecules, and therefore react to the electrical field. Using this knowledge, they developed a device that injects the filtered sample into a microfluidic capillary with a strong electric field. The nutrients are separated in the chip according to their chemical nature and measured by a detector at the end of the capillary.

The technology can be operated by people without prior laboratory training.

The measured data is referenced to GPS co-ordinates using a mobile app, and is sent via telecommunication to FieldClimate, where it is safely stored for the user. The data is easily converted into machine-readable formats, allowing site-specific variable rate application with any precision farm machinery.

MobiLab carries a list price of $4,995