Soil sampling gets on-the-go

By Larry Dreiling

In the last 20 years, as precision farming techniques have moved from gee-whiz stuff to everyday use, many different concepts for creating variable-rate prescriptions for crop inputs like seed and fertilizer have been developed.

Originally, the use of yield monitors coupled to Global Positioning System satellites was the big thing in creating yield maps for proper subsequent management decisions.

It led to higher use of soil sampling, and farmers and crop consultants patrolled fields in four-wheelers tied to GPS units to capture samples at just the right spot to determine everything from soil pH to nitrogen uptake. Since then, satellite-based auto-guidance and steering systems have been introduced.

Studies have shown that use of yield map and soil survey information has its limitations, since yield data are not always readily available to growers and soil properties are often not well defined near survey boundaries.

That's why scientists and equipment manufacturers are trying to modify existing laboratory methods or develop indirect measurement techniques that could allow on-the-go soil mapping. To date, only a few types of sensors have been investigated, including those using electromagnetic, optical, mechanical, electrochemical, airflow and acoustic.

NEWS

CROPS

LIVESTOCK

EDITOR

COLUMNS

MARKETS

RANGE

FAMILY