If you didn’t collect your soil samples last fall, which is the best time to do this, it is time to start thinking about doing so.

First, resist the urge to put off soil testing this year because of the difficult economic times we are experiencing. Soil testing is always important, but even more so under current conditions.

You cannot afford to have your crop come up short because of lack of nutrients after you have made a significant investment in the many inputs required to put out the crop.

At the same time you cannot afford to apply extra nutrients that will not give you an economic return.

The economics of soil testing are pretty simple. If you sample a 10 acre field every 3 years as recommended, the cost per acre is around $0.30 per acre per year. This very small investment in soil testing results in recommendations that are used to manage typically $100–$200 worth of nutrients on a crop that is probably worth $600–$800 per acre.

You can't risk this magnitude of input costs and potential returns on a guess. So when times get tight we should do more soil testing, not less.

Good soil test begin with good soil samples. Here are some guidelines for getting good soil samples.

Sample Uniform Areas

Usually we sample each field individually. However, there may be times when we need to subdivide fields if there is the potential for significant differences across the field.

Examples include: significant soil differences, part of the field receives manure but not the whole field, topographic differences such as low areas versus sidehills, etc.

Also, there are situations when we can combine fields. For example when we have small strips that are all managed the same we can lump these together into one sample.

Take lots of cores

At least 15 to 20 cores should be collected to make up a composite sample to send to the lab. More is better.