Guidelines provided to get good soil samples
Producers contacting the FSA office recently have been concerned about input costs for 2016.
In particular, fertilizer costs have producers concerned. Although fertilizer prices are lower than last year, producers will need to be careful as commodity prices could make it difficult to make a profit.
Because fertilizer is a major component of crop production, every effort should be made to only apply what nutrients are actually needed.
There has never been a better time to take soil tests. Soil conditions in the fall are ideal for taking samples.
Soil sample results will be back in time to enable farmers to plan fertilizer purchases needed for crop production in 2016. A complete soil test report shows the amount of lime, fertilizer and magnesium that is needed to produce the intended crop.
Guessing on the amount of lime and which fertilizer to use can increase the cost of planting and reduce production at the same time.
Penn State complete soil test kits cost $9 each and are available at the county FSA and Extension Service offices.
Remember, the results are only as good as the sample you send to the lab.
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 and topographic differences.
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.
Sample to uniform depth
Most routine soil testing samples should be collected to plow depth, even in no-till or permanent sods. Inconsistent sampling depth is one of the biggest sources of errors. This is especially true in no-till and reduced tillage systems where there is often significant stratification of nutrients in the soil.
Special note in no-till: In no-till fields an acid layer, called an acid roof, can develop right at the surface of the soil. This thin acid layer can have a significant impact on the crop but it can be missed in a normal plow depth sample.
If the normal plow depth soil sample in no-till recommends liming, apply the lime as recommended and no further testing is needed.
If the normal sample does not recommend lime and the field has been in long-term no-till and has not been limed recently, take a two in deep sample and test it for pH.
This sample can be submitted to a soil testing lab or you can use a field pH test kit for this purpose. If this sample has a pH less than 6.2, apply one ton of limestone even if the regular sample did not call for any limestone.
Avoid atypical areas or sample them separately
Sample between the rows and avoid any fertilizer bands as much as possible. Also, many fields have known atypical areas such as dead furrows, old fence rows, lime or manure stacking areas, wet spots, etc.
If the areas are too small to manage separately, do not sample them. Taking one or two cores from these odd areas just contaminates the sample for the rest of the field.
If the areas are large enough that you are able and willing to manage them separately, then take a separate sample from these areas.
Handle sample carefully
Collect the soil cores in a clean bucket so as not to contaminate it, crumble the sample cores and air dry the sample. Mix the cores thoroughly and take a subsample to fill the mailer to send to the lab.
Fill out the soil test information sheet
Additional information such as the crop, the expected yield, the crop rotation, tillage depth, etc. are used along with the soil test results to make the recommendation.
Thus, it is critical the soil test information sheet be filled out completely and accurately.
Luke Fritz is executive director of the Butler County Farm Service Agency.
