MONROE — For those thinking about doing soil sampling on their farm, now is the time to get it done. 

Soil testing can be a smart investment in the fall that could help save time and money in the spring. A large amount of information can be learned in just a few hours of taking soil samples around a farm. The results will reveal how many nutrients are left in the ground from the previous crop.

The Green County Land and Water Conservation Department has soil probes that can be borrowed and bags that can be used to take soil samples. Samples are sent to the lab to be analyzed and results are typically returned within a week.

Soil testing can help to make sure that farmers are getting the most bang for their buck when it comes to fertilizer. It can help to improve yields and profitability, increases consistency of nutrient availability across the field, which is important for a more uniform crop growth and maturity that helps with drying time and improves market quality. Soil testing can also allow for fine-tuning of which nutrients are most needed, helping allocate fertilizer dollars to those nutrients that will give the greatest profit increase.

Efficient use of fertilizers means there is less leaching or runoff of nutrients into groundwater and streams, which could be a boon for the local environment. A healthier crop has more residue which can protect and hold the soil in place after harvest. 

Soil sampling can be done by the farmer themself and is simple to do. Farmers will need a farm map, soil probe, a small bucket or box, and soil sample bags. One sample can cover about 5 acres of a uniform field. If the field isn’t uniform, then more samples may be needed. The probe should be pushed into the ground to 6 inches or to the depth of plowing. It is suggested to take at least 10 cores per five acres and doing so in a “W” or zig zag pattern, and then putting the samples in the bucket to mix thoroughly. Discard any rocks or crop residue, then put about two cups from the bucket into the soil sample bag making one composite sample. Repeat this across each field.

Soil sampling should be done at minimum every four years. The more frequent the sample, the faster results from management changes will be seen.  

Just completing soil sampling isn’t enough, though. Farmers must use the information provided by the soil samples, learn from it, and apply it to the fields to see full benefits. The easiest way is to incorporate them into a nutrient management plan. This is a plan for farmers that helps guide what fields need more of certain nutrients or what fields might be losing nutrients due to the crop rotation and management or tillage. The Green County LWCD offers a free class every winter to teach farmers how to write their own nutrient management plan.

For any questions about soil sampling, wanting to borrow one of the soil probes or are interested in writing a nutrient management plan, call Tonya Gratz at 608-325-4195 ext. 121.