Fall is the best time to put lime on fields
Wednesday, October 3, 2012 1:00 AM
Fall applications of lime make the most sense for state producers, but experts suggest a soil test before applying it.
If you've only got so much money to spend on a soil fertilizer input, invest in lime before you invest in mineral fertilizers such as phosphorous or potassium.
If you get your lime correct, the nutrients that are already in the soil will be more readily available.
Nutrient availability is affected by the pH of the soil.
Lime requires water to react with the soil, so lime applied in the fall can take advantage of winter rains.
This timing also allows it to be incorporated into the soil during fall tillage.
Before adding lime or other nutrients, have the soil tested.
Soils have different abilities to interact with lime; in addition to information on phosphorous, nitrogen and potassium, the test will come back with a pH and lime recommendation.
If you have not had a soil test done in more than 2 years, have your soil tested as soon as possible.
Soils must be tested periodically because of weather and land use.
Over time, high levels of rainfall and heavy crop production pulls nutrients from the soil.
Producers need to test soil at least every three years to determine nutrient needs.
How a soil sample is taken depends on the size and topography of the field and whether or not fertilizer has been applied.
Fields with less than 20 acres can be sampled as one unit, unless there is a topography difference within the field, such as bottomland and an adjacent slope.
Any field larger than 20 acres should have more than one sample.
Take two samples from fields that have received surface-applied fertilizers over several years.
Take the first sample from the regular 0- to 6-inch depth, and the other sample from the first 2 inches.
Follow the soil test recommendations from the deeper sample to determine phosphorous and potassium management, and the results of the more shallow sample for lime management.
Soil samples cost $6 each ad MSU's Soil Testing Laboratory.
The expense is well worth the benefit gained from knowing the nutritional requirements of a field.