Lime Takes Time

Maintaining soil pH is an important factor in achieving good crop performance. pH effects nutrient availability (a soil pH under 6.0 may reduce nutrient availability from 20-55%), solubility of toxic substances like Aluminum, rates of microbial activity and reactions, soil structure, soil health, and pesticide performance.

Most commercial crops do well in a soil pH range from 6.0 – 7.0. There are exceptions, like potatoes, which prefer pH range of 5.5 – 6.0 and Alfalfa or Asparagus that do best from 6.5 – 7.5. Corn will tolerate a pH from 6.0 – 7.0, however, pesticide performance may suffer below 6.2 or above 7.0.

Knowing field conditions, crop rotations, and desired results are important factors. As always – Information is the key.

An up to date soil test (less than 3 years old) is the best place to start. The older the soil test, the more information you will need regarding the cropping practices after the last sample (crop grown, yield, tillage). Additives used in growing crops since the last test (amount of N used can lower pH), weather, addition of organics (manure, etc.) will all effect soil chemistry especially pH. pH correction takes time.

Soil type, soil Cation Exchange Capacity (CEC), weather, and availability and quality of correction materials (Lime), will affect amounts needed and duration to have an effective change. CEC, Organic Matter (OM), and other nutrient levels are additional information provided by the soil test that will help determine the necessary amount of correction material that will be needed to create a positive change that will enhance crop performance.

Establishing a starting point (like when soils reach a pH of 6.2) to begin the correction process means fewer liming materials will be needed to produce the needed change. Know the ability of material supplies to create a change. Best to know the ENV or Effective Neutralizing Value as this gives the actual Calcium Carbonate content of the material, not the TNV (Total Neutralizing Value), as this is a measure of amount of Calcium in the material and estimates its Calcium Carbonate equivalent, which can take a long time to effect soil change. Now what you need, if soils need Magnesium (Magnesium) – a source of Dolomite Limestone may be desired.

Liming takes time. Soil reactions, mineralization, soil atmosphere conditions (amount of moisture vs. O2) and let’s not forget weather. Fall applications of pH correction materials (Lime) require time for reactions. With the lower amounts of competing nutrients that were removed by the crop, mineralization opportunity is increased, and soil is resting from stress provided during the warmer growing season. Update soil test following an August hay crop removal for those fields in perennial forage, and as soon as possible after annual harvest. Remember Lime Takes Time.