|Does it pay to use pelletized lime? Many say it is too expensive. Which is right? This is one of the questions most often asked of TSM® personnel.
Granu-Cal® is the registered name by which we call pelleted lime products meeting the TSM® standards.
First, it is important to understand the benefits of lime application in general. We know that lime provides the following benefits:
Soil acidity can have a detrimental effect by lessening stress tolerance, root growth, winter
hardiness, stand persistence, and quality and yield of alfalfa, hay, and pasture.
- Improves physical condition of the soil
- Stimulates microbial activity in the soil
- Increases availability of nutrients
- Supplies calcium and magnesium plant food
- Improves symbiotic nitrogen fixation by legumes
TSM® has established a standard for the pelleted lime product used in our fertilizer recommendations. Some of these standards include:
For those lime products which meet these standards, we have adopted
- Finely ground powder in its parent form to at least 150 mesh
(200 mesh preferred)
- High calcium, low magnesium
- Good quality pellet
- Low dust when handled
the registered name Granu-Cal®.
The question still remains however: does it pay to use pelleted lime which costs more per
ton than regular ag lime? Having used this product since the beginning of the
TSM® program (1979), we know there are obvious benefits in spite of higher product costs. These benefits include:
- Increased yield. Purdue University in Indiana did a study in 1988 comparing pelletized
lime and potash applied together versus potash by itself, ag lime by itself, potash with ag lime,
and pelletized lime by itself. The potash and pellet lime combination showed an increase
in yield by 12.9 bushels.
This study was conducted by C. Harms on 4 replications. An increase of this size may not always be possible, but any increase can help pay for added cost of pellet lime over time.
- More accurate spreading. Ag lime often is not evenly spread across
a field; however, like fertilizer, pellet lime can be much more evenly spread allowing for more level pH
readings across a field. Also, pellet lime can be applied with fertilizer, so an
application cost is saved every 4 to 6 years.
- Nutrients are more available in the proper pH range, therefore less fertilizer is needed to
produce the same yield. Having a proper pH
affects Nitrogen, Phosphorus, and Potassium availability.
- Nutrient "cycles" are reduced. (See the topic "Nutrient Cycles.")
This is very important when figuring potential savings using pellet lime.
- Fast action. Pellet lime is effective in the same season it is applied. The rule of thumb is that pH will increase one-tenth point per 100 pounds of pelletized lime. To get the same one-tenth point using ag lime in that season, we figure the rate of ag lime would have to be 1,000 pounds. This is strictly an average; the pH "cycle" may increase or lessen these pH movements.
Is there room for ag lime in the TSM® program? Yes, but only on those soils which have a lower pH. For example, if you have a pH of 6.0 or below, there may be room for ag lime. Be very careful though! Avoid applying an amount that would cause the pH to go higher than the ideal for the crop being raised. This is discussed in detail in the topic "Nutrient Cycles".
Also remember that ag lime will control what the pH does for a 4 to 6 year period (depending upon the mesh size), so do not over apply. The best recommendation is to use ag lime on lower (6.0 or below)
pH soils to build up a pH, then adjust pH to the crop need with pelletized lime.