Liquid or Dry Fertilizer–Which is Best?
Next to “What is the Cash Rent?”, one of the most commonly asked questions is “Which is better, liquid or dry fertilizer?” In the February 3, 2009 CORN Newsletter, this very question was answered by OSU Soil Fertility Specialist Robert Mullen. The answer is simple: they are both equally efficient in supplying nutrient needs in our area. Dr. Mullen writes:
For almost all situations (unless you are in the desert southwest), the choice of dry or liquid is one of material handling and price per pound, not plant availability. Both liquid and dry phosphate fertilizers will stay put in the soil when incorporated, too, so picking dry or liquid is up to you and your application equipment. Pick the cheapest commercial source once you calculate the value per pound (and read a recent soil test report for your field).
Recently, the discussion of using a polyphosphate or orthophosphate has received attention. In the same article, Dr. Mullen writes:
In the 60s, the old forms of phosphorus (P) fertilizer were all orthophosphates, but advances in chemistry led to the production of more concentrated P fertilizers, the polyphosphates and pyrophosphates. Some folks may choose all “ortho” liquid, as it is already plant available, however when polyphosphates are introduced into the soils in your field, they convert to orthophosphate anyway, usually in a very short period of time (in less than a day if the conditions are right). This process is fast enough to supply plants with the P they need, so again, pick the cheapest form of fertilizer that meets your needs.
Full podcast available here: