There have been many products developed to increase the efficiency of dry fertilizer programs. Two of these, well advertised, products make claims to reduce the volatilization of Nitrogen (Nutrisphere) and to increase availability of Phosphorus (Avail). Recently the Agronomy Journal published a technical paper summarizing research done by S. H. Chien and others. As a teaser here is the conclusion.
It is concluded from a meta-analysis of research that neither Avail nor Nutrisphere performs as claimed. They have little practical effect on crop production, which is inconsistent with claims made for these products. This conclusion is supported by a consideration of soil chemistry and the chemistry of the maleic-itaconic acid copolymer using coating on P or N. Importantly, these two lines of enquiry are independent and mutually reinforcing. These products should not be recommended to farms if their intention is to increase N or P use efficiency and/or increase crop production.
Click on the link above to read the entire article.
As always contact your CPS fieldman for more information on these and other nutritional products.