Evaluation of Phosphate and Nitrogen Fertilizers Treated with Polymer Additives to Increase Fertilizer Efficiency

The Richardson International Kelburn, MB research and demonstration farm was the site of experiments evaluating Avail additive for both dry granular and liquid phosphate fertilizers. there were also experiments evaluating Nutrisphere additive for urea N fertilizer.


30 Apr 2008


The use of polymer additives to regular soluble fertilizers has been shown to increase the uptake of fertilizer nutrients into target crops. The mechanism of activity of the polymers is thought to slow down the reaction of the fertilizer nutrient ions and molecules with soil compounds. In the case of phosphorous (P) the Avail polymer applied to mono-ammonium phosphate is thought to slow down the reaction of phosphate ions (H2PO4- or HPO4-2) with cations (i.e Ca+2 and Mg+2 under neutral to alkaline soil pH, and Fe+3 and Al+3 under acidic soil pH). For urea-nitrogen the Nutrisphere polymer is thought to have urease inhibiting and nitrification inhibiting properties that reduce ammonia volatilization, and N2O and N2 emissions respectively.