Evaluation of “Struvite” As a P Fertilizer Source for Irrigated Vegetables in the Arid Southwestern U.S.

Struvite derived from a proprietary fluidized bed reactor system that recovers ammonia and phosphate from nutrient rich fluids, including waste streams, is a pearl or granule based P fertilizer marketed by as “Crystal Green”.  However, the efficacy of this product as a P fertilizer source on calcareous soils in the southwestern United States was unknown.  Field studies were conducted from 2010 through 2013 comparing this struvite P fertilizer source, against, and in combination with, commonly used commercial P fertilizers (triple superphosphate and mono-ammonium phosphate).  Studies were conducted with lettuce (Lactuca sativa), watermelons (Citrullus lanatus), carrot (Daucus carota), and potato (Solanum tuberosum).  The struvite and the conventional P fertilizers produced similar changes in sodium bicarbonate extractable soil test P levels.  The results of these studies also indicate that this struvite based product produced marketable yield increases to P at least comparable to the conventional P sources.