Evaluation of Micro Carbon Technology– Based Phosphorus Fertilizer, Super Phos, in Spring Wheat.

Proper   phosphorus   (P)   nutrition   is   important   for   wheat   root   growth   and   tiller development. Furthermore,  P  is  an  essential  component  of  energy-carrying  phosphate  compounds  (ATP  & ADP), nucleic acids, essential coenzymes, and phospholipids. Phosphorus deficiency in wheat is expressed as slow-growing and late-maturing plants. Phosphate is the only form of P that plants able to take up, yet only 1 % of all P in most Montana agricultural soils is present in a phosphate form. Although typical Montana fields contain between 1 or 2 parts per million (ppm) to 20 or more ppm of P, its availability is directly affected by soil pH.  In Montana’s  predominantly  high  pH calcareous  soils, phosphate  ions tend to react with calcium (Ca) and magnesium  (Mg) to form  less soluble compounds. The primary  P fertilizer  sources  in  Montana  are ammonium  polyphosphate  (APP;  10-34-0), diammonium  phosphate (DAP;  18-46-0), and  triple  super  phosphate  (TSP;  0-46-0).  Super Phos® (SP; 0-50-0)  by  Bio  Huma Netics Inc. (Gilbert, AZ) is a Micro Carbon Technology® - based  P fertilizer specifically formulated to resist "tie-up" with  Ca and Mg to remain  water  soluble and available to plant roots. This product has been developed to aid P uptake in cold, high pH and calcareous soils. A  field  experiment  in spring wheat  was conducted  in 2013  at  Montana  State University's  Western  Triangle  Agricultural  Research Center (WTARC) near Conrad,  MT. The objective was to compare the efficiency and effectiveness of topdress  and  foliar   application  of  SP,  with   traditional   P  fertilizers  - APP,  DAP,  and  TSP  - for optimizing spring wheat grain yield and quality. Nitrogen was applied to treatments at seeding to assure N supplied for all treatments are identical. Treatment 1 was established as an unfertilized check plot. For Treatments 2 through 7, liquid APP and two granular P fertilizers - DAP, and TSP, were applied with the seed at planting.  Finally, for Treatments 8 and 9, SP diluted with water at a concentration of no greater than 5% (v/v) was applied at seeding by dribbling it at the same distance from the seed as that of the granular fertilizer particles.  SuperPhos® has performed well in terms of spring wheat grain yield and grain protein content in this study. Grain yields were typical for dryland spring wheat in the Conrad region, ranging from 55 to 64 bu ac^-1, with grain protein content from 11.7 to 14.0%. The highest  yields  of  64  bu  ac^-1  a n d  6 3  bu  ac^-1  were  obtained  with  SP applied  at the  rate  of  30  lb ac^-1 P₂0₅  ac   as topdress at seeding and with  SP applied as a foliar spray at tillering at 15 lb P₂0₅  ac^-1. Comparable grain yields of 62 bu ac^-1 were obtained with SP and OAP applied at 10 lb P₂0₅ ac^-1 as topdress at seeding. Furthermore, grain yield of 61 bu ac^-1 with application of SP as a foliar spray at tillering at 15 lb P₂0₅ ac^-1. Application  of  SP  at seeding  at  both 10 and  30  lb  P₂0₅  ac^-1    rate  had resulted in high grain yields; tripling the  rate from 10 to 30 had increased yield by 2 bu ac^-1. This confirmed that SP is much less corrosive and less likely to cause damage to the seeds, and suggests that SP could be applied with the seed at a higher rate compared to other P sources. Results indicated that  application  of  SP at seeding at the  rate  of  30  lb  P₂0₅   ac^-1    is  a  good  option  for  P  fertilization in dryland spring wheat cropping systems of Montana. "SuperPhos® applied at tillering as a foliar spray has also performed well in terms of grain yield, but lower grain protein value of just 12% indicated that a possible N loss via volatilization of urea applied at seeding have impacted the results. SuperPhos® applied at tillering as a foliar spray has also performed well in terms of grain yield, but lower grain protein value of just 12% indicated that a possible deficiency in P early in the growing season may have impacted N uptake. Therefore, substantial amount of N was taken up to produce high grain yield, but not enough to maximize grain protein content. Further studies aimed to pinpoint most appropriate application rate, time and method for optimization of wheat grain yield and quality are currently being carried out in Montana.  Future studies will include thorough economical analysis comparing traditional P fertilizers to Micro Carbon Technology® - based SP.