Enhanced Efficiency Phosphorus Application for a Corn-Soybean Rotation.

With higher fertilizer costs, farmers are evaluating application rates and considering enhanced efficiency phosphorus (P) applications or treatments. AVAIL®(Specialty Fertilizer Products, Leawood, KS), NutriLife Max® (Advanced Microbial Solutions, Pilot Point, TX), and P©üO₅ Max (Rosen’s Inc., Fairmont, MN) are three commercially-available products that are intended to enhance the efficiency of  P fertilizers. The first objective of this research initiated in 2010 was to evaluate the effect of P placement (surface broadcast or strip-till), rate, and type of P enhanced efficiency products on grain yield and P uptake in a corn-soybean rotation. The second objective was to determine the effect of P source, type of P enhanced efficiency product, and aglime (0 or recommended rate) on grain yield and P uptake in a corn-soybean rotation. The research was conducted at three locations in Missouri: the Greenley Memorial Research Center near Novelty, the Delta Center near Portageville, and the Hundley-Whaley Center near Albany.   Preliminary results indicate that AVAIL increased corn grain yield 500 kg ha^-1 when applied with P in a strip-till band. There was no effect of type of P enhanced efficiency product on grain yield when broadcast applied in a non-till system or when applied with the recommended aglime rate. Strip-till increased plant population 23000 plants ha^-1 and test weight 3.9 kg m^-3 compared to no-till at Novelty. Lime increased silage yields 2.5 Mg ha^-1 when compared to the non-treated control at Novelty, but grain yields were similar among lime treatments. However, lime had no effect on silage yields at Portageville, but grain yields increased 690 kg ha^-1. Grain yields were 440 kg ha^-1 greater when TSP was used compared to DAP.  The corn plots will rotate into soybean and another location will repeat this research in 2011.