Christopher Dudenhoeffer1, Kelly Nelson2 and Peter Motavalli1, (1)University of Missouri, Columbia, MO (2)University of Missouri, Novelty, MO
With high fertilizer costs, farmers are interested in reduced phosphorus (P) fertilizer application rates and use of enhanced efficiency P fertilizer applications or treatments. AVAIL®(Specialty Fertilizer Products, Leawood, KS) and P₂O₅ Max (Rosen’s Inc., Fairmont, MN) are commercially-available products that are intended to enhance the efficiency of P fertilizers. The first objective of this research initiated in 2010 was to determine the effects of tillage/fertilizer placement (no-till (NT)/surface broadcast or strip-till (ST)/deep banding), monoammonium phosphate (MAP) rate [0, half the recommended rate (56 kg ha-1), and recommended rate (112 kg ha-1)], and the presence and absence of two enhanced phosphorus efficiency products (Avail® and P2O5-Max®) on a corn-soybean rotation. The second objective was to determine the effect of liming application (0 and recommended rate), P source [non-treated control and a broadcast application of diammonium phosphate (DAP) or triple superphosphate (TSP)], and the presence and absence of two enhanced phosphorus efficiency products (Avail® and P2O5-Max®) on a corn-soybean rotation.