Non-Peer ReviewedYear 1 and 2 results of a research project are presented for two P fertilization studies, one with crop rotation and the other with residue management. The objectives of the two studies were to evaluate i) corn response to spring side-banded P and Zn fertilizer when corn follows canola versus soybeans, ii) corn response to fall banded and spring side-banded P fertilizer in strip tillage and conventional tillage. Each study was established at two locations in 2014 and 2015 with canola and soybeans grown as preceding crops for the rotation study, and fall conventional and strip tillage for the residue management study. The rotation study included a control (no P) and two rates of P (27 and 54 lb P2O5/ac) in the form of monoammonium phosphate (MAP) (11-54-0) or Microessentials MESZn (12-40-0-10-1) side-banded (2” to the side and 1” below the seed) during corn planting in the spring of 2015 and 2016. The residue management study treatments included a control (no P), two rates of P (27 and 54 lb P2O5/ac) in the form of MAP, applied either in the fall as a deep band (4 – 5”) with the strip till unit or in the spring as a side-band with the corn planter. Preliminary results for the rotation study showed a substantial early season vegetative response to all fertilizer P treatments, resulting in an 85-110% increase in biomass compared to the control, especially in corn following canola. Silking date was advanced by 3-7 days with application of starter P. At harvest, all starter P treatments reduced kernel moisture by 2-3% in corn following canola only, and there was a 10% yield increase in grain yield with the high rate of MAP compared to the control, regardless of preceding crop. Preliminary results for the residue management study showed that spring side-banded P treatments increased early season biomass by 77-81% and silking date was advanced by 3 days at 2 site-years, compared to the control. At harvest, fertilizer P reduced kernel moisture by 1-2% at both sites in 2016, and spring side-banded P out-yielded the control and fall applied treatments by 5%, regardless of tillage system
