Phosphorus and Zinc Fertilization Beneficial Management Practices for Corn in Manitoba: Crop Rotation and Strip-Tillage Preliminary Results.

Abstract: Results for the first year of a research project are presented for two P fertilization studies in Manitoba, one with crop rotation and the other with residue management. The objectives of the two studies are to evaluate i) corn response to spring sidebanded P and Zn fertilizer when corn follows canola versus soybeans, ii) corn response to fall banded and spring sidebanded P fertilizer in strip tillage and conventional tillage. Each study was established at two locations in 2014 with canola and soybeans 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 27 and 54 lb P₂O₅ ac^-1 in the form of monoammonium phosphate (MAP) and Microessentials MESZn (12-40-0-10-1) sidebanded during corn planting in the spring of 2015. The residue management study treatments included a control (no P), two rates of 27 and 54 lb P₂O₅ ac^-1 in the form of MAP, applied either in the fall of 2014 as a deep band (4-5”) with the strip till unit or in the spring of 2015 as a sideband with the corn planter. Preliminary results for the rotation study show that starter P increased early season biomass (V4) and plant height (V7-8), and decreased kernel moisture late in the growing season. However, grain yield responses to P were not significant, regardless of preceding crop. Preliminary results for the residue management study show that P fertilizer increased early season biomass and plant height. However, these differences did not translate into reduced kernel moisture or higher grain yields at harvest. These preliminary results represent only two site years of data for each study. Each of these studies is being conducted at another two locations in 2016.