Response to side-banded phosphorus and zinc fertilizer for corn grown after canola or soybean in southern Manitoba

Abstract

A 2-year crop rotation study in southern Manitoba assessed the effects of starter fertilizer on grain corn ( Zea mays L.) production when corn followed canola ( Brassica napus L.) versus soybean ( Glycine max L. Merr.). Treatments included a control (no starter) and two rates of phosphorus (P) (30 and 60 kg P2O5 ha−1) as monoammonium phosphate (MAP, 11–52–0) or MicroEssentials® SZ (MESZn, 12–40–0–10–1) side-banded at planting. The preceding crop did not have any influence on mycorrhizal colonization of corn roots at the V4 corn growth stage. However, side-banded fertilizer increased early-season biomass by as much as 111% compared to the unfertilized control, averaged across all site-years, with the largest increases occurring where corn followed canola. P concentration and uptake in early-season biomass increased as the P rate increased. Zinc (Zn) concentrations in early-season biomass were the greatest for the unfertilized control and MESZn treatments, while Zn uptake was significantly greater with the application of starter fertilizer compared to the unfertilized control. Starter P advanced silking date by 2–7 days relative to the unfertilized control. At maturity, starter P reduced grain moisture by 21–27 g kg−1 in corn only after canola. The high rate of MAP increased grain yield by an average of 770 kg ha−1 compared to the unfertilized control, regardless of the preceding crop. The negative influence of the preceding canola crop on early-season growth and mid-season development of corn can be managed with starter fertilization to provide adequate P and Zn to the corn crop and maintain successful production in Manitoba.