Corn Response To Banded Phosphorus Fertilizers With Or Without Manure Application In Eastern Canada

Legacy phosphorus (P), corn (Zea mays L.) hybrids, weather conditions, and regulation on land-applied manure affect site-specific mineral P requirements. Mineral P fertilizers are still banded at corn seeding as insurance policy even where manure P is applied in compliance with regulation in Eastern Canada. Our objective was to measure the effects of site-specific factors on the response of corn hybrids of the "new" era (1991+) to mineral and manure P fertilization under regulatory constraints. A dataset of 370 corn P fertilizer trials conducted between 1998 and 2004 in Quebec, Canada, comprised trials using mineral P alone (229 trials) or in combination with manure (141 trials). Linear mixed statistical models tested the effect of P fertilization on seedling biomass, grain yield, grain bulk density, and grain moisture content as affected by weather and soil indices. Early plant growth proved to be a poor indicator of final crop performance. Where no manure was applied, grain yield and quality were affected primarily by soil pH, texture, and genesis. There were responses to P additions only where the saturation index (P/Al)(M3) was less than 5%. Mineral P fertilizers showed no significant effect on crop performance where manure was applied, but manured soil generally showed (P/Al)(M3) percentages exceeding 5%. Banding mineral P at corn seeding where manure was applied at rates complying with the regulation and the (P/Al)(M3) percentage exceeded 5% appeared to be a waste of resource under the soil and climate conditions in Eastern Canada.