Impact of Nitrogen, Phosphorus and Potassium Chloride Fertilizer Management on the Growth and Yield of Oats

Oats grown for the milling and livestock feed markets have become a profitable crop diversification option for farmers in western Canada. Approximately 4 million acres are currently grown, with acreage continually expanding. However, there is limited research available on fertilizer management of oats. Studies were initiated in 2000 to determine the effect of N, P and K on the growth, yield and quality of oats. Field experiments were conducted at two locations in southern Manitoba (clay loam and sandy loam) containing low to moderate levels of soil nitrate-N (NO₃-N) and extractable P.

Preliminary analysis of yield data showed positive effects of N and P on oat growth and/or yield, but minimal effects of K; no interactions among the nutrients were evident. Nitrogen application increased crop biomass yield at tillering at the sandy loam site and increased biomass yield at heading at both field sites. In addition, grain yield increased with N applications of up to 70 lb N/A on the sandy loam soil and with applications up to 35 lb N/A on the clay loam soil. Phosphorus application resulted in a significant linear increase in plant biomass at tillering at both sites and heading biomass at the clay loam site. Presumably, cool conditions early in the growing season combined with marginal soil P levels contributed to this early-season crop response. However, despite these marked early-season effects, P application had no effect on grain yield at either site. Application of potassium chloride (KCl) had little effect on either biomass or grain yield of oats at either field site. While increasing N rate reduced the bushel weight of the oats at both locations, increasing P rate had the opposite effect at the sandy loam site. Potassium had no effect on oat test weight. MB-12F