Interpretive Summaries:

Under the drier than normal conditions recorded in 2003, wheat grain yields at the experimental site were very low. Using the same plots and fertilizer treatments, a P response was not recorded in field pea in 2004, regardless of the previous wheat crop history. For spring wheat in 2004, there was no effect of P additions on the long-term no-till site, but there was an effect on the short-term no-till site where yields were increased with addition of up to 20 lb P₂O₅/A. These results support past work indicating a lack of response for field pea to P fertilizer additions. They also show that residual P in the long-term no-till site met the wheat P requirements, while the absence of this nutrient supply resulted in a positive response on the short-term no-till site. In 2005, we did not observe a difference between long-term and short-term no-till for P response in either spring wheat and field pea. It was interesting to note the large yield differences between short-term (33.6 bu/A) and long-term no-till (43.8 bu/A) for the grain yields of spring wheat. Even after 4 years, the check plots are still producing similar grain yields to the fertilized P plots. This project will be continued in 2006. SK-36