Fertilizer responses of dry bean in southern Alberta

Previous reports suggest that the response of dry bean to N fertilizer is o ften dependent on bean cultivar. In addition to N, commercial producers of dry bean in southern Alberta frequently apply P, K and Zn, even though soil test levels of these nutrients are often high. To evaluate the fertilizer responses of commercial dry bean cultivars in southern Alberta, three exper iments were conducted. In the first experiment, the response of GN 1140 gre at northern bean, NW-63 small red bean, Othello pinto bean, and Viva pink b ean to N fertilizer rates and rhizobia inoculation was determined at three sites each year from 1994 through 1996. The second experiment was conducted at the same sites to determine the response of these cultivars to P and K fertilizer. The third experiment was conducted at the same sites in 1995 an d 1996 to determine the response of the same four cultivars and OAC Seafort h navy bean to soil-applied and foliar Zn application. The four cultivars r esponded similarly to N in the first experiment. Seed yields ranged from 81 to 100% of maximum yields when available N levels (fertilizer-N plus nitra te-N to 30 cm just prior to seeding) were less than 80 kg N ha(-1), but wer e always greater than 90% of maximum yields when available N levels were gr eater than 80 kg N ha(-1). Rhizobia inoculation did not significantly incre ase seed yields or reduce the response to N fertilizer, although early-seas on plant growth was frequently improved by inoculation. Seed yield was only increased by application of P fertilizer at one site and by application of K fertilizer at one site, while application of Zn did not increase seed yi eld at any of the sites. The critical soil test levels for responses to P, K or Zn were consistent with levels reported for other crops or regions, bu t further validation of these levels is required due to the lack of sites w ith low nutrient availability.