PRODUCTION PRACTICES FOR EARLY MATURING SOYBEANS IN SOUTHERN ALBERTA

Four experiments were conducted at two locations in southern Alberta, where no indigenous Rhizobium japonicum existed, to determine the effects of seeding dates, fertilizers, irrigation, and method of inoculant placement on the yield and quality of several early-maturing soybean (Glycine max (L.) Merrill) cultivars. Highest yields were obtained when soybeans were seeded during the first half of May. Irrigation requirements varied between years but yields were similar whether soil moisture was depleted to the 6 × 104-Pa or the 3 × 104-Pa level before irrigating to field capacity. Soybean yields increased substantially from N fertilizer when the inoculant was applied to the seed without a sticker. When granular inoculant was banded with the seed there was no response to N, and the yields of inoculated plants were higher than those of plants that were uninoculated and received up to 160 kg N/ha. When properly inoculated, early-maturing cultivars such as King Grain strain X005 and Maple Presto were capable of maturing and producing seed of acceptable yield and quality in southern Alberta.Key words: Cultivars, fertilizer, irrigation, inoculant, Glycine max (L.) Merrill