Effect of form, placement and rate of N fertilizer, and placement of P fertilizer on wheat in Saskatchewan

Mooleki, S. P., Malhi, S. S., Lemke, R. L., Schoenau, J. J., Lafond, G., Brandt, S., Hultgreen, G. E., Wang, H. and May, W. E. 2010. Effect of form, placement and rate of N fertilizer, and placement of P fertilizer on wheat in Saskatchewan. Can. J. Plant Sci. 90: 319-337. On the Canadian prairies, the one-pass seeding and fertilizing no-till system is very common. However, the close proximity of the fertilizer to the seed can cause damage to the emerging seedlings due to a combination of a salt effect and/or ammonia toxicity. Manufacturers have responded by developing openers that allow placement of seed and fertilizer in separate bands. A 3-yr study was initiated in 2000 to determine the effect of nitrogen (N) form [urea (U) and anhydrous ammonia (AA)], placement [broadcast (Br), side-band (SB) or mid-row band (MRB)], timing (fall or spring) and rate (0to 90or 120kg N ha-1), and phosphorus (P) placement (7 to 10kg P ha-1) on plant density, seed and straw yield, seed protein content, and N uptake of spring wheat (Triticum aestivum L.) under no-till at four sites representing different agro-ecological zones in Saskatchewan. Rate of applied N had the most dominant effect on agronomic variables, while form, placement, and timing of application of N had minor effects. Generally, SB and MRB were comparable in terms of seed yield, N uptake and seed protein content. From a practical perspective, SB and MRB could be used with equal success with either U or AA. Side banding P produced responses similar to seed-placed P, except under very dry conditions where side banding was superior. In general, placement of urea in soil in a band was more effective than broadcasting, while fall banding can be less effective than spring banding.