Effect of form, placement and rate of N fertilizer, and placement of P fertilizer on wheat in Saskatchewan
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 (0 to 90 or 120 kg N ha-1), and phosphorus (P) placement (7 to 10 kg 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.Key words: Anhydrous ammonia, N application timing, N form, N and P placement, N uptake, protein content, urea, wheat, yield