No-Till Spring Wheat and Canola Response to Side Banded Anhydrous Ammonia at Seeding

Abstract

Anhydrous ammonia (AA) is generally marketed as the most economical form of fertilizer N available to farmers. Application of AA in the fall or spring prior to seeding is a common practice on the Canadian Prairies. Growth in no-till seeding practices has increased interest in the adaptation of AA to low disturbance, one-pass, seed and fertilizer application. A research study was conducted in Saskatchewan and Alberta to determine the potential for precision side band application of partially liquified AA at seeding. While AA reduced plant stand over that observed with urea for both wheat (Triticum aestivum L.) and canola (Brassica rapa L.), no effect on grain yields of wheat were observed from seven field trials. The use of AA did not adversely affect the rate of wheat establishment as measured by main stem Haun stage or plant development as measured by number of root axes and frequency of tillers produced. With canola, a reduction in grain yield was observed at only one of the five trial sites. The lower canola yield reflects the N loss when AA is applied on clay soils. Loss of AA on clay and silty clay soils, which were wet at application, resulted in reduced crop N uptake and lowered N use efficiency relative to urea at one wheat and two of the canola trial locations. The results of this study indicate that given adequate seed-fertilizer separation, partially liquified AA can be safely applied at seeding in a precision side band application. Soil conditions that are known to cause N loss on application of AA, in particnlar wet clay and silty clay soils, may benefit more from an alternative N source such as granular urea or solution N. Producers interested in adapting this technology to their seeding system are encouraged to pay close attention to the type of opener used and field topography, especially eroded soils.