SNOW AND FERTILIZER MANAGEMENT FOR CONTINUOUS ZERO-TILL SPRING WHEAT

Abstract

In this 3-yr study the effect of snow management, by means of cereal straw trap strips, and fertilizer management (rates of N and P, time and placement of N) on spring wheat (Triticum aestivum L.) yield, N use efficiency, and moisture conservation were examined in a zero-till system on a Brown Chernozemic loam soil in southwestern Saskatchewan. Fall and winter precipitation equivalent to 132, 93 and 68 mm of water was received in 1981–1982, 1982–1983, and 1983–1984, respectively. Efficiency of soil water intake in short stubble was constant at 29% but in tall stubble it was 35, 33 and 65% for the 3 yr. The advantage of water conserved by cereal straw trap strips compared to the standard short stubble treatments averaged 13 mm to the 120 cm soil depth and ranged between 5 mm in 1982–1983 and 25 mm in 1983–1984. Growing season rainfall averaged 244, 176, and 100 mm in 1982, 1983, and 1984, respectively. The use of straw trap strips resulted in greater grain yields than when the straw was cut at one standard height (about 18 cm), the difference being most marked in the driest year. In the two wet years, yields were greater for spring-applied than for fall-applied urea N, and for deep-banded than for broadcast N. In the dry year, fertilizer treatments had no effect on yield. Broadcasting urea in the fall was the least efficient treatment. Yield response to P applied at rates as high as 53 kg ha⁻¹ was only significant in the second year, and even here the response was not large. Grain protein and N use efficiency generally responded in a manner similar to grain yield. Although the moisture conserving advantage of trap strips does not so far support a plausible move to continuous cropping in the Brown soil zone, the yield responses are encouraging and might result in producers making more extensive use of this inexpensive technique.Key words: Wheat, fertilizer placement, fertilizer timing, cereal straw trap strips, zero tillage, snow management