ABSTRACT
This experiment was conducted throughout the 1992 growing season on upper and lower slope positions at a site near Lanigan, Saskatchewan, Canada. Soil water reserves of 1 2 0 cm on the footslope were 38% more than on the shoulder at the beginning of the growing period and the difference decreased gradually with wheat growth. Soil temperature on the lower slope at both the 50-cm and 1 0 0 -cm depths was higher than on the upper slope before mid-July, whereas the opposite was true afterwards. Latent evaporation on the shoulder was higher than on the footslope. Significant differences occurred between slope positions as well as between fertilizer treatments for both the development of leaf area indices and for the accumulation of aboveground biomass. Throughout the growing season, leaf water potentials indicated a high level of stress occurred in all treatments, with the shoulder position exhibiting the greatest stress. No significant difference of leaf water potential occurred between fertilizer treatments. Fertilizer application increased both total biomass and total grain yields, and raised water use efficiency, on both slope positions. The effect of the amount of precipitation in flowering filling stage on harvest indices was enhanced with fertilizer application.
