Non-Peer ReviewedA field experiment (established in autumn 1979, with monoculture barley [1980-1990] and
barley/wheat-canola-triticale-pea rotation [1991-2008]) was conducted on a Black Chernozem
[Albic Agricryoll] silty clay loam soil at Ellerslie, Alberta, to determine the influence of tillage
(zero tillage [ZT] and conventional tillage [CT]), straw management (straw removed [SRem] and
straw retained [SRet]) and N fertilizer rate (0, 50 and 100 kg N ha-1 in SRet, and only 0 kg N ha-1 in
SRem plots) on seed yield, straw yield, total N uptake in seed + straw (1991-2008), and N balance
sheet (1980-2008). The N fertilizer urea was midrow-banded under both tillage systems in the
1991-2008 period. There was a considerable increase in yield and total N uptake up to 100 kg N
ha-1 under both tillage systems. On the average, CT produced greater seed yield (by 332 kg ha-1),
straw yield (by 323 kg ha-1) and total N uptake (by 6.3 kg N ha-1) than ZT. Compared to SRem
treatment, seed yield, straw yield and total N uptake tended to be greater with SRet at the zero-N
rate used in the study. The amounts of applied N unaccounted for over the 1980-2008 period
ranged from 845 to 1665 kg N ha-1, suggesting a great potential for N loss from the soil-plant
system through denitrification, and N immobilization from the soil mineral N pool. In
conclusion, crop yield and N uptake were lower under ZT than CT, and long-term retention of
straw suggests some gradual improvement in soil productivity
