The study of soil and crop responses to N fertilization under
different soil tillage systems is useful to understand the interaction
between these two factors, and to define best practices for
improved N fertilization. Conservation tillage systems may
improve water capture and retention, thus increasing crop growth
and N uptake. This may reduce the availability of soil mineral N and
may require increased N fertilization (Malhi et al., 2001; McConkey
et al., 2002). In our Mediterranean dryland systems, a previous
study in the area found that the interaction between these two
practices in the short-term (1–3 years) was not significant and no
additional fertilizer was needed when MT and NT were adopted.
However long-term adoption (>10 years) may lead to a different
response.