Oz wrote in message ...
>In article <893720515snz at spherica.demon.co.uk>, Matt
><mrr at spherica.demon.co.uk> writes
>IIRC Rothamstead have a field that has been in continuous wheat for
>several decades. At one time parts of it were with and without
>fertiliser. The work is old, and occasionally gets republished, but
A lot longer than decades, Oz, the Broad Balk as it is called was started by
Lawes and Gilbert very soon after they founded the research station in the
middle of the last century (around 1850-1860). It has strips, with no
treatment, FYM, N only, P only, K only and the various combinations. There
is also an area fenced off with no agricultural treatment or crops to
indicate climax vegetation - now an impenetrable mass..
In the Broad Balk near harvest time you have difficulty in finding wheat
plants in the strip with no treatment - or to find a difference between FYM
Altogether the place is very instructive to visit