No, it was just a comment in passing. It did relate to agricultural practices of course but their systems a very similar to gardeners, just on a bigger scale.
I have just come across this in an SAC leaflet:
Reduced Tillage and Pests
One of the benefits from reduced tillage is the increase in populations
of beneficial insects such as predatory ground beetles and parasitic
wasps over several seasons’ use. Ploughing tends to kill a proportion
of beneficial insects that overwinter in the soil, whereas adoption of
reduced tillage allows a greater degree of survival, and leads to a higher
level of natural control of pests such as slugs and aphids. Recent research
at SAC and elsewhere in the UK has demonstrated significant benefits
in pest management by natural enemies, with long term adoption of
reduced tillage techniques in conjunction with targeted insecticide use.
One potential downside of reduced tillage is a tendency for slug
populations to increase, as ploughing often kills slugs and slug eggs to
some extent. However, the increase in slug populations is overcome to
varying degrees by the build up of ground beetle populations that will
prey on slugs, and by the provision of alternative food sources such as
weeds and volunteers. Use of slug traps to gauge slug populations is
recommended, coupled with the use of metaldehyde slug pellets where
necessary to ensure that the newly sown crop does not get checked by
slugs.
So it looks like swings and roundabouts.