|Unit 4.1 explains
why life in the soil is so important, how farming
techniques have upset the original balance between soil
biota and the native vegetative cover and how a new
balance must be created.
VAMs are introduced in unit 4.3
and in unit 4.4, herbicides and their relationship with life in the
soil are examined.
Unit 4.5 suggests ideas for developing disease suppressive soil
are introduced and unit 4.6 examines the role of free nitrogen in the air.
Recent research and conclusions regarding soil disease suppressive
soils in unit 4.7 brings the
module to a conclusion.