Environmental Impact of Production Horticulture - Horticulture: Plants for People and Places - page 502

Fig. 15.4 A schematic representation of a reed bed for the cleaning of waste water (Wainwright
2009 )
Fig. 15.5 A wetland used for cleaning grey water leaving a horticultural pack-house in Kenya
the wetland too quickly. Four days is the minimum period recommended; however
this is dependent on many wetland factors such as temperature, type of plants used
and degree of pollution in the water. Wetlands are low cost, low maintenance and
a natural solution to dirty packhouse water (Wainwright 2009 ) or other sources of
waste water (Fig. 15.5 ).
Fertilisers
Good Nutrient Management (GNM) is an important method of growing crops with-
out harming the environment or health. Over the last two decades UK farmers have
succeeded in increasing yields while reducing the use of fertiliser and the associated