Environmental Engineering Reference
Because of its high irrigation water requirement, the most common cereal grown
with wastewater is rice (Raschid-Sally and Jayakody 2008 ). Other cereals such as
wheat, oats, millet, sesame, sorghum and maize are also irrigated with wastewater
(Bradford et al. 2002 ; Weckenbrock 2010 ; Siebe 2013 ).
3.3.3 Fodder Crops
Alfalfa, Paragrass ( Urochloa mutica ), Sorghum ( Sorghum spp.), Persian clover
( Trifolium resupinatum L.), Lucerne ( Medicago spp.), Berseem ( Trifolium alex-
andrinum L.) are among the fodder crops mentioned in the literature about
wastewater irrigation (Buechler et al. 2002 ; Moscoso Cavallini and Egocheaga
Young 2002 ; Amerasinghe et al. 2009 ; Weckenbrock 2010 ).
3.3.4 Energy Crops
The main energy crop cultivated with wastewater in tropical settings is sugarcane
(Melfi and Montes 2008 ; Weckenbrock 2010 ; Sandoval et al. 2013 ). In temperate
climates, other fast growing plants like willows are being used (Dimitriou and
Aronsson 2005 ).
With their high nutrient requirement and due to the fact that, if used appropri-
ately, they do not pose a risk for human consumption, there is a high potential for
the use of energy crops in wastewater irrigated systems even if the water quality is
fit for the production of food crops. In order to be economically viable, the
production of energy crops depends on infrastructure in terms of transport and
processing as well as power plants for the creation of electricity.
3.3.5 Other Crops
Other crops irrigated with wastewater that have been mentioned in the literature
include ornamental plants, timber plants and fruit trees (da Costa e Silva et al. 2002 ;
Moscoso Cavallini and Egocheaga Young 2002 ; Buechler et al. 2006 ).
The range of different crops cultivated with wastewater in different countries is
illustrated in the examples from case studies listed in Table 1 .
In water scarce regions, crops with high water requirements often fetch higher
market prices, which make them interesting for wastewater-irrigating farmers. A
study in Pakistan, for example, found that farmers using wastewater for irrigation
produced crops with higher market values than their non-wastewater-irrigating
neighbours (Weckenbrock 2010 ).