The Role of Intercropping in Plant Biofortification 3common form of multiple cropping is the mixed cropping of grains and of
grains with legumes. In this system, individual species can exploit different
resources or the same resources more efficiently, which can increase total
yield per unit area in comparison with the cultivation of a single species
(Rodrigo et al., 2001 ). Most grain-crop mixtures with similar ripening times
cannot be machine-harvested to produce a marketable commodity. Such
mixtures are useful for obtaining raw materials intended mainly for fodder.
Strip cropping is a form of intercropping which attempts to reconcile the
interests of the farmer and the environment. It involves growing two or more
species of plants in strips wide enough to allow independent mechanical
cultivation, yet narrow enough for the interaction of ecological factors
(Głowacka 2013a). Strip cropping as an alternative offers greater possibilities
through the individual sowing and harvesting of each species, and thus may be
more useful in cultivating plants for different purposes. This system can be
regarded as an adaptation of the more traditional intercropping systems but
one which allows the use of modern farm machinery (Hauggaard-Nielsen et
al., 2012 ). Placing plants in strips minimizes competition between them for
water, light and nutrients, while greater diversity increases the stability of the
agro-ecosystem. This cropping system can also play a role in protecting soil
from water and wind erosion, reducing losses of mineral nutrients due to
leaching and reducing the occurrence of pests and crop plant diseases (Kanwar
et al., 2005, Bucur et al., 2007, Ma et al., 2007, Rogobete and Grozav 2011).
Moreover, strip cropping has proven highly effective at reducing
contamination of rivers by herbicide residues from surface runoff (Holvoet et
al., 2007 ). The plants most frequently grown in this system are: maize,
soybean (or another legume) and often another cereal as the third crop (Francis
et al., 1986, Fortin et al., 1994, Iragavarapu and Randall 1996). The selection
of plants with different developmental cycles and morphological structures
enables more the efficient utilization of nutrients, water and light, and also
makes it possible to reduce inputs (Fukai and Trenbath 1993, Zhang and Li
2003 ). The increased number of species in strip cropping, and the spatial
diversity, can increase total yield and affect its structure (Ghaffarzadeh et al.,
1994, Lesoing and Francis 1999).
Human beings require at least 22 mineral elements for their wellbeing.
Crop plants are an important source of food for people, and are also used as
animal feed in fresh or processed form. Therefore, their nutritional value and
the proportion of nutrients they contain are very important for the health of
humans and animals (Graham et al., 2007, Albayrak and Turk 2013 ).
However, it was estimated that a considerable proportion of people worldwide