1 Introduction
Fertilizer is a material which is applied in the soil to supply
nutrients for the growth of plants. Considerable amount of
the applied fertilizer is wasted by water or wind before it is
used by plants. It can be utilized in a better way with the help
of modern advanced technologies. Nanotechnology is the
emerging technology that can support for the various fertilization practices to meet increasing demands of food.
Heavy usage of fertilizers results in accumulation of fertilizers in water bodies thus causing eutrophication problems.
Chemical fertilizers affect the soil mineral balance which
in turn decreases the soil fertility. Fertilizer formulations
made using engineered nanoparticles improve the uptake in
plant cells and minimize the nutrient loss. In addition, they
increase the rate of seed germination, seedling growth,
photosynthetic activity, nitrogen metabolism, synthesis of
carbohydrate and protein as well (Solanki et al. 2015).
Nanomaterials produced by applying nanotechnology have
properties different from their bulk materials. Particle size of
these materials is less than 100 nm (at least in any one
dimension). The large surface area and more active sites of
these materials lead them to function efficiently. Their
property like compatibility with flexible substrates is useful
in several agricultural applications.
Recently, nanotechnology-based products are developed
for the utilizations in agriculture. Agri-nanotechnology
products such as nanofertilizers, nano-biofertilizers, biofertilizers, nano-pesticides, nano-nutrients, agricultural nanosensors, storage materials for food grains or agricultural
harvested products protection, and food packaging/
protection materials are modernizing the agriculture and
allied fields. They are developed in parallel with the development of the emerging agri-nanotechnology.
Fertilizers are the materials that applied in agricultural
activities, i.e., to supply macro or micronutrients or both to
the plants. Applications of fertilizers are considerably
focused on primary macronutrients. Plants mostly utilize the
macronutrients in more quantity (according to the name, the
demand for macronutrients is in macrolevel). It leads to lack
of macronutrients availability in the agricultural land. Hence,
it is essential to complete the demand. In micronutrients
case, plants consume less quantity, i.e., microlevel. It leads
to the availability of micronutrients in the agricultural land.
Contrary to macronutrients, the demand for micronutrients is
in microlevel or negligible. In slow or controlled release
fertilizers, nutrients are coated by nano-coatings that help to
release the nutrients in slow or controlled method.
For the growth of the plants, microelements such as iron,
cobalt, copper, selenium, zinc, molybdenum, and other
metals are essential. They constitute biologically active
compounds like proteins, enzymes, hormones, vitamins, and
pigments in plants. Nanopowders of the said microelements
can be developed as innovative fertilizers. The advantages of
these fertilizers over traditional fertilizers are: increasing the
level of resistance to pests and diseases; their consumption is
only one gram per ton of processed seeds; reduction of
procedures involved; finally decreasing the costs of labor
and operating agricultural equipment (NUST MISIS 2017).
The micronutrient calcium can be supplied to plants with
the nanoparticles such as Ca-NPs, CaCO 3 NPs, and
hydroxyapatite NPs. Ca-NPs can improve the seedling
growth in plants. Mg-NPs are superior to regular Mg salt by
improving the uptake of Mg in plant stems and leaves. Fe
NPs are able to increase the chlorophyll contents in leaves.
Mn-NPs are applied to replace the conventional MnSO 4 salt
(Liu et al. 2015). Novel fertilizers can be made using various
nanoparticles to increase the crop production.
ZnO nanoparticles stimulate the lateral roots that modify
the root architecture and increase the overall uptake of
nutrients in wheat plant. Shoot growth is stimulated in bean,
chickpea, and green pea with a low dose (1 kg per 100 mg)
of ZnO nanoparticles. Stimulation of chlorophyll production
increases the rate of photosynthesis and reduction of the
severity of chlorosis in plants. Such stimulation is achieved
by iron oxide and manganese nanoparticles. TiO 2 nanoparticles are able to increase the RuBisCO activase enzyme
activity and chlorophyll production in spinach. Stimulation
of the root growth in soybean and cilantro is performed by
CeO 2 nanoparticles. These nanoparticles also prevent
membrane peroxidation and leakage in maize by inducing
the activity of antioxidative enzymes. CuO nanoparticles
allow for high uptake of cognate element into the plant. It
improves the level of the essential nutrient elements. Slow
releasing of fertilizers helps to avoid leaching and fixation of
nutrients and makes the nutrients available in proper time.
This method also rectifies the overuse of fertilizer (Dimkpa
et al. 2014).
Fertilizer leaching is the loss of water-soluble plant
nutrients. It leads to the natural environment concern like
groundwater contamination. It is caused by the dissolution of
fertilizers and different biocides (such as pesticides, herbicides, insecticides, and fungicides) due to rain and irrigation
(Wikipedia 2014). Excess NO 3 ions of the nitrogen fertilizers applied are not absorbed by plants or soils which are
leached into groundwater (Lin et al. 2001). Phosphorus loss
is a major threat to manage the surface water quality. It plays
a major role in the eutrophication of surface waters (Carpenter et al. 1998). It does not interact with soil particles
through adsorption and desorption. However, soils rich in
iron (ferrihydrite) and aluminum oxides or hydroxides
(gibbsite) retain phosphorus (Borling 2003; Schoumans
132
T. Thirugnanasambandan
Fertilizer is a material which is applied in the soil to supply
nutrients for the growth of plants. Considerable amount of
the applied fertilizer is wasted by water or wind before it is
used by plants. It can be utilized in a better way with the help
of modern advanced technologies. Nanotechnology is the
emerging technology that can support for the various fertilization practices to meet increasing demands of food.
Heavy usage of fertilizers results in accumulation of fertilizers in water bodies thus causing eutrophication problems.
Chemical fertilizers affect the soil mineral balance which
in turn decreases the soil fertility. Fertilizer formulations
made using engineered nanoparticles improve the uptake in
plant cells and minimize the nutrient loss. In addition, they
increase the rate of seed germination, seedling growth,
photosynthetic activity, nitrogen metabolism, synthesis of
carbohydrate and protein as well (Solanki et al. 2015).
Nanomaterials produced by applying nanotechnology have
properties different from their bulk materials. Particle size of
these materials is less than 100 nm (at least in any one
dimension). The large surface area and more active sites of
these materials lead them to function efficiently. Their
property like compatibility with flexible substrates is useful
in several agricultural applications.
Recently, nanotechnology-based products are developed
for the utilizations in agriculture. Agri-nanotechnology
products such as nanofertilizers, nano-biofertilizers, biofertilizers, nano-pesticides, nano-nutrients, agricultural nanosensors, storage materials for food grains or agricultural
harvested products protection, and food packaging/
protection materials are modernizing the agriculture and
allied fields. They are developed in parallel with the development of the emerging agri-nanotechnology.
Fertilizers are the materials that applied in agricultural
activities, i.e., to supply macro or micronutrients or both to
the plants. Applications of fertilizers are considerably
focused on primary macronutrients. Plants mostly utilize the
macronutrients in more quantity (according to the name, the
demand for macronutrients is in macrolevel). It leads to lack
of macronutrients availability in the agricultural land. Hence,
it is essential to complete the demand. In micronutrients
case, plants consume less quantity, i.e., microlevel. It leads
to the availability of micronutrients in the agricultural land.
Contrary to macronutrients, the demand for micronutrients is
in microlevel or negligible. In slow or controlled release
fertilizers, nutrients are coated by nano-coatings that help to
release the nutrients in slow or controlled method.
For the growth of the plants, microelements such as iron,
cobalt, copper, selenium, zinc, molybdenum, and other
metals are essential. They constitute biologically active
compounds like proteins, enzymes, hormones, vitamins, and
pigments in plants. Nanopowders of the said microelements
can be developed as innovative fertilizers. The advantages of
these fertilizers over traditional fertilizers are: increasing the
level of resistance to pests and diseases; their consumption is
only one gram per ton of processed seeds; reduction of
procedures involved; finally decreasing the costs of labor
and operating agricultural equipment (NUST MISIS 2017).
The micronutrient calcium can be supplied to plants with
the nanoparticles such as Ca-NPs, CaCO 3 NPs, and
hydroxyapatite NPs. Ca-NPs can improve the seedling
growth in plants. Mg-NPs are superior to regular Mg salt by
improving the uptake of Mg in plant stems and leaves. Fe
NPs are able to increase the chlorophyll contents in leaves.
Mn-NPs are applied to replace the conventional MnSO 4 salt
(Liu et al. 2015). Novel fertilizers can be made using various
nanoparticles to increase the crop production.
ZnO nanoparticles stimulate the lateral roots that modify
the root architecture and increase the overall uptake of
nutrients in wheat plant. Shoot growth is stimulated in bean,
chickpea, and green pea with a low dose (1 kg per 100 mg)
of ZnO nanoparticles. Stimulation of chlorophyll production
increases the rate of photosynthesis and reduction of the
severity of chlorosis in plants. Such stimulation is achieved
by iron oxide and manganese nanoparticles. TiO 2 nanoparticles are able to increase the RuBisCO activase enzyme
activity and chlorophyll production in spinach. Stimulation
of the root growth in soybean and cilantro is performed by
CeO 2 nanoparticles. These nanoparticles also prevent
membrane peroxidation and leakage in maize by inducing
the activity of antioxidative enzymes. CuO nanoparticles
allow for high uptake of cognate element into the plant. It
improves the level of the essential nutrient elements. Slow
releasing of fertilizers helps to avoid leaching and fixation of
nutrients and makes the nutrients available in proper time.
This method also rectifies the overuse of fertilizer (Dimkpa
et al. 2014).
Fertilizer leaching is the loss of water-soluble plant
nutrients. It leads to the natural environment concern like
groundwater contamination. It is caused by the dissolution of
fertilizers and different biocides (such as pesticides, herbicides, insecticides, and fungicides) due to rain and irrigation
(Wikipedia 2014). Excess NO 3 ions of the nitrogen fertilizers applied are not absorbed by plants or soils which are
leached into groundwater (Lin et al. 2001). Phosphorus loss
is a major threat to manage the surface water quality. It plays
a major role in the eutrophication of surface waters (Carpenter et al. 1998). It does not interact with soil particles
through adsorption and desorption. However, soils rich in
iron (ferrihydrite) and aluminum oxides or hydroxides
(gibbsite) retain phosphorus (Borling 2003; Schoumans
132
T. Thirugnanasambandan