compared to its bulk counterpart. These nanoparticles can be
coated on macronutrient fertilizers such as urea and
monoammonium phosphate (MAP). The results demonstrated that MAP granules released more Zn than urea
granules because of the more acidity produced by MAP
granules (Milani et al. 2012).
Green synthesized (using a soil fungus) ZnO nanoparticles are sprayed on the leaves of mung bean plants. Zinc
oxide nanoparticles are used to mobilize native phosphorus
in the soil. They help in utilizing phosphorus in a sustainable
way. ZnO nanoparticle interacts with the enzymes such as
phosphatases and phytase that mobilize the complex form of
phosphorus in the soil into a form that plants can absorb.
This can increase the phosphorous uptake by 11%. These
nanoparticles increase the root volume, stem height, and
phosphorous-mobilizing soil microbial population. Also,
toxicity studies have been performed to ensure the safety in
the plant. The nanoparticles did not accumulate in the mung
bean seeds beyond the safe limit. Green synthesis makes the
nanoparticles coated with fungal proteins which prevent the
direct contact between soil and the nanoparticles (Raliya
et al. 2016).
Excess nitrogen and phosphorus fertilizers are fixed in the
soil while applying fertilizers in the conventional method. In
this method, they form chemical bonds with other elements
and become unavailable for plants. The nitrogen and phosphorus are sent into rivers, lakes, and bays which results in
environmental problems. Nanotechnology allows the usage
of small quantities of fertilizers. Nanomaterials can be
applied in the soil or sprayed onto their leaves. Foliar
application is good for the environment because they do not
come in contact with the soil. Since the particles are
nanometer in size, plants can absorb more efficiently than via
soil application.
5.4 Iron Oxide Nanoparticles
Iron is a micronutrient. Iron oxide nanoparticles can be
utilized as fertilizers (to remove iron deficiency) and as seed
pre-soaking solutions. Rui et al. (2016) have reported that
nanotechnology can give solution to solve the shortcoming
present in the traditional fertilizers. Plants like peanut
(Arachis hypogaea L.) are highly sensitive to Fe deficiency.
Fe participates in physiological processes such as chlorophyll bio-synthesis, respiration, and redox reactions. Fe 2 O 3
NPs are able to increase root length, plant height, biomass,
and SPAD values in peanut plants (Rui et al. 2016). In this
case, Fe 2 O 3 NPs support for the plants health by overcoming
the weakness of the traditional fertilizers.
Iron oxide nanoparticles (Fe NPs) can be applied as
next-generation iron deficiency fertilizers. Iron oxide is used
as seed pre-soaking solutions. This technique is an
environment friendly because it uses less fertilizer. Effects of
iron oxide nanoparticles at low and high concentrations, at
varied pH and the effect on embryonic root growth in
legumes have been analyzed. The results show that iron
oxide nanoparticles improve root growth by 88–366% at low
concentrations (Palchoudhury et al. 2018).
The effects of iron nanoparticles (Fe NPs) on the
anatomical and ultrastructural responses of Capsicum
annuum L. have been studied. Iron nanoparticles show
positive effects only at low concentrations which is confirmed by light and electron microscope analyses. SEM and
TEM analysis results are shown in Fig. 8a–c. Iron
nanoparticles are able to support for the plant growth by
altering the leaf organization, increasing the chloroplast
number, and regulating the development of vascular bundles. Fe NPs are absorbed in the roots and transported to the
central cylinder in bio-available forms. However, in high
concentrations, Fe NPs are found to be aggregated into cell
walls and transported via the apoplastic pathway in the roots,
which may potentially block the transfer of iron nutrients.
Figure 8d, e show the effects of Fe NPs at different concentrations. Low concentration yields better plant growth
(Yuan et al. 2018).
6 Slow/Controlled Release Fertilizers
6.1 Properties of Slow/controlled Release
Fertilizers
Coating on the fertilizers improves many properties of the
fertilizers. Ultimately, it leads to the enhancement of plants
health, growth of the plants, and yield at the maturity. Fertilizers can be released in a slow or controlled manner using
polymers. For the preparation of slow or controlled release
fertilizers, the nutrient is the main active material. It is kept
in the central portion. It is covered externally using natural
or synthetic polymer coating. This polymer coating controls
the release of active nutrient material present in the central
portion. The nutrients will be released in a slow or controlled
manner after the damaging of external polymer coating.
Generally, the damage of the polymer is caused by water,
microbes, and physical forces.
Slow release fertilizers are less soluble in water. They are
slowly broken down by microbial action. Controlled release
fertilizers are soluble fertilizers coated with materials like
sulfur and polymers. In foliar application of fertilizers, the
nanoparticles are transported through phloem tissues. Hence,
the direct interaction of fertilizers with soil systems is
avoided. As per the report of Haifa Group, both slow and
controlled release fertilizers release the nutrients slowly.
However, there are some differences in between them such
as releasing mechanism, releasing factors, and longevity.
Advances of Engineered Nanofertilizers for Modern Agriculture
143
coated on macronutrient fertilizers such as urea and
monoammonium phosphate (MAP). The results demonstrated that MAP granules released more Zn than urea
granules because of the more acidity produced by MAP
granules (Milani et al. 2012).
Green synthesized (using a soil fungus) ZnO nanoparticles are sprayed on the leaves of mung bean plants. Zinc
oxide nanoparticles are used to mobilize native phosphorus
in the soil. They help in utilizing phosphorus in a sustainable
way. ZnO nanoparticle interacts with the enzymes such as
phosphatases and phytase that mobilize the complex form of
phosphorus in the soil into a form that plants can absorb.
This can increase the phosphorous uptake by 11%. These
nanoparticles increase the root volume, stem height, and
phosphorous-mobilizing soil microbial population. Also,
toxicity studies have been performed to ensure the safety in
the plant. The nanoparticles did not accumulate in the mung
bean seeds beyond the safe limit. Green synthesis makes the
nanoparticles coated with fungal proteins which prevent the
direct contact between soil and the nanoparticles (Raliya
et al. 2016).
Excess nitrogen and phosphorus fertilizers are fixed in the
soil while applying fertilizers in the conventional method. In
this method, they form chemical bonds with other elements
and become unavailable for plants. The nitrogen and phosphorus are sent into rivers, lakes, and bays which results in
environmental problems. Nanotechnology allows the usage
of small quantities of fertilizers. Nanomaterials can be
applied in the soil or sprayed onto their leaves. Foliar
application is good for the environment because they do not
come in contact with the soil. Since the particles are
nanometer in size, plants can absorb more efficiently than via
soil application.
5.4 Iron Oxide Nanoparticles
Iron is a micronutrient. Iron oxide nanoparticles can be
utilized as fertilizers (to remove iron deficiency) and as seed
pre-soaking solutions. Rui et al. (2016) have reported that
nanotechnology can give solution to solve the shortcoming
present in the traditional fertilizers. Plants like peanut
(Arachis hypogaea L.) are highly sensitive to Fe deficiency.
Fe participates in physiological processes such as chlorophyll bio-synthesis, respiration, and redox reactions. Fe 2 O 3
NPs are able to increase root length, plant height, biomass,
and SPAD values in peanut plants (Rui et al. 2016). In this
case, Fe 2 O 3 NPs support for the plants health by overcoming
the weakness of the traditional fertilizers.
Iron oxide nanoparticles (Fe NPs) can be applied as
next-generation iron deficiency fertilizers. Iron oxide is used
as seed pre-soaking solutions. This technique is an
environment friendly because it uses less fertilizer. Effects of
iron oxide nanoparticles at low and high concentrations, at
varied pH and the effect on embryonic root growth in
legumes have been analyzed. The results show that iron
oxide nanoparticles improve root growth by 88–366% at low
concentrations (Palchoudhury et al. 2018).
The effects of iron nanoparticles (Fe NPs) on the
anatomical and ultrastructural responses of Capsicum
annuum L. have been studied. Iron nanoparticles show
positive effects only at low concentrations which is confirmed by light and electron microscope analyses. SEM and
TEM analysis results are shown in Fig. 8a–c. Iron
nanoparticles are able to support for the plant growth by
altering the leaf organization, increasing the chloroplast
number, and regulating the development of vascular bundles. Fe NPs are absorbed in the roots and transported to the
central cylinder in bio-available forms. However, in high
concentrations, Fe NPs are found to be aggregated into cell
walls and transported via the apoplastic pathway in the roots,
which may potentially block the transfer of iron nutrients.
Figure 8d, e show the effects of Fe NPs at different concentrations. Low concentration yields better plant growth
(Yuan et al. 2018).
6 Slow/Controlled Release Fertilizers
6.1 Properties of Slow/controlled Release
Fertilizers
Coating on the fertilizers improves many properties of the
fertilizers. Ultimately, it leads to the enhancement of plants
health, growth of the plants, and yield at the maturity. Fertilizers can be released in a slow or controlled manner using
polymers. For the preparation of slow or controlled release
fertilizers, the nutrient is the main active material. It is kept
in the central portion. It is covered externally using natural
or synthetic polymer coating. This polymer coating controls
the release of active nutrient material present in the central
portion. The nutrients will be released in a slow or controlled
manner after the damaging of external polymer coating.
Generally, the damage of the polymer is caused by water,
microbes, and physical forces.
Slow release fertilizers are less soluble in water. They are
slowly broken down by microbial action. Controlled release
fertilizers are soluble fertilizers coated with materials like
sulfur and polymers. In foliar application of fertilizers, the
nanoparticles are transported through phloem tissues. Hence,
the direct interaction of fertilizers with soil systems is
avoided. As per the report of Haifa Group, both slow and
controlled release fertilizers release the nutrients slowly.
However, there are some differences in between them such
as releasing mechanism, releasing factors, and longevity.
Advances of Engineered Nanofertilizers for Modern Agriculture
143