the range of 100 mg/kg was exhibited to raise the pH of
loam soil, nevertheless, reduction in pH was observed for
sandy loam soil. The modification in pH was not influenced
by varying concentrations of nanoparticles. Displacement of
soil associated ions by addition of nanoparticles was considered as an important factor responsible for pH modification. Modifications in soil pH are also attributed to the
interaction of ENPs with plant roots. Alteration in secretory
products of plant root possibly induced by nanoparticle
addition, resulting into changes in soil pH is documented by
Rossi et al. (2018). Nevertheless, direct evidences regarding
modification in soil pH rendered by enhancement in root
exudates under the influence of nanoparticles are not
reported.
4.2 Cation Exchange Capacity
Cation exchange capacity is increasingly associated with
potential to hold nutrients as well as environmental contaminants, hence acting like an important parameter pointing
toward soil chemical attributes. The mobilization of
nanoparticles in terrestrial environment is also modulated
substantially by soil cation exchange capacity. The binding
of engineered nanoparticles to minerals present in soil (Zhao
et al. 2012) could greatly influence the inherent cation
exchange capacity. However, to date, limited studies have
been conducted pertaining to impact of nanoparticle addition
to soil onto cation exchange characteristics. Controlled
greenhouse condition-based experiment performed by De
Souza et al. (2019) demonstrated rise in rhizospheric ion
exchange capacity due to presence of ENPs consisting of
iron oxides. In a similar manner, increase in ion exchange
potential induced by silver nanoparticles biofabricated via
the action of leaf extract is described recently by Das et al.
(2019). Another investigation showing modulation in cation
exchange capacity galvanized by interaction of cerium oxide
nanoparticle with the soil mineral kaolinite leading to surface charge density variation has been indicated by Guo
et al. (2019).
4.3 Nutrient and Mineral Characteristics
Nutrients and minerals present in the soil are important
constituents governing the growth and development of various agricultural crops. Terrestrial incorporation of
nanoparticles is considered to modify the availability of
important mineral elements present in soil, thereby nutritional quality of cultivated crops. Intergenerational impact of
cerium oxide nanoparticles treatment to wheat responsible
for alterations in minerals and nutrients content of root and
grain as evident through synchrotron X-ray fluorescence
spectroscopy, elemental analysis and X-ray absorption near
edge spectroscopy is presented by Rico et al. (2017). Both
generation treatments with ENPs had considerable effect on
nutritional attributes as compared to only second generation
treatment. Study on the impact of ENPs including cerium
dioxide and titanium dioxide nanoparticle influencing the
phytoavailability of beneficial nutrient elements nitrogen,
phosphorus, and zinc as well as hazardous metal ion varying
with soil characteristics is demonstrated recently by Duncan
and Owens (2019). The observed effects on metal and
nutrient phytoavailability were ascribed to competition and
antimicrobial action of investigated nanoparticles.
Addition of titanium dioxide nanoparticle into biosolids
generally applied for soil fertilization is documented to
reduce the bioavailability of important elements including
manganese, zinc, iron, and phosphorus by 65%, 20%, and
27%, respectively (Bellani et al. 2020), and to some extent
was influenced by the amount and size of nanoparticles
applied. The reduced availability may be attributed to
interaction between minerals and highly reactive nanoparticle surface. In addition, the soil amendment with biosolids
spiked with titanium dioxide modulated the nutrient composition of grown pea plants causing decline in level of
manganese, zinc, potassium, and phosphorus in root and
shoot. Therefore, to avoid the non-target impact of ENPs on
soil ecosystem, extensive greenhouse condition should be
conducted prior to recommendation for field application.
4.4 Soil Organic Matter
The heterogeneous soil organic matter resulting from living
matter both by biological and non-biological processes
greatly regulates multitude of ecological functions in terrestrial environment (Wiesmeier et al. 2019). The characteristics of pores present in organic matter considerably
determine acquired air volume, reaction ability, water
holding potential, and environmental fate of externally sorbed substances (de Jonge et al. 1996; Pignatello 1998).
Being sink of numerous environmental contaminants, different nanoparticles of anthropogenic origin from different
sources are expected to accumulate in soil ecosystem. The
addition of metal-based nanoparticles consisting of copper
oxide and iron oxide into soil with no obvious alterations in
organic materials has been registered by Ben-Moshe et al.
(2013). Nevertheless, modifications in content of humic
substances as deciphered through fluorescence spectroscopy
were recorded. Investigation on influence of platinum
nanoparticles on features of soil organic matter (SOM) has
been represented recently (Komendová et al. 2019).
Nanoparticles with 3 nm size diminished the evaporation
enthalpy of water molecules present in SOM and facilitated
loss of water from soil. Further, the addition of nanoparticle
122
V. K. Singh et al.
loam soil, nevertheless, reduction in pH was observed for
sandy loam soil. The modification in pH was not influenced
by varying concentrations of nanoparticles. Displacement of
soil associated ions by addition of nanoparticles was considered as an important factor responsible for pH modification. Modifications in soil pH are also attributed to the
interaction of ENPs with plant roots. Alteration in secretory
products of plant root possibly induced by nanoparticle
addition, resulting into changes in soil pH is documented by
Rossi et al. (2018). Nevertheless, direct evidences regarding
modification in soil pH rendered by enhancement in root
exudates under the influence of nanoparticles are not
reported.
4.2 Cation Exchange Capacity
Cation exchange capacity is increasingly associated with
potential to hold nutrients as well as environmental contaminants, hence acting like an important parameter pointing
toward soil chemical attributes. The mobilization of
nanoparticles in terrestrial environment is also modulated
substantially by soil cation exchange capacity. The binding
of engineered nanoparticles to minerals present in soil (Zhao
et al. 2012) could greatly influence the inherent cation
exchange capacity. However, to date, limited studies have
been conducted pertaining to impact of nanoparticle addition
to soil onto cation exchange characteristics. Controlled
greenhouse condition-based experiment performed by De
Souza et al. (2019) demonstrated rise in rhizospheric ion
exchange capacity due to presence of ENPs consisting of
iron oxides. In a similar manner, increase in ion exchange
potential induced by silver nanoparticles biofabricated via
the action of leaf extract is described recently by Das et al.
(2019). Another investigation showing modulation in cation
exchange capacity galvanized by interaction of cerium oxide
nanoparticle with the soil mineral kaolinite leading to surface charge density variation has been indicated by Guo
et al. (2019).
4.3 Nutrient and Mineral Characteristics
Nutrients and minerals present in the soil are important
constituents governing the growth and development of various agricultural crops. Terrestrial incorporation of
nanoparticles is considered to modify the availability of
important mineral elements present in soil, thereby nutritional quality of cultivated crops. Intergenerational impact of
cerium oxide nanoparticles treatment to wheat responsible
for alterations in minerals and nutrients content of root and
grain as evident through synchrotron X-ray fluorescence
spectroscopy, elemental analysis and X-ray absorption near
edge spectroscopy is presented by Rico et al. (2017). Both
generation treatments with ENPs had considerable effect on
nutritional attributes as compared to only second generation
treatment. Study on the impact of ENPs including cerium
dioxide and titanium dioxide nanoparticle influencing the
phytoavailability of beneficial nutrient elements nitrogen,
phosphorus, and zinc as well as hazardous metal ion varying
with soil characteristics is demonstrated recently by Duncan
and Owens (2019). The observed effects on metal and
nutrient phytoavailability were ascribed to competition and
antimicrobial action of investigated nanoparticles.
Addition of titanium dioxide nanoparticle into biosolids
generally applied for soil fertilization is documented to
reduce the bioavailability of important elements including
manganese, zinc, iron, and phosphorus by 65%, 20%, and
27%, respectively (Bellani et al. 2020), and to some extent
was influenced by the amount and size of nanoparticles
applied. The reduced availability may be attributed to
interaction between minerals and highly reactive nanoparticle surface. In addition, the soil amendment with biosolids
spiked with titanium dioxide modulated the nutrient composition of grown pea plants causing decline in level of
manganese, zinc, potassium, and phosphorus in root and
shoot. Therefore, to avoid the non-target impact of ENPs on
soil ecosystem, extensive greenhouse condition should be
conducted prior to recommendation for field application.
4.4 Soil Organic Matter
The heterogeneous soil organic matter resulting from living
matter both by biological and non-biological processes
greatly regulates multitude of ecological functions in terrestrial environment (Wiesmeier et al. 2019). The characteristics of pores present in organic matter considerably
determine acquired air volume, reaction ability, water
holding potential, and environmental fate of externally sorbed substances (de Jonge et al. 1996; Pignatello 1998).
Being sink of numerous environmental contaminants, different nanoparticles of anthropogenic origin from different
sources are expected to accumulate in soil ecosystem. The
addition of metal-based nanoparticles consisting of copper
oxide and iron oxide into soil with no obvious alterations in
organic materials has been registered by Ben-Moshe et al.
(2013). Nevertheless, modifications in content of humic
substances as deciphered through fluorescence spectroscopy
were recorded. Investigation on influence of platinum
nanoparticles on features of soil organic matter (SOM) has
been represented recently (Komendová et al. 2019).
Nanoparticles with 3 nm size diminished the evaporation
enthalpy of water molecules present in SOM and facilitated
loss of water from soil. Further, the addition of nanoparticle
122
V. K. Singh et al.