Agriculture Reference
In-Depth Information
study on the uptake, translocation, and the accumulation of iron oxide nanoparticles
within the plant tissues (Zhu et al.
2008
). Using magnetization studies and micros-
copy, the authors determined that nanoparticles were transported to and accumu-
lated in the leaves and other plant tissues, with no visible impact. Interestingly,
pumpkin plants grown in sand and soil with irrigation using the iron oxide particle
suspensions showed significantly less uptake and accumulation of the particles.
This suggests that there is a difference in the bioavailability of the nanoparticles in
sand or soil versus in aqueous solution. It is important to mention that visual
indicators of toxicity, while valuable, are not always very sensitive, and whenever
possible proteomic, genomic, and metabolic studies are warranted (Rico
et al.
2011
).
Potential impact of nanofertilizers and nanomaterials as plant additives on the
health of soil microbial environments also warrants scrutiny. A 2009 study examined
the effect of silica, palladium, gold, and copper nanoparticles on the germination of
lettuce seeds, as well as their impact on soil microorganisms. Overall, no significant
influence on the microbial communities was noted (Shah and Belozerova
2009
). In
another study, the structural diversity of a soil bacterial community was altered by
gold nanorods, TiO
2
nanoparticles, and a number of polymer nanoparticles (Nogueira
et al.
2012
). Nano-CuO and magnetite were shown to negatively affect certain soil
bacterial groups, particularly in a sandy loam soil (Frenk et al.
2013
). Ag
nanoparticles were shown to decrease mycorrhizal colonization of
Helianthus annuus
(Dubchak et al.
2010
). Further study on the effects of nanoparticles and potential
nanofertilizers on the soil microbiome is critical to any evaluation of the risks and
benefits of nanotechnology in agriculture.
2.4 Limitations of Nanotechnology and Future Avenues
of Research in Fertilizer Inputs
As nanotechnology continues to grow and develop as a field of research, more
opportunities for the incorporation of nanomaterials into fertilizer inputs will
emerge. The relatively slow progress of nanotechnology in fertilizer formulations,
however, may at least partly be explained by lower levels of research funding, the
lack of clarity on regulations, and the perceptions on innovation in the fertilizer
industry. The trajectory of nanotechnology in the pharmaceutical industry may be a
useful point of reference to help inform predictions on nanotechnology applications
in fertilizer treatments. Many parallels can be drawn between the challenges of drug
delivery and fertilizer delivery. For example, both need to function in complex
biological systems and both have a requirement that the formulations be biocom-
patible, biodegradable, and nontoxic. One challenge however would relate to the
value proposition for innovative drugs versus fertilizers. Increasing the cost of
fertilizers due to the use of designer polymers as nanocoatings, for example, is
less likely to be tolerated by the industry and by producers.
