NANOTECHNOLOGY IS the utilization of materials having the size in nano (1-100 nm in dimension) at scale. The high reactivity of nanomaterials (nanoparticles) is related to their small size and thus the control of a large surface area which consults them with superior attributes over larger sized so its called bulk or microparticles of analogous chemistry. This upgraded the quality of materials at the nanoscale has led to the use of nanomaterials in a variety of applications. For example, zinc oxide nanoparticles are in heavily used in personal care products such as cosmetics, textile, paintings, industrial coatings, antibacterial agents and electronic materials. The magnetic properties of iron oxides are exploited at the nano-scale for enhancing environmental remediation of both organic and inorganic contaminants. It has been expected that more than $50 billion worth of nano-enabled products have been sold globally,with recent predictions that is approximately 1300 products including agriculture and food-related products worth $2.9 trillion.
Nanotechnology in crops:
In wheat ZnO nanoparticles cause the encouragement of lateral roots and change the root architecture, which could contribute in the overall uptake of nutrients. In bean low dose (100 mg/kg) of ZnO nanoparticles stimulated shoot growth, similar results show in chickpea and green pea. The concentrations of iron oxide (magnetite/hematite [Fe3O4/Fe2O3]) and Mn nanoparticles showed beneficial effects on plants through the stimulation of chlorophyll production and rate of photosynthesis.
In addition to enhancing chlorophyll formation, iron oxide nanoparticles also could reduce the harshness of chlorosis in plants. Other nanoparticles synthesized from non-mineral nutrients have also revealed positive effects on plants. Nanoparticles such as TiO2 in spinach and CeO2 in soybean increased photosynthesis and chlorophyll contents. In maize, CeO2 nanoparticles persuaded significant activity of antioxidative enzymes, helping to prevent membrane peroxidation and leakage in the plants. Collectively, the application of these nanoparticles, as well as of CuO, permit high uptake of the similar element into the plant, helping to improve crop nutrition in case of essential nutrient elements. The delivery of mineral nutrients in nano form is predicated on a variety of beneficial features, including timing of the nutrient release, sustained release of nutrients, synchronization or targeted environmental response, and directed nutrient delivery.
Two strategies for nanomaterial delivery into plants can be visualized. On the one hand, micronutrients from metallic elements (Zn, Fe, Cu, Mn, Mg and Ni) can be delivered as nanoparticles which can either be taken up directly by the plant or be solubilized in the rhizosphere prior to the uptake of the cognate ion. In addition to the individual mineral nutrients, composite nanoparticles of different but compatible nutrients also can be delivered via soil or foliar application into plant tissues, where they slowly dissolve to release the related ions for plant assimilation, motivated by specific environmental signals.
Irrespective the uptake mechanism, the cognate nutrients in nanoformulations is supposed to be released for plant use in a more efficient manner than those from bulk fertilizers. The plant use efficiency of the current bulk fertilizers is flawed by high leaching of nutrients away from the plant root rhizosphere, their forms of fixation in the soil that are not readily available to the plant, as well as other forms of losses such as volatilization.
Nanotechnology offers a great chance to improve the use efficiency of fertilizers. Slow release of fertilizers involves both leaching and fixation of nutrients could be reduced, with such release permitting a better timing of nutrient availability according to plant nutrient need. This aspect of nano application could be useful in agro-ecologies facing the negative consequences and misuse of fertilizer. In the case of nutrient deficient soils, because nanoparticles naturally release soluble ions quicker than bulk particles that enhanced and continual release of nutrients from nanomaterials will be important in supplying nutrients timely and quickly in contrast to slow release fertilizers.
Despite these potential benefits, the application of nanotechnology in plant fertilization could come with risks for the environment non-target plants, beneficial soil microbes and other life forms which could be affected if nanomaterials are misused.
Therefore, a better understanding of the agro-ecological consequences of nanotechnology, especially it relates to dose response, the release of ions, and nanoparticle specific effects of mineral nutrients is important to fully harness its promised benefits in nano-fertilizer applications.