Agriculture sector in Pakistan is facing major environmental challenges like global climate change, urbanization, depleting natural resources and buildup of pollutants in environments associated with the use of agrochemicals.
Increasing population is worsening the situation due to rising food demand. So there is need to find efficient and environment-friendly solutions to improve quantity and quality of food supply. Nanotechnology is one amongst the rising technology to combat these issues in agricultural production in an environment-friendly way.
Nanotechnology is science conducted at nano scale. It’s the study and application of extraordinarily little things that is regarding 1-100 nanometers in size and often used across all science fields like agriculture, biology, chemistry, physics, and engineering.
Nanotechnology applications in agriculture are the base of providing food, feed, fiber, fireplace and fuels. In the future, demand for food can increase whereas natural resources are constrained. Therefore, varieties of progressive techniques are offered for enhancing the production that may enable precise management at nanometer scale. Our objective is to highlight various applications of nano materials within agriculture including:
Precision Agriculture: Nanotechnology can be used as a tool for the precision agriculture. Through advancement in nanotechnology, crop growth and field conditions like soil fertility, wetness level, weeds, temperature, insects, plant diseases, etc. are often monitored.
For this network of wireless nano-sensors are used. By knowing the plant physiology, time and level of water, fertilizers and pesticides, processes are often administered that ultimately decrease the resource inputs and maximize yield.
Seed Technology: Seed is most essential input determining productivity of any crop. Usually, seeds are tested for germination and distributed to farmers for sowing. It is hardly reproduced in the field due to the insufficient moisture under rainfed conditions. Hence it is quite appropriate to develop technologies for rainfed agriculture.
Metal oxide nano particles and carbon nanotube can be used to progress the germination rate of rainfed crops through better permeation of moisture into seeds. Carbon nanotubes serve as new pores for water permeation by penetration of seed coat and act as a route to channelize the water from the substrate into the seeds. These can facilitate germination which can be exploited in rainfed agricultural system.
Weed management: Weeds are menace in agriculture. Herbicides in the market are designed to control or kill the above ground part of the weed plants. None of these inhibits activity of viable ground plant parts like rhizomes and tubers, which act as a source for new weeds. Improvements in the effectiveness of herbicides through the use of nanotechnology could result in higher yield of crops.
A target specific herbicide molecule encapsulated with nanoparticle is designed for particular receptor in the roots of target weeds which enter into root system and translocated to parts that inhibit glycolysis of food reserve in the root system. This will make the particular weed plant to starve for food and gets killed.
Efficient delivery of fertilizers and pesticides: Nanotechnology can be used to promote efficiency of agrochemicals like fertilizers, pesticides, herbicides, plant growth regulators, etc. By polymers, encapsulation and entrapment of fertilizer and pesticides, we improve their stability against degradation within the environment and reduce the quantity to be applied, that reduces chemical runoff and lowers environmental issues. Nanoscale carriers are used for this purpose.
The newly developed nano-fertilizer will bring down the use of chemical fertilizers by 80-100 times, thus saving significant foreign exchange in import of fertilizers. Clay nanotubes are used as carriers of pesticides for low value, extended unleash and higher contact with plants. They decrease the utilization of chemical pesticide atleast 70-80%. These carriers can slow the uptake of active ingredients, therefore scale back the number of inputs to be used and conjointly the waste created.
Remediation of contaminants: Nanotechnology has potential role in remediation of organic and inorganic pollutants, which otherwise may enter into food chain and may cause some serious health problems. Due to high surface area and smaller particle, nano mateirals offer great potential to sorb pollutants from the contaminated soils and water.
Potential of various nano materials have been tested in various remediation strategies including nano adsorbents (based on oxides, Fe, MgO, ZnO, MnO, CNT), electrocatalysts (Pt, Pd) and photocatalysts (CdS, TiO2, ZnO, CdS: Mn, CdS:Eu, ZnS:Cu).
Like photocatalysis involves the reaction of catalyst (nano particles) with chemical compounds in the presence of light. When nanoparticles are subjected to UV light, their electrons in the outermost shell are excited resulting in the formation of electron hole pairs, i.e. negative electrons and positive holes. These are excellent oxidizing agents. Due to their large surface-to-volume ratio, these have very efficient rates of degradation and disinfection.
Wastewater treatment: Nanotechnology conjointly plays a task in wastewater treatment. Due to high reactivity and high degree of functionalization and large surface area, make nanoparticles suitable for application and waste water treatment.
By adsorption, organic and inorganic contaminants are removed; iron oxide and titanium oxide are low cost heavy metals which are used for removal of dissolved metals. Some magnetic nanoparticles like Fe3O4 are used to draw the solute through flocculation. Nanoparticles like Ag, TiO2 and ZnO are used as antimicrobial nano material by suppression of DNA replication, protein damage, membrane damage and production of reactive oxygen species.
Food preservation: Nanotechnology has also a role in quality and shelf life enhancement of agricultural products. Nano-lamination helps in preserving quality and freshness of food. Nano-laminates are sprayed on food which enhance the texture level and help in food preservation. The negative electrons ensuing from the excitation of nano-particles are inoculated in food which eradicates bacteria. Hence used in food packaging.
Tracking and identification of agricultural products: Nano-barcodes are used for tracking and identification of agri-products. Then for the identification of nano-barcodes UV lamps and optical microscope is used.
Conclusion
This technology has also some drawbacks that need to be negotiated. Nano-particles are released into the environment during its processing and treatment. Their impact on human health and environment is still unpredicted.
Most of the nano-materials are expensive as compare to conventional materials. Proper knowledge of nano-material and its interactions in human body is not available. Therefore, research is needed on developing cost effective methods of synthesizing and testing the efficiency of nano-materials at large scale for successful field application and reduces its negative effects on humans and environment.
Future of nanotechnology is unpredicted due to the adverse impacts of nano-particles on non-target sites. So its new application must be examined and regulated carefully.
Success of nanotechnology depends on development of effective and practical risk management strategies, if succeeded in developing such strategies and applied wisely then agricultural sector, the food industry and the environment will really see remarkable changes in the coming years.
This article is written by Asim Yaseen Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad.