Agriculture is the largest interface between humans and the environment and, as a result, is a major influence on climate change and ecosystem degradation. The demand on agriculture increases as our demand for food increases while natural resources such as land, water and soil fertility are limited. Nanotechnology has an important role to play in addressing challenges faced by agriculture, while reducing its impact on the environment.
Research into nanotechnology and its application across the entire spectrum of agriculture and food technology is ongoing. Nanotechnology in agriculture can be applied to reduce the usage of plant protection chemicals (pesticides), minimise nutrient loss in fertilisation and increase yield through optimised nutrient management. Nanotechnology can also be used to detect and treat diseases, enhance nutrient absorption by plants and deliver active ingredients to a specific site.
An integral application of nanotechnology in agriculture is its use in smart delivery systems. Nanosensors and nano-based smart delivery systems help in the efficient use of agricultural natural resources like water, nutrients and chemicals through precision farming – the process of maximising crop yields and minimising the usage of pesticides, fertilisers, and herbicides through efficient monitoring procedures.
Nanobarcodes and nanoprocessing are also used to monitor the quality of agricultural produce. Through nanotechnology, scientists are able to study a plant’s regulation of hormones such as auxin, which is responsible for root growth and seedling establishment.
Nanoparticles can be used in the bioremediation of resistant or slowly degradable compounds like herbicides, insecticides and pesticides, thereby reducing their impact on the environment. Although the use of agricultural chemicals is very often necessary to maintain agricultural productivity and ensure agricultural products are safe for humans, for decades concerned companies and local authorities have demonstrated an interest in managing the adverse effects of spraying chemicals and the decontamination of agricultural soil. The concept of nanobioremediation integrates nanoparticles and bioremediation and aims for effective, efficient and eventually sustainable remediation of contaminated soils.
Nanotechnology is also applied to prevent waste in agriculture, particularly in the cotton industry. With the use of newly-developed solvents and a technique called electrospinning, scientists produce 100 nanometre-diameter fibres from some of the cellulose and/or the fibres discarded as waste from the processing of cotton. These can be used as a fertiliser or pesticide absorbent. These high-performance absorbents allow targeted application at a desired time and location.
Also, ethanol production from maize feedstocks has increased in recent years. Cellulosic feedstocks are now regarded as a viable option for biofuel production and nanotechnology can also enhance the performance of enzymes used in the conversion of cellulose into ethanol. Scientists are working on nano-engineered enzymes that will allow simple and cost-effective conversion of cellulose from waste plant parts into ethanol.
Rice husk – a rice-milling by-product – can be used as a source of renewable energy. When rice husk is burned into thermal energy or biofuel, a large amount of high-quality nanosilica is produced which can be further utilised in making other materials such as glass and concrete. Since there is a continuous source of rice husk, mass production of nanosilica through nanotechnology can alleviate the growing rice husk disposal concern.
The South African government has put in place regulations to govern the food industries. However, currently, there is no specific legislation for nanomaterials and the regulation of nanotechnology-based food products falls under several pieces of food-specific legislation, i.e. the Foodstuff, Cosmetics and Disinfectant Amendment Act 2007. Research is ongoing to determine the safety of the use of nanoparticles and nanotechnology. As knowledge grows in this area, relevant regulations will be developed.
Commercial applications of nanotechnology in the agricultural sector are numerous and varying and mostly have the potential to optimise the food industry.