Nano-fertilizers and Their Smart Delivery System

Abstract

Outburst of world population in the past decade has forced the agricultural sector to increase crop productivity to satisfy the needs of billions of people especially in developing countries. Widespread existence of nutrient deficiency in soils has resulted in great economic loss for farmers and significant decreases in nutritional quality and overall quantity of grains for human beings and livestock. Use of large-scale application of chemical fertilizers to increase the crop productivity is not a suitable option for long run because the chemical fertilizers are considered as double-edged swords, which on the one hand increase the crop production but on the other hand disturb the soil mineral balance and decrease soil fertility. Large-scale application of chemical fertilizers results in an irreparable damage to the soil structure, mineral cycles, soil microbial flora, plants, and even more on the food chains across ecosystems leading to heritable mutations in future generations of consumers.In recent years, nanotechnology has extended its relevance in plant science and agriculture. Advancement in nanotechnology has improved ways for large-scale production of nanoparticles of physiologically important metals, which are now used to improve fertilizer formulations for increased uptake in plant cells and by minimizing nutrient loss. Nanoparticles have high surface area, sorption capacity, and controlled-release kinetics to targeted sites making them "smart delivery system." Nanostructured fertilizers can increase the nutrient use efficiency through mechanisms such as targeted delivery, slow or controlled release. They could precisely release their active ingredients in responding to environmental triggers and biological demands. In recent lab scale investigations, it has been reported that nano-fertilizers can improve crop productivity by enhancing the rate of seed germination, seedling growth, photosynthetic activity, nitrogen metabolism, and carbohydrate and protein synthesis. However, as being an infant technology, the ethical and safety issues surrounding the use of nanoparticles in plant productivity are limitless and must be very carefully evaluated before adapting the use of the so-called nano-fertilizers in agricultural fields.

Recent developments in nanotechnology transforming the agricultural sector: a transition replete with opportunities

“…The excessive application of pesticides should be replaced by nanoemulsions, nanocomposites and nanoparticle formulations that are safe, effective and environmentally sustainable in the killing of agricultural pests and pathogens. The development of nanoformulations of agrochemicals for applying fertilisers (discussed in the next section) and pesticides is one aspect of the agriculture sector that is receiving increasing interest , …”

“…However, there is a need for sufficient development in nanoencapsulation, in terms of cost–benefits and effectiveness to enhance the applications of nanoencapsulated pesticides. In recent laboratory‐scale experiments, it has been identified that modern nano‐fertilisers can improve agricultural yield by increasing the rate of seed germination, photosynthetic activity, seedling growth, nitrogen fixation, and carbohydrate–protein metabolism , …”

“…Nonetheless, the high sorption capacity and high aspect ratio of nanoparticles are suitable for the controlled release of micronutrients to the target site. Consequently, nanofertiliser delivery systems have the prospective of increasing nutrient efficacy and crop productivity, through enhancing photosynthetic activity, nitrogen metabolism and protein synthesis . Development of nanoporous materials, nanopolymers and nanocomposites that can immobilise nutrients and release nutrients into the soil have the advantage of preventing the loss of nutrients from soil and also mitigate eutrophication .…”

“…The development of nanoformulations of agrochemicals for applying fertilisers (discussed in the next section) and pesticides is one aspect of the agriculture sector that is receiving increasing interest. 100,101 The huge usage of pesticides has increased potential to pollute the environment and pose a hazardous danger to living beings. In the green revolution, pesticides and chemical fertilisers have been practised markedly, thus there has been a loss of soil biodiversity, an increase of ground water contamination, and resistance has evolved in pathogens and pests as well.…”

“…In recent laboratory-scale experiments, it has been identified that modern nano-fertilisers can improve agricultural yield by increasing the rate of seed germination, photosynthetic activity, seedling growth, nitrogen fixation, and carbohydrate-protein metabolism. 101,121 Moreover, the increasing threat of resistance in plant pathogenic fungi is a major challenge for the agriculture sector. Hence, the need to explore novel and cost-effective antimicrobial bactericide and fungicide agents.…”