Chemical fertilizers can increase crop productivity but they also cause soil mineral imbalances and lower soil fertility. Chemical fertilizers can cause irreparable soil damage and soil microbial flora. It can affect the food chains of ecosystems that are responsible for future heritable mutations.
Researchers are concerned about the excessive use of chemical fertilizers in agriculture due to the rapid increase in world population. The promising alternative to chemical fertilizers is nano-fertilizers, which can ensure high crop production and soil rehabilitation.
Why are Nano-Fertilizers better than conventional fertilizers?
Nanoparticles have unique properties that can be used to enhance plant growth, including their high sorption capacity and increased surface-to-volume ratio.
These characteristics make nano-structured fertilizers a smart way to deliver nutrients to plants. Nano-fertilizers release nutrients much more slowly than conventional fertilizers. This improves nutrition management by increasing nutrient-use efficiency as well as decreasing nutrient leaching to groundwater.
Nano-fertilizers have been specifically engineered to release active ingredients in response of biological demands and environmental stresses. Scientists also believe that nano-fertilizers can increase agricultural productivity by increasing photosynthetic activity, seedsling growth, rate for seed germination, nitrogen metabolism and carbohydrate as well as protein synthesis.
The Development of Nano-Formulations Effectively
Ammonium humate and urea are used to make nano-formulations. These fertilizers can be made from plant wastes, urea or urea. Nano-sized nitrogen (N), which is made from ammonium humate, ammonia, urea and other synthetic fertilizers, is an example of nano-formulation. It is formed by the deposition of calcium cyanamide on urea.
The effectiveness of nano nitrogen fertilizers is crucial in increasing rice productivity. Because it promotes growth, this is an excellent option to chemical fertilizers. Excessive usage of conventional fertilizers can cause environmental pollution through leaching, denitrification and volatilization.
A second effective nano-fertilizer was created by grinding urea and combining it with other biofertilizers. This nano-fertilizer provides a slower and more gradual release of nutrients over a longer period.
The development of nano-fertilizers is done using both biochemical and mechanical processes. Materials are ground to produce nano-sized particles by mechanical means, while biochemical techniques are used to create effective nanoscale formulations.
Many fertilizers are encapsulated in nanoparticles. These nano-fertilizers have a higher absorption capacity and a higher nutrient use efficiency for the plant. There are three methods to encapsulate nutrients with nanomaterials. These are the three methods.
- A thin layer of nanomaterials (polymer films) is applied to nutrient particles.
- Nanomaterials with varying chemical composition and nature contain nutrients.
- Nano-emulsions deliver nutrients
How do nano-fertilizers enter the plant system?
Research has shown that nanomaterials (nanofertilizers), are more easily absorbed by the root system of plants than traditional fertilizers. Nanomaterials are also able to enter leaves through the stomatal openings.
To determine how effective nanoparticles can penetrate plant systems, scientists have used the Vicia faba bean. The researchers found that nanoparticles 43 nm in diameter could penetrate leaves in large quantities, compared with nanoparticles larger then 1.0 nm.
It is also known that nano-fertilizers can deliver nutrients via plasmodesmata. Plasmodesmata, which are small channels measuring between 50-60 nanometers in size that transport ions between cells, are described as nano-sized channels. Silica nanoparticles and carbon nanotubes are useful tools to transport and deliver cargoes (nutrients, and other important biochemicals), to the target plant site.
Sustainable Crop Development: Use of Nano-Fertilizers
Scientists believe zinc nano-fertilizers contribute to robust plant growth (shoot, root system) as well as increasing the leaf’s chlorophyll.
A previous study showed that the addition of zinc nano-fertilizers significantly improved the peanut yield. These nano-fertilizers can also increase vegetable seed production. Carbon nanotubes containing fertilizers have been reported to reduce the time it takes for seeds to germinate. These nano-fertilizers have also been shown to encourage the growth of root systems in rice seedlings.
Nano-fertilizers can also decrease the crop cycle time and increase crop yield. The addition of nanoparticles containing NPK (nitrogen-phosphorus and potassium) to wheat led to an increase in grain yield, as well as a 40 day shorter crop cycle. Similar results were also obtained with the maize cropping method.
Limitations of Nano Fertilizers
Although nano-fertilizers can help in sustainable crop production, they should be considered carefully before being sold. Nano-fertilizers are limited because of the lack of strict monitoring and gaps in research.
Below are some of the problems associated with using nano-fertilizers to sustain crop production.
- Inadequacy of risk management systems for nano-fertilizers
- There is a shortage of the required quantity of nano fertilizers. This hinders the widespread adoption of nano fertilizers as a source for plant nutrients.
- Nano fertilizers are expensive
- The formulation process is not standardized. This can lead to different results for the same nanomaterial in different pedoclimatic environments.
Manufacturers of nano-fertilizer approved
These are some of the most widely used nano-fertilizers in the world, as well as their manufacturers:
- Nano Calcium (AC International Network Co., Ltd., Germany)
- Nano-Micro Nutrient (Shan Maw Myae Trading Co. Ltd., India).
- Nano Green (Nano Green Sciences, Inc., India)
- Biozar Nano-Fertilizer (Fanavar Nano-PazhooheshMarkazi Company, Iran)
References and Further Reading
Zulfiqar, F. et al. (2019) Nanofertilizer use for sustainable agriculture: Advantages and limitations. Plant Science. 289:110270. https://doi.org/10.1016/j.plantsci.2019.110270
Al-Juthery, H.W.A. et al. (2019) Effect of foliar nutrition of nano-fertilizers and amino acids on growth and yield of wheat. Conference Series: Earth and Environmental Science. 388, 012046. https://doi.org/10.1088%2F1755-1315%2F388%2F1%2F012046
Muhammad, A.I. (2019) Nano-Fertilizers for Sustainable Crop Production under Changing Climate: A Global Perspective. https://www.intechopen.com/books/sustainable-crop-production/nano-fertilizers-for-sustainable-crop-production-under-changing-climate-a-global-perspective
León-Silva, S. et al. (2018) Design and Production of Nanofertilizers. In: López-Valdez F., Fernández-Luqueño F. (eds) Agricultural Nanobiotechnology. Springer, Cham. https://doi.org/10.1007/978-3-319-96719-6_2
Solanki, P. et al. (2015) Nano-fertilizers and Their Smart Delivery System. In: Rai M., Ribeiro C., Mattoso L., Duran N. (eds) Nanotechnologies in Food and Agriculture. Springer, Cham. https://doi.org/10.1007/978-3-319-14024-7_4