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Nanomaterials

NATIONAL RURAL ISSUES

Transformative technologies

A fact sheet series on new and emerging transformative technologies in Australian agriculture

� Because of their very small size and unique chemical, optical, electronic or mechanical properties, nanomaterials can be used to manufacture products that are much smaller, lighter, reactive or soluble than conventional products.

� In agriculture, a key characteristic of interest is that nanomaterials are readily transported into the cells of both plants and animals.

� Nanomaterials present opportunities to develop more targeted and efficient agricultural inputs, soil sensors and intelligent food packaging.

� Being an emerging technology, it is important to understand the potential effects of agricultural nanomaterials on human health and the environment.

Snapshot

Nanomaterials exist in nature or can be manufactured. Often they are nanoscale forms of naturally-occurring materials but with different characteristics, or properties, to the natural or bulk form. It is the unique properties of nanomaterials that have enabled the development of innovative products across many industries.

The term ‘nanomaterial’ generally refers to a material (or its component particles) that is

measured in the scale of nanometres. A nanometre (nm) is one billionth of a metre — too

tiny to imagine. A sheet of paper is about 100,000 nm thick and most animal cells are 10,000

to 20,000 nm in diameter.

The use of a nanomaterial is determined by its physical and/or chemical properties. Its

behaviour will depend on the biological, chemical and physical environment in which it

interacts. The same nanomaterial may behave quite differently in atmospheric, aquatic

and terrestrial environments.

Naturally-occurring nanomaterials are common in everyday life. They exist in the human body

in blood, body fat and certain viruses. The wax layer on some plants contains nanomaterials

as do volcanic ash, bushfire emissions, ocean spray, fine sand and dust.

Manufactured nanomaterials are present in a number of consumer products. For example,

many sunscreens contain nanoforms of titanium oxide and zinc oxide, to produce an easier

to apply and more opaque product with better light deflection properties than sunscreens

made using bulk forms of the oxides.

Widespread application of nanomaterials is constrained in agriculture due to uncertain

commercial viability and, to some extent, public concerns about the effects of nanomaterials

on food quality and human and environmental health.

A fact sheet series on new and emerging

transformative technologies in Australian agriculture

Agricultural applications

Nanomaterials, because of their very small size, can be used in the manufacture of much smaller, stronger or lighter products than those made of the ‘non-nanoscale’ material. They are also used to make devices that transmit energy and products that are readily transported within human, animal and plant systems.

Materials that are nanoscale have been used by humans for centuries, however the term nanotechnology

was only coined in the 1970s and commercial applications of nanomaterials appeared during the 1990s.

Nanomaterials have applications in many sectors, including construction, transport (including space), energy,

health, cosmetics and consumer goods. Nanomaterials are found in products such as electronic devices,

paint, glue, cleaning products, sports equipment, fabric coatings, plastics, medicines, sunscreen, toothpaste

and food additives.

Developing and emerging uses of nanomaterials include products for environmental remediation and water

filtration, solar cells, sensors for soil and water quality, devices for sensing and tracking food (for quality and

spoilage), and formulations for site-specific and slow-release agricultural chemicals.

The unique chemical and physical properties of nanomaterials, particularly high surface area, high reactivity

and tunable pore size (i.e. pore size that can be modified or manufactured to requirement), can be used to

advantage in many agricultural applications. Nanotechnology is predicted to revolutionise agriculture and

food in the same ways hybrid varieties, synthetic chemicals and biotechnology have done.

As at 2016, the main areas of innovation in agricultural nanomaterials that are moving towards

commercialisation are in the production of pesticides, fertiliser and vaccines.

Safely protecting crops Nanopesticides have the potential to provide site-specific and slow-release activity on pests and diseases

of plants, with benefits in reduced input costs and less risk to the environment.

Nanopesticides may contain a nanoscale active ingredient that because of its very small size has increased

solubility, therefore more active ingredient is taken into the cells of the plant than is the case with conventional

pesticides. Alternatively, a nanopesticide may be a nanoscale material that is used as a carrier or coating for a

conventional active ingredient. The carrier or coating can be formulated to be slow release or to release the

active ingredient in response to a trigger, such as the chemicals released by a plant in the presence of a

pathogen.

Nanopesticides can also be formulated using biological ‘active ingredients’ rather than chemical ones. The

University of Queensland has developed a pesticide by impregnating nanoclay with biological material (gene

silencing RNA) that triggers a plant’s defence response to a target pathogen. Several other nanoclay based

nanopesticides are being investigated by scientists in Australia.

Nanopesticides are not commercially available in Australia, and availability is limited overseas. Globally there

are 3000 registered patents for pesticides developed using nanotechnology, indicating to some extent, the

potential for future commercialisation.

Increasing fertiliser efficiencyThe unique chemical and physical properties of nanomaterials present many possibilities for the development

of nanofertilisers. Research is currently focused on three main forms: nutrient contained within a nonporous

nanomaterial for direct application to plants; conventional fertiliser coated with nanoscale polymer film; and

nutrient delivered as particles or emulsions at nanoscale dimensions. A very recent development is conventional

fertiliser or nanofertilisers coated with polymer containing nanoscale biosensors.

3


Nanomaterials

Scientists from the Indian Agriculture Research Institute have produced phosphorus nanofertiliser, which

is three time more efficient in terms of uptake of applied nutrient, compared with conventional inorganic

phosphorus fertilisers. This nano-phosphorus was produced by biosynthesis, with microbial enzymes

breaking down the bulk form inorganic phosphorus to its nanoscale. In 2015, the Institute was negotiating

commercialisation of the technology with an investor.

Fertilisers coated in nanoscale polymers increase product stability and control nutrient release from the

granules. Based on this concept, researchers in Canada, led by the Department of Agriculture and Agri-food,

have developed intelligent fertiliser. Plant roots release chemical signals to stimulate micro-organisms in the soil

to mineralise nitrogen from organic matter. Biosensors incorporated into a polymer coating on urea granules

also respond to the signals by changing the permeability of the polymer coating and releasing

nitrogen from the urea granule as required by the plant.

Scientists at the Australian Institute for Bioengineering and Nanotechnology are investigating the potential

of engineered nanoclay to develop fertiliser products for a range of macro and micro-nutrients.

Advancing animal husbandryNanomaterials can provide innovative animal health products, through vaccines and patches, with improved

shelf life and controlled delivery of active ingredients. Smart products can be designed for target delivery,

increasing the concentration of medicine at the affected tissue or organ and decreasing concentration in

healthy non-target tissues. Globally, a range of animal health and veterinary products is available with many

more in development but as at 2016, a small animals’ anaesthetic is the only nanomaterial-based product

available in Australia.

Research has demonstrated that a range of nanomaterials, e.g. liposomes, dendrimers and nanoclays, can be

engineered to be ‘loaded’ with a specific medicine. Once administered to an animal, the medicine is released

at a target site or at a sustained rate to provide extended protection.

Other potential applications of nanomaterials include additives in stock feed to enhance availability of minerals

and vitamins to the animal and protect it against mycotoxins and food-borne pathogens. Self-regulating drugs,

delivered by nanomaterials, provide opportunities to better regulate livestock growth and improve fertility. In

food-producing animals, nanotechnology provides many opportunities to reduce the use of antibiotics.

Enhancing agriculture and environmentIn addition to the main areas of development of agricultural nanomaterials (pesticides, fertilisers and animal

health), there are many other proposed applications from plant breeding to environmental remediation.

Engineered nanomaterials based on nanoclays and silica could be potential delivery systems of DNA to plant

cells, in order to transform the plant’s genetics for a range of agronomic advantages. Electrochemically-active

nanomaterials such as carbon nanotubes, nanofibres and fullerenes are highly sensitive biochemical sensors.

The materials could be used to closely monitor environmental conditions, plant health and plant growth, to

provide feedback to a range of crop management systems. Biochemical sensors such as nanodots could also

have a role in pesticide detection and determining soil nutrient status. Some nanomaterials, including nanoclays

and nanozeolites, enhance the water-holding capacity of soil, and therefore have the potential to extend the

period of water availability during the growing season of a crop.

Improving food and water qualityNanomaterials have the potential to be food ingredients, additives or supplements, to enhance colour,

nutritional value, shelf life and eating quality. Nanomaterials used in food may be naturally occurring or

manufactured (engineered) oxides of titanium, silicon and zinc.

Nanomaterials can be used in food packaging for a range of purposes. Nanoparticles of clay will make

packaging more robust, a nanoform biopolymer (vegetable origin) can make packaging more water resistant

and easily recyclable, and nanosilver in packaging will act as a disinfectant.

Intelligent food packaging that contains nanomaterials or nanosensors is sensitive to air and moisture changes,

or can indicate temperature changes, leakage or spoilage. This technology has the potential to improve food

quality and public health.

Nanomaterials could be developed to improve water quality and safety in treatment and filtration processes.

For example, nanoporous membranes could remove arsenic, viruses, bacteria, organic material, nitrates and salt

from groundwater and surface water, without the need for chlorine or other sanitisation agents; and graphene,

due to its high surface area and electronic characteristics, can detect heavy and/or toxic metals in water.



Photo - Karl Robinson

Tiny technology with big potential in crop protection

An environmentally-friendly and easy-to-deliver pesticide for broadacre and intensive crops has been developed by Queensland scientists. The new pesticide is a non-toxic formulation of clay and RNA molecules that can target one or a combination of viruses and insects.

The issueEven with the best crop management plans in place,

viruses and insects challenge all farmers. A certain set

of weather conditions or an ill-fated combination of

crops across neighbouring farms can suddenly and

quickly put a successful cropping season at risk.

Farmers have access to many effective pesticides

based on chemical formulations; and many of these

have been integral to successful pest management

programs and sustainable farm businesses. However,

the ongoing usefulness of chemical pesticides

depends on the availability of a range of product

options with different modes of chemical action on

the target pathogens and pests. A variety of products

is essential to reduce the opportunity for targets to

develop pesticide resistance.

Genetic engineering or modification (GM) provides

a crop protection solution, with inbuilt resistance to

some pests and diseases. However a GM solution is

not available for all crops, and it is not the preferred

choice for all producers and consumers. Similarly,

not all producers and consumers wish to produce

or consume food products from crops that have

been treated with chemical-based pesticides.

Associate Professor Neena Mitter and Associate

Professor Zhiping Xu at the University of Queensland

have identified a way to protect crops from viruses

and insects without the use of toxic chemicals or

engineered plants.

The technologyBased at the University of Queensland, the Queensland

Alliance for Agriculture and Food Innovation and

the Australian Institute for Bioengineering and

Nanotechnology, Drs Mitter and Xu have determined

how to manufacture a naturally-occurring nanoscale

clay mineral.

Called BioClay, the material is a very safe and effective

delivery agent for a range of biomolecules in living

systems. The group claims that BioClay is the world’s

first non-toxic, non-GM, biodegradable crop protection

platform. BioClay also has potential use in the delivery

of medicines for animals and humans.

Based on principles of nanotechnology and

biotechnology, Dr Mitter identified the potential

to use BioClay to encapsulate and deliver gene

silencing RNA to plants.

RNA is a single stranded ribonucleic acid, which is a

molecule that occurs in all living cells, and is involved

in the coding, decoding, regulation and expression of

genes. Gene silencing molecules are double-stranded

RNA or dsRNA.

When dsRNA molecules derived from a target virus

or insect pest are applied to leaves, the plant ‘thinks’

it is being attacked and its immune system develops

a response. In the instance of Dr Mitter’s work, the

applied molecule is a gene silencing RNA, which

effectively means that the plant’s immune system has

gained the ‘knowledge’ to destroy the pathogen about

to or already attacking the plant. The process of using

a target’s own RNA to act against it is called RNA

interference (or RNAi).

The benefitsAs a potential crop protection system, BioClay

offers new advantages or complements current

crop protection methods for both agriculture

and horticulture.

The immediate benefits of the BioClay technology will

be to provide industry with a lower cost option for

developing crop protection systems, explained Dr Mitter.

Protecting food crops

against viruses and insects

can be difficult when

available chemical options

are limited or pose a risk

to humans and the

environment.


Nanomaterials

5


Nanomaterials

Case study

Contact detailsA/Prof Neena Mitter

Queensland Alliance

for Agriculture and

Food Innovation

University of Queensland

E: [email protected]

T: 07 3346 6513

W: www.qaafi.uq.edu.au/

mitter-neena

Photo - University of Queensland

“On average it costs about $250 million to research,

develop and register a new crop protection product

based on chemistry.

“Community aversion to GM produce, pesticide

resistance, risks for human and wildlife health, and

pollution into waterways due to pesticide toxicity

act as major setbacks to the development and

acceptance to some of these products.”

In particular, BioClay provides a new system to

combat viral diseases of crops. Viruses are one of the

major pathogens responsible for plant diseases but

there are no control products available commercially

that target the virus itself.

Dr Mitter’s RNA approach means the product is target

specific, and therefore very safe in biological systems.

Because BioClay is biodegradable, there will be no

residues in the soil or end-product.

BioClay can carry the RNA of a range of pathogens

and pests that affect crops. Further it can carry RNA

from several different organisms at once, as well as

RNA from viruses and insects in the same product.

The slow-release nature of the BioClay product is

another advantage compared with conventional pest

control. When applied to the surface of leaves on its

own, RNA breaks down quickly. When formulated

with BioClay and sprayed onto plants, RNA is released

slowly, at a sustained rate for an extended time.

The product is convenient and easy to use, so the

practical aspects of crop protection for farmers

remain unchanged; maybe with the added benefit

of less spraying due to the extended action.

The futureDr Mitter’s work received a ‘Grand Challenges

Explorations Award’ from the Bill & Melinda Gates

Foundation in 2012. The award recognised the

benefits of BioClay for crop protection in agriculture

in developed and developing countries.

In 2016, Dr Mitter and her colleagues have completed

several years of glasshouse trials targeting pathogens

that cause significant economic losses to crops

such as tomatoes, beans, chickpeas and cotton —

with success.

The promising prospects of BioClay have attracted

an industry partner, Nufarm Australia Limited,

which is investing in the proof of concept and

product development along with UniQuest,

the commercialisation arm of the University

of Queensland.

With the use of new and emerging technologies,

BioClay has the potential to play an important role

in the future of agriculture. Increased production

will rely on new and alternative methods of crop

protection and improved sustainability requires inputs

with minimal risk to human and environmental health.

A formulation of nano-sized

clay and precisely-targeted

pest molecules is a safe and

promising crop protection

option of the future.



Transforming agriculture

Photo - CSIRO

With the expectation that the world’s population will exceed nine billion by 2050, nanomaterials are regarded as part of the solution of meeting the rising demand for food, water and energy without increasing the consumption of natural resources.

Over the last five to ten years, leading organisations including the International Food Policy Research Institute,

the United Nations Food and Agriculture Organisation and the European Union, have called for more research

into the role of nanotechnology in feeding the world, by improving farm production and water safety,

particularly in the poorest regions of the world.

Nanomaterials are widely promoted as being central to improved productivity and profitability of agriculture

in the future, in both developed and developing countries. Input products formulated using nanomaterials

are regarded as more environmentally friendly and require less energy, water and non-renewable resources

to manufacture.

In addition to innovative farm inputs, nanomaterials have potential to transform the entire agricultural supply

chain, from plant breeding to food processing and packaging. New products made possible with the use of

nanomaterials are generally viewed as having a positive effect on the environment, through fewer off-target

impacts, reduced residues in soil and water, and greater biodegradability.

Higher production efficiency Agricultural nanomaterials will have the ability to increase production efficiency due to lower application rates

or doses to achieve the desired effect, compared with conventional products. In addition, many formulations of

nanopesticides, nanofertilisers and nanovaccines are described as ‘smart’ or ‘intelligent’ and are designed to act,

or react, only in certain conditions (the presence of a pest, presence of infection or in response to nutrient

demand), therefore applied product is not lost from the production system.

In particular for pesticides, nanomaterials can reduce the volume of spray required, which in turn reduces spray

drift and off-target impact. The high solubility of nanopesticides and nanoclays means that spray products are

easy to prepare and do not require frequent stirring, they will not block up filters and nozzles in spray equipment

as conventional pesticides may do, and the product remains in solution for a longer time than conventional

pesticide products.

The stable nature and much lower volume of spray mixture paves the way for autonomous application (smart

delivery) of pesticides, in response to in-field sensors that could detect and locate crop infestations.

The novel formulations of pesticides using nanomaterials present an opportunity to introduce new modes of

pesticidal action to pest and disease control programs in crops. This is essential for overcoming existing resistance

in target organisms to conventional pesticides, as well as for developing future management programs.

Nanomaterials, including nanosensors, will complement and augment precision agriculture, where farmers are

using a range of data collection and decision-support technologies to refine and vary the application of inputs,

in order to maximise yield and minimise waste. Pesticides, fertilisers and animal health products formulated

using nanomaterials will further refine the goal of precision application through intelligent products that release

active ingredients as required or in response to target situations.

7


Nanomaterials

Reduced environmental impactThe high solubility of nanomaterials means that nanopesticides are quickly absorbed through the leaves

of the plant, reducing not only potential wastage of product through spray drift and run-off, but also

minimising the risk to human health and the environment. With lower application rates and more targeted

activity made possible by nanotechnology, off-site impacts, runoff and residues are much less likely, reducing

risks of contaminating soil and water.

Nanotechnology has identified a potential range of ‘greener’ nanopesticides to achieve environmental

sustainability benefits derived from naturally-occurring active ingredients, such as pheromones and essential oils.

Nanomaterials could also be the basis for safer adjuvants such as biodegradable polymers or clay nanoparticles.

There is also potential to develop delivery systems for agricultural inputs using nanomaterials based on proteins

and carbohydrates (biopolymers), which have low impact on human health and the environment.

Nanofertilisers are regarded as more environmentally friendly and sustainable than conventional fertiliser

because less volume of product is required to achieve the effective nutrient application rates. Researchers

in India claim that nano-phosphorus fertiliser enhances nutrient mobilisation, soil structure and moisture

retention, and ultimately, improves yield, while using less natural resource for its manufacture, compared

with conventional fertilisers.

Similarly, developers of intelligent fertilisers in Canada assert that polymer-coated nitrogen fertiliser that releases

nutrient at times and amounts required by the crop, minimises losses of nitrogen to the atmosphere, leaching

and runoff of nitrates.

Promising opportunitiesWhile there are promising opportunities for using nanomaterials in agriculture, most products have not been

commercialised. In reality, until farmers can be shown clear and demonstrated benefits over conventional

technologies and the demand is sufficient to convince developers to invest, agricultural nanomaterials

are unlikely to have the transformative effect on agriculture that the technology promises. However,

the experience of other industries in Australia and globally, is that nanomaterials have steadily become

economical and effective ingredients or components of choice for thousands of everyday products.



Challenges for adoption

Agriculture is a new frontier for nanotechnology and nanomaterials, both in Australia and overseas. The main challenges for adoption of the technology are the significant cost to develop commercial products and uncertain public attitudes and regulatory requirements.

The adoption of nanomaterials in agriculture lags behind the uptake of nanotechnology and nanomaterials in

many other industries, such as electronics, construction, cosmetics and pharmaceuticals, and consumer goods.

In 2015, there were over 3000 patents registered globally for nanopesticides, which indicates the anticipated

potential of such products. However, very few of these products are available commercially overseas, and in

Australia, there are no agricultural nanomaterials in use — although there is a veterinary anaesthetic for small

animals containing a nanomaterial in its formulation.

Ready to use nanotechnologyThere are many promising applications of nanomaterials in agriculture, however there have also been

applications that have showed no benefit at all. The adoption and success of nanomaterials in agriculture

requires the discovery of unique properties and processes, followed by time and resource-consuming

development to ensure the product can deliver benefits to farmers, the environment and/or consumers.

Currently, the nanomaterials that provide delivery systems and slow-release mechanisms for active ingredients

of pesticides and vaccines appear to be the main focus of development; whereas products that are nanoscale

versions of conventional active ingredients or nutrients have not always shown benefits over their bulk forms.

Cost of developmentCompanies developing agricultural products based on nanomaterials face the same challenge as companies

developing conventional agricultural products. That is, balancing the investment required to develop, validate

and register a product with likely returns from a relatively small market, when compared with markets for

consumer goods such as electronic equipment and sporting goods. While there is uncertainty displayed by

consumers and regulatory authorities, globally and locally, there will be very cautious development of product.

Consumer confidenceWhile there is strong advocacy by some organisations for a moratorium on the commercial use of

nanomaterials until risks and safety are satisfactorily assessed, public attitude to nanotechnology and

nanomaterials is more positive. An Australian government survey showed about half of respondents believed

that the benefits of nanomaterials outweighed the risks. While only 22% of respondents claimed to have an

understanding of the technology — the lack of knowledge had not translated into negative sentiment, as had

been observed for other emerging technologies, such as genetically modified foods. A survey by University

of Sydney found that the public regarded nanomaterials differently to and more favourably than ‘chemicals’

but researchers concluded that if nanomaterials were treated as chemicals by Australian regulators, public

perception may become more negative. A review of nanomaterials published in a US reported similarly, that the

public seemed to be unconcerned about many applications of nanotechnology, except in areas where there is

pre-existing social concern, such as pesticides.

Uncertain regulationsThe diversity and complexity of public attitude towards nanomaterials creates uncertainty about future public

policy and regulations, which in turn may deter investment in the development and commercialisation of many

agricultural nanomaterials.

Governments of many countries are still developing a definition for nanomaterials, for regulatory purposes,

and reviewing food labelling protocols for products containing nanomaterials. There is concern among

scientists that labelling requirements will create a stigma for nanomaterials, preventing future development

and application. Many ingredients that will require identification on labels have been used for decades and

are naturally occurring nanomaterials such as clay, silica, polymers and pigments.

9


Nanomaterials

Policy and regulation

Nanomaterials have the potential to increase farm productivity and efficiency, and reduce off-target impacts of agricultural chemicals. However, the very characteristics of nanomaterials that enable these benefits may also pose a threat to human health and the environment.

It has been generally accepted that nanomaterials are safe to humans and the environment, which is

reflected by the fact that nanomaterials exist in many readily available consumer products and foods.

However, as nanotechnology becomes more sophisticated and complex, and novel and innovative products

are developed, scientists and governments recognise the need for a cautious approach, particularly where

nanomaterials are applied to food crops.

At a policy level, nanomaterials generally are not a prominent issue. Many industries have been using

products that contain nanomaterials for several decades. However, there is concern from some scientists, and

environmental and food safety groups about potential dangers going unheeded by government and regulators.

Currently there are no mandatory standards covering the use of nanoscale particles in consumer goods. In 2014,

in response to concern of some consumer groups, the European Union changed its food labelling legislation and

now requires engineered nanomaterial ingredients, such as whiteners, colours and preservatives, to be listed.

In Australia, products containing nanomaterials are regulated by several different authorities, depending on the

end use of the product. These authorities include: Food Standards Australia New Zealand (food), Therapeutic

Goods Administration (medicines and some sunscreens), National Industrial Chemicals Notification and

Assessment Scheme (cosmetics and sunscreens, as well as industrial chemicals) and Australian Pesticides and

Veterinary Medicines Authority (pesticides and animal medicines). Definitions for nanomaterials vary across the

world and in Australia, industry-specific definitions have been developed by regulatory organisations.

The Australian regulator of agricultural chemicals published the results of a review of regulation of agricultural

nanomaterials in 2015, and concluded that “existing regulatory frameworks developed for macroscale chemicals

will be used to regulate nanomaterials. Over time, however, the framework will evolve as new information

highlighting limitations in the current risk assessment paradigm becomes available”.

Australia’s regulations in regards to nanomaterials and nanotechnology are evolving in line with worldwide

regulatory approaches for industrial, human therapeutic and agvet chemicals. Countries such as Canada,

Australia, the European Union, the UK and the USA face similar challenges in areas such as terminology,

measurement, testing methods and standards.

Government is well aware that certain nanomaterials in the workplace could put the health of workers at risk.

Safe Work Australia provides policy direction, conducts research and provides guidance on the potential work

safety and health implications from applications of nanotechnology. It also contributes to international efforts

on the same. As with all industries, employers and workers in agriculture need to keep abreast of the evolving

knowledge of the safety of nanomaterials.



Instant soil test results in the field with nanosensors

Nanosensors already have a track record for detecting nutrient levels and contaminants to manage water quality. A team of researchers is now investigating nanosensors to detect soil nutrient levels, paving the way for more precise application of agricultural fertilisers.

Assessment of soil nutrient

status currently depends

on removing soil cores

from the paddock but

frequently samples are

too few or too variable

to be a reliable measure.

The issueFaced with the challenge of feeding nine billion

people by 2050, as well as developing and expanding

their own businesses, the world’s farmers are looking

to new technologies to lift production and food

quality with minimal impact on the environment.

Agricultural researchers say that the next ‘green

revolution’ will depend on greater efficiencies and

more precise management of growing environments.

While crop rotations and pasture phases enhance soil

fertility, natural and synthetic fertilisers will remain an

essential part of high-yielding farming systems.

Fertiliser application has become more efficient and

average yields have increased in recent decades with

the advent of yield mapping and variable rate fertiliser

application. However these approaches do not

provide background information on soil health or

nutrient levels. More efficient fertiliser use, particularly

phosphorus, is also driven by the world heading

towards ‘peak phosphorus’ as finite reserves of rock

phosphate diminish and costs increase.

Refining fertiliser application by soil nutrient monitoring

depends on the laborious task of physically collecting

soil from the paddock. Soils are notoriously variable, so

the number of samples taken and accurate sampling

method are important to ensure that the sample is

representative and the results that come back from

the laboratory are meaningful.

The technologyResearchers from the CSIRO Manufacturing Flagship

and the Chinese Academy of Science are involved in

a project that could take the hard work and inaccuracy

out of monitoring soil nutrients.

CSIRO Research Program Director, Dr Ivan Cole,

explained that certain nanomaterials were used

already to monitor water quality and heavy metals

in soils, however there were not similar commercial

applications for agriculture.

“Research is needed to identify appropriate

nanomaterials and develop a device that can detect

a range of nutrients and other soil characteristics

important to farmers. Our aim is to develop a low-cost

sensing device for monitoring and mapping soil

nutrients and contaminant levels.

“Currently, we don’t know what materials would

be most suitable for detecting key soil nutrients,

such as phosphates and nitrates. These nutrients,

which are of principle interest in agriculture, are

challenging to monitor accurately owing to their

dynamic nature in soils.”

It is proposed that nanodots (or quantum dots), one

of seven main classes of nanomaterials could be used

to make the sensors. Nanodots are semi-conducting,

crystalline nanomaterials, with unique optical

properties. They make ideal sensors because they have

a high level of fluorescence, exhibit long-term stability,

detect multiple signals simultaneously and their light

emission can be customised.

While a major aim of the project is to identify the

most effective nanomaterials for sensing nutrients

in a dynamic agricultural environment, the materials

must also be environmentally friendly and economic

to manufacture.

The researchers will build a library of suitable

nanomaterials and determine their sensitivity to a

range of concentrations of phosphate and nitrate.

The relationships between the sensing material

and the nutrients within the soil are complex but

understanding these will be both a scientific and

industrial breakthrough.


Nanomaterials

11


Nanomaterials

Case study

Contact detailsDr Ivan Cole

High Performance

Metal Industries Program

CSIRO Manufacturing

E: [email protected]

T: 03 9545 2054

Photo - CSIRO

The benefitsWith laboratory and field testing planned, the

research has the potential to identify an easy-to-

operate and low-cost method for monitoring and

mapping soil nutrient levels. The resulting technology

will be simpler, quicker and cheaper than current soil

analysis procedures.

Sensor technology enables a vast number of sites

in a paddock to be sampled, whereas conventional

soil sampling often amounts to about ten samples

per paddock, which are then bulked and mixed,

for laboratory analysis of a subsample.

The researchers envisage a new attachment to

cultivation or seeding equipment that will house

soil sampling apparatus and the sensing devices.

“Such a system could be adapted to existing farm

equipment or transported to various sites as a

separate device. It could provide spatial monitoring

of key soil parameters including nutrient levels,

salinity and pH.

“By affixing the system to existing equipment,

farmers or contractors could go about their daily

routines and simultaneously acquire soil nutrient

data without having to dedicate specific resources

and costs to the task of soil monitoring.

“Understanding and optimising the health and

condition of soils is paramount for maintaining

the health of our soil environment as well as

for maintaining viable agricultural crop yields.”

The futureAt the completion of the research project, Dr Cole

and his colleagues hope they have identified suitable

nanomaterials for sensing soil nutrients and designed

a device that is robust in the field.

“Ultimately we are about making real world devices

driven by leading-edge science.

“The next step would be to enhance the nanosensors

with wireless capacity to integrate the data with

computer-controlled, GPS-guided, precision-farming

equipment. In the future, fertiliser could be applied

according to soil maps determined by the sensors.

Ultimately, the soil maps could drive equipment

such as automated robotic fertiliser systems that

provide the required rate of fertiliser to each sub-unit

of a paddock.”

While there is much technical detail to be established,

the researchers believe that nanosensors play an

important role in making fertiliser application to

farmland more efficient, economic and environmentally

responsible, as farmers rise to the challenge of feeding

the world.

Nanosensors may lift

future farm productivity

by providing real-time

soil nutrient information

to increase the efficiency

of fertiliser applications.

The components of the food and fibre

supply chain that may be transformed by

nanomaterials.

Processing

Farm operations

Natural resources

Consumers

Labour and skills

Logisitics

Inputs

The Rural Industries Research and Development Corporation (RIRDC) invests in research and development to support rural industries to be productive, profitable and sustainable. RIRDC’s National Rural Issues program delivers independent, trusted and timely research to inform industry and government leaders who influence the operating environment of Australia’s rural industries. This research informs policy development and implementation, identifies future opportunities and risks, and covers multiple industries and locations.

Published by the Rural Industries Research & Development Corporation, C/- Charles Sturt University, Locked Bag 588, Wagga Wagga NSW 2678, August 2016

© Rural Industries Research & Development Corporation, 2016. This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968.

ISBN 978-1-74254-883-8

RIRDC publication no. 16/037

Please note This fact sheet has been developed through research of publicly available information and interviews with industry participants and experts. The content is for general information purposes only and should not be relied upon for investment decisions. Case studies were prepared from interviews conducted in 2016 and reflect the use of the technology at that time.

More information � Nanotechnology regulation (Australian Pesticides

and Veterinary Medicines Authority)

apvma.gov.au/node/15631

� Nanotechnology and Work Health and Safety

(Safe Work Australia)

www.safeworkaustralia.gov.au/sites/swa/

whs-information/nanotechnology/pages/

nanotechnology

� Nanotechnology in agriculture (Nanowerk)

www.nanowerk.com/spotlight/spotid=37064.php

Series detailsThis fact sheet is one of a series on new and emerging

transformative technologies in Australian agriculture.

You may also be interested in reading about:

� Sensors

� 3D printing

� Synthetic biology

EnquiriesE: [email protected]

W: www.rirdc.gov.au

Documents

NATIONAL RURAL ISSUES Transformative …...paint, glue, cleaning products, sports equipment, fabric coatings, plastics, medicines, sunscreen, toothpaste and food additives. Developing