The role of RFID in agriculture: Applications, limitations and challenges

TL;DR: In this paper, the authors present a comprehensive view of current applications and new possibilities of RFID, but also explain the limitations and challenges of this technology, including the operation in harsh environments, with dirt, extreme temperatures; the huge volume of data that are difficult to manage; the need of longer reading ranges, due to the reduction of signal strength due to propagation in crop canopy; the behavior of different frequencies, understanding what is the right one for each application; the diversity of the standards and the level of granularity are some of them.

About: This article is published in Computers and Electronics in Agriculture.The article was published on 2011-10-01 and is currently open access. It has received 296 citations till now. The article focuses on the topics: Cold chain & Traceability.

Summary

1. Introduction

• The recent advances offer vast opportunities for research, development and innovation in agriculture.
• Also, RFID shows several differences and advantages over previous technologies like barcode.

2. RFID applications in agriculture

• The development of RFID applications in agro-food has attracted considerable research efforts in the last years.
• Some areas have been developed faster than others.
• UHF frequencies typically offer better range and can transfer data faster than lowand high-frequencies.
• The use of other frequencies than 2.4 GHz avoids interference from water and the metal, and thus is typical for irrigation, greenhouse or cold chain applications.
• Low-Frequency tags use less power and are better able to penetrate non-metallic substances.

2.1. Food traceability

• A retailer that knew which of the cases had the shorter shelf life could put it out before the one with the longer shelf life.
• Another possibility of improving the traceability in the food supply chains is the integration of RFID in packaging.
• Animal identification, cold chain tracking, temperature measuring Frequency band available worldwide Same physical limitations than the 125 kHz tags because they are also inductively powered Ultra High Frequency (UHF) 433 MHz Active 3 m 10 m 10 - 100 mW.

2.2. Animal identification and tracking

• Modern animal production has changed in recent years due to the use of precision tools.
• RFID systems have been effective tools in identifying, tracking and monitoring livestock.
• Reading errors are estimated to occur in six of every 100 animals processed via traditional mechanisms, while RFID devices are estimated to produce only one error for every 1000 animals (Trevarthen, 2007).
• Also, through the use of electronic animal identification subsidies based on the number of animals or their genetic background can be allocated properly, electronic feeding stations can be implemented or tracing back of stolen stock (Voulodimos et al., 2010).

2.3. Other livestock applications

• RFID has been used as a new technique for measuring core body temperature.
• RFID sensing devices can be injected into the animal (under the skin), and provide temperature readings when interrogated by an RFID reader (Opasjumruskit et al., 2006).
• Application tests have been performed in horses (Marsh et al., 2008), poultry, beef and dairy cattle, showing good accuracy, resolution and response time for temperature measurement (Brown-Brandl et al., 2003).
• Also, the chewing and ruminating behaviors can be studied by the implementation of wireless automatic systems, addressing the dietary factors affecting normal rumen function of dairy cows (Kononoff et al., 2002; Schirmann et al., 2009).

2.4. Precision agriculture

• The development of RFID applications in precision agriculture makes possible to increase efficiencies, productivity and profitability while minimizing unintended impacts on wildlife and the environment, in many agricultural production systems.
• Moreover, the real time information from the fields will provide a solid base for farmers to adjust strategies at any time.
• Measurements showed a high correlation (greater than 99%) with those obtained using a thermocouple (Hamrita and Hoffacker, 2005).
• The marked plants can be monitored, and will be able to supply some information, including identity, growth parameters, susceptibility to biotic stress factors and productivity.

2.5. Cold chain applications

• Every day, millions of tons of temperature sensitive goods are produced, transported, stored or distributed worldwide.
• Several applications for monitoring cold chain logistics by means of RFID have been reported.
• Thus immediate decisions on the quality and/or safety of fresh produce can be made based on the temperature profile of the supply chain (McMeekin et al., 2006).
• At 433 MHz the wavelength is approximately a meter, enabling signals to diffract around obstructions.

3. Challenges and limitations

• RFID itself is not a very new technology, but its commercial use is very recent.
• Thus, implementing RFID involves a multitude of challenges.

3.1. Harsh environments

• In agricultural applications, RFID is often exposed to harsh environments with excessive dirt, dust, moisture, and they must function in both extreme heat and cold, from 30 to 70 .
• Haapala (2008) validated the performance of electronic identification tags for animals, under extremely cold temperature ( 25 C) (Haapala, 2008).
• Moreover, in the food industry tags should withstand the pasteurization process, boiling point temperatures, X-ray and gamma radiation, which is commonly used for sterilization.
• Advances in RFID make the technology more useful to food processors with new developments, like the gamma sterilizable tags now available, with a resistant up to 500 kilogray (kGy) of gamma energy (Andrechak and Wiens, 2008).

3.2. Huge volumes of data

• One limitation might be that these monitoring systems create huge volumes of data that are difficult to manage, causing a huge increase in the daily volume of data in a corporate information technology system.
• An RFID implementation can generate 10– 100 times more information than traditional barcode technology.
• Database administrators need to be able to deal with the potential stresses on the databases, both in terms of speed and volume.
• Thus, the solution lies in implementing a decentralized data management system.
• Data can be pre-processed and duplicate information eliminated close to their point of origin by intelligent systems, which could be sited at the level of the tag or reader (Roberti, 2003; Ruiz-Garcia, 2008).

3.3. Reading range

• The read range performance of tags differs extraordinarily.
• Radio propagation in real environments is complex due to multipath propagation, shadowing and attenuation.
• In agriculture, the radio frequency faces challenges due to placement of nodes for wide-area mesh coverage and reliable link quality above crop canopies.
• RFID must be able to operate in a wide range of environments such as bare fields, vineyards, orchards, from flat to complex topography and over a range of weather conditions, all of which affect radio performance (Andrade-Sanchez et al., 2007).
• For applications inside buildings like burns, greenhouses or warehouses, the radio signal has to go through many objects like walls, windows, pallets, machines, etc. which also cause a significant reduction in signal strength.

3.4. Fault detection and isolation

• An important research topic that must be faced is fault detection and isolation.
• False reads can be done as a result of radio waves being distorted, deflected, absorbed, and interfered with.
• Wrong information provided by the monitoring system should be identified and skipped.
• Also the implementation of artificial intelligence in the core of the system can block the transmission of erroneous data (Angeles, 2005).

3.5. Physical limitations

• Another important issue is to deal with the physical limitations of RFID.
• Metals and liquids inhibit the propagation of electromagnetic waves.
• This is particularly true for UHF and microwave frequencies (2.4 GHz).
• Some temperature sensitive products such as fruits, vegetables or juices have high water content, sometimes more than 90%.
• The tags can communicate each other to get to a reader circumventing environmental obstacles and extend the size of the system (Engels and Sarma, 2005).

3.6. Standards

• RFID and EPCglobal have defined a series of standards (see Tables 4 and 5), but the situation is complicated.
• There is a proliferation of incompatible standards with major RFID vendors offering proprietary systems.
• Conventional readers do not read tags at different frequencies.
• These readers are called ‘‘agile’’ and can operate at the same time at different bands (Mallison, 2005).

3.7. Level of granularity

• Normally three levels of granularity are considered: pallet, case or item-level.
• The primary advantage of case or item-level tagging over pallet-level tagging is more detailed and accurate information, since each pallet in a load and each carton on a pallet can experience temperature variations.
• But high granularity also means much more tags to handle with, higher costs and huge data to be processed (Angeles, 2005).

3.8. Cost

• An average RFID costs roughly 20–30 cents per tag, which is too costly for some products with only 50 cents value such as fruits and vegetables.
• They are still expensive as compared to a barcode label, which costs less than 1 cent.
• Thus, this higher cost of RFID makes it uneconomical to incorporate tags into every retail item (Roberts, 2006).

3.9. Lack of skilled personnel

• The lack of skilled personnel is another limitation in many agricultural implementations.
• Many companies have no qualified personnel for this purpose; there is a shortfall between the supply of talent and the market demand.
• The expansion of RFID in agriculture requires more agriculture engineers, computer scientists and technicians with RFID skills.

3.10. Information sharing

• Information sharing is probably one of the greatest challenges, but is essential for achieving a trustable and efficient traceability control in Agriculture.
• Obtaining the required level of trust and cooperation across the supply chain, collaboration with supply chain partners both up and down the chain, is necessary.
• There is a strong resistance to share information on applications that depend on data from various trading partners, information sharing issues must be resolved to achieve maximum benefit.

3.11. Integration with chemical sensors

• One of the current challenges in smart tags is the integration of chemical sensors onboard of flexible tags (Abad et al., 2009).
• In the case of fruit logistics, volatile compounds like ethanol and ethylene are very important to detect and quantify (Ruiz-Garcia, 2010).
• Resistive sensors such as Metal Oxide Sensors (MOS) for volatile evaluation have been developed into commercial MEMS (Microelectromechanical systems) by means of the development of Ultra Low Consumption.
• Hot plates which allow the reduction of the size of the sensor and thus the power required for proper operation.
• The developed platform integrates a commercial off the shelf inductive coupling RF transceiver in the 13.56 MHz band, fully compliant with the ISO15693 standard, micro-hotplate gas sensors, driving and readout electronics (Vergara et al., 2006).

3.12. Recycling issues

• As the use of RFID grows, the potential environmental impact of this kind of devices should be taken into account (Roberts, 2006).
• Moreover, when RFID tags are attached or embedded within products and not properly removed, the effects on the recycling process could be serious.
• Adhesives, computer chips, pieces of metal from antennae, and conductive inks of an RFID tag can affect the process of recycling paper, glass, plastic, and metal (Foley, 2006; Thomas, 2008).

4. Conclusions and future trends

• While the technology has been available for several decades, the 21st century has marked the beginning of a new era in RFID development and usage.
• Also improving operations by providing early warning of equipment failure and a predictive maintenance tool, improving energy management, providing automatic record-keeping for regulatory compliance, eliminating personnel training costs or reducing insurance costs.
• An important benefit of the systems is the visibility that it can give along the food chain.
• Measurements obtained are consistent and provide valuable information on the conditions encountered during the life cycle of the products.

Figures

Table 4 ISO standards related with RFID.

Table 5 RFID standards as applied to frequency.

Table 2 Classification of RFID applications by topics, power source and frequency.

Fig. 1. RFID applications in agriculture by power source and frequency.

Frequently asked questions

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The aim of this paper is to give readers a comprehensive view of current applications and new possibilities, but also explain the limitations and challenges of this technology.