## 3 The AgroTRACE Infrastructure
### Event Capturing and IoT Application Platform
#### 3.1.2 IoT Applications  
In fresh produce traceability systems, there is the need for continuous monitoring of the location and conditions of a product throughout the supply chain from farm to store. Starting from the in-field crop production management practices, the need for informed decisions on fertilization, plant protection, harvesting, transport, storage and standardization has led to the development and deployment of IOT in agriculture. Such wireless sensing systems allow for measuring crop, soil, weather and environmental parameters as can be seen in Table 2. In short, the sensing systems of AgroTRACE can be classified into systems implemented at farms and during transportation and storage. In practice, weather stations and wireless sensing systems are used at farm level for measuring weather parameters, including ambient temperature, relative humidity, atmospheric pressure, wind velocity and precipitation. Furthermore, important soil parameters are measured, such as soil temperature, moisture content and electrical conductivity. Finally, greenhouse gas emissions are measured at points of interest, while tracking tractors' activity is accomplished through Global Navigation Satellite System (GNSS). Checking the conditions of transport and storage of vulnerable products and tracking their location is also of major importance. For this purpose, measurements of temperature, humidity and CO\({}_{2}\) concentration are continuously taking place. The IoT applications include also the use of RFID technology at several stages of the fresh produce supply chain ranging from the field level to the store and also to waste management. In particular, the following five cases of using RFID take place:  
* From field to the packaging plant: Each pallet leaves from the field having an RFID with an EPC number. In the packaging plant, RFID readers are used to scan each batch at the sorting lines and the temporary storage sites, where the products are pending sorting and packaging. Regarding the EPC numbers, they are linked to new EPC numbers to be assigned to different batches and pallets by using sorting systems. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Supply Chain Part** & **Parameter Type** & **Measured Parameter** \\ \hline \hline \multirow{4}{*}{Farm} & \multirow{4}{*}{Weather} & Ambient temperature \\  & & Relative humidity \\  & & Atmospheric pressure \\  & & Wind velocity \\  & & Precipitation \\  & & Soil temperature \\  & Soil & Moisture content \\  & & Electrical conductivity \\  & Environment & Greenhouse gas emissions \\  & Location & Tractor’s location tracking \\  & Transportation and storage & \
\begin{tabular}{c} Transportation and storage \\ environment conditions \\ \end{tabular} &
\begin{tabular}{c} Transportation and storage \\ Relative humidity \\ CO\({}_{2}\) concentration \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The main parameters measured by IoT systems across the agri-food supply chain. In the packaging plant: Each package (at the level of cardboard box or the corresponding reusable packaging item) and each pallet have an RFID tag with EPC number, while the packaging plant has RFID readers at the exits of the products to be sent. During transportation: The trucks are equipped with both RFID readers and beacon devices for recording useful data pertaining to humidity, ethylene concentration and temperature, as a means of continuously monitoring the transportation conditions. To this end, the LoRaWAN network is also used for data transmission at the level of city-logistics for enabling prompt response of the supply chain as the fresh commodities approach the retail point. In the store: The retail stores are equipped with beacon devices providing useful information to the customer's smartphone via reading EPC numbers with RFID readers. During waste management process: Each partner of the supply chain that produce organic waste has to assure the correspondence of each departing pallet with an EPC number on an RFID tag.