## 4 Challenges and Open Research Directions
### Economic Efficiency  
In agricultural economics, one of the most important characteristics is a low rate of profit of an investment project, which presents many risks from natural conditions. The benefit-cost of a new technology seeking deployment in agriculture should be carefully calculated to ensure a trade-off between the cost of technology implementation and the profit potential. Therefore, we discuss the economic aspects related to IoT implementation in smart agriculture. There are several types of costs related to the implementation of IoT in agriculture. We divided them into categories, including (1) the system initialization cost and (2) the system operating cost. The system initialization cost includes hardware purchases (IoT devices, gateways, base station infrastructure). The system operating cost includes service registration cost and the cost of labour to manage IoT devices. Furthermore, additional operating costs include incurred costs from energy consumption, maintenance, data exchange among IoT devices, gateways and cloud servers. According to the opinion of [PERSON]_[PERSON] and [PERSON] [116], the successful deployment of the IoT technologies will only happen if the customer benefits (customers need to know the benefits and potential) that IoT systems provide exceed their physical value and privacy costs. The businesses participating in the IoT domain will profit and achieve success. We can describe this process using these two conditions, as follows:  
\[\textit{Success of IoT Applications}=\left\{ \begin{array}{c}V_{service}>C_{pri}+C_{h}^{ user}+C_{pay},\ \textit{Farmer Benefits}\\ V_{info}+R_{pay}>C_{h}^{business},\ \textit{Businesses Benefits}\end{array} \right. \tag{1}\]  
where  
\(V_{service}\) is the expected value received by the IoT service users. \(C_{pri}\) is the cost of the loss of privacy. \(C_{h}^{user}\) is the equipment and hardware costs the user pays. \(C_{pay}\) is the payment for the service fee. \(V_{info}\) is the received information value. \(R_{pay}\) is the received direct payment. \(C_{h}^{business}\) is the share of the hardware and maintenance costs of the business. According to the opinion of the service user (farmers or the owner of the farm), Equation (1) shows that the perceived value of the service for the user (\(V_{service}\)) must be higher than the total of costs, including: the cost of the loss of privacy (\(C_{pri}\)), the equipment and hardware costs the user pays (\(C_{h}^{user}\)), and the payments for the service fee (\(C_{pay}\)), while the opinion of the service provider, as shown in Equation (2), shows that the received information value (\(V_{info}\)) and the received direct payments (\(R_{pay}\)) must be higher than the share of the hardware and maintenance costs of the business (\(C_{h}^{business}\)). There is still a gap between service providers and service users (farmers or the owner of the farm), leading to the slow deployment of IoT applications in smart agriculture. In terms of the economic aspect, the analyzed results show that the need for a support policy from regulatory agencies and governments to allow service providers and service users to use IoT-based smart agriculture applications in their infancy can be met. As discussed in [117], to promote smart agriculture, the European Union has issued supportive economic policies, the so-called the European CAP (Common Agricultural Policy), whose annual budget amounts to approximately EUR 59 billion and is paid for by the nations of the EU. In our view, to be able to apply IoT in the field of smart agriculture, service costs (\(C_{pay}\)) and the operating and system initialization cost of IoT (\(C_{h}^{user}\)) needs to constantly be improved and optimized to reduce the cost of the IoT services for farmers. In addition, IoT businesses (service providers) also need to maximize the value of information obtained (\(V_{info}\)) to improve the profitability of the service providers.