# Blockchain Applications in Agriculture: A Scoping Review
## 3 Results
### Characteristics of Sources and Synthesis of Results  
The characteristics and data chart for each of the 104 research papers included in the scoping review are presented in Table 1.  
The service areas (RQ1) addressed in our findings on the current use of blockchain technology in agriculture are shown in Figure 5. The majority of papers address the application of blockchain technology for management purposes (75%) and the monitoring of products (55%), which, as we expected, are the most common uses. The next favorite provided service is the certification of products (8%). Other service areas that are addressed include access control devices (4%), producers' reputation (4%), products' trading (4%), auctions (3%), reward systems (3%), and for data sharing reasons (2%). Overall, blockchain applications in the agricultural sector are at a relatively early stage of maturity (RQ2), as we found. More than half of the papers propose a solution that has not been implemented yet, as shown in Figure 6. Most of the research works (39%) are at a conceptual level, 7% are simulations, and 9% are partially experimental. On the contrary, 19 papers (18%) at the experimental level perform various experiments in blockchain technology, and 14 papers (13%) are at the proof-of-concept level. Only 14 research papers are at a high level of maturity, 7 of them (7%) are at the evaluation level using existing datasets to test their proposals, 3 papers (3%) have created a prototype implementation, and finally, 4 solutions (4%) are in a pilot phase. Figure 7 depicts the classification of the research papers by the agricultural sector and products (RQ3) primarily used in agricultural blockchain applications. Most papers (39%) refer to the farming sector, while a significantly smaller percentage refers to the livestock sector (14%). Our findings show that many research solutions (38%) do not explicitly  
Figure 4: Number of papers from different types of publication. Figure 5: Service areas addressed in the papers included in our scoping review. mention either the product or a specific sector. There is also a small percentage (9%) that refers to essential goods for the agricultural process. Furthermore, the products on which the solutions are focused are quite different from each other. The most common are crops (15%) and organic foods (4%), followed by grain, beef, and milk with 3%. There are also solutions that belong to the 2% and refer to corn, soybean, oil, wine, chickens, and cows. Other products that only referred to one solution are: citrus, tea, pumpkin, etc. Finally, we observe that there are solutions that do not refer directly to the agricultural sector but do so indirectly, such as water irrigation (6%), photovoltaics (2%), and wastes (1%). Figure 8 illustrates the geographical location for which the proposed solutions were created or implemented. Only 36% of the total solutions have been made for a specific geographical area. More than half of the proposed solutions referred to the Asian continent. More precisely, 11 papers (30%) focus on China, 5 papers (14%) on India, and 2 papers (5%) on Vietnam and Pakistan. The remaining 17 blockchain solutions in the agricultural sector (46%) are scattered in 16 countries; only Spain is referred to with more than one solution, specifically in 2 papers (5%). The analysis of each source identified more specific attributes about the blockchain technology framework (if any) used, the blockchain type utilized in the applications, the specific data stored on-chain and off-chain, and the reasons for using blockchain; a summary of the data charted is shown in Table 2.  
Figure 6: Maturity of the research presented in the papers included in our scoping review. Figure 7: Agriculture sector and products addressed in the papers included in our scoping review. Figure 9 shows the various blockchain technology frameworks (RQ5) that are considered by the proposed solutions. The most used blockchain technologies are Ethereum (35%) and Hyperledger Fabric (20%).