# Blockchain Applications in Agriculture: A Scoping Review
## 4 Discussion
### Overall Findings in Brief  
In this section, we summarize the main findings of our research, giving detailed answers to each research question based on the observations made in the included papers and also providing the limitations. The overall results of our analysis are presented below:  
**RQ1--Service area**:
**Summary**: The most common use of blockchain is for monitoring, product management, or their combination. In recent years, its use has been proposed for the certification of various stages of production or processes. In the agricultural sector, it has also been proposed for the auctioning or trading of products. Finally, there are proposals for its uses in reputation and reward systems. **Limitations**: It is not always obvious for which service area the application is designed. The terminology used is sometimes confusing. **RQ2--Maturity level**:
**Summary**: Although the majority of solutions are in the early stages of maturity, a large percentage of solutions are at a developed level. Unfortunately, no application on Ethereum has reached the highest level of maturity. **Limitations**: A key difficulty was determining the right level of maturity in the identified solutions. It was often unclear at what stage the provided solutions were, while in other works, the terminology used for the maturity level has different meanings to the authors of the papers. This was primarily solved by precisely defining each maturity level as described in the methodology. **RQ3--Agriculture product**:
**Summary**: Most works refer generally to an agricultural sector rather than a specific product. Moreover, there are more implementations in agricultural products than in livestock. In addition, a small percentage of papers focus on the goods needed in the agricultural sector. **Limitations**: It could be considered which products can be helped by the use of blockchain. Moreover, the use of blockchain for utility products (e.g., water) is limited, but it can help automate processes and precision agriculture. **RQ4--Country**:
**Summary**: Most implementations concern Asian countries and, more specifically, China. **Limitations**: There are not enough solutions that focus on the particularities of each country and its most important products. **RQ5--Blockchain technology**:
**Summary**: Most of the solutions are developed on Ethereum and Hyperledger Fabric. Fewer of the other blockchain technologies have been used. **Limitations**: Many conceptual solutions do not mention technology. No solutions have been presented that propose a cross-chain blockchain among agricultural entities. **RQ6--Blockchain type**:
**Summary**: The majority of solutions use a private permissioned blockchain type, while a large percentage also use public permissionless ones. Finally, in some cases, both blockchain types are combined. **Limitations**: Different agricultural operators have different needs; this is not considered when choosing the type of blockchain to be used. Moreover, the benefits of each type are not analyzed on a case-by-case basis. **RQ7--Data on blockchain**  
**Summary**: The most common data stored on blockchain are data from IoT devices. Due to the cost of data storage, it is often stored periodically (in public blockchains) or off-chain; only the hash is stored on the blockchain. Finally, due to the trend of tokens, they are also stored on-chain. **Limitations**: In many cases, the cost of data storage is not a consideration, especially in a public permissionless blockchain. Moreover, many papers have not yet proposed tokens for the agricultural production line. **RQ8--Off-chain data**  
**Summary**: The most common data stored off-chain are again IoT data. The most common technologies that have been used are mainly IPFS and, to a lesser extent, BigchainDB and QLDB. Of course, a conventional database can also be used. **Limitations**: There are no investigations into how data are secured in case of deletion from off-chain storage. Moreover, known solutions such as Swarm have also not been tested.