## 6 Discussion--Challenges and Future Work
### Blockchain Implementation Challenges
\begin{table}
\begin{tabular}{c c} \hline \hline
**Company/Commercial Product** & **Website** \\ \hline agrichain & [[https://agrichain.com](https://agrichain.com)]([https://agrichain.com](https://agrichain.com)) \\ agridigital & [[https://www.agridigital.io](https://www.agridigital.io)]([https://www.agridigital.io](https://www.agridigital.io)) \\ agrid ledger & [[http://www.agrid](http://www.agrid)]([http://www.agrid](http://www.agrid)) ledger.io/about/ \\ arc-net & [[https://arc-net.io](https://arc-net.io)]([https://arc-net.io](https://arc-net.io)) \\ Bühler Smart Supply Chain & [[https://digital.buhlergroup.com/smartsupplychain/](https://digital.buhlergroup.com/smartsupplychain/)]([https://digital.buhlergroup.com/smartsupplychain/](https://digital.buhlergroup.com/smartsupplychain/)) \\ Demeter.life & [[https://demeter.life](https://demeter.life)]([https://demeter.life](https://demeter.life)) \\ DOWNSTREAM & [[https://www.down-stream.io](https://www.down-stream.io)]([https://www.down-stream.io](https://www.down-stream.io)) \\ Fischoin & [[https://fischoin.co](https://fischoin.co)]([https://fischoin.co](https://fischoin.co)) \\ Honeyusuckle White & [[https://www.honeystacklewhite.com](https://www.honeystacklewhite.com)]([https://www.honeystacklewhite.com](https://www.honeystacklewhite.com)) \\ Ripe.io & [[https://www.ripe.io](https://www.ripe.io)]([https://www.ripe.io](https://www.ripe.io)) \\ TE-FOOD & [[https://tefoodint.com](https://tefoodint.com)]([https://tefoodint.com](https://tefoodint.com)) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Companies and websites which promote blockchain solutions for agriculture supply chains. not concretely specify the blockchain implementation, still concentrating on more conceptual designs. Moreover, a large number of research works (Section 3.4) use public blockchains, and the same applies to some of the commercial products identified in Section 5. However, the trade-offs of this choice in terms of performance are not always sufficiently discussed; this is because, in agri-food supply chains that involve several actors, the completion of a transaction using a public blockchain can take a considerable amount of time and computing power. In this respect, the selection of the type of blockchain to be used should be done with care, as it might affect the traceability system's performance. From a financial point of view, blockchains may increase the transparency of the food supply chain as well as consumer trust, but its usage comes with an enormous energy and financial cost [61]. It is mandatory for companies to invest a lot of money, as well as time, to train all the involved personnel and also to obtain the required equipment. On the other hand, such investments in time and money may lead to high traceability costs which may exceed the product's own cost, both in short and long term, thus a cost-benefit analysis is essential. A very interesting study considering the challenges of blockchain applications in the agriculture supply chain was conducted [PERSON] and [PERSON] [94]. This study identifies 18 boundary conditions for food traceability, 5 of which directly apply to blockchain technology. According to the authors, a significant number of these are related to regulatory requirements, the internal supply chain and production processes, which require significant organizational changes in order to support the full benefits of traceability. In the same context, [PERSON] et al. make an analysis of the blockchain's impact on the agriculture supply chain, and discuss the overall implications and challenges [95]. The main challenges highlighted include the accessibility to blockchain technology, governance and sustainability, policy and regulation rules, technical challenges and design decisions that must be taken, as well as the bridging of the digital gap between developed and developing countries in order to achieve successful adoption of such emerging technologies. [PERSON] et al.