Notes

1. INTRODUCTION:
Agribusiness refers to any business associated with farming and farming-related commercial activities. The existing agriculture structure lacks (1) the traceability of the product,(2) the security of product information, and (3) the trust among the partners in the supply chain.Blockchain is a distributed database technology that maintains the list of data records that are verified by all the participating nodes in the network. Instead of information routed through a central node, each participating nodes store a copy of the data records and forwards to all the remaining nodes within a network. Blockchain technology has been applied successfully in the financial sector especially in banking and cryptocurrency. Its application in agribusiness is gradually increasing motivated by the Agri-product fraud that leads to adverse effects on the health of consumers. Some of the promising benefits of adopting this technology can be outlined.The paper presents a brief overview of the background study, past works and tries to identify the need and usage of BCT in the agri-food sector. Section "Discussion," provides a discussion about the state of practice and the current open issues related to BCT.

2. LITERATURE REVIEW
2.1. Blockchain in Supply Chain Management:
The paper examines the influence of blockchain technology on agriculture and the food supply chain. It presents various ongoing projects that make use of the technology in their supply chain focusing on food security, food safety, food integrity, small farmer support, waste reduction, supervision, and management. The proposed system is a web application using BigchainDB, Linux(Ubuntu), Python 3.6, and Monit. The web-based user-friendly agricultural supply chain enables greater transparency and enhanced product quality. Fair and timely payment is ensured and the involvement of the middleman is eliminated. The paper highlights the major problems faced by Indian farmers. The proposed system is believed to provide transparency about the product's status while maintaining a good relationship between producer and consumer. System also helps to track the changing market price and incorporate the current market price in the blockchain.

2.2. Blockchain in Food Traceability:
Authors propose a food traceability system that is self-trust and self-organized. The authors highlight some of the companies who have built blockchain-based systems for tracking and tracing agri-food products. IoT technologies eliminate human intervention by replacing manual recording and verification as possible. The article discuss the application of blockchain in the safety and quality of agri-food. The digital data is recorded at every stage of the supply chain, e.g. farmer, food processor, packer, distributors, and retailer. Data recorded in blockchain are immutable and accessible to all parties, which enables to trace of the products.

2.3. Blockchain in Farmer Direct Marketing :
Author proposes a Producer-Consumer Model(BPCM) which enables the farmer to sell their commodities directly to the consumer while preventing inter-agents from using smart contracts. The BPCM is developed using. a public blockchain where farmers and consumers are provided with a unique identity. The proposed model allows farmers to directly sell their products to consumers. Consumers also get the product at a reasonable price while maintaining a direct relationship with the farmer. The Proof of Work (PoW) consensus algorithm is used to ensure that all the nodes in the BPCM agree to the transaction.

2.4 Blockchain in Simplifying Transaction
System enables transaction peer-to-peer and smart contracts that execute automatically when specified conditions are met. Sensor data and transactional information can be recorded in the blockchain permanently. Farmer store all the details of their crops that are available to who wants to know its history before buying it.

3. BLOCKCHAIN APPROACHES IN AGRICULTURE:
The use of blockchain technology in agriculture is growing. Six start-up companies have been selected as case studies to examine the application and benefits of adopting the technology. Table 2 highlights some of the insights of the cases while Table 3 summarizes the findings of the analysis.

Case 1- AgriDigital -: AgriDigital is the world's first settlement of an agricultural commodity on a blockchain which enables real-time payment removing the counterparty risk for the seller. The platform records all the critical data about farming, production, transportation, and delivery of products on the cloud. Agridigital is the world's first company to executed live-ever settlement of the physical product on the blockchain between grower and a buyer. The company now has 300 active users and is operating in 30 countries, tracking of real-time data (location, status of assets at any given time).

Case 2- TE-FOOD: TE-FOOD is a public permissioned blockchain-based farm-to-table food traceability system that enables all supply chain participants and the customer to trace the food's information. Its mission is to offer transparency in the food supply chain by monitoring the items through the whole supply chain. TE-FOOD is a complete package of tools and applications needed to implement food traceability by end-to-end operational visibility and process control. To identify the tracked physical objects (products, locations, etc), the system implements three different identifications materials: plastic seals with QR codes, plastic identification tags with RFID, and paper-based label stickers.
TE-FOOD is a food trackability solution that offers different services B2B, B2C and B2A (Business-to-Consumer) to businesses, consumers and regulatory bodies. TFD token that runs on the Etherum network has low transaction/second(15 TPS) which is relatively slow.

Case 3- Etherisc: Etherisc builds decentralized, blockchain-centric applications for different sectors of the insurance industry. Crop insurance solution has been successfully tested in a Srilanka in collaboration with Aon and Oxfam. In November 2020, Etherisc will team up with Chainlink to deliver crop insurance in Kenya.Etherisc is a crop insurance company based on blockchain technology. Instant payment are triggered based on the weather data without making farmer to claim. Some of the challenges/issues faced by Etherisc are: Basis risk caused by poorly designed goods, distance between index measuring site and actual production field and unpredictability of the region covered.

Case 4- AgriLedger: The mission of AgriLedger is to empower small farmers by making easy processes to access the global market via the mobile platform and financial services. It is a mobile application build on top of R3's Corda (blockchain platform) for the supply chain building trust among each other. AgriLedger is a blockchain-based mobile application for simplifying the transaction in the agri-food supply chain. The digital wallet facilities the farmer in applying and receiving a direct deposit from the financial institution. Also, implementation of financial transaction from buyer to farmer allows the farmer to receive payment for their products faster. With AgriLedger, every farmer, supplier, Agri-product receives a unique ID or QR code sticker that must be processed at each stage of the way. This way digital information is recorded at every stage of supply chain that can be trusted by everyone in the chain.Small farmers in developing countries are benefited from the AgriLedger, a digital ledger that helps them track their crops and produce. Digital identity to small farmer open opportunity to reach financial services (banking, microfinances and loans) that boost farmer's income by 50%.

Case 5-Ripe.io:The "Blockchain of Food" is a food tracking network that aims to provide information about the origin of the food, its growing circumstances, how it was delivered and other food data. The system comprises a software stack that includes a blockchain, on top of which a hardware solution may plugin and upload data.Ripe.io aims to reconnecting the supply chain by use of blockchain technology and IoT sensors. The company's aim is to ensure that all parties involved in the food supply chain have access to information about the origin and production conditions of the crops they are growing [41].

Case 6-AgUnity: AgUnity is a smartphone app that helps small farmers in planning, trading, and tracking their daily transactions. It is built on a Multichain blockchain platform that enables to connects farmers with buyers. So far AgUnity has initiated two pilots projects in Kenya and Bougainville.Farmers are given smartphones pre-loaded with the AgUnity software. Smartphones provided for farmer with inbuilt application play major role in storing and maintaining immutable records. Each farmer is assigned a digital wallet to hold receipts, which are subsequently converted to cash at the cooperative.

4. DISCUSSION
Many pilot projects have been launched all around the globe that aims to address the current problems seen in the agriculture industry. Experts believe that permissioned blockchain lacks the property of trustless and publicly open so in near future, the trend would shift from permissioned to permissionless. The current trend of blockchain adoption has shifted from non-adoption to planning and exploration of alternatives and early-stage adoption. Some of the challenges faced by blockchain for its adoption in the agriculture industry are[50]: fraud risk, centralized control, data tempering danger, and lack of consensus mechanism.

5. CONCLUSION
Blockchain technology would be a transformative technology in the agriculture industry. But for it to come to full fruition, issues (cost, scalability, performance, data privacy, technical maturity, security) need to be resolved. Further research on large use cases and mature block-chain projects would give real picture of advantages.