The Sickle can be used to gather wheat a lot more efficiently and get Plant Fiber which can be used to craft string making it a good early game alternative to killing spiders in order to aquire string. The Sickle can also be used as a weapon as it has higher attack speed than an Iron Sword but it deals less damage. The Sickle similar to the Shears can only be crafted out of Iron and not with any other matterial. It also can be enchanted with Unbreaking, Mending and Fortune (fortune can only be used to get more Plant Fiber and will not further increase the amount of wheat dropped).
You can aquire Plant Fiber by harvesting short grass, tall grass, fern or large fern with the Sickle (all of them normally drop 1 Plant Fiber). You can use 4 Plant Fiber in any configuration to craft 2 string. Plant fiber can also be used as a fuel source and is compostable.
