Hi Ebenezer,
I think this is a really interesting question because a farmer can take great pictures of his/her products and share it on Instagram. It's all about creativity and how you are able to tell a story. His/Her problem will be less about the platform and the ability to reach his/her customers but more about exposure, he/she should definitely not be #land though because that isn't their product, depending on their products, they can look at more popular hashtags like #greens #healthyeating #organic, etc. I have a cousin who is pretty much a farmer, he also makes juices from his products, but check out his page, they sometimes just post images of the farm and the produce - @simplygreen.farms.
I hope this answers your question, if he doesn't feel free to clarify further.