The part of the grain people favor the most is the head of the plant. You don't eat the stems and leaves of rice or wheat plants, right? You eat the head where the grains are.
When you want to harvest the head of the plant you'd like to eat, you need to use a hoe (ほ). Using a hoe, you can dig up the bottom of the plant without injuring the head.
Currently there are no similar looking kanji which exist in the WaniKani learning system