Fields are fertilized to replenish the soil with nutrients that have been depleted during cultivation. In the past, farmers used animal manure, but this could not fully meet the needs of the land, leading to practices such as abandoning fields or leaving them fallow. The use of industrial fertilizers has become common, but has caused environmental concerns. To address these issues, sustainable fertilization practices are being explored. Fertilization traditionally occurs during plowing before planting, usually around September. The manure was transported in manure wagons, placed in piles on the field at regular intervals, and then spread evenly with four-pronged pitchforks.