Thinning is a farm operation in which the number of seedlings per stand is reduced to one or two. Thinning is done to ensure that each remaining seedling has enough space, light, water, and nutrients to grow properly. When too many seedlings are growing in a stand, they compete with each other for resources, and this can lead to reduced growth and yields. By thinning the stand, the farmer can improve the overall health and productivity of the crops.