Agriculture is referred to as the science of cultivation of crops. A crop can be both a plant and animal product which is primarily harvested for earning profit. Crop yield is defined as the measure of production of yield of crop per unit area and generation of seeds of the plant itself. It is also known as agricultural output. The primary categories of crop are horticulture, floriculture and industrial crops. Examples of horticultural crops include tomatoes, oranges, cucumbers, etc. Floriculture crops include houseplants, cut flowers and bedding plants. Industrial crops include those crops which are grown for clothing and biofuel such as cotton, elephant grass, etc. The growth and production of forest and agricultural crops for profit is known as agricultural production. The techniques used in measuring crop yield are seed ratio and area ratio. Seed ratio is defined as the number of grain harvested for each grain seeded whereas area ratio is the number of grain harvested per unit land. This book discusses the fundamentals as well as modern approaches of agricultural and crop yield. It also unravels the recent studies in this field that unfold the innovative aspects of crop yield which will be crucial for the progress of this field in the future. The readers would gain knowledge that would broaden their perspective about agricultural yield and production.