Agronomy is a branch of agricultural science that deals with the study of crops and the soils in which they grow. Agronomists work to develop methods that will improve the use of soil and increase the production of food and fibre crops. They conduct research in crop rotation, irrigation and drainage, plant breeding, soil classification, soil fertility, weed control, and other areas.

Agronomy involves selective breeding of plants to produce the best crops under various conditions. Plant breeding has increased crop yields and has improved the nutritional value of several crops, including corn and wheat. It also has led to the development of new types of plants. For example, a hybrid grain called triticale was produced by crossbreeding rye and wheat. Triticale contains more usable protein than does either rye or wheat.

However, most growers agree that selective breeding and genetic modification by corporations and other centralized breeding stations decrease both the gastronomic quality and agronomic performance under low-input and other sustainable agriculture systems. Genetic diversity may be adversely affected by this practice as well.

Agronomy is the science of the successful growing of corps, whether it is under dry land conditions or irrigation. This includes crops such as corn, maize, sorghum, peanuts, sunflower, cotton, sugarcane, potatoes and forage.

An agronomist must develop and implement production systems with the aim to have maximum economical production without harming the environment. It would be his responsibility to choose the correct crops and use the best harvesting techniques to ensure a successful and high quality yield from the area. Before doing this, he has to study the soil and the weather, water and transport facilities, available machinery, staff, budget, possible improvements to existing conditions and anything else which might have an influence on the crop. His main objective would be to effectively manipulate the interaction between plant and environment through the use of correct management practices.