Agronomists generally work with crops that are grown on a large scale (e.g., small grains) and that require relatively little management. Agronomic experiments focus on a variety of factors relating to crop plants, including yield, diseases, cultivation, pest and weed management, and sensitivity to factors such as climate and soil. Agronomists may specialize in plant breeding and biotechnology to improve crops. Many agronomists also utilize ecological principles to conserve and protect the environment from the negative effects of agriculture, a field known as agroecology.
Agronomy is the study of the intersection of crop genetics/physiology, their management, and the environment, including soils, in which they are grown. There are some basic physical requirements inherent in a crop's genetics and basic physiology that need to be known about individual crops so that they are grown where they will be productive. These include the optimum growing season length, temperature range, and moisture requirements. In addition, some crops such as soybeans have day length – hours of light and dark – requirements that impact where they are grown.
Some of these requirements are subject to manipulation; for example, many crops have a range of growing season length, so cultivars of specific season lengths are grown. Because soybeans are sensitive to day length, different cultivars are planted from north to south to optimize growing season. The time when flowers are initiated is determined by the length of sunlight hours which will be different as one changes latitude. Flowering has to begin soon enough so that there is time for the soybean seed to grow and mature in the pod. Most agricultural crops are annuals – growth is completed in one growing season, but some are perennials that are managed as annuals. Sorghum is an example of this. Agronomists focus their study and research on such issues as planting date, row spacing, seeding rates, and nutrient needs for a particular crop.
Nitrogen’s impact on soil carbon sequestration
These are known as cultural practices. Cultural practices change as technology changes; agronomy is the science that combines these various elements into a functional production system. In addition, the order and type of crops planted over time is important and known as crop rotation. Taken together, the whole set of information is discussed as a cropping system.
Agronomy looks at agriculture from an integrated, holistic perspective. Agronomists are specialists in crop and soil science, as well as ecology. Some things they look at are:
The properties of the soil;
How the soil interacts with the growing crop;
What nutrients (fertilizers) the crop needs;
When and how to apply these nutrients;
The ways that crops grow and develop;
How climate and other environmental factors affect the crop at all stages;
How best to control weeds, insects, fungi, and other crop pests; and,
How to grow crops effectively and profitably while conserving and protecting the environment.
Agronomic crops can also be grouped by the type of crop grown. Many agronomists specialize in one or more types of crops. The major crops grown in the US are, based on USDA statistics.
Soybeans
Corn
Wheat
Hay
Cotton
Grain sorghum
Rice
Oats
Barley
