# Agronomy

Agronomy, generally known as agriculture, is the science and technology of producing and using plants by agriculture for food, fuel, fiber, chemicals, recreation, or land conservation. Agronomy has come to include research of plant genetics, plant physiology, meteorology, and soil science. It is the application of a combination of sciences such as biology, chemistry, economics, ecology, earth science, and genetics. Professionals of agronomy are termed agronomists.

## History

Early humans practiced hunter-gathering, but by around 10,000 BCE, they began to domesticate plants like wheat, barley and rice. This laid the foundation for agriculture.
Ancient civilizations such as the Sumerians, Egyptians and Romans made significant advances in farming. They introduced irrigation systems, crop rotation, and early forms of fertilization.
During this period, agricultural knowledge remained relatively static in Europe, though Islamic scholars made advances in agronomy. Ibn al-'Awwam, a 12th-century Andalusian agronomist, wrote the Kitāb al-Filāḥa, a comprehensive guide on farming practices, crop management and soil conservation.
The Renaissance saw a renewed interest in scientific exploration, including agriculture. Leonardo da Vinci and other scholars contributed to early agronomic theory, studying plant growth, crop rotation, and animal husbandry.
Agronomy emerged as a distinct scientific discipline in the 1800s, driven by advancements in chemistry and biology. The development of scientific methods led to the study of plant physiology, soil chemistry, and the role of fertilizers in crop production. Justus von Liebig, a German chemist, made groundbreaking discoveries about plant nutrition, establishing that plants require specific minerals, such as nitrogen, phosphorus and potassium, for growth.
In the early 20th century, industrialization began transforming agriculture. Mechanization, the development of synthetic fertilizers and pesticides, and improved crop varieties, led to higher agricultural productivity. The Green Revolution (1940s-1960s), led by scientists like Norman Borlaug, introduced high-yield crop varieties and modern farming techniques, helping to avert hunger in many parts of the world.
By the late same century, concerns over the environmental impact of industrial agriculture, such as soil degradation, water pollution, and biodiversity loss, led to a push toward sustainable agriculture. Today agronomy continues to adapt to challenges of climate change, global food security and the need to balance productivity with environmental stewardship.

## Plant breeding

This topic of agronomy involves selective breeding of plants to produce the best crops for various conditions. Plant breeding has increased crop yields and has improved the nutritional value of numerous crops, including corn, soybeans, and wheat. It has also resulted in the development of new types of plants. For example, a hybrid grain named triticale was produced by crossbreeding rye and wheat. Triticale contains more usable protein than does either rye or wheat. Agronomy has also been instrumental for fruit and vegetable production research. Furthermore, the application of plant breeding for turfgrass development has resulted in a reduction in the demand for fertilizer and water inputs (requirements), as well as turf-types with higher disease resistance.

## Biotechnology

Agronomists use biotechnology to extend and expedite the development of desired characteristics. Biotechnology is often a laboratory activity requiring field testing of new crop varieties that are developed.
In addition to increasing crop yields agronomic biotechnology is being applied increasingly for novel uses other than food. For example, oilseed is at present used mainly for margarine and other food oils, but it can be modified to produce fatty acids for detergents, substitute fuels and petrochemicals.

## Soil science

Agronomists study sustainable ways to make soils more productive and profitable. They classify soils and analyze them to determine whether they contain nutrients vital for plant growth. Common macronutrients analyzed include compounds of nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. Soil is also assessed for several micronutrients, like zinc and boron. The percentage of organic matter, soil pH, and nutrient holding capacity (cation exchange capacity) are tested in a regional laboratory. Agronomists will interpret these laboratory reports and make recommendations to modify soil nutrients for optimal plant growth.

### Soil conservation

Additionally, agronomists develop methods to preserve soil and decrease the effects of [erosion] by wind and water. For example, a technique known as contour plowing may be used to prevent soil erosion and conserve rainfall. Researchers of agronomy also seek ways to use the soil more effectively for solving other problems. Such problems include the disposal of human and animal manure, water pollution, and pesticide accumulation in the soil, as well as preserving the soil for future generations such as the burning of paddocks after crop production. Pasture management techniques include no-till farming, planting of soil-binding grasses along contours on steep slopes, and using contour drains of depths as much as 1 metre.

## Agroecology

Agroecology is the management of agricultural systems with an emphasis on ecological and environmental applications. This topic is associated closely with work for sustainable agriculture, organic farming, and alternative food systems and the development of alternative cropping systems.

## Theoretical modeling

Theoretical production ecology is the quantitative study of the growth of crops. The plant is treated as a kind of biological factory, which processes light, carbon dioxide, water, and nutrients into harvestable products. The main parameters are temperature, sunlight, standing crop biomass, plant production distribution, and nutrient and water supply.