What is difference between agriculture and horticulture?

Horticulture is defined in the strict sense as the science that employs special techniques and methods to cultivate plants, including methods used to properly condition the soil for seed planting or planting tubers. The domain of horticulture includes cultivation, plant propagation, breeding of plants, production of crops, plant physiology as well as biochemistry and genetic engineering. The plants looked at are mainly vegetables, trees, flowers, turf, shrubs, fruits and nuts. Horticulturalists carry out extensive research in their domain in order to get better quality crop yields, improve their nutritional value to humans, make crops pest and disease resistant and adjust to environmental stresses. The most notable difference from agriculture is that horticulture deals with small scale gardening and usually in enclosed gardens although this is not a necessity while agriculture is done on large scale with extensive crop cultivation.

Agriculture is the science of growing food crops and rearing animals for farming. It involves the whole web of processes employed in the redirection of the natural flow of the food chain and the rechanneling of energy. The natural food web starts with the sun providing sunlight to plants which is then converted to sugars which are processed into plant food in a process called photosynthesis. Herbivores animals will eat plants as their food and the carnivores animals will eat the herbivores for food. Dead animals and plants will be decomposed by bacteria and return to the soil as plant nutrients and the whole chain repeats afresh. Agriculture actually rearranges this web so that plants are protected for human consumption although plants can be grown specifically for animal (herbivores) consumption like cattle, which is in turn reared for human consumption. Agriculture can be divided into two categories, which are conventional and sustainable agriculture. Conventional agriculture deals with modifying some environmental factors like trees, soil tilling, and irrigation and all activities that favor single crop growing especially for crops like wheat, rice and corn. Sustainable agriculture is where ecological principles are employed in the farming. It is also known as agro-ecology. It aims at sustainable farming practices. It involves planting of a variety of crops together so the farming garden will never be bare at any time.