Question

What is agriculture ​

Answer 1

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the science or practice of farming, including cultivation of the soil for the growing of crops and the rearing of animals to provide food, wool, and other products

Answer 2

What is agriculture?

Agriculture, or farming, is the simplification of nature's food webs and the rechanneling of energy for human planting and animal consumption.  Huh?  You may ask.  To simplify, agriculture involves redirecting nature's natural flow of the food web.  The natural flow of the food web is-the sun provides light to plants.  Plants convert sunlight into sugars which provide food for the plants(this process is called photosynthesis).  Plants provide food for herbivores (plant-eating animals, i.e., sloths) and the herbivores provide food for carnivores (meat-eating animals, i.e., jaguars).  Decomposers or bacteria, break down plants or animals that have died.  Nutrients from the plants and animals go back into the soil and the whole process starts anew.  

What happens with agriculture is that this web is interrupted.  Instead of having herbivores eat the plants, the plants are protected for human consumption.  This means that not only are plant eating animals excluded from the food web, but also carnivorous animals and even decomposers.  However, if a farmer is planting corn to feed their cattle, the cattle eat the corn to fatten up and then are eventually slaughtered for human consumption.  Even though a herbivore (cow) is eating the plant (corn) the web in interrupted when the cow is killed for human consumption.  

Are there different types of agriculture?

Yes.  There is conventional agriculture and sustainable agriculture (agro-ecology).

Conventional agriculture, most commonly practiced in the United States, usually involves the following criteria:

altering or changing the natural environment (removing trees, tilling the soil, installing an irrigation system, etc.

mono-cropping, or planting one crop (ex: only corn is grown in a plot).

the crops grown are nonrenewable- after harvesting, the plot is bare again and requires cultivation (tilling and plowing of the soil), fertilization, planting, irrigation (watering), and harvesting all over again.

diversity is eliminated in order to maintain uniformity

using insecticides and pesticides to keep insects and animals from eating the crops; these chemicals are not only poisonous to insects, animals and humans, they also pollute ground water, streams, rivers, and oceans.  

using inorganic fertilizers to provide nutrients to the soil

a lot of energy and work for the farmer to maintain this unnatural farming system; nature is more aligned with diversity (it wants to be wild), rather than controlled and uniform.