not_spam.txt

Practical AI in Java 人工智能编程

    * 8 See also
    * 9 External links
          o 9.1 Specific countries

[edit]

Overview
Tea plantation in Java, Indonesia
Enlarge
Tea plantation in Java, Indonesia

Agriculture can refer to subsistence agriculture, the production of enough food to meet just the needs of the farmer/agriculturalist and his/her family. It may also refer to industrial agriculture, (often referred to as factory farming) long prevalent in "developed" nations and increasingly so elsewhere, which consists of obtaining financial income from the cultivation of land to yield produce, the commercial raising of animals (animal husbandry), or both.

Agriculture is also short for the study of the practice of agriculture—more formally known as agricultural science. Agricultural students are known (sometimes derisively) as "Aggies".

Increasingly, in addition to food for humans and animal feeds, agriculture produces goods such as cut flowers, ornamental and nursery plants, timber or lumber, fertilizers, animal hides, leather, industrial chemicals (starch, sugar, ethanol, alcohols and plastics), fibers (cotton, wool, hemp, and flax), fuels (methane from biomass, biodiesel) and both legal and illegal drugs (biopharmaceuticals, tobacco, marijuana, opium, cocaine). Genetically engineered plants and animals produce specialty drugs.

In the Western world, the use of gene manipulation, better management of soil nutrients, and improved weed control have greatly increased yields per unit area. At the same time, the use of mechanization has decreased labour requirements. The developing world generally produces lower yields, having less of the latest science, capital, and technology base.

Modern agriculture depends heavily on engineering and technology and on the biological and physical sciences. Irrigation, drainage, conservation and sanitary engineering, each of which is important in successful farming, are some of the fields requiring the specialized knowledge of agricultural engineers.

Agricultural chemistry deals with other vital farming concerns, such as the application of fertilizer, insecticides (see Pest control), and fungicides, soil makeup, analysis of agricultural products, and nutritional needs of farm animals.

Plant breeding and genetics contribute immeasurably to farm productivity. Genetics has also made a science of livestock breeding. Hydroponics, a method of soilless gardening in which plants are grown in chemical nutrient solutions, may help meet the need for greater food production as the world's population increases.

The packing, processing, and marketing of agricultural products are closely related activities also influenced by science. Methods of quick-freezing and dehydration have increased the markets for farm products (see Food preservation; Meat packing industry).

Mechanization, the outstanding characteristic of late 19th and 20th century agriculture, has eased much of the backbreaking toil of the farmer. More significantly, mechanization has enormously increased farm efficiency and productivity (see Agricultural machinery). Animals, including horses, mules, oxen, camels, llamas, alpacas, and dogs; however, are still used to cultivate fields, harvest crops and transport farm products to markets in many parts of the world.

Airplanes, helicopters, trucks and tractors are used in agriculture for seeding, spraying operations for insect and disease control, Aerial topdressing, transporting perishable products, and fighting forest fires. Radio and television disseminate vital weather reports and other information such as market reports that concern farmers. Computers have become an essential tool for farm management.
Farming, ploughing rice paddy, in Indonesia
Enlarge
Farming, ploughing rice paddy, in Indonesia

According to the National Academy of Engineering in the US, agricultural mechanization is one of the 20 greatest engineering achievements of the 20th century. Early in the century, it took one American farmer to produce food for 2.5 people, where today, due to engineering technology (also, plant breeding and agrichemicals), a single farmer can feed over 130 people [1]. This comes at a cost, however, of large amounts of energy input, from unsustainable, mostly fossil fuel, sources.

Animal husbandry means breeding and raising animals for meat or to harvest animal products (like milk, eggs, or wool) on a continual basis.

In recent years some aspects of industrial intensive agriculture have been the subject of increasing discussion. The widening sphere of influence held by large seed and chemical companies, meat packers and food processors has been a source of concern both within the farming community and for the general public. There has been increased activity of some people against some farming practices, raising chickens for food being one example. Another issue is the type of feedgiven to some animals that can cause Bovine Spongiform Encephalopathy in cattle. There has also been concern because of the disastrous effect that intensive agriculture has on the environment. In the US, for example, fertilizer has been running off into the Mississippi for years and has caused a dead spot in the Gulf of Mexico, where the Mississippi empties. Intensive agriculture also depletes the fertility of the land over time and the end effect is that which happened in the Middle East, were some of the most fertile farmland in the world was turned into a desert by intensive agriculture.

The patent protection given to companies that develop new types of seed using genetic engineering has allowed seed to be licensed to farmers in much the same way that computer software is licensed to users. This has changed the balance of power in favor of the seed companies, allowing them to dictate terms and conditions previously unheard of. Some argue these companies are guilty of biopiracy.

Soil conservation and nutrient management have been important concerns since the 1950s, with the best farmers taking a stewardship role with the land they operate. However, increasing contamination of waterways and wetlands by nutrients like nitrogen and phosphorus are of concern in many countries.

Increasing consumer awareness of agricultural issues has led to the rise of community-supported agriculture, local food movement, slow food, and commercial organic farming, though these yet remain fledgling industries.
[edit]

History
Ancient Egyptian farmer
Enlarge
Ancient Egyptian farmer

Archaeobotanists have traced the selection and cultivation of specific food plant characteristics, such as a semi-tough rachis and larger seeds, to just after the Younger Dryas (about 9,500 BC) in the early Holocene in the Levant region of the Fertile Crescent. Limited anthropological and archaeological evidence both indicate a grain-grinding culture farming along the Nile in the 10th millennium BC using the world's earliest known type of sickle blades. There is even earlier evidence for conscious cultivation and seasonal harvest: grains of rye with domestic traits have been recovered from Epi-Palaeolithic (10,000+ BC) contexts at Abu Hureyra in Syria, but this appears to be a localised phenomenon resulting from cultivation of stands of wild rye, rather than a definitive step towards domestication. It is not until ca. 8,500 BC, in middle-Eastern cultures referred to as Pre-Pottery Neolithic B (PPNB), where there is the first definite evidence for the emergence of a widespread subsistence economy that was dependent on domesticated plants and animals. In these contexts lie the origins of the eight so-called founder crops of agriculture: firstly emmer wheat, einkorn wheat, then hulled barley, pea, lentil, bitter vetch, chick pea and flax. These eight crops occur more or less simultaneously on PPNB sites in this region, although the consensus is that wheat was the first to be sown and harvested on a significant scale. There are many sites that date to between ca. 8,500 BC and 7,500 BC where the systematic farming of these crops contributed the major part of the inhabitants' diet. From the Fertile Crescent agriculture spread eastwards to Central Asia and westwards into Cyprus, Anatolia and, by 7,000 BC, Greece. Farming, principally of emmer and einkorn, reached northwestern Europe via southeastern and central Europe by ca. 4,800 BC (see, among others, Price, D. [ed.] 2000. Europe's First Farmers. Cambridge University Press; Harris, D. [ed.] 1996 The Origins and Spread of Agriculture in Eurasia. UCL Press).
A tractor ploughing an alfalfa field
Enlarge
A tractor ploughing an alfalfa field

The reasons for the earliest introduction of farming may have included climate change, but possibly there were also social reasons (e.g. accumulation of food surplus for competitive gift-giving). Most certainly there was a gradual transition from hunter-gatherer to agricultural economies after a lengthy period when some crops were deliberately planted and other foods were gathered from the wild. Although localised climate change is the favoured explanation for the origins of agriculture in the Levant, the fact that farming was 'invented' at least three times, possibly more, suggests that social reasons may have been instrumental. In addition to emergence of farming in the Fertile Crescent, agriculture appeared by at least 6,800 BC in East Asia (rice) and, later, in Central and South America (maize, squash). Small scale agriculture also likely arose independently in early Neolithic contexts in India (rice) and Southeast Asia (taro).
Sumerian Harvester's sickle, 3000 BCE. Baked clay. Field Museum
Enlarge
Sumerian Harvester's sickle, 3000 BCE. Baked clay. Field Museum

Full dependency on domestic crops and animals (i.e. when wild resources contributed a nutritionally insignificant component to the diet) was not until the Bronze Age. If the operative definition of agriculture includes large scale intensive cultivation of land, mono-cropping, organised irrigation, and use of a specialized labour force, the title "inventors of agriculture" would fall to the Sumerians, starting ca. 5,500 BC. Intensive farming allows a much greater density of population than can be supported by hunting and gathering and allows for the accumulation of excess product to keep for winter use or to sell for profit. The ability of farmers to feed large numbers of people whose activities have nothing to do with material production was the crucial factor in the rise of standing armies. The agriculturalism of the Sumerians allowed them to embark on an unprecedented territorial expansion, making them the first empire builders. Not long after, the Egyptians, powered by effective farming of the Nile valley, achieved a population density from which enough warriors could be drawn for a territorial expansion more than tripling the Sumerian empire in area.

The invention of a three field system of crop rotation during in the Middle Ages vastly improved agricultural efficiency.

After 1492 the world's agricultural patterns were shuffled in the widespread exchange of plants and animals known as the Columbian Exchange. Crops and animals that were previously only known in the Old World were now transplanted to the New and vice versa. Perhaps most notably, the tomato became a favorite in European cuisine, while certain wheat strains quickly took to western hemisphere soils and became a dietary staple even for native North, Central and South Americans.

By the early 1800s agricultural practices, particularly careful selection of hardy strains and cultivars, had so improved that yield per land unit was many times that seen in the Middle Ages and before, especially in the largely virgin lands of North and South America. With the rapid rise of mechanization in the 20th century, especially in the form of the tractor, the demanding tasks of sowing, harvesting and threshing could be performed with a speed and on a scale barely imaginable before. These advances have led to efficiencies enabling certain modern farms in the United States, Argentina, Israel, Germany and a few other nations to output volumes of high quality produce per land unit at what may be the practical limit.

Education is a social science that encompasses teaching and learning specific skills. Practicing teachers in the field of education use a variety of methods and materials in their instruction to impart a curriculum. There has been a plethora of literature in the field of education that addresses these areas. Such literature addresses the facets of teaching practices to include instructional strategies, behavior management, environmental control, motivational strategies, and technological resources. However, the single most important factor in any teacher's effectiveness is the interaction style and personality of the teacher, for the quality of their relationships with the students provides the impetus for inspiration. The best teachers are able to translate good judgment, experience, and wisdom into the art of communication that students find compelling. It is their compassion for varied human qualities, passion, and the creativity of potential that assists teachers to invigorate students to higher expectations of themselves and society at large. The goal of education is the growth of students so that they become productive citizens of a dynamic, everchanging, society. Fundamentally, the imparting of culture from generation to generation (see socialisation)promotes a greater awareness and responsiveness through social maturity to the needs of an increasingly diversified society.
Contents
[hide]

    * 1 Overview
    * 2 Origins of the Word "Education"
    * 3 Formal Education
    * 4 Technology and Education
    * 5 History of education
          o 5.1 Europe
          o 5.2 China
          o 5.3 Japan
          o 5.4 India
          o 5.5 Recent world-wide educational trends
    * 6 Challenges in education
          o 6.1 In well-developed countries
          o 6.2 In developing countries
    * 7 Parental involvement
    * 8 Prominent educationalists
    * 9 References
    * 10 See also
    * 11 External links

[edit]

Overview

It is widely accepted that the process of education begins at birth and continues throughout life. Some believe that education begins even earlier than this, as evidenced by some parents' playing music or reading to the baby in the womb in the hope it will influence the child's development.

The word 'education' is often used to refer solely to formal education (see below). However, it covers a range of experiences, from formal learning to the building of understanding through day to day experiences.

Individuals can receive informal education from a variety of sources. Family members and society have a strong influence on the informal education of the individual.
[edit]

Origins of the Word "Education"

The word "education" is derived from the Latin educare meaning "leading out" or "leading forth". This reveals one of the theories behind the function of education - of developing innate abilities and expanding horizons.
[edit]

Formal Education

Formal education occurs when society or a group or an individual sets up a curriculum to educate people, usually the young. Formal education can become systematic and thorough. Formal education systems can be used to promote ideals or values as well as knowledge and this can sometimes lead to abuse of the system.