Agriculture

Agriculture involving domestication of plants was developed around 11,500 years ago separately in both the Fertile crescent and at Chogha Golan in modern day Iran, where wild barley, wheat and lentils were cultivated and with domesticated forms of wheat appeared about 9,800 years ago.[1] Agriculture has undergone significant developments since the time of the earliest cultivation. The Fertile Crescent of Western Asia, Egypt and India were sites of the earliest planned sowing and harvesting of plants that had previously been gathered in the wild. Independent development of agriculture occurred in northern and southern China, Africa's Sahel, New Guinea, parts of India and several regions of the Americas.[2] Agricultural techniques such as irrigation, crop rotation, the application of fertilizers were developed soon after the Neolithic Revolution but have made significant strides in the past 200 years.

Agricultural practices such as irrigation, crop rotation, application of fertilizers and pesticides, and the domestication of livestock were developed long ago, but have made great progress in the past century. The history of agriculture has played a major role in human history, as agricultural progress has been a crucial factor in worldwide socio-economic change. Division of labour in agricultural societies made commonplace specializations rarely seen in hunter-gatherer cultures, which allowed the growth of towns and cities, and the complex societies we call civilizations. When farmers became capable of producing food beyond the needs of their own families, others in their society were free to devote themselves to projects other than food acquisition. Historians and anthropologists have long argued that the development of agriculture made civilization possible. According to geographer Jared Diamond, the costs of agriculture were: "the average daily number of work hours increased, nutrition deteriorated, infectious disease and body wear increased, and lifespan shortened."[3]

Prehistoric origins
Forest gardening, a plant-based food production system, is thought by one researcher to be the world's oldest agroecosystem.[4] Forest gardens originated in prehistoric times along jungle-clad river banks and in the wet foothills of monsoon regions. In the gradual process of a family improving their immediate environment, useful tree and vine species were identified, protected and improved whilst undesirable species were eliminated. Eventually superior foreign species were selected and incorporated into the family's garden.[5]

Evidence of oat harvesting dating to 21340 A c—– has been found in Paglicci Cave, Italy.[6] Evidence of plant cultivation dating from 23,000 years ago has been found at the Ohalo II site.[7]

Neolithic
The Fertile Crescent of Western Asia first saw the domestication of animals, starting the Neolithic Revolution. Between 10,000 and 13,000 years ago, the ancestors of modern cattle, sheep, goats and pigs were domesticated in this area. The gradual transition from wild harvesting to deliberate cultivation happened independently in several areas around the globe.[8] Agriculture allowed for the support of an increased population, leading to larger societies and eventually the development of cities. It also created the need for greater organization of political power (and the creation of social stratification), as decisions had to be made regarding labor and harvest allocation and access rights to water and land. Agriculture bred immobility, as populations settled down for long periods of time, which led to the accumulation of material goods.[9]

Early Neolithic villages show evidence of the ability to process grain, and the Near East is the ancient home of the ancestors of wheat, barley and peas. There is evidence of the cultivation of figs in the Jordan Valley as long as 11,300 years ago, and cereal (grain) production in Syria approximately 9,000 years ago. During the same period, farmers in China began to farm rice and millet, using man-made floods and fires as part of their cultivation regimen.[8] Fiber crops were domesticated as early as food crops, with China domesticating hemp, cotton being developed independently in Africa and South America, and the Near East domesticating flax.[10] The use of soil amendments, including manure, fish, compost and ashes, appears to have begun early, and developed independently in several areas of the world, including Mesopotamia, the Nile Valley and Eastern Asia.[11]

Roman harvesting machine

Squash was grown in Mexico nearly 10,000 years ago, while maize-like plants, derived from the wild teosinte, began to be seen at around 9,000 years ago. The derivation of teosinte into modern corn was slow, however, and it took until 5,500[8] to 6,000 years ago to turn into what we know today as maize. It then gradually spread across North America and was the major crop of Native Americans at the time of European exploration.[12] Beans were domesticated around the same time, and together these three plants formed the Three Sisters nutritional foundation of many native populations in North and Central America. Combined with peppers, these crops provided a balanced diet for much of the continent.[13] Grapes were first grown for wine approximately 8,000 years ago, in the Southern Caucasus, and by 3000 BC had spread to the Fertile Crescent, the Jordan Valley and Egypt.[14]

Agriculture advanced to Europe slightly later, reaching the northeast of the continent from the east around 4000 BC. The idea that agriculture spread to Europe, rather than independently developing there, has led to two main hypotheses. The first is a "wave of advance", which holds that agriculture traveled slowly and steadily across the continent, while the second, "population pulse" theory, holds that it moved in jumps.[15] Also around 6000 years ago, horses first began to be domesticated in the Eurasian steppes. Initially used for food, it was quickly discovered that they were useful for field work and carrying goods and people.[16] Around 5,000 years ago, sunflowers were first cultivated in North America, while South America's Andes region was developing the potato.[8] A minor center of domestication, the indigenous peoples of the eastern United States appear to have domesticated numerous crops, including tobacco.[17]

Bronze and Iron Ages
Beginning around 3000 BC, nomadic pastoralism, with societies focused on the care of livestock for subsistence, appeared independently in several areas in Europe and Asia. The main region was the steppes stretching from the Great Hungarian Plain to the Northeast China Plain, where cattle, sheep, horses, and to a lesser extent yaks and bactrian camels provided sustenance. The second was in Arabia, where one-humped camels were the main animal, with sheep, goats and horses also seen. The third area was a band of societies in areas of eastern and central Africa with a tropical savannah climate. Cattle and goats were found most often in this area, with smaller numbers of sheep, horses and camels. A fourth area, more minor than the others, was found in northern Europe and Asia and was focused on reindeer herding.[18]

Between 2500 and 2000 BC, the simplest form of the plough, called the ard, spread throughout Europe, replacing the hoe. This change in equipment significantly increased cultivation ability, and affected the demand for land, as well as ideas about property, inheritance and family rights.[19] Before this period, simple digging sticks or hoes were used. These tools would have also been easier to transport, which was a benefit as people only stayed until the soil's nutrients were depleted. However, as the continuous cultivating of smaller pieces of land became a sustaining practice throughout the world, ards were much more efficient than digging sticks.[20] As humanity became more stationary, empires, such as the New Kingdom of Egypt and the Ancient Romans, arose, dependent upon agriculture to feed their growing populations, and slavery, which was used to provide the labor needed for continually intensifying agricultural processes. Agricultural technology continued to improve, allowing the expansion of available crop varieties, including a wide range of fruits, vegetables, oil crops, spices and other products.[21][22] China was also an important center for agricultural technology development during this period. During the Zhou dynasty (1666–221 BC), the first canals were built, and irrigation was used extensively. The later Three Kingdoms and Northern and Southern dynasties (221–581 AD) brought the first biological pest control, extensive writings on agricultural topics and technological innovations such as steel and the wheelbarrow.[23]

In the ancient world, fresh products, such as meats, dairy products and fresh fruits and vegetables, were likely consumed relatively close to where they were produced. Less perishable products, such as grains, preserved foods, olive oil and wine, were often traded over an extensive network of land and sea routes. The ancient trade in agricultural goods was well established, with wine traded in the Mediterranean region in the 6th century BC and Rome receiving extensive shipments of grain as tax payments by the 2nd century BC. Huge amounts of grain were transported, mainly by sea, and it was during this period that the subsidization of grain farming began, for the prevention of famine. Ancient Rome was a major center for agricultural trade. Trade routes stretched from Britain and Scandinavia in the west to India and China in the east, and included major crops, such as grain, wine and olive oil (also a fuel for oil lamps), as well as additional products, including spices, fabrics and drugs.[24]

In Ancient Greece and Rome, many scholars documented farming techniques, including the use of fertilizers.[11] Much of what was believed about farming and plant nutrition at this time was later found to be incorrect, but their theories provided the scientific foundation for the development of agricultural theories through the Middle Ages. Ideas about soil fertility and fertilization remained much the same from the time of Greco-Roman scholars until the 19th century, with correspondingly low crop yields.[11] By the time of Alexander the Great's conquests (330–323 BC), the role of horses had developed, and they played a huge role in warfare and agriculture. Innovations continued to be developed which allowed them to work longer, harder and more efficiently. By medieval times they became the primary source of power for agriculture, transport and warfare, a position they held until the development of the steam and internal combustion engines.[16] The Mayan culture developed several innovations in agriculture during its peak, which ranged from 400 BC to 900 AD and was heavily dependent upon agriculture to support its population. The Mayans used extensive canal and raised field systems to farm the large portions of swampland on the Yucatán Peninsula.[25][26]

Middle Ages
The Middle Ages saw significant improvements in the agricultural techniques and technology. During this time period, monasteries spread throughout Europe and became important centers for the collection of knowledge related to agriculture and forestry. The manorial system, which existed under different names throughout Europe and Asia, allowed large landowners significant control over both their land and its laborers, in the form of peasants or serfs.[27] During the medieval period, the Arab world was critical in the exchange of crops and technology between the European, Asia and African continents. Besides transporting numerous crops, they introduced the concept of summer irrigation to Europe and developed the beginnings of the plantation system of sugarcane growing through the use of slaves for intensive cultivation.[28] Population continued to increase along with land use. From 100 BC to 1600 AD, methane emissions, produced by domesticated animals and rice growing, increased substantially.[29]

By 900 AD in Europe, developments in iron melting allowed for increased production, leading to developments in the production of agricultural implements such as ploughs, hand tools and horse shoes. The plough was significantly improved, developing into the mouldboard plough, capable of turning over the heavy, wet soils of northern Europe. This led to the clearing of forests in that area and a significant increase in agricultural production, which in turn led to an increase in population.[30] A similar plough, which may have developed independently, was also found in China as early as the 9th century.[31] At the same time, farmers in Europe moved from a two field crop rotation to a three field crop rotation in which one field of three was left fallow every year. This resulted in increased productivity and nutrition, as the change in rotations led to different crops being planted, including legumes such as peas, lentils and beans. Inventions such as improved horse harnesses and the whippletree also changed methods of cultivation.[30] Watermills were initially developed by the Romans, but were improved throughout the Middle Ages, along with windmills, and used to grind grains into flour, cut wood and process flax and wool, among other uses.[32]

Ancient methods of planting are still widespread in many countries. Here, two members of the Brao ethnic group plant seeds on their land in Laos

Crops included wheat, rye, barley and oats. Peas, beans, and vetches became common from the 13th century onward as a fodder crop for animals and also for their nitrogen-fixation fertilizing properties. Crop yields peaked in the 13th century, and stayed more or less steady until the 18th century.[33] Though the limitations of medieval farming were once thought to have provided a ceiling for the population growth in the Middle Ages, recent studies[34][35] have shown that the technology of medieval agriculture was always sufficient for the needs of the people under normal circumstances, and that it was only during exceptionally harsh times, such as the terrible weather of 1315–17, that the needs of the population could not be met.[36] The Medieval Warm Period, between 900–1300 AD, brought generally warmer global temperatures, leading to increased harvests throughout Europe and a greater northern range for subtropical crops such as figs and olives. Greenland and Iceland were settled by Europeans during this period, and supported agricultural activities. The long-term warming period is generally thought to have occurred mainly in Europe, but other areas of the world experienced shorter warming periods at different times during this period, including China in the 11th and 12th centuries, with similar effects on agriculture. The climate variations found in Europe during the Medieval Warm Period returned to more moderate levels in the 15th century, and terminated in the Little Ice Age of the 16th-mid 19th centuries.[37]

Origin hypotheses
Scholars have developed a number of hypotheses to explain the historical origins of agriculture. The transition from hunter-gatherer to agricultural societies, based on evidence from south west Asia and China, indicates an antecedent period of intensification and increasing sedentism known as the Natufian in south West Asia and the Early Chinese Neolithic in China. Current models indicate that a range of food resources was being used more intensively. Wild stands that had been harvested previously started to be planted. Evidence is also now emerging that the crops grown initially were wild and not domesticated.[65] Crops such as emmer and einkorn wheat do not appear to have become domesticated until well into the Neolithic and 'ancient cultivated rice' (Oryza sativa) took 3000 years to become domesticated.

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 elsewhere, suggests that social reasons may have been instrumental. When major climate change took place after the last ice age (c. 11,000 BC), much of the earth became subject to long dry seasons.[66] These conditions favoured annual plants which die off in the long dry season, leaving a dormant seed or tuber. These plants tended to put more energy into producing seeds than into woody growth. An abundance of readily storable wild grains and pulses enabled hunter-gatherers in some areas to form the first settled villages at this time

The Oasis hypothesis was proposed by Raphael Pumpelly in 1908, and popularized by Vere Gordon Childe who summarized the hypothesis in his book Man Makes Himself[67] This hypothesis maintains that as the climate got drier, communities contracted to oases where they were forced into close association with animals which were then domesticated together with planting of seeds. The hypothesis has little contemporary support[citation needed], as the climate data for the time does not support the hypothesis.

The Hilly Flanks hypothesis, proposed by Robert Braidwood in 1948, suggests that agriculture began in the hilly flanks of the Taurus and Zagros Mountains, and that it developed from intensive focused grain gathering in the region.[68]

The Feasting model by Brian Hayden[69] suggests that agriculture was driven by ostentatious displays of power, such as throwing feasts to exert dominance. This required assembling large quantities of food which drove agricultural technology.

The Demographic theories were proposed by Carl Sauer[70] and adapted by Lewis Binford[71] and Kent Flannery. They describe an increasingly sedentary population, expanding up to the carrying capacity of the local environment, and requiring more food than can be gathered. Various social and economic factors help drive the need for food.

The evolutionary/intentionality hypothesis, advanced by scholars including David Rindos,[72] is the idea that agriculture is a co-evolutionary adaptation of plants and humans. Starting with domestication by protection of wild plants, followed specialization of location and then domestication.

The Levantine Primacy Model was developed in the 1980s by Ofer Bar-Yosef and his collaborators. This provides a cultural ecology explanation, based on the idea that some areas were better favoured with domesticable plants and animals than others.[73]

The domestication hypothesis put forth by Daniel Quinn and others states that first humans stayed in particular areas, giving up their nomadic ways, then developed agriculture and animal domestication.

Another hypothesis is that humans were prevented from staying in one place for much of their history, due to the risk of attacks from other tribes.[74]

The Innovation and Specialisation Model was put forward recently by Rupert Gerritsen, in Australia and the Origins of Agriculture (2008). This hypothesis considers the question in terms of economic development and treats agriculture as a form of specialisation arising from two factors, higher population densities and innovation in areas of higher net natural productivity, and long-term advantageous information acquisition at nodal points in communication in long range scale-free networks.

Early development[edit]
Sumerian harvester's sickle, 3000 BC, made from baked clay.

Early people began altering communities of flora and fauna for their own benefit through other means such as fire-stick farming very early.[75][76]

Anthropological and archaeological evidence from sites across Southwest Asia and North Africa indicate use of wild grain (e.g., from the c. 20,000 BC site of Ohalo II in Israel, many Natufian sites in the Levant and from sites along the Nile in the 10th millennium BC). There is even evidence of planned cultivation and trait selection: 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.[citation needed]

Previously, archaeobotanists/paleoethnobotanists had traced the selection and cultivation of specific food plant characteristics in search of the origins of agriculture. One notable example is the semi-tough rachis (and larger seeds) traced to just after the Younger Dryas (about 9500 BC) in the early Holocene in the Levant region of the Fertile Crescent. However, studies have demonstrated monophyletic characteristics attained without any human intervention, implying that what some may perceive as domestication among rachis could have occurred quite naturally.[77] In fact, the timescale insisted upon for rachis domestication (approx. 3,000 years) coincidentally has been demonstrated to directly coincide with the statistically generated timeframe numerically modeled that would be required for monophyly to be reached if a population were simply abandoned and left to only natural demands, implying that if any sort of human intervention had occurred at all then the timescale insisted upon should be considerably shorter (than 3,000 years).[77]

It was not until after 9500 BC that the eight so-called founder crops of agriculture appear: first emmer and einkorn wheat, then hulled barley, peas, lentils, bitter vetch, chick peas and flax. These eight crops occur more or less simultaneously on Pre-Pottery Neolithic B (PPNB) sites in the Levant, although the consensus is that wheat was the first to be grown and harvested on a significant scale.

At around the same time (9400 BC), another study argues, parthenocarpic fig trees appear to have been domesticated.[78] The simplicity associated with cutting branches off fig trees and replanting them alongside wild cereals owes to the basis of this argument.[79]

By 7000 BC, sowing and harvesting reached Mesopotamia, and there, in the fertile soil just north of the Persian Gulf, Sumerians systematized it and scaled it up. By 8000 BC, farming was entrenched on the banks of the Nile River. About this time, agriculture was developed independently in the Far East, probably in China, with rice rather than wheat as the primary crop. Maize, a domesticate of the wild grass teosinte, was domesticated in West Mexico by 6700 BC.[80] The potato, the tomato, the pepper, squash, several varieties of bean, and several other plants were also developed in the New World, as was quite extensive terracing of steep hillsides in much of Andean South America. Agriculture was also independently developed on the island of New Guinea.[81]

Recent discoveries in Europe, such as Cyprus and mainland Greece has shown that farming started early in south east Europe. In Franchthi Cave in Greece there are no certain gathering of plant foods attested before c. 11,000 BC, although large numbers of seeds of the Boraginaceae family may come from plants gathered to furnish soft bedding or for the dye which their roots may have supplied. First appearing at c. 11,000 BC are lentils, vetch, pistachios, and almonds. Then c. 10,500 BC appear a few very rare seeds of wild oats and wild barley. Neither wild oats nor wild barley become at all common until c. 7000 BC[82][83] in Cyprus. The oldest agricultural settlement ever found on a Mediterranean island has been discovered in Klimonas. between 9100 and 8600 BC organized communities were farming and they build half-buried mud brick communal buildings, 10 meters in diameter and surrounded by dwellings, that must have been used to store the village's harvests. Remains of carbonized seeds of local plants and grains introduced from the Levantine coasts (including emmer, one of the first Middle Eastern wheats) have also been found in Klimonas.[84]

There is evidence of emmer and einkorn wheat, barley, sheep, goats and pigs that suggest a food producing economy in Greece and the Aegean by 7000 BC.[85] Archaeological evidence from various sites on the Iberian peninsula suggest the domestication of plants and animals between 6000 and 4500 BC.[85] Céide Fields in Ireland, consisting of extensive tracts of land enclosed by stone walls, date to 3500 BC and are the oldest known field systems in the world.[86][87] The horse was domesticated in the Pontic steppe around 4000 BC.[88] Evidence of cannabis use by 4000 BC and domestication by 3000 BC survive in Siberia. Domesticated marijuana had also begun in China by 2500 BC.[89]

In China, rice and millet were domesticated by 8000 BC, followed by the beans mung, soy and azuki. In the Sahel region of Africa local rice and sorghum were domestic by 5000 BC. Local crops were domesticated independently in West Africa[citation needed] and possibly in Ethiopia. In New Guinea, ancient Papuan peoples are thought to have begun practicing agriculture around 7000 BC. They began domesticating sugarcane and root crops. Pigs may also have been domesticated around this time. By 3000 BC, Papuan agriculture was characterized by water control for irrigation.[90][page needed] Evidence of the presence of wheat and some legumes in the 6th millennium BC have been found in the Indus Valley. Oranges were cultivated in the same millennium. The crops grown in the valley around 4000 BC were typically wheat, peas, sesame seed, barley, dates and mangoes. By 3500 BC, cotton growing and cotton textiles were quite advanced in the valley. By 3000 BC farming of rice had started. Other monsoon crops of importance of the time was cane sugar. By 2500 BC, rice was an important component of the staple diet in Mohenjodaro near the Arabian Sea. By this time the Indians had large cities with well-stocked granaries. Three regions of the Americas independently domesticated corn, squashes, potato and sunflowers.

Sumer[edit]
See also: Neolithic Revolution

Agricultural scene from Ancient Egypt.

By the Bronze Age, wild food contributed a nutritionally insignificant component to the usual diet. If the operative definition of agriculture includes large scale intensive cultivation of land, mono-cropping, organized irrigation, and use of a specialized labour force, the title "inventors of agriculture" would fall to the Sumerians, starting c. 5500 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 for off-season use, or to sell/barter. The ability of farmers to feed large numbers of people whose activities have nothing to do with agriculture was the crucial factor in the rise of standing armies. Sumerian agriculture supported a substantial territorial expansion which along with internecine conflict between cities, made them the first empire builders. Not long after, the Egyptians, powered by farming in the fertile 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.[citation needed]

In Sumer, barley was the primary crop; wheat, flax, dates, apples, plums, and grapes were grown as well. Mesopotamian agriculture was both supported and limited by flooding from the Tigris and Euphrates rivers, as floods came in late spring or early summer from snow melting from the Anatolian mountains. The timing of the flooding, along with salt deposits in the soil, made farming in Mesopotamia difficult. Sheep and goats were domesticated, kept mainly for meat and milk, butter and cheese being made from the latter. Ur, a large town that covered about 50 acres (20 hectares), had 10,000 animals kept in sheepfolds and stables and 3,000 slaughtered every year. The city's population of 6,000 included a labour force of 2,500, cultivating 3,000 acres (12 km²) of land. The labour force contained storehouse recorders, work foremen, overseers, and harvest supervisors to supplement labourers. Agricultural produce was given to temple personnel, important people in the community, and small farmers.[citation needed]

The land was plowed by teams of oxen pulling light unwheeled plows and grain was harvested with sickles in the spring. Wagons had solid wheels covered by leather tires kept in position by copper nails and were drawn by oxen. Animals were harnessed by collars, yokes, and headstalls. They were controlled by reins, and a ring through the nose or upper lip and a strap under the jaw. As many as four animals could pull a wagon at one time. The horse was domesticated in Ukraine around 4000 BC, and was in use by the Sumerians around 2000 BC.[citation needed]

Ancient Egypt[edit]
Main article: Ancient Egyptian agriculture

Indus civilization and Ancient India[edit]
Main article: Agriculture in India

Cotton was cultivated by the 5th-4th millennium BC.[91]

Wheat, barley, and jujube were domesticated in the Indian subcontinent by 9000 BC; Domestication of sheep and goat soon followed.[92] Barley and wheat cultivation—along with the domestication of cattle, primarily sheep and goat—continued in Mehrgarh culture by 8000-6000 BC.[93][94] This period also saw the first domestication of the elephant.[92] Agro pastoralism in India included threshing, planting crops in rows—either of two or of six—and storing grain in granaries.[94][95] By the 5th millennium BC, agricultural communities became widespread in Kashmir.[94] Archaeological evidence indicates that rice was a part of the Indian diet by 8000 BC.[96][unreliable source?] The Encyclopædia Britannica—on the subject of the first certain cultivated rice—holds that:[97] A number of cultures have evidence of early rice cultivation, including China, India, and the civilizations of Southeast Asia.

Irrigation was developed in the Indus Valley Civilization by around 4500 BC.[98] The size and prosperity of the Indus civilization grew as a result of this innovation, which eventually led to more planned settlements making use of drainage and sewers quite ahead of its time .[98] Archeological evidence of an animal-drawn plough dates back to 2600 BC in the Indus Valley Civilization.[99]

Ancient China[edit]
Further information: Agriculture in China and Agriculture (Chinese mythology)

Han Dynasty tomb mural depicting ploughing by Shennong, the legendary "Divine Husbandsman".

Records from the Warring States, Qin Dynasty, and Han Dynasty provide a picture of early Chinese agriculture from the 5th century BC to 2nd century AD which included a nationwide granary system and widespread use of sericulture. An important early Chinese book on agriculture is the Chimin Yaoshu of AD 535, written by Jia Sixia.[100] Jia's writing style was straightforward and lucid relative to the elaborate and allusive writing typical of the time. Jia's book was also very long, with over one hundred thousand written Chinese characters, and it quoted many other Chinese books that were written previously, but no longer survive.[101] The contents of Jia's 6th century book include sections on land preparation, seeding, cultivation, orchard management, forestry, and animal husbandry. The book also includes peripherally related content covering trade and culinary uses for crops.[102] The work and the style in which it was written proved influential on later Chinese agronomists, such as Wang Zhen and his groundbreaking Nong Shu of AD 1313.[101]

For agricultural purposes, the Chinese had innovated the hydraulic-powered trip hammer by the 1st century BC.[103] Although it found other purposes, its main function to pound, decorticate, and polish grain that otherwise would have been done manually. The Chinese also began using the square-pallet chain pump by the 1st century AD, powered by a waterwheel or oxen pulling an on a system of mechanical wheels.[104] Although the chain pump found use in public works of providing water for urban and palatial pipe systems,[105] it was used largely to lift water from a lower to higher elevation in filling irrigation canals and channels for farmland.[106] By the end of the Han dynasty in the late 2nd century, heavy ploughs had been developed with iron ploughshares and mouldboards.[107][108] These would slowly spread west, revolutionizing farming in Northern Europe by the 10th century. (Glick, however, argues for a development of the Chinese plough as late as the 9th century, implying its spread east from similar designs known in Italy by the 7th century.)[109]

Roman Empire[edit]
In classical antiquity, Roman agriculture built from techniques pioneered by the Sumerians, transmitted to them by subsequent cultures, with a specific emphasis on the cultivation of crops for trade and export. Romans laid the groundwork for the manorial economic system, involving serfdom, which flourished in the Middle Ages. The farm sizes in Rome can be divided into three categories. Small farms were from 18-88 iugera (one iugerum is equal to about 0.65 acre). Medium-sized farms were from 80-500 iugera (singular iugerum). Large estates (called latifundia) were over 500 iugera.[110]

The Romans had four systems of farm management: direct work by owner and his family; slaves doing work under supervision of slave managers; tenant farming or sharecropping in which the owner and a tenant divide up a farm’s produce; and situations in which a farm was leased to a tenant.[110] There was a great deal of commerce between the provinces of the empire, all the regions of the empire became interdependent with one another, some provinces specialized in the production of grain, others in wine and others in olive oil, depending on the soil type.

Middle Ages and early modern period[edit]
An Indian farmer with a rock-weighted scratch plough pulled by two oxen. Similar ploughs were used throughout antiquity before being replaced in many places by the carruca and other turnploughs during the Middle Ages.

Population continued to increase along with land use. From 100 BC to AD 1600, methane emissions rose an average of 31 million tons per year. This average annual rise is almost as high as the United States produced annually in 2012. Methane gas was produced primarily by domesticating animals and the growing of rice.[129]

Arab world[edit]
Main article: Arab Agricultural Revolution

From the 8th century, the medieval Islamic world underwent a transformation in agricultural practice which has been described by some as the "Arab Agricultural Revolution". This transformation was driven by a number of factors including the diffusion of many crops and plants along Muslim trade routes, the spread of more advanced farming techniques, and an agricultural-economic system which promoted increased yields and efficiency. The shift in agricultural practice led to significant changes in economy, population distribution, vegetation cover, agricultural production, population levels, urban growth, the distribution of the labour force, cooking and diet, clothing, and numerous other aspects of life in the Islamic world.[130][131]

Muslim traders covered an expansive area of the Old World, and these trade routes enabled the diffusion of many crops, plants and farming techniques across the Islamic world, as well as the adaptation of crops, plants and techniques from beyond the Islamic world.[131] Historian Andrew Watson has argued that this diffusion introduced a number of crops of major importance to Europe by way of Al-Andalus, along with the techniques for their cultivation. Important crops involved in this transfer included sugar cane, rice, and cotton. A number of additional fruit trees, nut trees, and vegetables were also transferred.

Agricultural technologies that were widely adopted during this period included intensive irrigation systems, crop rotation systems, and use of agricultural manuals. A sophisticated system of irrigation made use of norias, water mills, water raising machines, dams and reservoirs. Some irrigation infrastructure and technology was continued from Roman times, and some introduced by Muslims.

Europe[edit]
Agricultural calendar from a manuscript of Pietro de Crescenzi.

The Middle Ages saw significant improvements in the agricultural techniques and technology. During this time period, monasteries spread throughout Europe and became important centers for the collection of knowledge related to agriculture and forestry. The manorial system, which existed under different names throughout Europe and Asia, allowed large landowners significant control over both their land and its laborers, in the form of peasants or serfs.[132] During the medieval period, the Arab world was critical in the exchange of crops and technology between the European, Asia and African continents. Besides transporting numerous crops, they introduced the concept of summer irrigation to Europe and developed the beginnings of the plantation system of sugarcane growing through the use of slaves for intensive cultivation.[133] Population continued to increase along with land use. From 100 BC to AD 1600, methane emissions rose an average of 31 million tons per year. This average annual rise is almost as high as the United States produced annually in 2012. Methane gas was produced primarily by domesticating animals and growing rice.[134]

By AD 900, developments in iron smelting allowed for increased production in Europe, leading to developments in the production of agricultural implements such as ploughs, hand tools and horse shoes. The carruca plough offered a significant improvement over the earlier scratch plough, having adopted the Chinese mouldboard plough to turn over the heavy, wet soils of northern Europe. This led to the clearing of forests in that area and a significant increase in agricultural production, which in turn led to an increase in population.[30] At the same time, farmers in Europe moved from a two field crop rotation to a three field crop rotation in which one field of three was left fallow every year. This resulted in increased productivity and nutrition, as the change in rotations led to different crops being planted, including legumes such as peas, lentils and beans. Inventions such as improved horse harnesses and the whippletree also changed methods of cultivation.[30] Watermills were initially developed by the Romans, but were improved throughout the Middle Ages, along with windmills, and used to grind grains into flour, cut wood and process flax and wool, among other uses.[135]

Crops included wheat, rye, barley and oats. Peas, beans, and vetches became common from the 13th century onward as a fodder crop for animals and also for their nitrogen-fixation fertilizing properties. Crop yields peaked in the 13th century, and stayed more or less steady until the 18th century.[33] Though the limitations of medieval farming were once thought to have provided a ceiling for the population growth in the Middle Ages, recent studies[34][35] have shown that the technology of medieval agriculture was always sufficient for the needs of the people under normal circumstances, and that it was only during exceptionally harsh times, such as the terrible weather of 1315–17, that the needs of the population could not be met.[136][137]

Columbian exchange[edit]
The Harvesters. Pieter Bruegel – 1565

After 1492, a global exchange of previously local crops and livestock breeds occurred. Key crops involved in this exchange included maize, potatoes, sweet potatoes and manioc traveling from the New World to the Old, and several varieties of wheat, barley, rice and turnips going from the Old World to the New. There were very few livestock species in the New World, with horses, cattle, sheep and goats being completely unknown before their arrival with Old World settlers. Crops moving in both directions across the Atlantic Ocean caused population growth around the world, and had a lasting effect on many cultures.[138] Maize and cassava were introduced from Brazil into Africa by Portuguese traders in the 16th century.[139] They are now important staple foods, replacing native African crops.[140]

After its introduction from South America to Spain in the late 1500s, the potato became an important staple crop throughout Europe by the late 1700s. The potato allowed farmers to produce more food, and initially added variety to the European diet. The nutrition boost caused by increased potato consumption resulted in lower disease rates, higher birth rates and lower mortality rates, causing a population boom throughout the British Empire, the US and Europe.[141] The introduction of the potato also brought about the first intensive use of fertilizer, in the form of guano imported to Europe from Peru, and the first artificial pesticide, in the form of an arsenic compound used to fight Colorado potato beetles. Before the adoption of the potato as a major crop, the dependence on grain caused repetitive regional and national famines when the crops failed: 17 major famines in England alone between 1523 and 1623. Although initially almost eliminating the danger of famine, the resulting dependence on the potato eventually caused the European Potato Failure, a disastrous crop failure from disease resulting in widespread famine, and the death of over one million people in Ireland alone.[142]