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Intensive agriculture, also known asintensive farming (as opposed toextensive farming),conventional, orindustrial agriculture, is a type ofagriculture, both ofcrop plants and ofanimals, with higher levels of input and output per unit ofagricultural land area. It is characterized by a lowfallow ratio, higher use of inputs such ascapital,labour,agrochemicals and water, and highercrop yields per unit land area.[1]
Mostcommercial agriculture is intensive in one or more ways. Forms that rely heavily onindustrial methods are often calledindustrial agriculture, which is characterized by technologies designed to increase yield. Techniques include planting multiple crops per year, reducing the frequency of fallow years, improvingcultivars,mechanised agriculture, controlled by increased and more detailed analysis of growing conditions, including weather,soil, water, weeds, and pests. Modern methods frequently involve increased use of non-biotic inputs, such asfertilizers, plant growth regulators,pesticides, andantibiotics for livestock. Intensive farms are widespread indeveloped nations and increasingly prevalent worldwide. Most of the meat,dairy products,eggs, fruits, and vegetables available insupermarkets are produced by such farms.
Some intensive farms can usesustainable methods, although this typically necessitates higher inputs of labor or lower yields.[2] Sustainably increasingagricultural productivity, especially onsmallholdings, is an important way to decrease the amount of land needed for farming and slow and reverseenvironmental degradation caused by processes such asdeforestation.[3]
Intensive animal farming involves large numbers of animals raised on a relatively small area of land, for example byrotational grazing,[4][5] or sometimes asconcentrated animal feeding operations. These methods increase the yields of food and fiber per unit land area compared to those of extensiveanimal husbandry; concentrated feed is brought to seldom-moved animals, or, with rotational grazing, the animals are repeatedly moved to fresh forage.[4][5]
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Agricultural development in Britain between the 16th century and the mid-19th century saw a massive increase in agricultural productivity and net output. This in turn contributed to unprecedented population growth, freeing up a significant percentage of the workforce, and thereby helped enable theIndustrial Revolution. Historians citedenclosure,mechanization,four-field crop rotation, andselective breeding as the most important innovations.[6]
Industrial agriculture arose in the Industrial Revolution. By the early 19th century, agricultural techniques, implements, seed stocks, andcultivars had so improved that yield per land unit was many times that seen in theMiddle Ages.[7][page needed]
The first phase involved a continuing process of mechanization. Horse-drawn machinery such as theMcCormick reaper revolutionized harvesting, while inventions such as thecotton gin reduced the cost of processing. During this same period, farmers began to usesteam-poweredthreshers andtractors.[8][9][10] In 1892, the firstgasoline-powered tractor was successfully developed, and in 1923, theInternational HarvesterFarmall tractor became the first all-purpose tractor, marking an inflection point in the replacement of draft animals with machines. Mechanical harvesters (combines), planters, transplanters, and other equipment were then developed, further revolutionizing agriculture.[11] These inventions increased yields and allowed individual farmers to manage increasingly large farms.[12]
The identification ofnitrogen,phosphorus, andpotassium (NPK) as critical factors in plant growth led to the manufacture of syntheticfertilizers, further increasingcrop yields. In 1909, theHaber-Bosch method to synthesizeammonium nitrate was first demonstrated. NPK fertilizers stimulated the first concerns about industrial agriculture, due to concerns that they came with side effects such assoil compaction,soil erosion, and declines in overallsoil fertility, along with health concerns about toxic chemicalsentering the food supply.[13]
The discovery ofvitamins and their role innutrition, in the first two decades of the 20th century, led to vitamin supplements, which in the 1920s allowed some livestock to be raised indoors, reducing their exposure to adverse natural elements.[14]
FollowingWorld War II synthetic fertilizer use increased rapidly.[15]
The discovery ofantibiotics andvaccines facilitated raising livestock by reducing diseases.[16][17] Developments in logistics and refrigeration as well as processing technology made long-distance distribution feasible.Integrated pest management is the modern method to minimize pesticide use to more sustainable levels.[18][19]
There are concerns over thesustainability of industrial agriculture, and the environmental effects of fertilizers and pesticides, which has given rise to theorganic movement[20] and has built a market for sustainable intensive farming, as well as funding for the development ofappropriate technology.
Pasture intensification is the improvement ofpasture soils and grasses to increase the food production potential of livestock systems. It is commonly used to reverse pasturedegradation, a process characterized by loss offorage and decreased animalcarrying capacity which results fromovergrazing, poornutrient management, and lack ofsoil conservation.[21] This degradation leads to poor pasture soils with decreased fertility andwater availability and increased rates of erosion, compaction, andacidification.[22] Degraded pastures have significantly lowerproductivity and highercarbon footprints compared to intensified pastures.[23][24][25][26][27]
Management practices which improve soil health and consequentlygrass productivity includeirrigation, soil scarification, and the application oflime, fertilizers, andpesticides. Depending on the productivity goals of the target agricultural system, more involved restoration projects can be undertaken to replaceinvasive and under-productive grasses with grass species that are better suited to thesoil andclimate conditions of the region.[21] These intensified grass systems allow higherstocking rates with faster animal weight gain and reduced time to slaughter, resulting in more productive, carbon-efficientlivestock systems.[25][26][27]
Another technique to optimizeyield while maintaining thecarbon balance is the use of integrated crop-livestock (ICL) and crop-livestock-forestry (ICLF) systems, which combine several ecosystems into one optimized agricultural framework.[28] Correctly performed, such production systems are able to create synergies potentially providing benefits to pastures through optimal plant usage, improvedfeed and fattening rates, increased soil fertility and quality, intensifiednutrient cycling, integratedpest control, and improvedbiodiversity.[21][28] The introduction of certainlegume crops to pastures can increasecarbon accumulation andnitrogen fixation in soils, while their digestibility helps animal fattening and reducesmethane emissions fromenteric fermentation.[21][25] ICLF systems yield beef cattle productivity up to ten times that of degraded pastures; additional crop production frommaize,sorghum, andsoybean harvests; and greatly reducedgreenhouse gas balances due to forest carbon sequestration.[22]
In the Twelve Aprils grazing program for dairy production, developed by theUSDA-SARE, forage crops for dairy herds are planted into aperennial pasture.[29]
Rotational grazing is a variety of foraging in which herds or flocks are regularly and systematically moved to fresh, rested grazing areas (sometimes calledpaddocks) to maximize the quality and quantity of forage growth. It can be used with cattle, sheep, goats, pigs, chickens, turkeys, ducks, and other animals. The herds graze one portion of pasture, or a paddock, while allowing the others to recover. Resting grazed lands allows the vegetation to renew energy reserves, rebuild shoot systems, and deepen root systems, resulting in long-term maximumbiomass production.[4][5][30][31] Pasture systems alone can allow grazers to meet their energy requirements, but rotational grazing is especially effective because grazers thrive on the more tender younger plant stems. Parasites are also left behind to die off, minimizing or eliminating the need for de-wormers. With the increased productivity of rotational systems, the animals may need less supplemental feed than in continuous grazing systems. Farmers can therefore increase stocking rates.[4][32]
Intensive livestock farming or "factory farming", is the process of raising livestock in confinement at high stocking density.[33][34][35][36][37] "Concentrated animal feeding operations" (CAFO), or "intensive livestock operations", can hold large numbers (some up to hundreds of thousands) of cows, hogs, turkeys, or chickens, often indoors. The essence of such farms is the concentration of livestock in a given space. The aim is to provide maximum output at the lowest possible cost and with the greatest level of food safety.[38] The term is often used pejoratively.[39] CAFOs have dramatically increased the production of food from animal husbandry worldwide, both in terms of total food produced and efficiency.
Food and water is delivered to the animals, and therapeutic use of antimicrobial agents, vitamin supplements, and growth hormones are often employed. Growth hormones are not used on chickens nor on any animal in theEuropean Union. Undesirable behaviors often related to the stress of confinement led to a search for docile breeds (e.g., with natural dominant behaviors bred out), physical restraints to stop interaction, such as individual cages for chickens, or physical modification such as thedebeaking of chickens to reduce the harm of fighting.[40][41]
The CAFO designation resulted from the 1972 U.S.Federal Clean Water Act, which was enacted to protect and restore lakes and rivers to a "fishable, swimmable" quality. TheUnited States Environmental Protection Agency identified certain animal feeding operations, along with many other types of industry, as "point source"groundwater polluters. These operations were subjected to regulation.[42]
In 17 states in the U.S., isolated cases ofgroundwater contamination were linked to CAFOs.[43] The U.S. federal government acknowledges thewaste disposal issue and requires thatanimal waste be stored inlagoons. These lagoons can be as large as 7.5 acres (30,000 m2). Lagoons not protected with an impermeable liner can leak into groundwater under some conditions, as can runoff from manure used as fertilizer. A lagoon that burst in 1995 released 25 million gallons of nitrous sludge in North Carolina'sNew River. The spill allegedly killed eight to ten million fish.[44]
The large concentration of animals, animal waste, and dead animals in a small space poses ethical issues to some consumers.Animal rights andanimal welfare activists have charged that intensive animal rearing is cruel to animals.
TheGreen Revolution transformed farming in many developing countries. It spread technologies that had already existed, but had not been widely used outside of industrialized nations. These technologies included "miracle seeds", pesticides, irrigation, and synthetic nitrogen fertilizer.[45]
In the 1970s, scientists created high-yielding varieties of maize,wheat, and rice. These have an increased nitrogen-absorbing potential compared to other varieties. Since cereals that absorbed extra nitrogen would typically lodge (fall over) before harvest, semi-dwarfing genes were bred into their genomes.Norin 10 wheat, a variety developed byOrville Vogel from Japanesedwarf wheat varieties, was instrumental in developing wheat cultivars.IR8, the first widely implemented high-yielding rice to be developed by theInternational Rice Research Institute, was created through a cross between an Indonesian variety named "Peta" and a Chinese variety named "Dee Geo Woo Gen".[46]
With the availability of molecular genetics inArabidopsis and rice the mutant genes responsible (reduced height (rht),gibberellin insensitive (gai1) andslender rice (slr1)) have been cloned and identified as cellular signalling components ofgibberellic acid, aphytohormone involved in regulating stem growth via its effect on cell division.Photosynthate investment in the stem is reduced dramatically in shorter plants and nutrients become redirected to grain production, amplifying in particular the yield effect of chemical fertilizers.
High-yielding varieties outperformed traditional varieties several fold and responded better to the addition of irrigation, pesticides, and fertilizers.Hybrid vigour is utilized in many important crops to greatly increase yields for farmers. However, the advantage is lost for the progeny of theF1 hybrids, meaning seeds for annual crops need to be purchased every season, thus increasing costs and profits for farmers.
Crop rotation or crop sequencing is the practice of growing a series of dissimilar types ofcrops in the same space in sequential seasons for benefits such as avoiding pathogen and pest buildup that occurs when one species is continuously cropped. Crop rotation also seeks to balance the nutrient demands of various crops to avoidsoil nutrient depletion. A traditional component of crop rotation is the replenishment of nitrogen through the use of legumes andgreen manure in sequence with cereals and other crops. Crop rotation can also improvesoil structure and fertility by alternating deep-rooted and shallow-rooted plants. A related technique is to plant multi-speciescover crops between commercial crops. This combines the advantages of intensive farming with continuous cover andpolyculture.
Crop irrigation accounts for 70% of the world's fresh water use.[47]Flood irrigation, the oldest and most common type, is typically unevenly distributed, as parts of a field may receive excess water in order to deliver sufficient quantities to other parts.Overhead irrigation, using center-pivot or lateral-moving sprinklers, gives a much more equal and controlled distribution pattern.Drip irrigation is the most expensive and least-used type, but delivers water to plant roots with minimal losses.[48]
Water catchment management measures include recharge pits, which capture rainwater and runoff and use it to recharge groundwater supplies. This helps in the replenishment of groundwater wells and eventually reduces soil erosion. Dammed rivers creatingreservoirs store water for irrigation and other uses over large areas. Smaller areas sometimes use irrigation ponds or groundwater.
In agriculture, systematic weed management is usually required, often performed by machines such as cultivators or liquid herbicide sprayers.Herbicides kill specific targets while leaving the crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often based on planthormones.Weed control throughherbicide is made more difficult when the weeds become resistant to the herbicide. Solutions include:
Inagriculture, aterrace is a leveled section of ahilly cultivated area, designed as a method of soil conservation to slow or prevent the rapidsurface runoff of irrigation water. Often such land is formed into multiple terraces, giving a stepped appearance. The human landscapes of rice cultivation in terraces that follow the natural contours of the escarpments, likecontour ploughing, are a classic feature of the island ofBali and theBanaue Rice Terraces inBanaue, Ifugao,Philippines. InPeru, theInca made use of otherwise unusable slopes by buildingdrystone walls to create terraces known asAndéns.
Apaddy field is a flooded parcel ofarable land used for growing rice and othersemiaquatic crops. Paddy fields are a typical feature of rice-growing countries ofeast andsoutheast Asia, including Malaysia, China, Sri Lanka, Myanmar, Thailand, Korea, Japan, Vietnam, Taiwan, Indonesia,India, and the Philippines. They are also found in other rice-growing regions such asPiedmont (Italy), theCamargue (France), and theArtibonite Valley (Haiti). They can occur naturally alongrivers ormarshes, or can be constructed, even on hillsides. They require large water quantities for irrigation, much of it from flooding. It gives an environment favourable to the strain of rice being grown, and is hostile to manyspecies ofweeds. As the onlydraft animal species which is comfortable inwetlands, thewater buffalo is in widespread use in Asian rice paddies.[49]
A recent development in the intensive production of rice is theSystem of Rice Intensification.[50][51] Developed in 1983 by theFrenchJesuitFatherHenri de Laulanié inMadagascar,[52] by 2013 the number of smallholder farmers using the system had grown to between 4 and 5 million.[53]
Aquaculture is the cultivation of the natural products ofwater (fish,shellfish,algae,seaweed, and other aquatic organisms). Intensive aquaculture takes place on land using tanks, ponds, or other controlled systems, or in the ocean, using cages.[54]
Intensive farming practices which are thought to besustainable[by whom?] have been developed to slow the deterioration of agricultural land and even regeneratesoil health andecosystem services.[citation needed] These developments may fall in the category oforganic farming, or the integration of organic and conventional agriculture.
Pasture cropping involves planting grain crops directly into grassland without first applying herbicides. The perennial grasses form a living mulch understory to the grain crop, eliminating the need to plantcover crops afterharvest. The pasture is intensively grazed both before and after grain production. This intensive system yields equivalent farmer profits (partly from increased livestock forage) while building newtopsoil andsequestering up to 33 tons of CO2/ha/year.[55][56]
Biointensive agriculture focuses on maximizing efficiency such as per unit area, energy input and water input.
Agroforestry combines agriculture and orchard/forestry technologies to create more integrated, diverse, productive, profitable, healthy and sustainable land-use systems.
Intercropping can increase yields or reduce inputs and thus represents (potentially sustainable) agricultural intensification. However, while total yield per unit land area is often increased, yields of any single crop often decrease. There are also challenges to farmers who rely on farming equipment optimized formonoculture, often resulting in increased labor inputs.
Vertical farming is intensive crop production on a large scale in urban centers, in multi-story, artificially-lit structures, for the production of low-calorie foods like herbs,microgreens, and lettuce.
An integrated farming system is a progressive,sustainable agriculture system such aszero waste agriculture orintegrated multi-trophic aquaculture, which involves the interactions of multiple species. Elements of this integration can include:
Industrial agriculture uses huge amounts ofwater,energy,[59] andindustrial chemicals, increasingpollution in thearable land,usable water, andatmosphere.Herbicides,insecticides, andfertilizers accumulate inground andsurface waters. Industrial agricultural practices are one of the main drivers ofglobal warming, accounting for 14–28% of netgreenhouse gas emissions.[60]
Many of the negative effects of industrial agriculture may emerge at some distance from fields and farms. Nitrogen compounds from the Midwest, for example, travel down the Mississippi to degrade coastal fisheries in the Gulf of Mexico, causing so-calledoceanic dead zones.[61]
Many wild plant and animal species have become extinct on a regional or national scale, and the functioning of agro-ecosystems has been profoundly altered. Agricultural intensification includes a variety of factors, including the loss of landscape elements, increased farm and field sizes, and increase usage of insecticides and herbicides. The large scale of insecticides and herbicides lead to the rapid developing resistance among pests renders herbicides and insecticides increasingly ineffective.[62]Agrochemicals have may be involved incolony collapse disorder, in which the individual members of bee colonies disappear.[63] (Agricultural production is highly dependent on bees topollinate many varieties of fruits and vegetables.)
Intensive farming creates conditions for parasite growth and transmission that are vastly different from what parasites encounter in natural host populations, potentially altering selection on a variety of traits such as life-history traits and virulence. Some recent epidemic outbreaks have highlighted the association with intensive agricultural farming practices. For example theinfectious salmon anaemia (ISA) virus is causing significant economic loss for salmon farms. The ISA virus is an orthomyxovirus with two distinct clades, one European and one North American, that diverged before 1900 (Krossøy et al. 2001).[64] This divergence suggests that an ancestral form of the virus was present in wild salmonids prior to the introduction of cage-cultured salmonids. As the virus spread from vertical transmission (parent to offspring)[clarification needed].
Intensivemonoculture increases the risk of failures due topests, adverse weather and disease.[65][66]
A study for the U.S.Office of Technology Assessment concluded that regarding industrial agriculture, there is a "negative relationship between the trend toward increasing farm size and the social conditions in rural communities" on a "statistical level".[67] Agricultural monoculture can entail social and economic risks.[68]
{{cite web}}:|author= has generic name (help)rotational grazing involves a higher level of management with greater paddock numbers, shorter grazing periods, and longer rest periods.
There are many reasons why producers move to intensive grazing systems. These include...
The largest hypoxic zone in the United States, and the second largest hypoxic zone worldwide, forms in the northern Gulf of Mexico adjacent to the Mississippi River. This image from a NOAA animation shows how runoff from farms (green areas) and cities (red areas) drains into the Mississippi. This runoff contains an overabundance of nutrients from fertilizers, wastewater treatment plants, and other sources.
In the north-central States, the intensive culture of certain species and hybrids of poplars presents the greatest opportunity to achieve maximum wood fiber production, provided that adequate provision can be made for control of the many insects and diseases that may attack them. [...] The [...] trend toward monoculture [...] increases the vulnerability of the cropping system to insects and diseases. The greatest potential for insidious disaster due to virus diseases is with monocultures of vegetatively propagated perennial crops.
Industrial monocultures—single crops where there was once diversity, and single varieties of each crop where there used to be thousands—are also blows against biological and genetic diversity. [...] Monocultures are weak, subject to insect blights, diseases, and bad weather.
In addition to being relatively unstable agricultural ecosystems, monocultures are also vulnerable to disaster from social and economic disruptions.
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