Wate r p o llutio n in a rural s tre am d ue to runo ff fro mfarming activity in Ne w Ze aland .

Environmental impact of agricultureen.wikipedia.org /wiki/Environmental_impact_of _agriculture

The environmental impact of agriculturevaries based on the wide variety of agriculturalpractices employed around the world.

Contents

1 Issues

1.1 Climate change

1.2 Def orestation

1.3 Genetic engineering

1.4 Irrigation

1.5 Pollutants

1.6 Soil degradation

1.7 Waste

1.7.1 Issues by region

2 Sustainable agriculture

3 See also

4 Ref erences

5 External links

Issues

Climate change

Main article: Climate change and agriculture

Climate change and agriculture are interrelated processes, both of which take place on a globalscale. Global warming is projected to have signif icant impacts on conditions af f ecting agriculture,including temperature, precipitation and glacial run-of f . These conditions determine the carryingcapacity of the biosphere to produce enough f ood f or the human population and domesticatedanimals. Rising carbon dioxide levels would also have ef f ects, both detrimental and benef icial, oncrop yields. The overall ef f ect of climate change on agriculture will depend on the balance ofthese ef f ects. Assessment of the ef f ects of global climate changes on agriculture might help toproperly anticipate and adapt f arming to maximize agricultural production.

At the same time, agriculture has been shown to produce signif icant ef f ects on climate change,primarily through the production and release of greenhouse gases such as carbon dioxide,methane, and nitrous oxide, but also by altering the Earth's land cover, which can change itsability to absorb or ref lect heat and light, thus contributing to radiative f orcing. Land use changesuch as def orestation and desertif ication, together with use of f ossil f uels, are the majoranthropogenic sources of carbon dioxide; agriculture itself is the major contributor to increasingmethane and nitrous oxide concentrations in earth's atmosphere.[1]

Deforestat ion

Main article: Def orestation

One of the causes of def orestation is to clear land f or pasture or crops. According to Brit ishenvironmentalist Norman Myers, 5% of def orestation is due to cattle ranching, 19% due to over-heavy logging, 22% due to the growing sector of palm oil plantations, and 54% due to slash-and-burn f arming.[2]

In 2000 the United Nations Food and Agriculture Organization (FAO) f ound that "the role ofpopulation dynamics in a local setting may vary f rom decisive to negligible," and thatdef orestation can result f rom "a combination of population pressure and stagnating economic,social and technological conditions."[3]

Genetic engineering

See also: Genetically modif ied f ood controversies

Genetic engineering has caused controversies.

Seed contamination is problematic.

Irrigat ion

Main article: Environmental impact of irrigation

Irrigation can lead to a number of problems:[4]

Depletion of underground aquif ers through overdraf ting.

Ground subsidence.

Groundwater recharge – an ecological restoration, mitigation, and remediationtechnique.

Underirrigation gives poor soil salinity control which leads to increased soil salinity withconsequent build up of toxic salts on soil surf ace in areas with high evaporation. Thisrequires either leaching to remove these salts and a method of drainage to carry the saltsaway.

Overirrigation because of poor distribution unif ormity or management wastes water,chemicals, and may lead to water pollution.

Deep drainage (f rom over- irrigation) may result in rising water tables which in someinstances will lead to problems of irrigation salinity requiring watertable control by somef orm of subsurf ace land drainage.

Irrigation with saline or high-sodium water may damage soil structure owing to thef ormation of alkaline soil.

Runof f causing surf ace water and groundwater-aquif er hydrologic cycle water pollution.

Bioretention – an ecological restoration, mitigation, and remediation technique.

Pollutants

See also: Environmental impact of pesticides

A wide range of agricultural chemicals are used and some become pollutants through use,

misuse, or ignorance.

Pesticide drif t

soil contamination

groundwater and water pollution

air pollution spray drift

Pesticides, especially those based on organochloride

Pesticide residue in f oods

Pesticide toxicity to bees

List of crop plants pollinated by bees

Pollination management

Bioremediation

Soil degradation

Main article: Soil degradation

soil contamination

erosion

sedimentation

Waste

Plasticulture, the use of plastic materials in agriculture, raises problems around how to carry outthe recycling of agricultural plastics.

Issues by region

Hedgerow removal in the United Kingdom.

Soil salinisation, especially in Australia.

Phosphate mining in Nauru

Methane emissions f rom livestock in New Zealand. See Climate change in New Zealand.

Some environmentalists attribute the hypoxic zone in the Gulf of Mexico as beingencouraged by nitrogen f ertilization of the algae bloom.

Sustainable agricultureMain article: Sustainable agriculture

The exponential population increase in recent decades has increased the practice of agriculturalland conversion to meet demand f or f ood which in turn has increased the ef f ects on theenvironment. The global population is still increasing and will eventually stabilise, as some crit icsdoubt that f ood production, due to lower yields f rom global warming, can support the globalpopulation.

Organic f arming is a multif aceted sustainable agriculture set of practices that can have a lowerimpact on the environment

Other specif ic methods include: permaculture; and biodynamic agriculture which incorporates aspiritual element.

Category: Sustainable agriculture

Biological pest control

See also

Agricultural pollution

Agro-hydro-salinity model (f or environmental impacts of irrigated agriculture)

List of environmental issues

Habitat

Holistic management

Livestock's Long Shadow – Environmental Issues and Options

Report by the Food and Agriculture Organization of the United Nations

Principles of Organic Agriculture

Research Institute f or Organic Agriculture

Spatial agro-hydro-salinity model 9=(f or environmental impacts of irrigated agriculture)

Stock-f ree agriculture

References

1. ^ UN Report on Climate Change. Retrieved 25 June 2007.

2. ^ Hance, Jeremy (May 15, 2008). "Tropical def orestation is 'one of the worst crises sincewe came out of our caves' ". Mongabay.com / A Place Out of Time: Tropical Rainforests andthe Perils They Face.

3. ^ Alain Marcoux (August 2000). "Population and def orestation". SD Dimensions. SustainableDevelopment Department, Food and Agriculture Organization of the United Nations (FAO).

4. ^ ILRI, 1989, Ef f ectiveness and Social/Environmental Impacts of Irrigation Projects: aReview. In: Annual Report 1988, International Institute f or Land Reclamation andImprovement (ILRI), Wageningen, The Netherlands, pp. 18–34 . On line: [1]

External links

[2] Holistic Management International

Environmental Issues in Animal Agriculture – Choices magazine article

[3] Website with f ree articles and sof tware on environmental impacts of irrigated agriculturelike waterlogging and salinization

Environmental Planning on Livestock and Poultry Operations describes several dif f erentplanning processes that can be used on f arms. It also includes links to several webcasts.Part of the Livestock and Poultry Environmental Learning Center

This page was last modif ied on 8 April 2014 at 07:19.

Text is available under the Creative Commons Attribution-ShareAlike License; additionalterms may apply. By using this site, you agree to the Terms of Use and Privacy Policy.Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-prof itorganization.