Environmental issues with agriculture | Wikipedia audio article


The environmental impact of agriculture is
the effect that different farming practices have on the ecosystems around them, and how
those effects can be traced back to those practices. The environmental impact of agriculture varies
based on the wide variety of agricultural practices employed around the world. Ultimately, the environmental impact depends
on the production practices of the system used by farmers. The connection between emissions into the
environment and the farming system is indirect, as it also depends on other climate variables
such as rainfall and temperature. There are two types of indicators of environmental
impact: “means-based”, which is based on the farmer’s production methods, and “effect-based”,
which is the impact that farming methods have on the farming system or on emissions to the
environment. An example of a means-based indicator would
be the quality of groundwater, that is effected by the amount of nitrogen applied to the soil. An indicator reflecting the loss of nitrate
to groundwater would be effect-based. The means-based evaluation looks at farmers’
practices of agriculture, and the effect-based evaluation considers the actual effects of
the agricultural system. For example, means-based analysis might look
at pesticides and fertilization methods that farmers are using, and effect-based analysis
would consider how much CO2 is being emitted or what the Nitrogen content of the soil is.The
environmental impact of agriculture involves a variety of factors from the soil, to water,
the air, animal and soil variety, people, plants, and the food itself. Some of the environmental issues that are
related to agriculture are climate change, deforestation, genetic engineering, irrigation
problems, pollutants, soil degradation, and waste.==Negatives=====Climate change===Climate change and agriculture are interrelated
processes, both of which take place on a worldwide scale. Global warming is projected to have significant
impacts on conditions affecting agriculture, including temperature, precipitation and glacial
run-off. These conditions determine the carrying capacity
of the biosphere to produce enough food for the human population and domesticated animals. Rising carbon dioxide levels would also have
effects, both detrimental and beneficial, on crop yields. Assessment of the effects of global climate
changes on agriculture might help to properly anticipate and adapt farming to maximize agricultural
production. Although the net impact of climate change
on agricultural production is uncertain it is likely that it will shift the suitable
growing zones for individual crops. Adjustment to this geographical shift will
involve considerable economic costs and social impacts. At the same time, agriculture has been shown
to produce significant effects on climate change, primarily through the production and
release of greenhouse gases such as carbon dioxide, methane, and nitrous oxide. In addition, agriculture that practices tillage,
fertilization, and pesticide application also releases ammonia, nitrate, phosphorus, and
many other pesticides that affect air, water, and soil quality, as well as biodiversity. Agriculture also alters the Earth’s land cover,
which can change its ability to absorb or reflect heat and light, thus contributing
to radiative forcing. Land use change such as deforestation and
desertification, together with use of fossil fuels, are the major anthropogenic sources
of carbon dioxide; agriculture itself is the major contributor to increasing methane and
nitrous oxide concentrations in earth’s atmosphere.===Deforestation===Deforestation is clearing the Earth’s forests
on a large scale worldwide and resulting in many land damages. One of the causes of deforestation is to clear
land for pasture or crops. According to British environmentalist Norman
Myers, 5% of deforestation 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 farming.Deforestation
causes the loss of habitat for millions of species, and is also a driver of climate change. Trees act as a carbon sink: that is, they
absorb carbon dioxide, an unwanted greenhouse gas, out of the atmosphere. Removing trees releases carbon dioxide into
the atmosphere and leaves behind fewer trees to absorb the increasing amount of carbon
dioxide in the air. In this way, deforestation exacerbates climate
change. When trees are removed from forests, the soils
tend to dry out because there is no longer shade, and there are not enough trees to assist
in the water cycle by returning water vapor back to the environment. With no trees, landscapes that were once forests
can potentially become barren deserts. The removal of trees also causes extreme fluctuations
in temperature.In 2000 the United Nations Food and Agriculture Organization (FAO) found
that “the role of population dynamics in a local setting may vary from decisive to negligible,”
and that deforestation can result from “a combination of population pressure and stagnating
economic, social and technological conditions.”===
Genetic engineering===Genetically engineered crops are herbicide-tolerant,
and their overuse has created herbicide resistant “super weeds”, which may ultimately increase
the use of herbicides. Seed contamination is another problem of genetic
engineering; it can occur from wind or bee pollination that is blown from genetically-engineered
crops to normal crops. About 50% of corn and soybean samples and
more than 80% of canola samples were found to be contaminated by Monsanto’s (genetic
engineering company) genes. This accidental contamination can cause organic
farmers to lose a lot of money because they needed to recall their products. There are various cases of this such as in
the corn and alfalfa industry.===Irrigation===Irrigation can lead to a number of problems:Among
some of these problems is the depletion of underground aquifers through overdrafting. Soil can be over-irrigated because of poor
distribution uniformity or management wastes water, chemicals, and may lead to water pollution. Over-irrigation can cause deep drainage from
rising water tables that can lead to problems of irrigation salinity requiring watertable
control by some form of subsurface land drainage. However, if the soil is under irrigated, it
gives poor soil salinity control which leads to increased soil salinity with consequent
buildup of toxic salts on soil surface in areas with high evaporation. This requires either leaching to remove these
salts and a method of drainage to carry the salts away. Irrigation with saline or high-sodium water
may damage soil structure owing to the formation of alkaline soil.===Pollutants===Synthetic pesticides such as ‘Malathion’,
‘Rogor’, ‘Kelthane’ and ‘confidor’ are the most widespread method of controlling pests
in agriculture. Pesticides can leach through the soil and
enter the groundwater, as well as linger in food products and result in death in humans
and non-targeted wildlife. A wide range of agricultural chemicals are
used and some become pollutants through use, misuse, or ignorance. The erosion of topsoil, which can contain
chemicals such as herbicides and pesticides, can be carried away from farms to other places. Pesticides can be found in streams and ground
water. Atrazine is a herbicide used to control weeds
that grow among crops. This herbicide can disrupt endocrine production
which can cause reproductive problems in mammals, amphibians and fish that have been exposed. Pollutants from agriculture have a huge effect
on water quality. Agricultural nonpoint source (NPS) solution
impacts lakes, rivers, wetlands, estuaries, and groundwater. Agricultural NPS can be caused by poorly managed
animal feeding operations, overgrazing, plowing, fertilizer, and improper, excessive, or badly
timed use of Pesticides. Pollutants from farming include sediments,
nutrients, pathogens, pesticides, metals, and salts. Animal agriculture can also cause pollutants
to enter the environment. Bacteria and pathogens in manure can make
their way into streams and groundwater if grazing, storing manure in lagoons and applying
manure to fields is not properly managed.Listed below are additional and specific problems
that may arise with the release of pollutants from agriculture. Pesticide drift
soil contamination air pollution spray drift
Pesticides, especially those based on organochloride Pesticide residue in foods
Pesticide toxicity to bees List of crop plants pollinated by bees
Pollination management Bioremediation===
Soil degradation===Soil degradation is the decline in soil quality
that can be a result of many factors, especially from agriculture. Soils hold the majority of the world’s biodiversity,
and healthy soils are essential for food production and an adequate water supply. Common attributes of soil degradation can
be salting, waterlogging, compaction, pesticide contamination, decline in soil structure quality,
loss of fertility, changes in soil acidity, alkalinity, salinity, and erosion. Soil erosion is the wearing away of topsoil
by water, wind, or farming activities. Topsoil is very fertile, which makes it valuable
to farmers growing crops. Soil degradation also has a huge impact on
biological degradation, which affects the microbial community of the soil and can alter
nutrient cycling, pest and disease control, and chemical transformation properties of
the soil. soil contamination
sedimentation===Waste===
Plasticulture is the use of plastic mulch in agriculture. Farmers use plastic sheets as mulch to cover
50-70% of the soil and allows them to use drip irrigation systems to have better control
over soil nutrients and moisture. Rain is not required in this system, and farms
that use plasticulture are built to encourage the fastest runoff of rain. The use of pesticides with plasticulture allows
pesticides to be transported easier in the surface runoff towards wetlands or tidal creeks. The runoff from pesticides and chemicals in
the plastic can cause serious deformations and death in shellfish as the runoff carries
the chemicals towards the oceans.In addition to the increased runoff that results from
plasticulture, there is also the problem of the increased amount of waste form the plastic
mulch itself. The use of plastic mulch for vegetables, strawberries,
and other row and orchard crops exceeds 110 million pounds annually in the United States. Most plastic ends up in the landfill, although
there are other disposal options such as disking mulches into the soil, on-site burying, on-site
storage, reuse, recycling, and incineration. The incineration and recycling options are
complicated by the variety of the types of plastics that are used and by the geographic
dispersal of the plastics. Plastics also contain stabilizers and dyes
as well as heavy metals, which limits the amount of products that can be recycled. Research is continually being conducted on
creating biodegradable or photodegradable mulches. While there has been minor success with this,
there is also the problem of how long the plastic takes to degrade, as many biodegradable
products take a long time to break down.===Issues by region===
The environmental impact of agriculture can vary depending on the region as well as the
type of agriculture production method that is being used. Listed below are some specific environmental
issues in a various different regions around the world. Hedgerow removal in the United Kingdom. Soil salinisation, especially in Australia. Phosphate mining in Nauru
Methane emissions from livestock in New Zealand. See Climate change in New Zealand. Environmentalists attribute the hypoxic zone
in the Gulf of Mexico as being encouraged by nitrogen fertilization of the algae bloom.==Sustainable agriculture==Sustainable agriculture is the idea that agriculture
should occur in a way such that we can continue to produce what is necessary without infringing
on the ability for future generations to do the same. The exponential population increase in recent
decades has increased the practice of agricultural land conversion to meet demand for food which
in turn has increased the effects on the environment. The global population is still increasing
and will eventually stabilise, as some critics doubt that food production, due to lower yields
from global warming, can support the global population. Agriculture can have negative effects on biodiversity
as well. Organic farming is a multifaceted sustainable
agriculture set of practices that can have a lower impact on the environment at the small
scale. However, in most cases organic farming results
in lower yields in terms of production per unit area. Therefore, widespread adoption of organic
agriculture will require additional land to be cleared and water resources extracted to
meet the same level of production. A European meta-analysis found that organic
farms tended to have higher soil organic matter content and lower nutrient losses (nitrogen
leaching, nitrous oxide emissions and ammonia emissions) per unit of field area but higher
ammonia emissions, nitrogen leaching and nitrous oxide emissions per product unit. It is believed by many that conventional farming
systems cause less rich biodiversity than organic systems. Organic farming has shown to have on average
30% higher species richness than conventional farming. Organic systems on average also have 50% more
organisms. This data has some issues because there were
several results that showed a negative effect on these things when in an organic farming
system. The opposition to organic agriculture believes
that these negatives are an issue with the organic farming system. What began as a small scale, environmentally
conscious has now become just as industrialized as conventional agriculture. This industrialization can lead to the issues
shown above such as climate change, and deforestation.===Conservation tillage===
Conservation tillage is an alternative tillage method for farming which is more sustainable
for the soil and surrounding ecosystem. This is done by allowing the residue of the
previous harvest’s crops to remain in the soil before tilling for the next crop. Conservation tillage has shown to improve
many things such as soil moisture retention, and reduce erosion. Some disadvantages are the fact that more
expensive equipment is needed for this process, more pesticides will need to be used, and
the positive effects take a long time to be visible. The barriers of instantiating a conservation
tillage policy are that farmers are reluctant to change their methods, and would protest
a more expensive, and time consuming method of tillage than the conventional one they
are used to.Other specific methods include: permaculture; and biodynamic agriculture which
incorporates a spiritual element. Category: Sustainable agriculture
Biological pest control==
See also==Agroecology
Agricultural pollution Agro-hydro-salinity model (for environmental
impacts of irrigated agriculture) Environmental impact of meat production
Ethical eating Concentrated animal feeding operations
List of environmental issues Habitat
Holistic management Livestock’s Long Shadow – Environmental
Issues and OptionsReport by the Food and Agriculture Organization of the United NationsPrinciples
of Organic Agriculture Research Institute for Organic Agriculture
Stock-free agriculture

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