Another way agriculture refers to the production of food and goods through farming and forestry. Agriculture was the key development that led to the rise of civilization, with the husbandry of domesticated animals and plants (i.e. crops) creating food surpluses that enabled the development of more densely populated and stratified societies. The study of agriculture is known as agricultural science (the related practice of gardening is studied in horticulture).
Agriculture encompasses a wide variety of specialties and techniques, including ways to expand the lands suitable for plant rising, by digging water-channels and other forms of irrigation. Cultivation of crops on arable land and the pastoral herding of livestock on rangeland remain at the foundation of agriculture. In the past century there has been increasing concern to identify and quantify various forms of agriculture. In the developed world the range usually extends between sustainable agriculture (e.g. perm culture or organic agriculture) and intensive farming (e.g. industrial agriculture).
Agriculture is necessary because-
There is conventional agriculture and sustainable agriculture (agro-ecology).
Conventional agriculture, most commonly practiced in the United States, usually involves the following criteria:
- Altering or changing the natural environment (removing trees, tilling the soil, installing an irrigation system, etc.
- Mono-cropping or planting one crop (ex: only corn is grown in a plot).
- The crops grown are nonrenewable- after harvesting, the plot is bare again and requires cultivation (tilling and plowing of the soil), fertilization, planting, irrigation (watering), and harvesting all over again.
- Using insecticides and pesticides to keep insects and animals from eating the crops; these chemicals are not only poisonous to insects, animals and humans, they also pollute ground water, streams, rivers, and oceans.
- Using inorganic fertilizers to provide nutrients to the soil.
- A lot of energy and work for the farmer to maintain this unnatural farming system; nature is more aligned with diversity (it wants to be wild), rather than controlled and uniform.
- Maintaining the natural environment and using ecological principles for sustained farming practices.
- Poly-cropping or planting many crops together (ex: planting rows of corn, bean, and squash together rather than in separate plots, like in mono-cropping).
- Since many plants are planted together, and each one has a different harvesting period, the plot is never bare. This reduces soil erosion.
- A diverse system of plants may attract several species of herbivores. Some of these herbivores like to eat specific kinds of plants. Predator species usually do not have a preference for which herbivores to eat. This predation keeps the herbivore population in check, thus reducing predation of any one crop.
- Nutrients from each intercrop plant provide different nutrients to the soil, thus increasing its fertility (ability to sustain life).
- Less energy is required from the farmer because the agriculture system sustains itself.
(1) Abiotic components
It has three parts:
a) Atmosphere b) hydrosphere c) lithosphere d) biosphere
It has three parts:
a) Producer b) consumer c) de-composer
Agriculture and environment are closely connected each other. Both are most important for the existence of human being. If one is disordered then other is severely affected. So it’s very important for us to keep both environment and agriculture on the real track. Now I m going to describe effect of agriculture on the environment.
4. Habitat and landscape features
5. Soil degradation:
Agriculture increases the risk of erosion through its disturbance of vegetation by way of:
- Overgrazing of animals.
- Planting of a monoculture.
- Row cropping.
- Tilling or plowing.
- Crop removal.
- Land-use conversion.
- Farmers use ground water for irrigation.
- Lack of adequate attention to water conservation.
- Lack of efficiency in water use.
- An uncontrolled use of the borewell technology.
- Contribution to water accumulation and flood control.
- Nutrient recycling and fixation.
- Soil formation.
- Carbon sequestration by trees and soil.
- Wildlife and biodiversity protection.
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, but also by altering the earth's land cover, which can change its ability to absorb or reflect heat and light, thus contributing to radioactive 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.
A study published in Science suggest that, due to climate change, "southern Africa could lose more than 30% of its main crop, maize, by 2030. In South Asia losses of many regional staples, such as rice, millet and maize could top 10%".
More favorable effects on yield tend to depend to a large extent on realization of the potentially beneficial effects of carbon dioxide on crop growth and increase of efficiency in water use. Decrease in potential yields is likely to be caused by shortening of the growing period, decrease in water availability and poor vernalization.
- Productivity, in terms of quantity and quality of crops.
- Agricultural practices, through changes of water use (irrigation) and agricultural inputs such as herbicides, insecticides and fertilizers.
- Environmental effects, in particular in relation of frequency and intensity of soil drainage (leading to nitrogen leaching), soil erosion, reduction of crop diversity.
- Rural space, through the loss and gain of cultivated lands, land speculation, land renunciation, and hydraulic amenities.
- Adaptation, organisms may become more or less competitive, as well as humans may develop urgency to develop more competitive organisms, such as flood resistant or salt resistant varieties of rice.
- Shortage in grain production
- Poverty impacts
· Temperature potential effect on growing period. An increase in temperature will speed up development. In the case of an annual crop, the duration between sowing and harvesting will shorten (for example, the duration in order to harvest corn could shorten between one and four weeks). The shortening of such a cycle could have an adverse effect on productivity because senescence would occur sooner.
· Climate changes and Agricultural surfacesClimate change may increase the amount of arable land in high-latitude region by reduction of the amount of frozen lands. A 2005 study reports that temperature in Siberia has increased three degree Celsius in average since 1960 (much more than the rest of the world). However, reports about the impact of global warming on Russian agriculture indicate conflicting probable effects : while they expect a northward extension of farmable lands, they also warn of possible productivity losses and increased risk of drought.
Low lying areas such as Bangladesh, India and Vietnam will experience major loss of rice crop if sea levels are expected to rise by the end of the century. Vietnam for example relies heavily on its southern tip, where the Mekong Delta lies, for rice planting. Any rise in sea level of no more than a meter will drown several sq. km. of rice paddies, rendering Vietnam incapable of producing its main staple and export of rice.
· Erosion and fertilityWith global warming, soil degradation is more likely to occur, and soil fertility would probably be affected by global warming. However, because the ratio of carbon to nitrogen is a constant, a doubling of carbon is likely to imply a higher storage of nitrogen in soils as nitrates, thus providing higher fertilizing elements for plants, providing better yields. The average needs for nitrogen could decrease, and give the opportunity of changing often costly fertilization strategies.
· Ozone and UV-BSome scientists think agriculture could be affected by any decrease in stratospheric ozone, which could increase biologically dangerous ultraviolet radiation B. Excess ultraviolet radiation B can directly effect plant physiology and cause massive amounts of mutations, and indirectly through changed pollinator behavior, though such changes are simple to quantify
- Increasing temperature and Water scarcity
- Using environmental friendly fertilizer for the production that will help to increase fertility of the land so the production will be increased.
- Reducing cutting of trees to protect the environment from different hazard.
- Re used industrial waste for protecting water pollution
- Managing tree plantation.
- Using more surface water than underground water.
- Using environmental friendly technology.
- Managing water reuse system.Conclusion
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Composition of raw wastewater (mg/l)
Existing Approaches for Regulating Wastewater Reuse in Agriculture
Wastewater contains high concentrations of excreted pathogens such as viruses, bacteria, helminths eggs, and fecal coliforms. These excreted pathogens have the potential to cause disease if present in a human host in sufficient quantities. Intestinal nematodes pose the highest degree of risk of infection while bacteria pose a lower risk. Viruses exhibit the lowest risk. To minimize the potential risk of infection, the World Bank, World Health Organization and International Reference Centre for Waste Disposal at Engelberg, Switzerland, convened a group of experts comprising of epidemiologists, social scientists and sanitary engineers in 1985, to review recent epidemiological evidence, and make recommendations. This report was the basis for the WHO guidelines on the safe use of water for agriculture and aquaculture. The rationale behind the WHO guidelines outlined below, was to develop criteria that would prevent the transmission of communicable diseases while optimizing resource conservation and recycling.
Posted by Imran Irshad at 08:52