Irrigation

Irrigation is the artificial application of water to the soil usually for assisting in growing crops. In crop production it is mainly used in dry areas and in periods of rainfall shortfalls, but also to protect plants against frost.

Additionally irrigation helps to suppress weed growing in rice fields. In contrast, agriculture that relies only on direct rainfall is referred to as rain-fed farming. Irrigation is often studied together with drainage, which is the natural or artificial removal of surface and sub-surface water from a given area.

Types of irrigation

 Surface irrigation

  In surface irrigation systems water moves over and across the land by simple gravity flow in order to wet it and to infiltrate into the soil. Surface irrigation can be subdivided into furrow, borderstrip or basin irrigation. It is often called flood irrigation when the irrigation results in flooding or near flooding of the cultivated land.

 Localized irrigation

Localized irrigation is a system where water is distributed under low pressure through a piped network, in a pre-determined pattern, and applied as a small discharge to each plant or adjacent to it. Drip irrigation, spray or micro-sprinkler irrigation and bubbler irrigation belong to this category of irrigation methods.

 Drip Irrigation

Drip irrigation, also known as trickle irrigation, functions as its name suggests. Water is delivered at or near the root zone of plants, drop by drop. This method can be the most water-efficient method of irrigation, if managed properly, since evaporation and runoff are minimized.Recent technology developments on drip installers like the drip installer at New Mexico State University Arrow Head Center, places the line underground and covers the slit leaving no soil exposed.

 Sprinkler irrigation

In sprinkler or overhead irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure sprinklers or guns. A system utilizing sprinklers, sprays, or guns mounted overhead on permanently installed risers is often referred to as a solid-set irrigation system. 

 and many more.....

Farm Management

 

 

Reduce total nitrogen loading

·                  Ensure livestock feed rations are not any higher than necessary to meet production targets. This will save both feed costs and excess nitrogen loss in the manure.

·                  Use nitrogen from sources available on the farm first, where possible (e.g., manure), before buying any nitrogen sources produced off-farm.

Prevent runoff from manure or other nutrient materials

·                  Store manure properly until it is ready for land application. Be sure your storage area is properly sited, designed and sized.

Manage fields to avoid excess nitrate that could leach to groundwater

·                  Identify fields and areas sensitive to nitrogen in areas where nutrient applications are planned. For instance, sandy or gravelly soils, and soils with shallow water tables are more susceptible to nitrogen leaching.

·                  Match nitrogen applications with crop requirements. Use the spring or pre-sidedress soil nitrogen test where available (e.g., for corn and barley).

·                  In your Nutrient Management Plan, account for nitrogen contributions from green manure crops and any previous crop rotations.

·                  In your Nutrient Management Plan, account for nitrogen from any manure or biosolid application.

·                  Apply most of the nitrogen just before the time of maximum crop uptake (e.g., sidedress corn).

·                  Split applications of nitrogen through techniques such as fertigation.

·                  Practise crop rotations to make efficient use of nitrogen and maintain healthy soils.

·                  Establish cover crops as needed to tie up any excess nitrogen at the end of the season.

Manage nutrient application to avoid ammonium losses to surface water

·                  Practice timely tillage to incorporate manure, balancing the risk of soil compaction with the losses of nitrogen to the atmosphere if the manure is not incorporated quickly.

·                  Avoid applying manure near surface water or on steeply sloping land.

·                  Keep application rates low enough to prevent runoff.

·                  Mix manure into the soil as soon possible after applying it.

·                  On tile-drained land, keep application rates of liquid manure below 40 m³/ha (3,600 gal/ac) or pre-till the field before applying it. This will help prevent the movement of manure directly to tile through cracks or earthworm channels.

·                  Use buffer strips and erosion control structures to filter runoff before it enters surface water. Buffer strips in riparian zones have proven to reduce nutrient movement off the field into nearby surface water sources. Buffer strips consume excess nutrients before they flow into surface water and enhance opportunities for groundwater denitrification. 

 

Ozone Layer Depletion

ozone depletion: Destruction of the stratospheric ozone layer, which shields earth from ultraviolet radiation harmful to life. This destruction of ozone is caused by the breakdown of certain compounds that contain chlorine, bromine, or both (chlorofluorocarbons or halons), which occurs when they reach the stratosphere and then catalytically destroy ozone molecules.

ozone hole: A well-defined, large-scale area of significant thinning of the ozone layer. It occurs over Antarctica each spring.

ozone layer: The protective stratum in the atmosphere, about 15 miles above the ground, that absorbs some of the sun’s ultraviolet rays, thereby reducing the amount of potentially harmful radiation that reaches earth’s surface.

ozone precursors: Chemicals that contribute to the formation of ozone.

Sunlight contains some ultraviolet light, and when we expose ourselves to too much of it, we get a sunburn. Over time, too much exposure to ultraviolet light can lead to cataracts and skin cancer. The earth has a layer in the upper atmosphere, consisting mostly of ozone gas, that filters out most of the ultraviolet in the sun's radiation. Recently there has been scientific evidence that we have been releasing gases that damage this layer. Our country and others have reacted by invoking legislation that should eliminate these contaminants from the atmosphere.

The ozone (O3) layer in the stratosphere protects life on earth from exposure to dangerous levels of ultraviolet light. It does so by filtering out harmful ultraviolet radiation from the sun. When CFCs and other ozone-degrading chemicals are emitted, they mix with the atmosphere and eventually rise to the stratosphere. There, the chlorine and the bromine they contain catalyze the destruction of ozone. This destruction is occurring at a more rapid rate than ozone can be created through natural processes.


The chemicals most responsible for the destruction of the ozone layer are chlorofluorocarbons, carbon tetrachloride, methyl bromide, methyl chloroform, and halons. Chlorofluorocarbons have long been widely used as coolants in refrigerators and air conditioners and as foaming agents, solvents, and aerosol propellants. Carbon tetrachloride and methyl chloroform are solvents used for essential industrial applications. In the United States, carbon tetrachloride is now used almost entirely as a feedstock for the production of chlorofluorocarbons. Hydrogenated CFCs (HCFCs) have many of the same uses as CFCs and are increasingly employed as interim substitutes for CFCs. Halons have been used in fire extinguishers.

Health Effects of Exposure to Lead

Lead, a naturally occurring metal, has been used to produce gasoline, ceramic products, paints, and solder. In homes built before 1978, lead-based paint and lead-contaminated dust from paint are the primary sources of exposure to lead. Major initiatives have been implemented to reduce lead exposure by phasing lead out of gasoline, paint, solder, and plumbing fixtures.

Health problems from lead exposure are a major environmental health problem because exposure to lead is widespread and can cause health effects at relatively low levels. Substantial data are available to link lead exposure with health effects. Lead adversely affects the nervous system, can lower intelligence, and has been associated with behavioral and attention problems. It also affects the kidney and blood-forming organs.Children and the developing fetus are more vulnerable to the effects of lead than adults.

The level of lead in blood has long been used as an indicator of exposure to lead. And, because the linkage between lead exposure and health effects is so strong, blood lead is also used as an indicator of adverse effects on the nervous system.

In the 1970s, lead poisoning occurred increasingly in children who did not live in dwellings with lead-based paint, suggesting that another source or sources of lead exposure were of even greater concern than lead paint. Research found that combustion of leaded gasoline was the primary source of lead in the environment. In the 1970s, EPA promulgated regulations to ban lead in gasoline. Since that time, concentrations of lead in blood samples and in ambient air have declined significantly (Exhibit 4-7). In young children, the median concentration of lead in blood decreased by 85 percent from 1976 to 1999-2000 based on nationwide surveys.

But national averages of blood levels tell only part of the story. Between 1999 and 2000, approximately 430,000 children ages 1 to 5 (about 2 percent) had elevated blood lead levels (10 µg/dL or greater) from eating paint chips or inhaling lead-containing dust in older homes, primarily in urban areas. Even today, lead poisoning is considered to be a serious environmental hazard in young children in the U.S. Several major metropolitan areas, including Chicago, Detroit, Milwaukee, Palo Alto, and St. Louis, are evaluating blood lead levels of young children, focusing on areas at high risk (i.e., older housing and poorer neighborhoods), to study and address potential problems (see box, “Children’s Lead Levels Remain a Concern in Urban Hot Spots”). These blood lead screening programs, however, do not report in a systematic fashion to a central location where the data can be evaluated.

Environment Pollution and Disease

Many studies in people have demonstrated an association between environmental exposure and certain diseases or other health problems. Examples include radon and lung cancer; arsenic and cancer in several organs; lead and nervous system disorders; disease-causing bacteria such as E. coli O157: H7 (e.g., in contaminated meat and water) and gastrointestinal illness and death; and particulate matter and aggravation of heart and respiratory diseases.

Elucidating the linkage between environmental pollution and disease is challenging. We understand this linkage fairly well for some pollutants, such as those listed above, but poorly for others. This section describes some of the challenges to elucidating those linkages, and uses examples to highlight the role that indicators can play in strengthening our understanding of that linkage and in supporting environmental management efforts.

History of life through time

Life! It's everywhere on Earth; you can find living organisms from the poles to the equator, from the bottom of the sea to several miles in the air, from freezing waters to dry valleys to undersea thermal vents to groundwater thousands of feet below the Earth's surface. Over the last 3.7 billion years or so, living organisms on the Earth have diversified and adapted to almost every environment imaginable.
This exhibit provides a survey of that biodiversity through time, focusing on major lineages of organisms. Many of these lineages have gone extinct or currently exist at a much lower diversity than in the past, so there may be large exhibits on groups of organisms that are unfamiliar to you. They are featured because they play an important role in the history of life on Earth.

Effects of nitrogen Nitrogen

Nitrogen is a common element in nature. Approximately 78% of the earth?s atmosphere consists of nitrogen gas (N2). As nitrogen naturally cycles through the air, soil and water, it undergoes various chemical and biological transformations. These reactions result in the formation of nitrogen-based compounds and molecules, which are essential for the growth of plants, animals and humans. Agricultural production is dependent, in part, on the cycling of nitrogen within the rural environment.

Nitrogen forms and pathways within an agricultural production systemIdeally, it would be most economically and environmentally beneficial to keep all the nitrogen in this tight cycle for food production. In reality, however, some leakage occurs. Where there is too much nitrogen leakage, there can be environmental harm.

This Factsheet describes some of the impacts on the environment that can result when certain forms of agricultural nitrogen enter our surface water, groundwater and air, and identifies best management practices for minimizing nitrogen losses.

Tsunami Videos

See the real video exclusively
to see just click here Tsunami - Incredible Video Footages
tsunami
Tsunami - Koh Lanta, Thailand 2004

Earth Day

Earth Day is either of two different observances, both held annually during spring in the northern hemisphere, and autumn in the southern hemisphere. These are intended to inspire awareness of and appreciation for the Earth's environment. The United Nations celebrates an Earth Day each year on the March equinox, a tradition which was founded by peace activist John McConnell in 1969. A second Earth Day, which was founded by US politician Gaylord Nelson as an environmental teach-in in the late 1960s, is celebrated in many countries each year on April 22.

In September 1969, at a conference in Seattle, Washington, U.S. Senator Gaylord Nelson of Wisconsin announced that in the spring of 1970 there would be a nationwide grassroots demonstration on the environment. Senator Nelson first proposed the nationwide environmental protest to thrust the environment onto the national agenda.” "It was a gamble," he recalls, "but it worked."

Five months before the first April 22 Earth Day, on Sunday, November 30, 1969, The New York Times carried a lengthy article by Gladwin Hill reporting on the rising tide of environmental events

Noise pollution

Noise pollution (or environmental noise) is displeasing human or machine created sound that disrupts the activity or happiness of human or animal life. A common form of noise pollution is from transportation, principally motor vehicles.
The source of most noise worldwide is transportation systems, motor vehicle noise, but also including aircraft noise and rail noise.
Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential area.
Other sources are office equipment, factory machinery, construction work, appliances, power tools, lighting hum and audio entertainment systems.

Noise from recreational vehicles has become a problem.

POINT AND NONPOINT SOURCES

According to the American College Dictionary, pollution is defined as: ?to make foul or unclean; dirty.?
Water pollution occurs when a body of water is adversely affected due to the addition of large amounts of materials to the water. When it is unfit for its intended use, water is considered polluted. Two types of water pollutants exist; point source and non-point source. Point sources of pollution occur when harmful substances are emitted directly into a body of water. The Exxon Valdez oil spill best illustrates a point source water pollution.
A non-point source delivers pollutants indirectly through environmental changes. An example of this type of water pollution is when fertilizer from a field is carried into a stream by rain, in the form of run-off which in turn effects aquatic life.
The technology exists for point sources of pollution to be monitored and regulated, although political factors may complicate matters. Nonpoint sources are much more difficult to control. Pollution arising from non-point sources accounts for a majority of the contaminants in streams and lakes.

What is Air Pollution?

Air is the ocean we breathe. Air supplies us with oxygen which is essential for our bodies to live. Air is 99.9% nitrogen, oxygen, water vapor and inert gases. Human activities can release substances into the air, some of which can cause problems for humans, plants, and animals.

There are several main types of pollution and well-known effects of pollution which are commonly discussed. These include smog, acid rain, the greenhouse effect, and "holes" in the ozone layer. Each of these problems has serious implications for our health and well-being as well as for the whole environment.

One type of air pollution is the release of particles into the air from burning fuel for energy. Diesel smoke is a good example of this particulate matter . The particles are very small pieces of matter measuring about 2.5 microns or about .0001 inches. This type of pollution is sometimes referred to as "black carbon" pollution. The exhaust from burning fuels in automobiles, homes, and industries is a major source of pollution in the air. Some authorities believe that even the burning of wood and charcoal in fireplaces and barbeques can release significant quanitites of soot into the air.

Another type of pollution is the release of noxious gases, such as sulfur dioxide, carbon monoxide, nitrogen oxides, and chemical vapors. These can take part in further chemical reactions once they are in the atmosphere, forming smog and acid rain.

Pollution also needs to be considered inside our homes, offices, and schools. Some of these pollutants can be created by indoor activities such as smoking and cooking. In the United States, we spend about 80-90% of our time inside buildings, and so our exposure to harmful indoor pollutants can be serious.