Man has had many far reaching effects on the environment over the years. Global warming, pollution and the damage to the ozone layer are a few of the major things that can be heard about in the news. Man has damaged the earth gradually over the years and this damage cannot be reversed, we are now trying to stop any more damage being caused to the environment. Not all of man's effects on the environment are harmful; some are beneficial. Conservation work is going on across the world and this is helping to preserve the wildlife and countryside that we have left. The expanding human population has placed a huge demand on the food production of the country. The resources are limited but the population is increasing quite rapidly so the problems are growing. The demand for food means that crops need to be perfect so the use of fertilizers and herbicides is increasing too. One of the problems in the countryside affecting the environment is the disposal of effluent and other pollutants. The main type of waste that we have to dispose of is organic effluent particularly from farms and sewage works. This is disposed of in several ways, the main one being pumping it into the sea and rivers around the country. In more recent years sewage recycling plants have been developed to reuse the water in the waste. Water treatment works are used to treat the waste before it is pumped into the river or sea.

Phosphates are products formed by the replacement of some or all of the hydrogen of a phosphoric acid by metals. Depending on the number of hydrogen atoms that are replaced, the resulting compound is described as a primary, secondary, or tertiary phosphate. Also known as disodium phosphate, tertiary sodium phosphate is used as a detergent and water softener. Primary and secondary phosphates contain hydrogen and are acid salts. Phosphates are important to metabolism in both plants and animals. Primary calcium phosphate is an ingredient of plant fertilizers. When it is used as a fertilizer it can be washed into the waterways by the rain and pollute the rivers and streams. Increasing attention has been focused on the environmentally harmful effects of phosphates in household detergents. Detergents containing phosphates are known to be water pollutants because phosphates are a primary nutrient of algae. When an alga grows in excess, it can choke a lake or river and draw off needed oxygen from aquatic life. Nitrates are also harmful to the environment. Calcium, sodium, potassium, and ammonium nitrates are used in fertilizers to provide a source of nitrogen for plant growth. If these nitrates get into the water flow then they can, like phosphates, have damaging effects on the life that live there. Crude oil, known as petrol, is used in the manufacture of fertilizers, medicines, plastic, building materials, paints and to generate electricity. It is also used for the fuelling of transport such as cars and planes. Petrol contains hydrocarbons and sulphur. When the hydrocarbons and sulphur are burned for use they give off sulphur dioxide and carbon dioxide. These gases are harmful to the environment. Sulphur dioxide forms sulphuric acid and causes acid rain, carbon dioxide adds to the greenhouse effect. The greenhouse effect means that the levels of carbon dioxide and other greenhouse gases that usually prevent heat loss from the earth are increasing. This results in raised temperatures on earth leading to partial melting of the polar ice caps. If the ice caps melted too much some countries would be flooded, if they were all to melt then the whole world would be underwater.

There is a need to produce more food for the population and a need to preserve the wildlife and the environment. It is essential to satisfy the needs of the expanding population but it is also essential to preserve the environment. Living organisms are dependent on each other, if a tiny little fungus or algae plants were destroyed then the rest of the food chain would be affected. The algae or fungi are the producers so the primary consumers have nothing to eat so they die and the secondary consumers then have nothing to eat so they die. Plants and can be used for many purposes which is why they are becoming extinct. Drugs have been derived from plants. Genetic variation also decreases with the loss of species and new genes can never be discovered e.g. for crop breeding. The reduction of trees is leading to more carbon dioxide in the air and therefore increasing global warming.

The human population is expanding rapidly and the demand for food is increasing too. There are limited resources with which to produce this food so therefore the demand is greater than the production. Farmers are under pressure to produce more and more food. The crops they produce all have to be perfect, there can be no waste so herbicides and fertilizers have to be used to maintain the high production rate. The farmland has to be maintained, this is done with regular grazing of cattle to keep eating the grass and with plugging to prepare the soil for re-use next time. Plugging removes the plants that would compete with the crop and gives the seedlings the chance to establish themselves quickly and easily. Plugging also helps to aerate the soil. Harrows are used to break up the lumps of soil and make the surface smooth. This allows the seedling to be planted at a consistent depth. The farmer uses herbicides to control the weeds among the crops, to do this he uses a crop sprayer. To harvest the crops a combine harvester would be used. This cuts down the crop and chops it and then it is pout into a tractor and trailer. Other crops such as potatoes and peas are harvested differently, picks the peas from the rest of the plant. Potatoes are picked using a potato drill. The farmer will then use fertilizer or farmyard manure to replace the nutrients removed by the plants; they would use a muck spreader to do this. Cattle remove nutrients from the soil so it has to be fertilized regularly to maintain the productivity and allow the animals to eat.