The agriculture practices have been found on every side for hundreds of years and become fundamental for life in all over the world. Over a few years as agriculture processes have progressed and become more effective with new technologies and research. The agriculture practices have some negative effect on our environment and farms. Major 4 problem due to agriculture practices is emission of carbon dioxide in the environment and damage both local and global environment, it also help in increasing greenhouse gases in air and toxic chemicals in water.
Pesticides The effect of pesticide on environment consists the effect on non-target species, over 98% of insecticides and 95% of herbicides kill the non-target species, runoff of pesticides carry them to aquatic environment and wind carry them to other places as grazing areas, undeveloped areas and human colonies. Transportation, poor production and storage places also cause many problems. Repeated exposure of pesticides cause insect resistance and affect the natural beneficial insects that help to decrease population of insect pest naturally.
Fertilizers are any substance used to add nutrients to the soil to increase soil fertility and plant growth. In recent years, the use of fertilizer increase and cause serious environmental problems. Fertilization can effect as assemblage of heavy metals in soil and water and in plant system. It also cause water, soil and air pollution.
Effects of agriculture
The environment effected due to agriculture practices used in all over the world. Environment effect depends upon the production patterns of the system applied by farmers and expelling in the environment and farming system are collateral. Mean based which are founded production methods of farmers and effecting based which is the effect of farming system on farming and environment. The agricultural effect on environment included a variety of elements from the soil to water, air, people, and animal diversity and plants. Climate change, deforestation, irrigation system, soil degradation, and waste are environmental problems due to agriculture. Climate change and agriculture are interconnected processes and both are take place worldwide. Global warming, temperature, precipitation, glacial runoff also included. These considerations influence the carrying capacity of the biosphere to produce food for humans and animals. Increasing in carbon dioxide level also effect on environment both beneficially and detrimentally. Deforestation is cutting of forest for the use of land for other purposes according to British environmentist Norman Myers, the cutting of forest is 5% due to cattle ranching, 19% due to over-heavy logging,22% due to growing sector, and 54% for farms. Deforestation also cause climate change. Trees act as carbon sink as they absorbed carbon dioxide and unwanted greenhouse gasses out of the atmosphere and by clearing trees carbon dioxide releases into the\environment and less tree are left to absorb carbon dioxide and so carbon dioxide level increase in the atmosphere and other disadvantage of cutting tree is soil tend to dry out as no longer shade and not enough trees to help in water cycle by returning water vapors back to the environmentreduction in the underground aquifers through over drafting is also a major problem due to agriculture. Soil can be over irrigated due to poor distribution and management and waste water, chemicals and may cause water pollution. Over irrigation help in rising water table that can lead to different problems. In under drainage system condition it gives week salinity control which leads to increasing soil salinity with formation of toxic salts on soil surface in those areas having high evaporation. This involves leaching in remove these salts. Soil degradation is the decline in soil quality can be a result of many factors especially from agriculture. Soil hold the majority of the world biodiversity, healthy soil is essential for food production and an enough water supply. Common assigns of soil degradation are salting, water logging, compaction, pesticides. Carbon dioxide from agriculture cause to increase carbon dioxide level in atmosphere. Used of fossil fuel is main source of production and second main source is land conversion. Land conversion includes the demolition of plant life that contributes in releasing carbon dioxide into the air with respect to all over the world. Emission of carbon dioxide in environment due to agriculture activates is 20% of the total carbon dioxide added to the atmosphere through burning of biomass by different procedures as deforestation. By these activates decomposition rate of organic carbon in soil increased. The burning of trees also increased the carbon dioxide level in the biomass and permit of oxidation to occur in temperate region excess of clearing land and loss of organic carbon in vegetation and soil, resultantly carbon dioxide level in atmosphere increased and average global temperature increased. Animal form also having a negative effect on environment and human health. Disease carried animals and can transfer to human called as zoonotic disease. The runoff from animal farms through seeping or precipitation runoff mixed ground water and causes diseasedin humans and addition of heavy metals in ground water causes water pollution.
Pesticides are used for controlling pest in agriculture. Pesticides can leach via soil and enter ground water as well as food products. It also effect on non-target plants, birds, fishes and wildlife. Waste range of agriculture chemicals are used and become pollutant by use, misuse, and have huge effect on water quality, air and environment. Pollutants from farming included sediments, nutrients, pathogens, metals mostly heavy metals, and salts.
The eco-toxicology started with acute poisoning effect in late 19th century public concern over the undesirable environmental effects of chemical originated in early 1960’s. shortly thereafter DDT applied to control malaria and its metabolic were shown to cause population- level effect on fishes and birds since 1993,the united states and European unit have modified of pesticides risk judgment ceasing the use of using organophosphate and carbamates. Newer pesticides have effect on non-target organism pesticides drift cause air pollution and water pollution. When pesticides set aside in the air as particles carried by wind to other areas and highly contaminated pesticides are applied to crop can volatilized and blow by wind into nearby areas laying a threat to wildlife. The weather conditions at the time of pesticide application as well as temperature and relative humidity can changing the disperse in the air as wind velocity increased the spray drift and exposure. Low humidity and high temperature result in increasing evaporation. The particle from pesticide used as dust also move from one place to another area through wind. Ground spraying produce less as compared to Arial spray. Pesticides can pollute the water, more than 90% of wells sampled in a study by the US geological survey and residues also found in rain and ground water. There are four major ways through which pesticides can reach the water are drifting from the intended area when it is sprayed, 2nd it percolate or leach through the soil, 3rd carried through runoff, the solubility in the water increased the pesticides effect. The distance from application site to body of water-weather, soil type, presence of growing crop and method used to apply chemicals. Many chemicals used in the pesticides are persistent to soil contamination whose effects are adverse on environment. The use of pesticides the general biodiversity in the soil and by using chemicals, the soil quality decreased and the effect that more organic matter in the soil allows for higher water holding the smaller amount of pesticides that leave the area of application because organic matter bind to and help in breaking down pesticides degradation and natural action are both factors which increased the persistence of pesticides in the soil. Depending on the chemical nature of the pesticide. Such procedure control directly transportation from soil to water and add in the air and food natural action effect on bioaccumulation of pesticides which are depend on organic matter in the soil. Weak organic acid have been shown to be weakly sorbed by soil by soil due to PH and acidic structure. Nitrogen fixation which is required for the growth of higher plants is blocked by pesticides in the soil, the DDT, methyl parathion, have been shown to interfere with legume rhizobium chemical signals reduction of the symbiotic chemical signal results in reduced nitrogen fixation and finally to reduce crop yield. Root nodule formation in these plants saves the world economy 10 million dollars in synthetic nitrogen fertilizer every year. Pesticide kill bees and strongly concern in decline of pollinators, and loss of species that pollinate plants include through the mechanism of colony collapse disorder in which worker bees disappear. Application of pesticide on the crop that blooms can kill the honey bees which act as pollinators. On other hand, pesticides have direct harmful effect on plants include poor room hair development, yellowing of shoots, and reduction of plant growth. Many kinds of animals can harmed by pesticides residues including humans may be poisoned by pesticide residues that remain on food .Pesticide can eliminate animals and important food sources causing the animals to relocate, change there diet. Residues can move to food chain, for example, birds can harmed when they eat poisoned worms and insects. Pesticides also effect on humans, as pesticides can enter to human body through inhalation, by skin, through direct contact and oral exposure by consuming food or water, pesticides leach into ground water and add in the drinking water and by drift pollute the air and through breathing enter in to human body, the effect on human depends upon toxicity of the chemical and time of exposure remain. Children are most susceptible to pesticides because they are in developing stage and have weaker immune system than adult. Exposure effects can range from mild skin irritation to birth defects, tumors, genetic change, blood and nerve disorder, endocrine disruption, coma and death. Pest resistance is also effect of pesticides and secondary pest out break also a effect of pesticide. Pesticides also effect on fish and other aquatic biota and may be harmed by pesticides contaminated water. Pesticides surface runoff into rivers and streams can be highly lethal to aquatic life. Sometimes killing of fishes in stream due to toxicity of pesticides. When dead plants decay and consume the water’s oxygen, suffocating the fish. Herbicides such as copper sulfite that are applied to water to kill plants are toxic for fishes and other water animal. Repeated used of some pesticides cause physiological and behavioral changes that reduce fish population. Application of herbicide to water bodies kills plants on which fishes depend for habitat.
The largest effect facing the use of chemical fertilizer’s is ground water contamination. Nitrogen fertilizers breakdown into nitrates and mixed in water through soil. Because it is water-soluble and can remain in ground water for decades, the addition of more nitrogen over the year has an effect. The University of Wisconsin Madison, they found the chemical fertilizers are compound when mixed with a single pesticide. They discover alternate immune, endocrine system and nerves system breakdown in children. One popular fertilizer ‘UREA’ produce ammonia emanation, contributes to acid rain and contamination of ground water, and also play a role in depletion in ozone due to release of nitrous oxide by gentrification process. With the excess use of urea this problem increased contamination of ground water associated with gastric cancer, goitve, hypertension, testicular cancer, stomach cancer. Air and water borne nitrogen from fertilizers may cause respiratory complaints, cardiac disease, several cancer, as well as inhibit crop growth, and increasing of allergic pollen production, potentially effect the dynamics of several vector bore disease including WEST NILE VIRUS, malaria, cholera, one of the effect of fertilizers is called as methemoglobinemia in infants it is alternatively known as blue baby syndrome. The risk most often occur when infants are given the formula of restructure with nitrate contaminated water. The condition causes a decrease in oxygen in the blood and results in a BLUE-GREY SKIN color causes lethargic and/or irritability and can lead comma and finally death. And unable to find the same risk exist for breastfeeding babies whose mother drank contaminated water.Nitrogen ground water contaminated also contributes to marine “dead zone”. The increase in the water-soluble nitrates creates can inflow of plant-life which eat up oxygen and starve out fish. This has as affect not only the aquatic ecosystem, but on local societies who depend on food sourced from those areas. In some countries, raw, composted and untreated human waste is applied directly to crops and soil, a practice known as night soil. Chemical fertilizers have high amount of heavy metals and high concentration of radionuclides. Greenhouse, aquaculture especially large amount of chemical fertilizer used during the peak season dangerously polluted well and water sources, crop production quantity and quality of product degenerates. When fertilizers used in inadequate manner, rates of productivity and quality are caused significant losses, when it is too much applied, it causes air pollution by nitrogen oxides emission. There are some gasses water vapor, carbon dioxide, methane, hydrogen sulfite with choloro-floro hydrocarbons. These gasses contribute in greenhouse effect as a global atmosphere n2o increased from 0.2 to 0.3% each year. Due to high use of nitrogen.
Muhammad Yahya, Dr.Anjum Aqeel, Mubasshir Sohail, Awais Farooq, Asad Hameed, Imran Bashir, Hanan Khalid
University college of Agriculture, University of Sargodha