Agro Chemicals

Agro Chemicals:

An agrochemical or agrichemical is a chemical product used in agriculture. Agrochemical are pesticides including fungicides,insecticides, herbicides and nematicides. It also include hormones, synthetic fertilizers and other chemical growth agents, and concentrated stores of raw animal manure.
Agrochemicals are toxic, and in bulk storage may posses environmental and/or health risks, particularly in the event of accidental spills. These are used in agricultural to facilitate plant growth and protection. Excessive use of such chemicals in crops generates a significant amount of residues. These residues cause nutrient imbalance and quality reduction of agricultural produce. The residues can lead to long-term adverse effects on the health of organisms that consume them. For example, pesticide residues in food have been linked to being one of the causes of asthma in humans.

Types of Agrochemicals:

Types of agrochemicals include:

• Pesticides: Chemicals used to destroy insects and other organisms, weeds, and fungus that could spoil crop yields
• Synthetic fertilizers:  Ammonium nitrate (NH4NO3) is an example , which is used to encourage crop growth by saturating soils with nutrients
• Acidifiers and liming agents: These are used to alter the pH levels of soils to suit the planting properties of given crops
• Soil conditioners: for example gypsum (CaSO4·2H2O), which can be used to condition soils with high sodium (Na) contents to improve planting conditions
• Growth hormones, or synthetic chemicals: These can be used to increase growth rates in animals and crops.

Harmful Effects of Agrochemicals:

Some of the harm chemical fertilizers may cause include waterway pollution, chemical burn to crops, increased air pollution, acidification of the soil and mineral depletion of the soil.

Effect on Soil:

The excessive use of chemical fertilizers can lead to soil acidification because of a decrease in organic matter in the soil. If nitrogen applied to fields in excessive amount, it damages topsoil over time, resulting in reduced crop yields. Sandy soils are more prone to soil acidification than clay soils. Clay soils have an ability to buffer the effects of excess chemical fertilization. Continuous use of chemical fertilizers on soil depletes the essential nutrients of soil. As a result, the food produced in these soils have less vitamin and mineral content. The foods grown in soils that are chemically fertilized are found to have less potassium, magnesium and calcium content.

• They may kill helpful bacteria
• Increase nitrate content in soil
• Alter pH levels
• Kill soil organisms
• Unnatural growth effects
• Residual effects

Effect on Water:

The use of chemical fertilizers on crops can have adverse effects on waterways. Because of the use of excessive fertilizer, the over-abundance of nutrients in the water reduces the amount of oxygen. The oxygen that is left is used by the existing organisms living in the water. The fish present in these water die because of oxygen depletion.

• Make water unfit for consumption.
• Agrochemicals in water diffusing with larger water bodies promote the growth of algae.
• Excess chemicals lead to Eutrophication.
• Lead to water pollution thereby affecting aquatic animals.
• Alter the chemical properties of water.

Effect on Air:

The excessive use of  nitrogen in crop fertilization can contribute to the release of greenhouse gases such as carbon dioxide and nitrous oxide into the atmosphere. This effect is due to the use of greater amount of chemical fertilizer than the plants can readily absorb. Excess greenhouse gases trapped in the atmosphere may contribute to the increase of ocean and land surface temperatures.

• Pesticide particles diffuse with air altering their nature.
• Wind drifts carry polluted air to other parts thereby spreading their adverse effects.
• Depending on weather conditions, more amount of spray may evaporate.
• Air polluted in this way is inhaled by surrounding living organisms having drastic effects on their health.