What are Agrochemicals? Biology Notes for Class 12
In this article, we will learn Agrochemicals, Fertilizers, Soil conditioners and more from Online Class 12 Biology
An agrochemical or agrichemical a short form of the agricultural chemical is a chemical substance used in agricultural processes. It is a substance that is used by humans for the management of an agricultural ecosystem. Agrochemicals include fertilizers, liming and acidifying agents (which are designed to change the pH), soil conditioners, pesticides, and chemicals used in the raising of livestock such as antibiotics and hormones.
The use of agrochemicals has become critical in raising crops for food. Therefore, the use of agrochemicals is a prominent and important part of modern agriculture. Due to extensive agricultural practices on large farms, the challenges to keep the crops free of damage have increased on a priority basis.
(2) Liming and acidifying agents
(3) Soil conditioners
(4) Pesticides and
(5) Chemicals that are used in animal husbandries, such as antibiotics and hormones.
Fertilizers are substances manufactured in factories that are used to provide plant nutrients to the deficient soils. For example, urea and ammonium nitrate are synthetic substances that provide the plants/crops with the same nutrients that are found naturally in the soil. Thus the fertilizers are used to encourage plant growth and increase crop yields. Most fertilizers contain varying amounts of nitrogen, phosphorus, and potassium, which are inorganic elements and are essential nutrients that plants need to grow.
What are fertilizers?
Materials used to increase plant growth, production, and increase health.
Six primary Nutrients
Liming and acidifying agents
Agricultural soils are commonly very acidic or very alkaline, so they are not suitable for the growth of many crop species. So, certain chemicals have to be added to the soil to adjust the appropriate pH of the soil. The acidity of the soil can be caused by various factors like, acid rain (precipitation that contains weak sulphuric and nitric acids), the use of certain types of fertilizers, etc. In order to neutralize the acidic nature of the soil, acid-neutralizing (or liming) materials are used as the most important agrochemical. Acidic soils are neutralized by adding compounds that contain calcium, usually in the form of powdered limestone or crushed oyster or mussel shells.
The acidity of soil may also be neutralized by using faster-acting lime (Ca [OH] 2). The rate of application of acid-neutralizing substances in agriculture varies from several hundred pounds per acre per year to more than 1,000 pounds per acre per year. The rates depend on the acidity of the soil, the rate at which new acidity is generated, and the needs of specific crops.
Soil conditioners are materials that are used to increase its ability of the soil to hold water and oxygen. Materials used as soil conditioners include peat (is an accumulation of partially decayed vegetation or organic matter), livestock manure, sewage sludge, and even shredded newspapers. Compost is an organic matter that has been decomposed and produces a soil conditioner. It is rich in nutrients and is considered to be the best soil conditioner because it keeps soil from becoming too acidic or too alkaline and supplies the soil with organic nutrients.
Importance of soil conditioners
- Many soil conditioners are designed to improve soil structure in some way.
- Soils tend to become compacted over time, which is bad for plants, and soil conditioners can add more loft and texture to keep the soil loose.
- They also add nutrients, enriching the soil and allowing plants to grow bigger and stronger.
- Soil conditioners improve the water retention in dry, coarse soils which are not holding water well, and they can be added to adjust the PH of the soil to meet the needs of specific plants or to make highly acidic or alkaline soils more usable.
Pesticides are the chemicals used to eradicate the presence of pests. Pests are a destructive insect or another animal that attacks crops, food, livestock, etc… Pesticides are grouped according to the types of pests which they kill:
- Insecticides– insects.
- Herbicides– weeds (Weeds are unwanted wild plants that grow in the field. Weeds compete with the crop for nutrients, light, and space.)
- Rodenticides– rodents (rats and mice)
- Bactericides– bacteria.
- Fungicides– fungi.
- Larvicides– larvae.
Agrochemicals used for animal husbandry
Animal Husbandry is a branch of agriculture which is concerned with the breeding and caring for livestock animals. Livestock animals include cows, horses, chickens, goats, pigs, or any animal that is raised for meat, wool, or other functional use. A large number of farmers in India depend on animal husbandry for their livelihood. In addition to supplying milk, meat, eggs, wool, their castings (dung) and hides, animals, like bullocks, are the major source of power for farmers. Thus, animal husbandry plays a chief role in the rural economy.
Contagious diseases of livestock pose an important problem in modern agriculture. This is especially true when animals are being reared at a high density, for example, in feed-lots. A feedlot or feed yard is a type of animal feeding operation (AFO) which is used in intensive animal farming for finishing livestock, like beef cattle, but also swine, horses, sheep, turkeys, chickens or ducks, prior to slaughter.
Various agrochemicals are used to control infectious diseases and parasites when animals are reared on a large scale. Antibiotics are important in this respect. Antibiotics are administered by injection whenever bacterial diseases are diagnosed, or sometimes administered with the feed, as a prophylactic treatment to prevent the occurrence of infections. In such crowded conditions, antibiotics must be administered routinely to animals. Sometimes, hormones and other animal-growth regulators are used to increase the productivity of livestock. For example, bovine growth hormone (BGH) is routinely administered in some agricultural systems to increase the growth rates of cows and their milk production.
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Tag: Agrochemicals, What are fertilizers?, liming and acidifying agents, Soil conditioners, Pesticides, Agrochemicals used for animal husbandry, Importance of soil conditioners, Biology Notes for Class 12