What are Agrochemicals? Biology Notes for Class 12

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What are Agrochemicals? Biology Notes for Class
12
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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.
• Agrochemicals include
• (1) Fertilizers
• (2) Liming and acidifying agents
• (3) Soil conditioners
• (4) Pesticides and
• (5) Chemicals that are used in animal
  husbandries, such as antibiotics and hormones.

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What are Agrochemicals? Biology Notes for Class
12

• Fertilizers
• 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
• Nitrogen
• Phosphorus
• Potassium
• Sulfur
• Magnesium
• Calcium

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What are Agrochemicals? Biology Notes for Class
12

•    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.

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What are Agrochemicals? Biology Notes for Class
12

• 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
• 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.

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What are Agrochemicals? Biology Notes for Class
12

• 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
• 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.

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What are Agrochemicals? Biology Notes for Class
12

• 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.

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What are Agrochemicals? Biology Notes for Class
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• Various agrochemicals are used to control
  infectious diseases and parasites when animals
  are reared on 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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What are Agrochemicals? Biology Notes for Class
12

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