"Salt Chemical Fertilizer" Initial Acid, Alkali and Salt PPT Courseware 2

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"Salt Chemical Fertilizer" Initial Acid, Alkali and Salt PPT Courseware 2

1. Introduction to chemical fertilizers

Plants need nutrients to grow, and the nutrients that the soil can provide are limited, so they must be supplemented by fertilization. The fertilizers initially used were natural organic fertilizers made from human and animal excrement, plant matter, etc. With people's understanding of the relationship between chemical elements and plant growth, chemical fertilizers containing nutrients needed for crop growth have emerged using chemical and physical methods. Nowadays, the application of chemical fertilizers has become the most powerful measure to increase crop yields. The yield-increasing effect of chemical fertilizers accounts for 30% to 60% of the total of various yield-increasing factors. There are many kinds of nutrients needed by crops. Among them, nitrogen, phosphorus and potassium are required in large amounts. Therefore, nitrogen fertilizer, phosphate fertilizer and potassium fertilizer are the most important chemical fertilizers.

2. The relationship between the use of chemical fertilizers and the environment

Chemical fertilizers are food for plants and the material basis for improving agricultural production. Reasonable application of chemical fertilizers plays an important role in increasing yield per unit area and continuously improving soil fertility. However, unreasonable application can also cause harm and cause pollution to the environment. Improper application of chemical fertilizers can cause:

(1) Pollution of water bodies (increased N and P content in water, resulting in eutrophication)

(2) Pollution of the atmosphere (emission of harmful gases such as NH3)

(3) Destroy the soil (making the soil acidified and hardened)

1. Nitrogen fertilizer

The role of nitrogen fertilizer:

Nitrogen is a component element of nucleic acids, proteins and chlorophyll in plants.

Nitrogen fertilizer can promote the growth of plant stems and leaves and make the leaves dark green.

Common nitrogen fertilizers:

Urea: CO(NH2)2

Ammonia: (NH3·H2O)

Ammonium salt: NH4HCO3, NH4Cl, (NH4)2SO4

Nitrates: NH4NO3, NaNO3

knowledge accumulation

①Although the air contains a large amount of nitrogen, plants can usually only absorb nitrogen in compounds and cannot directly absorb nitrogen in the air.

② Leguminous plants with rhizobia in their roots can convert nitrogen into nitrogen-containing compounds and absorb it.

③The method of converting nitrogen gas into nitrogen compounds is called nitrogen fixation.

2. Phosphate fertilizer

Phosphorus is a component element of many important compounds such as nucleic acids, proteins and enzymes in plants. It participates in various important metabolic activities and is closely related to plant cell division, production and transformation of organic matter. Phosphorus can promote crop growth, make the ears plump, and can also enhance cold and drought resistance.

Symptoms of phosphorus deficiency in crops: stunted growth and reduced yield.

Common phosphate fertilizers:

① Phosphate rock powder: Ca3(PO4)2

②Calcium magnesium phosphate fertilizer: phosphate of calcium and magnesium

③Superphosphate: Ca(H2PO4)2+CaSO4

How to reduce pollution and harm?

1. Fair use

2. Mixed use of organic fertilizers and chemical fertilizers

3. Reduce the use of highly toxic pesticides and develop efficient and low-toxic pesticides

4. Vigorously develop soilless plants

Compare some characteristics of chemical fertilizers and farm fertilizers

chemical fertilizer

Contains few types of nutrients, but large amounts of nutrients

Generally soluble in water, easy to be absorbed by crops, and fast fertilizer effect

Convenient for industrial production and higher cost

Some types of chemical fertilizers can cause soil compaction if applied in large amounts for a long time

farm fertilizer

Often contains a variety of nutrients, but the content of nutrients is small

Generally, it is difficult to dissolve in water. After being decomposed, it is gradually transformed into a substance that is soluble in water and can be absorbed by crops. The fertilizer effect is slow but long-lasting.

Easy to obtain local materials and low cost

Can improve soil structure

【Classroom Exercise】

[Example 1] The cotton grown on a farm does not have lush branches and leaves. The amount of chemical fertilizer that needs to be applied is ( )

A.K2SO4

B.CO(NH2)2

C.Ca(H2PO4)2

D.KCl

[Example 2] Which of the following chemical fertilizers cannot be mixed with hydrated lime ( )

A.Potassium chloride

B.Ammonium bicarbonate

C. Ammonia

D.Potassium nitrate

[Example 3] Among the following common chemical fertilizers, which one is a compound fertilizer ( )

A.K2S04

B.NH4N03

C.KN03

D.Ca(H2P04)2

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For more information about the PPT courseware "Initial Acid, Alkali and Salt Chemical Fertilizer", please click on the Initial Acid Alkali and Salt ppt Salt Chemical Fertilizer ppt tag.

"Salt Chemical Fertilizer" initial acid, alkali and salt PPT courseware:

"Salt Chemical Fertilizer" Initial Acid, Alkali and Salt PPT Courseware What is salt? 1. The composition of salt: NaCl: HCl+NaOH==NaCl+H2O CaSO4: H2SO4+Ca(OH)2==CaSO4+2H2O From salt Compositionally, salt is composed of metal ions and acid ions..

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Update Time: 2024-10-03

This template belongs to Chemistry courseware Hunan Education Edition Ninth Grade Chemistry Volume 2 industry PPT template

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