Tiếng Việt
The nutrient level of calcium is estimated as the percentage of Ca or CaO in the manure.
1. The effect of calcium on soil and plants
Calcium (Ca2+) accounts for most of the cell wall structure. Calcium mainly participates in the cell wall formation and the activity of many yeasts, which are important in maintaining membrane function. Calcium has a special effect on maintaining the balance of the external environment, enhancing bloating and increasing flower strength.
* For land:
– Reduced acidity in the soil, reducing the toxicity of Mn, Fe, Cu, Al (if high content).
– Very essential for nitrogen fixing bacteria.
* For crops:
– Stimulate root and leaf growth.
– Formation of compounds that make up the cell membrane, making the plants become stronger.
– Helps reduce the nitrogen content of nitrate in the tree.
– Enhance the activity of some enzyme systems in the plant.
– Neutralize organic acids in plants
– Very necessary for the development of beans.
– Strengthen the growth of the root system, stimulate the activity of VSV, attract other nutrients.
– Strongly regulates the metabolism and physiology of the cell.
– Intermediate bridge between the chemical components of the primary substance
– Maintain cation balance – Anion in the cell.
– Limit the penetration of cations K+, Mg2+, Na+, NH4+ into the cell, which is the antioxidant factor for plants.
Ca2+ helps stabilize pH
– Ca2+ also help the development and division of cells, help the roots grow, sprout buds, stimulate flowering, fruit.
* The lack of calcium for plants
The calcium deficiency of plants is often not due to calcium deficiency in the soil, most of the natural soils supply enough calcium for the plant, exhibiting calcium deficiency mainly in plants with high calcium requirements or grown on the lips. The soil is lacking in calcium (substrate) or due to the change of soil moisture, it can also be caused by other external factors that cause calcium deficiency in the soil.
Appearance of plants lacking calcium (dark green shoots, young green shoots, curved and dying at the tip of the leaf and leaf edges, eventually buds to death).
Expression of calcium deficiency in young leaves
– Damaged cells, roots, leaves, and other parts of the plant are rotten and dead.
Expression on old leaves
First appears is the tip of the leaf and the leaf margin is whitened after black and the leaf blade is bent and twisted, the structure of the plasma membrane and the membrane of the organ are damaged.
Expressed in the young tissues are fragmented and the root system is damaged (brown inside the bulb).
– The dividing cell does not form a new cell wall.
– Occurrence of multi-core cells characteristic for calcium-deficient human tissue.
– Increasing the appearance of secondary roots and suction, slow growing roots
Lack of calcium, under developed plants, small and short roots, mollusks, small leaves, weak trees vulnerable to fall and pests attack
Appearance of the stem and root germination; Rot rotten flowers, mottled leaves.
Leaves deformed
2. The role of lime (CaCO3) during soil improvement
* Lime response in soil:
* The reaction of lime with carboxylic acid group in organic matter.
RCOO]
2R – COOH + CaCO3 = Ca2+ + H2O + CO2
RCOO]
– If less acidity, bicarbonate can be formed after liming
RCOO]
2R – COOH + CaCO3 = Ca2+ + 2H2CO3 + Ca2+
RCOO]
* Al3+ reaction on clay minerals, reducing the toxicity of the group
2Al3+ – Soil + 3CaCO3 = 2Al (OH)3 + 3Ca2+ – Soil + 3H2O + 3CO2
* Neutralize the acidity of the soil
[KD] -2H + CaCO3 = [KD] -Ca + H2O + CO2
H2CO3 + CaCO3 = Ca (HCO3)2
* Removes the harmful effects of salty soils
[KD] -2Na + CaSO4 = [KD) -Ca + Na2SO4
Washout
3. Types of materials, fertilizers and compounds containing Calcium:
* Types of natural calcium:
Materials containing Calcium: (A) Limestone, (B) Dolimte, (C) Dolomite fired, (D) Shell and shell powder
Pure limestone 54.7 – 56.1% CaO
– Limestone and dolomite 42.4 – 54.7% CaO
– Dolomitic limestone 31.6 – 42.4% CaO
– Gypsum (CaSO4) 56% CaO
Shell, shell, coral 40% CaO
* Types of calcium-containing fertilizers:
– Superphosphate (Ca2+ + CaP4): 18 – 21% Ca
Triple Superphosphate 12 – 14% Ca
– Calcium nitrate (Ca (NO3)2): 15 – 19% CaO
– Melting furnace: 25 – 30% CaO
* Calcium Calcium (Calcium Chelate – CaEDTA):
Content: 10% Ca
Chemical name: Ethylenediaminetetraacetic acid, calcium disodium complex
Chemical formula: EDTA-CaNa2.2H2O
Molecular formula: C10H12N2O8CaNa2.2H2O
Molecular weight: 410.13
pH = 6 – 7
Properties: White powder, very soluble and stable in water, soluble in water 99%
4. Liming measures:
– Liming is most effective for sour soils and poor soil.
– In addition to the effect of improving the character and rationality of the soil, creating acidity suitable for the normal development of plants and useful microorganisms while ensuring the supply of plants a very nutritious element. necessary.
Limestone cycle
– Salty soils, alkaline soils 45 – 60 quintals / ha to crop 2 have expired.
– The soil of fertilizing 5.6 – 23 quintals per hectare is also higher than crop 3.
– Alluvial soil is 12.5 – 50 quintal / ha effective till the fourth crop.
