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Class 9, Science, Chapter-12, Lecture-2, Crop Management (Notes)

Stages of Farming Practices for Improving Crop Yield:

  1. Crop Variety Improvement and Management - Seed selection
  2. Crop Production Improvement and Management - Nurturing of the crop plant
  3. Crop protection Improvement and Management - Protection of crops and harvest

Characteristics of Seeds Considered for Crop Variety Management:

  1. Higher yield.
  2. Improved quality.
  3. Greater resistance to biotic and abiotic factors.
  4. Change in maturity duration.
  5. Desirable Agronomic traits.
  6. Wider adaptability.

Methods of Crop Variety Improvements:

  1. Hybridization:
    The method of obtaining new variety of crop by crossing two genetically dissimilar plants is termed as hybridisation.
    (i) Intervarietal
    (ii) Interspecific
    (iii) Intergeneric
  2. Genetic Modification

Crop Production Practices (on the basis of Cost):

  1. No cost production practices.
  2. Low-cost production practices.
  3. High-cost production practices.

Nutrients Required by Crops:

NutrientsSource

Carbon, Oxygen

Air

Hydrogen, Oxygen

Water

Macronutrients

Micronutrients

Soil

Nitrogen

Iron

Phosphorus

Manganese

Potassium

Boron

Calcium

Zinc

Magnesium

Copper

Sulphur

Chlorine

MACRONUTRIENTS:

The essential elements required by plants in quantities more than 1 milligram per gram of dry matter are called macronutrients.
Examples: Non-mineral macronutrients- Carbon, Oxygen, Hydrogen
Mineral macronutrients- Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur.

MICRONUTRIENTS:

The essential elements required by plants in quantities less than 1 milligram per gram of dry matter are called micronutrients.
Examples: Iron, Manganese, Boron, Zinc, Copper, Molybdenum, Chlorine.

DIFFERENCES BETWEEN:

MacronutrientsMicronutrients
1. These are required in large quantities1. These are required in very small quantities.
2. Concentration of each macronutrient in plants is more than 1mg per gram of dry matter.2. Concentration of each micronutrient is quite less than 1 mg per gram of dry matter.
3. Macronutrients have no significant role in enzyme activity and electron transport.3. They are involved in enzyme activity and electron transport.
4. They take part in synthesis of plant body and different protoplasmic structures.4. They do not take part in synthesis of plant body and different protoplasmic structures.