UNIT -2 Crop nutrition, manures and fertilizers, nutrient use efficiency, Classification of crops, Agroclimatic zones

UNIT -2 AGRON 111 – Fundamentals of Agronomy 4(3+1)

Crop nutrition, manures and fertilizers

Crop nutrition refers to the provision of essential nutrients to plants to support their growth, development, and productivity. Proper crop nutrition is critical for achieving high yields and maintaining soil health.

In nature there are 109 elements and out of these only 17 elements are essential.
Arnon and Stout (1939) first proposed the term criteria of essentiality and later Arnon (1954)
revised some of the criteria and concluded the three essential criteria.

Criteria of essentiality of nutrients:

1. A mineral element is considered essential to plant growth and development if theelement is directly involved in plant metabolic function.
2. Plants are unable to complete its lifecycle if the element is absent.
3. Deficiency symptoms in the plant of the element can only be corrected by the supply of the particular element.

Classification of Essential Nutrients

Plants require a variety of nutrients that can be categorized into macronutrients and micronutrients.

Macronutrients

Nutrients available in air and water – Carbon, Hydrogen and oxygen.

Primary Macronutrients:

1. Nitrogen (N): Essential for leaf and stem growth; a component of amino acids, proteins, and chlorophyll.
2. Phosphorus (P): Important for root development, energy transfer, and reproductive structures.
3. Potassium (K): Regulates various physiological processes, including water uptake, enzyme activation, and photosynthesis.

Secondary Macronutrients:

1. Calcium (Ca): Critical for cell wall structure and stability.
2. Magnesium (Mg): Central component of chlorophyll and involved in photosynthesis.
3. Sulfur (S): Integral part of certain amino acids and vitamins.

Micronutrients – These are required in smaller amounts but are equally vital for plant health.

1. Boron (B): Important for cell wall formation and reproductive growth.
2. Chlorine (Cl): Involved in osmotic and ionic balance.
3. Copper (Cu): Essential for photosynthesis and enzyme activity.
4. Iron (Fe): Vital for chlorophyll synthesis and electron transport.
5. Manganese (Mn): Plays a role in photosynthesis, respiration, and nitrogen assimilation.
6. Molybdenum (Mo): Necessary for nitrogen fixation and enzyme function.
7. Zinc (Zn): Important for growth regulation and enzyme activity.

Manures

Manures are the organic materials derived from animal, human and plant residues which contain plant nutrients in complex organic forms. Manures have low nutrient content per unit quantity.

Major sources of manures are:

1. Cattle shed wastes – dung, urine and slurry from biogas plants
2. Human habitation wastes – night soil, human urine, town refuse, sewage, sludge
3. Poultry litter, droppings of sheep and goat
4. Slaughter house wastes – bone meal, meat meal, blood meal, horn and hoof meal, Fish
   wastes
5. Byproducts of agro industries – oil cakes, bagasse and press mud, fruit and vegetable
   processing wastes etc.
6. Crop wastes – sugarcane trash, stubbles and other related material
7. Water hyacinth, weeds and tank silt, and
8. Green manure crops and green leaf manuring material.

Classification of Manures

1. Bulky organic manures
   Bulky organic manures contain small percentage of nutrients and they are applied in
   large quantities. FYM, compost and green-manure.
2. Concentrated organic manures: Concentrated organic manures have higher nutrient content than bulky organic manure. The important concentrated organic manures are oilcakes, blood meal, fish manure etc.

Fertilizer

A fertilizer is any material of natural or synthetic origin (other than liming materials)
that is applied to soils or to plant tissues (usually leaves) to supply one or more plant nutrients
essential to the growth of plants.

Classification of Fertilizers:

1. Straight fertilizers: Straight fertilizers are those which supply only one primary plant nutrient, namely nitrogen or phosphorus or potassium. eg. Urea, Ammonium sulphate, Potassium chloride and Potassium sulphate.
2. Complex fertilizers: Complex fertilizers contain two or three primary plant nutrients of
   which two primary nutrients are in chemical combination. These fertilisers are usually
   produced in granular form.
   eg. Diammonium phosphate, Nitrophosphates and Ammonium phosphate.
3. Mixed fertilizers: are physical mixtures of straight fertilisers. They contain two or three primary plant nutrients. Mixed fertilisers are made by thoroughly mixing the ingredients either mechanically or manually.

Nutrient use efficiency

Nutrient Use Efficiency (NUE) refers to the ability of plants to utilize available nutrients effectively to produce biomass or yield.

Components of NUE

1. Nutrient Uptake Efficiency (NUpE): The ability of plants to absorb nutrients from the soil.
2. Nutrient Utilization Efficiency (NUtE): The ability of plants to convert absorbed nutrients into biomass or yield.

Factors Affecting NUE

Soil Properties:

• pH: Influences nutrient availability and root growth.
• Texture and Structure: Affect water and nutrient retention.
• Organic Matter: Improves soil structure and nutrient supply.

Plant Factors:

• Root Architecture: Influences nutrient acquisition from different soil layers.
• Genetic Traits: Some plant varieties are more efficient in nutrient uptake and utilization.

Environmental Conditions:

• Climate: Temperature, light, and rainfall impact nutrient availability and plant growth.
• Soil Moisture: Adequate water is necessary for nutrient dissolution and transport.

Agronomic Practices:

• Fertilizer Type and Application: The form, timing, and method of fertilizer application affect NUE.
• Crop Rotation and Intercropping: Enhance soil fertility and nutrient cycling.
• Tillage Practices: Influence soil structure and nutrient distribution.

Classifications of crops:

Crops can be classified based on various criteria, including their life cycle, usage, climatic requirements, and botanical characteristics. Here is a detailed overview of the different classifications of crops:

1. Based on Life Cycle

a. Annual Crops

• Definition: Complete their life cycle within one growing season.
• Examples: Wheat, rice, maize, sunflower.

b. Biennial Crops

• Definition: Take two growing seasons to complete their life cycle. Usually, vegetative growth occurs in the first year, and flowering and seed production occur in the second year.
• Examples: Carrot, beetroot, onion, cabbage.

c. Perennial Crops

• Definition: Live for more than two years, often producing flowers and seeds annually after reaching maturity.
• Examples: Sugarcane, banana, apple, tea, coffee.

2. Based on Usage

a. Food Crops

• Definition: Grown primarily for human consumption.
• Examples:
• Cereals: Rice, wheat, maize, barley.
• Pulses: Lentils, chickpeas, beans.
• Fruits: Apples, bananas, oranges.
• Vegetables: Tomatoes, potatoes, spinach.

b. Forage Crops

• Definition: Grown for animal feed.
• Examples: Alfalfa, clover, silage corn, sorghum.

c. Fiber Crops

• Definition: Grown for their fiber, used in textiles and other industries.
• Examples: Cotton, jute, hemp, flax.

d. Oilseed Crops

• Definition: Grown for the extraction of oils.
• Examples: Soybean, sunflower, canola, groundnut.

e. Plantation Crops

• Definition: Grown on a large scale for commercial purposes, often in tropical regions.
• Examples: Tea, coffee, rubber, coconut, oil palm.

f. Medicinal and Aromatic Crops

• Definition: Grown for their medicinal properties and aromatic oils.
• Examples: Aloe vera, mint, lavender, turmeric.

g. Industrial Crops

• Definition: Grown for use in various industries, not directly consumed as food.
• Examples: Tobacco, cotton (also fiber), sugarcane (for ethanol production).

3. Based on Climatic Requirements

a. Tropical Crops

• Definition: Require warm climates with little temperature variation.
• Examples: Rice, sugarcane, banana, coffee.

b. Subtropical Crops

• Definition: Thrive in regions with warm summers and mild winters.
• Examples: Citrus fruits, cotton, tobacco.

c. Temperate Crops

• Definition: Grow best in regions with distinct seasons, including cold winters.
• Examples: Wheat, barley, apples, grapes.

4. Based on Botanical Characteristics

a. Monocotyledons (Monocots)

• Definition: Have one seed leaf (cotyledon) in their seeds.
• Examples: Rice, wheat, maize, lilies.

b. Dicotyledons (Dicots)

• Definition: Have two seed leaves (cotyledons) in their seeds.
• Examples: Beans, peanuts, tomatoes, sunflowers.

5. Based on Photoperiodism

a. Short-day Crops

• Definition: Require longer nights (shorter days) to flower.
• Examples: Rice, soybean, cotton.

b. Long-day Crops

• Definition: Require shorter nights (longer days) to flower.
• Examples: Wheat, barley, oats.

c. Day-neutral Crops

• Definition: Flower irrespective of the length of the day.
• Examples: Tomatoes, cucumbers, corn.

6. Based on Root Depth and Growth Habit

a. Shallow-rooted Crops

• Definition: Roots do not penetrate deeply into the soil.
• Examples: Lettuce, spinach, mustard.

b. Deep-rooted Crops

• Definition: Roots penetrate deeply into the soil, accessing deeper water and nutrients.
• Examples: Alfalfa, carrots, lucerne.

7. Based on Season of Cultivation

a. Kharif Crops

• Definition: Sown in the rainy season (June to September).
• Examples: Rice, maize, sorghum, soybeans.

b. Rabi Crops

• Definition: Sown in the winter season (October to March).
• Examples: Wheat, barley, peas, mustard.

c. Zaid Crops

• Definition: Grown in the short season between Kharif and Rabi (March to June).
• Examples: Watermelon, cucumber, pumpkin.

Agroclimatic zones of India:

1. Western Himalayan Region

• States Covered: Jammu & Kashmir, Himachal Pradesh, Uttarakhand
• Climate: Cool and temperate with high rainfall in the lower regions and snowfall in the higher regions.
• Crops: Wheat, barley, maize, fruits (apples, pears), and vegetables.

2. Eastern Himalayan Region

• States Covered: Sikkim, Arunachal Pradesh, parts of Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura
• Climate: Humid subtropical with high rainfall, particularly during the monsoon.
• Crops: Rice, maize, tea, citrus fruits, and various vegetables.

3. Lower Gangetic Plains Region

• States Covered: West Bengal
• Climate: Humid subtropical with high rainfall and a warm climate.
• Crops: Rice, jute, sugarcane, pulses, and vegetables.

4. Middle Gangetic Plains Region

• States Covered: Bihar, Eastern Uttar Pradesh
• Climate: Humid subtropical with moderate to high rainfall.
• Crops: Rice, wheat, sugarcane, pulses, and oilseeds.

5. Upper Gangetic Plains Region

• States Covered: Western Uttar Pradesh
• Climate: Semi-arid to sub-humid with moderate rainfall.
• Crops: Wheat, rice, sugarcane, pulses, and oilseeds.

6. Trans-Gangetic Plains Region

• States Covered: Punjab, Haryana, Delhi, Chandigarh, Western Uttar Pradesh
• Climate: Semi-arid with moderate to low rainfall.
• Crops: Wheat, rice, sugarcane, cotton, and vegetables.

7. Eastern Plateau and Hills Region

• States Covered: Eastern Madhya Pradesh, Chhattisgarh, Odisha
• Climate: Sub-humid to humid with moderate to high rainfall.
• Crops: Rice, maize, pulses, oilseeds, and minor millets.

8. Central Plateau and Hills Region

• States Covered: Madhya Pradesh, Uttar Pradesh, Rajasthan
• Climate: Semi-arid with moderate rainfall.
• Crops: Wheat, sorghum, maize, pulses, and oilseeds.

9. Western Plateau and Hills Region

• States Covered: Maharashtra, parts of Madhya Pradesh
• Climate: Semi-arid with moderate rainfall.
• Crops: Cotton, sorghum, pearl millet, pulses, and oilseeds.

10. Southern Plateau and Hills Region

• States Covered: Karnataka, Tamil Nadu, parts of Andhra Pradesh
• Climate: Semi-arid to sub-humid with moderate rainfall.
• Crops: Sorghum, millets, pulses, oilseeds, and cotton.

11. East Coast Plains and Hills Region

• States Covered: Coastal areas of Tamil Nadu, Andhra Pradesh, Odisha
• Climate: Humid tropical with high rainfall.
• Crops: Rice, sugarcane, groundnut, and fruits.

12. West Coast Plains and Ghat Region

• States Covered: Coastal areas of Maharashtra, Goa, Karnataka, Kerala
• Climate: Humid tropical with high rainfall.
• Crops: Rice, coconut, spices, and cashew.

13. Gujarat Plains and Hills Region

• States Covered: Gujarat
• Climate: Semi-arid to arid with low to moderate rainfall.
• Crops: Cotton, groundnut, wheat, and pulses.

14. Western Dry Region

• States Covered: Rajasthan
• Climate: Arid with very low rainfall.
• Crops: Pearl millet, barley, pulses, and oilseeds.

15. The Islands Region

• Territories Covered: Andaman and Nicobar Islands, Lakshadweep
• Climate: Humid tropical with very high rainfall.
• Crops: Coconut, rice, fruits, and spices.

Importance of Agroclimatic Zones

1. Tailored Agricultural Practices: Helps in implementing region-specific agricultural strategies.
2. Resource Management: Efficient use of water, soil, and other resources based on regional characteristics.
3. Crop Planning: Facilitates planning of crop cycles and selection of suitable crop varieties.
4. Risk Mitigation: Aids in managing risks related to climate variability and natural disasters.

Understanding and utilizing the concept of agroclimatic zones enables more sustainable and productive agricultural practices, contributing to food security and economic stability in India.

UNIT –3 Water resources, soil plant water relationship, crop water requirement, water use efficiency.