Glossary of terms applicable to landscape and horticulture work
1981 Edition

Overview of IS 4919 Scope

Scope:
IS 4919 standardizes terminology related to landscape and horticultural practices throughout India, aligning with global standards while accommodating local conditions.

Key Measurement Units (SI Units)

Important Notes on the Scope:

• Covers materials, design, construction, testing, and safety aspects relevant to landscape and horticulture.
• Emphasizes harmonization with international standards.
• Addresses topics such as soil, plants, irrigation, pruning, and maintenance.
• Includes documentation and drawing conventions.

Conceptual Diagram of Scope

graph LR
A[IS 4919 Scope] --> B[Materials]
A --> C[Design and Construction]
A --> D[Testing and Quality]
A --> E[Documentation]
B --> F[Soils]
B --> G[Plants]
C --> H[Landscape Design]
C --> I[Horticultural Practices]

Refer to specific clauses in IS 4919 for detailed terminology and definitions.

IS 4919 functions primarily as a comprehensive glossary for terms related to landscape and horticultural activities, ensuring uniform interpretation across the industry.

Key Highlights:

• Scope: Defines terms linked to landscape architecture, planting, maintenance, and horticultural operations.
• Objective: To provide a standardized vocabulary for clear communication among practitioners.
• Sample Definitions:
  • Landscape: The visible features of an area including physical, biological, and human-made elements.
  • Horticulture: The science and art of cultivating plants.
  • Planting Bed: A prepared soil area designated for planting vegetation.
  • Mulching: The practice of applying organic or inorganic material over soil to conserve moisture.

Notes:

• The standard does not include structural formulas or calculation tables.
• For engineering design and structural calculations related to landscape elements, refer to other IS codes such as IS 456 and IS 3370.

flowchart LR
    A[IS 4919] --> B[Glossary of Terms]
    B --> C[Landscape Concepts]
    B --> D[Horticulture Concepts]
    B --> E[Planting and Maintenance Vocabulary]

For detailed design specifications, consult relevant Indian Standards beyond IS 4919.

Definition of Absorption (Clause 2.3)

Absorption refers to the capability of a material to take in and retain water within its pores or voids, similar to how a sponge functions.

Key Aspects:

• Expressed as a percentage:
  [ \text{Absorption} = \frac{\text{Water absorbed (weight)}}{\text{Dry weight of material}} \times 100 ]
• Importance:
  • Reflects porosity and durability properties of construction and landscaping materials such as bricks and stones.
  • Higher absorption can negatively impact strength and increase susceptibility to weathering.

Typical Absorption Ranges:

Test Procedure Summary:

1. Dry the specimen until weight is constant (Dry weight, (W_d)).
2. Immerse in water for 24 hours.
3. Remove, surface dry, and weigh immediately (Wet weight, (W_w)).
4. Calculate absorption percentage.

flowchart LR
    A[Dry Sample] --> B[Soak in Water 24h]
    B --> C[Surface Dry Sample]
    C --> D[Weigh Wet Sample]
    D --> E[Compute Absorption Percentage]

Note: IS 4919 provides definitions; detailed test methods and limits are covered in related standards like IS 1725.

Definition (Clause 2.4): Aeration is the process or techniques that enable air to enter the spaces within soil, enhancing oxygen availability for plant root respiration.

Key Details:

• Purpose: To increase soil porosity and oxygen access.
• Techniques: Mechanical methods (e.g., spiking, treading), biological activity, or natural processes.
• Related Term: Xerophyte (Clause 2.166) – plants adapted to dry conditions that benefit from efficient aeration.

Relevant SI Units:

Typical Aeration Parameters:

Conceptual Flow:

flowchart LR
    A[Soil Surface] --> B[Soil Pores]
    B --> C[Air Penetration]
    C --> D[Root Zone]
    D --> E[Improved Root Respiration]

Summary: IS 4919 defines aeration as facilitating air movement into soil pores, which is vital for plant health, particularly for drought-resistant species.

Overview (Clause 2.10): Blending refers to horticultural practices aimed at combining plant species or colors to enhance aesthetic appeal and functional resilience in lawns and borders.

• (a) Grass Blending for Lawns: Combining multiple grass species or varieties to improve texture, color variation, and adaptability, resulting in more durable turf.

• (b) Blending Herbaceous Plants: Mixing various herbaceous species in borders to achieve continuous flowering and diverse textures.

• (c) Color Mixing in Annual Borders: Arranging plants with different flower colors thoughtfully to avoid clashes and produce pleasing visual effects.

Guidelines:

Practical Example:

Blend Ratio (%) = Dominant Grass % + Complementary Grass % = 100%
Example: 70% Bermuda + 30% Ryegrass

flowchart LR
    A[Select Grass Species] --> B{Assess Soil & Climate}
    B --> C[Choose Dominant Species]
    B --> D[Choose Complementary Species]
    C --> E[Mix Seeds According to Ratio]
    D --> E
    E --> F[Prepare Soil & Working In Amendments]
    F --> G[Seed and Maintain Lawn]

Summary: IS 4919 highlights blending as a method to achieve visual harmony and turf durability by carefully combining plant species and colors.

Definition (Clause 2.14): Charring is the surface carbonization of wood due to exposure to fire, which forms a protective char layer that slows further burning and decay.

Charring Rate:

• Denoted as (\beta), representing the thickness of wood charred per unit time (mm/min).
• Typical values:
  • Softwood: 0.6 mm/min
  • Hardwood: 0.8 mm/min

Residual Thickness Calculation:

[ d_{residual} = d_{original} - \beta \times t ] Where:

• (d_{residual}) = remaining thickness after fire exposure (mm)
• (d_{original}) = initial thickness (mm)
• (\beta) = charring rate (mm/min)
• (t) = duration of fire exposure (minutes)

Design Considerations:

• Account for charring when designing timber elements for fire resistance.
• Use fire retardant coatings or encasements to reduce charring.
• Employ fire-treated wood where appropriate.

Summary Table:

flowchart LR
    A[Original Thickness] --> B[Fire Exposure Time]
    B --> C[Calculate Char Depth (\u03b2 × t)]
    C --> D[Residual Thickness]
    D --> E[Post-Fire Structural Capacity]

Note: IS 4919 defines terms; detailed fire design provisions are found in IS 401 and IS 1642.

Definition (Clause 2.21): Consolidation is the process by which soil volume decreases due to water expulsion and particle rearrangement under applied pressure, without causing excessive compaction.

Key Equations:

1. Primary Consolidation Settlement (S): [ S = \frac{H}{1 + e_0} \log \frac{\sigma'_0 + \Delta \sigma'}{\sigma'_0} ] Where:

• (H): thickness of compressible soil layer
• (e_0): initial void ratio
• (\sigma'_0): initial effective stress
• (\Delta \sigma'): increase in effective stress

2. Coefficient of Consolidation ((C_v)) governs consolidation rate.

3. Time Factor ((T_v)): [ T_v = \frac{C_v t}{H^2} ] Where (t) is time, (H) is drainage path length.

Process Flow:

flowchart LR
    A[Load Application] --> B[Increase Effective Stress]
    B --> C[Water Expelled from Soil Pores]
    C --> D[Particle Rearrangement]
    D --> E[Volume Reduction - Consolidation]

SI Units:

Note: For detailed soil property tables, consult IS 1888 and IS 2720 (Part 15). IS 4919 focuses on terminology and general principles.

Definition (Clause 2.25): Cultivation involves tilling or working the soil mechanically or manually to prepare it for planting and promote healthy crop growth.

• Minimal Cultivation (Clause 2.88): Reducing physical tillage by employing chemical agents to prepare soil.
• Re-setting (Clause 2.114): Replanting of crops or trees.
• Sod Culture (Clause 2.130): Growing perennial grasses permanently between orchard trees with minimal tillage near tree roots.

Cultivation Types and Purposes:

Notes:

• Typical tillage depth: 15-20 cm for effective cultivation.
• Chemical herbicides reduce tillage frequency, preserving soil health.
• Sod culture minimizes soil disturbance, beneficial for erosion-prone sites.

flowchart LR
    A[Cultivation] --> B[Full Tillage]
    A --> C[Minimal Tillage]
    A --> D[Sod Culture]
    B --> E[Ploughing & Tilling]
    C --> F[Chemical + Reduced Tillage]
    D --> G[Permanent Grass Cover]

These definitions align with IS 4919 and orchard soil management best practices.

IS 4919 defines various digging types:

• Digging In (Clause 2.32.1): Incorporation of soil amendments like organic matter or fertilizers by digging to improve soil quality.
• Digging Single/One Spit (Clause 2.32.3): Digging to full spade depth, approximately 20-25 cm.
• Digging Over (Clause 2.32.2): Shallow cultivation to loosen surface soil, typically 5-10 cm depth.

Practical Depths and Purposes:

Notes:

• Use appropriate tools based on soil texture.
• Digging In improves fertility by integrating amendments.
• Depth adjustments depend on crop and soil condition.

flowchart LR
    A[Digging] --> B[Shallow Digging (5-10 cm)]
    A --> C[Full Depth Digging (20-25 cm)]
    A --> D[Digging with Additives]

This classification assists in selecting suitable digging methods per IS 4919.

Definition (Clause 2.36): Draw Up refers to moving soil toward the base of plants using tools like drawhoes to improve root environment.

Key Points:

• Commonly used in horticulture and agriculture for soil management around plants.
• No specific formulas in IS 4919; it is a manual or mechanical operation.

Relevant Units:

Practical Notes:

• Enhances soil aeration and moisture retention near roots.
• Uniform soil movement is essential to avoid damage.
• Use appropriate tools for effective soil displacement.

flowchart LR
    A[Soil] --> B[Drawhoe Operation]
    B --> C[Soil Moved Toward Plants]
    C --> D[Improved Root Zone]

Summary: IS 4919 defines Draw Up as a soil-moving technique near plants to improve growth conditions.

Definition (Clause 2.53): Flame gunning is the use of a flame gun to burn off above-ground vegetation for control purposes.

Purpose and Application:

• Used for vegetation management especially at construction sites or where chemical control is unsuitable.
• Employ controlled flames to avoid soil or underground damage.
• Safety precautions are critical to prevent fire hazards.

Typical Parameters:

Process Flow:

flowchart LR
    A[Identify Vegetation] --> B[Prepare Flame Gun]
    B --> C[Adjust Flame Temperature]
    C --> D[Apply Flame Evenly]
    D --> E[Monitor Burn Completion]
    E --> F[Ensure Fire Control Measures]
    F --> G[Vegetation Eradicated]

Summary: IS 4919 defines flame gunning as vegetation burning using flame tools without detailed operational parameters.

Definition (Clause 2.58): Friable materials are soils or organic substances that can be easily crumbled or broken down by hand or minor mechanical force.

Importance:

• Friable soils are significant in foundation engineering affecting compaction, stability, and bearing capacity.
• No specific formulas in IS 4919; friability is a qualitative characteristic assessed by field or lab tests.

Engineering Considerations:

Summary:

• Friable means easily breakable material.
• Use conventional soil testing methods to evaluate.
• Design assumptions should be conservative for friable soils.

flowchart LR
    A[Material] --> B{Friable?}
    B -- Yes --> C[Easy to Break Down]
    B -- No --> D[Stable Material]
    C --> E[Low Cohesion]
    E --> F[Careful Compaction & Design]

For detailed soil behavior, refer to IS 6403 and IS 2720.

Definition (Clause 2.65): Green manuring involves growing nitrogen-rich crops and incorporating them into the soil to enhance fertility.

Key Details:

• Use fast-growing leguminous crops such as Sunn hemp and Sesbania.
• Incorporate crops at flowering stage for optimal nitrogen content.
• Typical nitrogen content ranges from 2% to 4% of dry biomass.

Calculation:

• Nitrogen added to soil (kg/ha) = Biomass yield (kg/ha) × N content (%) / 100

Example Data:

Benefits:

• Enhances soil fertility and structure.
• Reduces synthetic fertilizer dependency.
• Improves moisture retention and microbial activity.

flowchart TD
    A[Grow Green Manure Crop] --> B[Reach Flowering Stage]
    B --> C[Plough into Soil]
    C --> D[Decompose and Release Nitrogen]
    D --> E[Improved Soil Health]

Green manuring is a sustainable soil improvement method per IS 4919.

Definition (Clause 2.89): Mound-up is the practice of heaping soil around the base of a plant stem to protect tubers, provide mechanical support, or to blanch stems by limiting light exposure.

Purpose:

• Shield tubers from sunlight and pests.
• Provide stability to the plant stem.
• Facilitate blanching by reducing light.

Related Terms:

• Earth Up (Clause 2.42): Similar soil heaping for support or blanching.
• Draw Up (Clause 2.36): Moving soil toward plants.
• Underfill (Clause 2.158): Filling soil beneath sunken turf areas.

Practice:

• Soil is mounded to a height generally between 10 and 30 cm depending on crop requirements.

flowchart LR
    A[Plant Stem] --> B[Apply Soil Mound]
    B --> C[Protect Tubers]
    B --> D[Provide Support]
    B --> E[Blanch Stem]

Summary: Mound-up is a soil management method for plant health enhancement without fixed formulas, guided by specific crop needs.

Mowing is defined as cutting grass through manual or mechanical means (Clause 2.90).

• Rotary Mowing (Clause 2.119): Using machines with spinning blades.
• Edge Cutting (Clause 2.43.1): Trimming lawn edges.
• Flying (Clause 2.54): Dispersing cut grass without collection, typical with some mowers.

Specifications:

• Typical grass cutting height: 25–50 mm.
• Rotary mower blade speed: 3000–3600 rpm.
• Overlap between passes: 30–50% for uniformity.
• Cutting width varies (0.5 to 1.2 m).

Time Estimation Formula:

[ T = \frac{A}{W \times S} ] Where:

• (T): Time in hours
• (A): Area to mow (m²)
• (W): Cutting width (m)
• (S): Speed of mower (m/h)

flowchart LR
  A[Mowing] --> B[Manual]
  A --> C[Mechanical]
  C --> D[Rotary Mowers]
  C --> E[Edge Cutting]
  C --> F[Flying (Dispersal)]

Note: IS 4919 provides definitions; operational details depend on specific equipment and project requirements.