Land Resources and Solid Waste Management Notes

Land Resources

  • Land & soil are vital resources, not waste; require care.
  • Land is a renewable but finite resource.
  • Earth's surface is ~ 5.1 × 10^8 \, km^2, land area ~ 1.4 × 10^8 \, km^2.
  • Land is crucial for life, biodiversity, habitation, agriculture, industry, and resource storage.
  • Soil is a mix of eroded rock, organic matter, water, air, and organisms.
  • Humus aids soil structure and plant needs; soil renewal is slow.
  • Soil profile: distinct layers (horizons) differing in properties.

Land Degradation

  • Land degradation: reduced land quality/productivity due to natural or human activities.
  • Soil erosion: movement of soil, mainly topsoil, by water & wind.
  • Weathering: rock breakdown; erosion: movement of weathered material.

Causes of Land Degradation:

  • Natural hazards: landslides, rainfall, drought, etc.
  • Human activities: urbanization, deforestation, overgrazing, mining.
  • Soil erosion: Loss of green cover.
  • Fertilizers & pesticides: affect soil fertility.
  • Waterlogging & salinization: from improper irrigation.

Adverse Effects

  • Landslides destroy in their path.
  • Fires result in soil burning.
  • Drought leads to desertification.
  • Urbanization depletes land for agriculture.
  • Soil erosion reduces fertility and water retention.
  • Fertilizers/pesticides damage topsoil, cause desertification.
  • Waterlogging/salination stunts plant growth, causes financial loss.

Sustainable Agriculture

Principles:

  • Slow water concentration/movement on slopes.
  • Encourage water infiltration.
  • Increase soil particle size.
  • Reduce wind velocity via vegetation.

Tillage Farming

  • Tillage farming is mixing residues into soil by ploughing.
  • Reduces soil erosion.
  • Improves soil permeability.
  • Conventional tillage: <15% residue on surface.
  • Conservation tillage: at least 30% residue, minimum soil disruption.
  • No-till farming: 100% residue cover, direct injection of seeds/fertilizers

Other Methods to Reduce Soil Erosion

  • Terracing: Level terraces to retain water & control runoff.
  • Strip Cropping: Alternating row crops with cover crops.
  • Alley Cropping/Agroforestry: Crops between trees/shrubs.
  • Shelter Belts/Wind Breaks: Trees to block wind.

Soil Fertility Maintenance

  • Soil conservation methods (tillage, terracing).
  • Fertilizers to restore nutrients.
  • Crop rotation (e.g., legumes after nutrient-depleting crops).
  • Organic fertilizers (manure, compost).
  • Inorganic fertilizers (N, P, K).

Urea and Neem Coating

  • Urea provides N for plant growth.
  • Neem coating ensures gradual urea release.
  • Reduces water contamination.

Water Logging and Salinization

  • Water logging: Soil saturation due to excess irrigation without drainage.
  • Salinization: Salt accumulation from irrigation water evaporation.
  • Prevention: Reduce irrigation, grow salt-tolerant crops.
  • Cleanup: Flush soil, install drainage.

Landslides

  • Masses of land sliding down, destroying paths.
  • Causes: Deforestation, heavy rains, earthquakes.

Desertification

  • Productivity fall in drylands.
  • Causes: Climate change, human activities.
  • Consequences: Drought, famine, economic losses.
  • Control: Reduce overgrazing, deforestation; plant trees.

Solid Waste Management

  • Solid waste: unwanted solid materials from various activities.
  • Solid waste management: collection, transport, treatment, disposal.
  • India generates over 55 million tons of MSW annually.

Classification of Solid Waste

  • Sources: residential, commercial, industrial, etc.
  • Physical nature: garbage, combustible, ashes, etc.
  • Hazardous wastes: pose danger to health/environment (ignitability, corrosivity, reactivity, toxicity, radioactivity).

Engineered Systems

  • Collection, handling, transportation, processing, disposal.

Treatment Methods

  • Open Dumps: Untreated, unsegregated waste areas are breeding grounds for diseases and contaminants.
  • Landfills: Waste disposal by burial; can have adverse environmental impacts.
  • Sanitary Landfills: Designed to reduce risks to public health and the environment.
  • Composting: Biological decomposition of organic waste under aerobic conditions.
  • Anaerobic Digestion: Controlled release of methane-rich biogas in the absence of oxygen.
  • Vermicomposting: Using earthworms to enhance waste conversion.
  • Incineration: Burning waste at high temperatures, converts hazardous substances into less hazardous components.
  • Encapsulation: Coating waste with resins.

Management of Solid Waste

  • Reduce waste through recycling.
  • Four R’s: Refuse, Reuse, Recycle, Reduce.
  • Different management per waste nature: medical, non-degradable, hazardous, e-waste.

Types of Solid Waste and Management

  • Medical solid waste: Requires incineration or sanitary landfills.
  • Non-degradable solid waste: Recycling, landfills, or incineration.
  • Hazardous waste: Thermal or biological treatment.
  • Non-hazardous/biodegradable: Open dumps, landfills, anaerobic digestion, composting, vermicomposting.

Electronic Waste (E-Waste)

  • Concern due to toxicity (lead, mercury, cadmium).
  • Treatment: Encapsulation, Incineration, Sanitary landfill (recycling).

Affecting Factors

  • Per capita income.
  • Climate.
  • City growth.
  • Municipal status.
  • Available resources.