1. Introduction

Saline and sodic soils pose significant challenges to agricultural productivity due to excessive salt accumulation and poor soil structure. These soils require proper reclamation and management techniques to restore their fertility and ensure sustainable crop production.

2. Characteristics of Saline and Sodic Soils

Saline Soils

• Contain high soluble salts (EC > 4 dS/m)
• Exchangeable sodium percentage (ESP) < 15
• pH usually below 8.5
• Poor water infiltration due to high salt concentration
• White crust formation on the soil surface
• Adversely affects seed germination and plant growth

Sodic Soils

• High exchangeable sodium percentage (ESP > 15)
• Electrical conductivity (EC) < 4 dS/m
• pH > 8.5, often exceeding 10
• Poor soil structure, leading to compaction and reduced permeability
• Dispersed soil particles causing poor aeration and drainage

3. Reclamation Strategies

Reclamation of Saline Soils

1. Leaching with Good Quality Water: Application of excess water helps in flushing out soluble salts from the root zone. Requires well-drained soils to avoid waterlogging.
2. Improving Drainage: Installation of surface or subsurface drainage systems to remove excess salts. Raised bed planting to improve aeration.
3. Use of Amendments: Application of gypsum (CaSO₄·2H₂O) if saline soil has excessive sodium. Application of sulfuric acid or elemental sulfur to help in leaching salts.
4. Salt-Tolerant Crops: Growing salt-tolerant crops such as barley, sorghum, sugar beet, and certain grasses.
5. Mulching and Organic Matter Addition: Adding organic matter such as farmyard manure (FYM), compost, and green manure enhances microbial activity and soil fertility.
6. Irrigation Management: Avoiding saline water for irrigation. Using drip or sprinkler irrigation to minimize salt accumulation.

Reclamation of Sodic Soils

Chemical Amendments:

• • Gypsum Application: The most effective amendment for replacing sodium with calcium.
  • Sulfuric Acid or Elemental Sulfur: Helps in reducing pH and promoting soil structure.
  • Calcium Chloride (CaCl₂): Effective in certain conditions for sodic soil reclamation.
• Leaching with Water: Application of excess water helps in removing sodium ions. Requires good drainage to avoid waterlogging.
• Improving Soil Structure: Adding organic matter to enhance soil aggregation and microbial activity. Deep plowing to break compacted layers and improve water infiltration.
• Salt-Tolerant Crop Cultivation: Crops such as rice, barley, and certain legumes can help in gradual reclamation.
• Agroforestry and Biological Reclamation: Planting deep-rooted trees and grasses (e.g., Karnal grass, eucalyptus) to help in lowering the water table and removing excess salts.
• Proper Irrigation Management: Avoiding high-sodium irrigation water. Using alternate irrigation with good-quality water.

Long-Term Management Practices

• Crop Rotation: Alternating salt-sensitive and salt-tolerant crops.
• Use of Cover Crops: Legumes and green manure crops improve soil fertility and structure.
• Conservation Tillage: Reducing soil disturbance to maintain structure.
• Regular Soil Testing: Monitoring soil EC, pH, and ESP to assess the effectiveness of reclamation.
• Integrated Nutrient Management (INM): Balanced use of organic and inorganic fertilizers to maintain soil health.