Increasing food production requires soil that is free from issues. Here’s an overview of some key soil challenges affecting agriculture in Tamil Nadu, along with solutions.
Challenges Due to Chemicals
- Salinity, Sodicity, Acidity, and Excess Nutrients: These issues arise due to chemical imbalances in the soil, impacting plant growth.
Natural Challenges
- Drainage Issues, Hardpan Formation, Surface Crusting, Sandy Soil, etc.: These conditions affect water absorption and retention, impacting crop yield.
Saline Soil
Problem: High salt levels in the soil restrict crop growth.
Solution: Create main and side drains 60 cm deep and 45 cm wide to remove salts. Apply 5 tons of farmyard manure per hectare about 10–15 days before planting rice or other crops.
Sodic Soil
Problem: High sodium content (over 15%) and pH above 8.5, affecting soil structure.
Solution: Till the soil when it’s adequately moist. Add gypsum as needed and maintain good drainage to allow salts to leach out. Use 15 tons of green manure per hectare and incorporate it into the soil.
Acidic Soil
Problem: Soil pH below 6, leading to deficiencies in essential nutrients like calcium, magnesium, molybdenum, and boron.
Solution: Add lime to the soil as required. Dolomite, wood ash, and limestone from mills can also help neutralize acidity.
Iron and Aluminum Toxicity
Problem: High iron and aluminum concentrations, especially in waterlogged soils, common in districts like Kanyakumari and Pudukkottai.
Solution: Mix necessary amounts of lime and nutrient-rich organic materials into the soil.
Poorly Draining Clay Soil
Problem: Dense clay soils restrict water infiltration, causing water to pool and hindering root growth.
Solution: Mix 100 tons of river sand per hectare into the soil and plow deeply in summer.
Low Retention Sandy Soil
Problem: Sandy soil lacks water and nutrient retention, causing both to drain away quickly.
Solution: Roll over the soil using a stone roller weighing 400 kg every three years. Apply lake silt to improve productivity.
Hard Surface Soil
Problem: Compacted soil prevents roots from penetrating deeply, limiting growth.
Solution: Use a chisel plow every three years and add 12.5 tons of manure or decomposed coconut coir per hectare.
Surface Crusting Soil
Problem: Soil crusting from rainfall impacts seedling emergence and growth.
Solution: Lightly till the soil using small tilling tools and add 2 tons of lime or gypsum and 12.5 tons of farmyard manure per hectare. Leave crop residue to decompose naturally.
Heavy Clay Soil
Problem: High clay content restricts water infiltration, trapping nutrients in the top layer.
Solution: Add 100 tons of river sand per hectare and deep-plow in summer.
Compacted Black Soil with Poor Water Infiltration
Problem: Black soil compaction limits water and nutrient infiltration.
Solution: Add a mixture of red soil with subsoil (20 cm deep) per hectare. Deep-plow and add 25 tons of manure or organic waste per hectare.
Highly Absorptive Red Soil
Problem: Red soil absorbs water too quickly, causing nutrients to leach.
Solution: Apply 25 tons of lake silt or black soil per hectare and add 25 tons of manure or organic waste.
Deep Tillage for Hard Subsoil
Problem: Hard sublayers limit water and nutrient absorption, affecting crop growth, especially in districts like Coimbatore, Erode, Dharmapuri, Trichy, Madurai, and Salem.
Solution: Deep-till the land every 50 cm in both directions. Apply 12.5 tons of manure or organic waste.
By addressing these soil-related issues with targeted methods, soil quality and productivity can be significantly improved, promoting sustainable agricultural growth.
N. Marikannu, P. Karuppasamy, Dr. J. Thiraviyam, Agricultural Science Center, Pulutheri, Karur District.
