Lettuce, a popular crop in salads, is perfectly suited for hydroponic systems like the Nutrient Film Technique (NFT), which provides an ideal environment for optimal growth and yields. At INHYDRO, we specialize in NFT systems, designed to support thriving lettuce crops in hydroponics. This guide covers essential tips on selecting the best varieties, creating nutrient recipes, and achieving success with lettuce cultivation in an NFT setup.

Why Grow Lettuce in NFT Hydroponics?

NFT hydroponics is ideal for lettuce due to its shallow root system, which benefits from the continuous flow of nutrient-rich water provided by NFT channels. The NFT system helps maintain balanced nutrients, optimizing lettuce growth and yield compared to traditional soil cultivation.

Best Lettuce Varieties for Hydroponics

Rijk Zwaan Varieties:

1. Salanova® Butter: Known for compact growth and high yield, with tender leaves and a mild flavor.
2. Concept: A romaine-type variety that grows well in NFT systems, offering excellent texture and shelf life.
3. Amaze: Features crisp leaves and rapid growth, making it a good choice for hydroponics.
4. Oakleaf: Known for its sweet flavor and long shelf life, ideal for commercial production.

Enza Zaden Varieties:

1. Eazyleaf®: A multi-leaf lettuce that produces uniform-sized leaves, perfect for salad mixes.
2. Xandra: A butterhead variety with dense, crispy leaves that suit NFT hydroponics well.
3. Curio: A loose-leaf lettuce with smooth, vibrant green leaves, perfect for fresh salads.
4. Salanova® Crispy: Known for high yield, long shelf life, and resistance to bolting, ideal for hydroponic systems.

Optimal Environmental Conditions for Lettuce in NFT Hydroponics

• Temperature: Maintain an ideal range of 20-30°C. For germination, keep it at 25-30°C.
• Humidity: Moderate levels with good airflow to prevent fungal issues.
• Light: Provide 12-16 hours of light daily using natural sunlight or supplemental LED grow lights.
• pH Level: 5.5 to 6.5 is ideal.
• Electrical Conductivity (EC): 0.8-1.2 mS/cm.

Nutrient Recipe for Hydroponic Lettuce

A balanced nutrient solution is essential for healthy lettuce growth. Here’s a recommended recipe for lettuce in an NFT system:

Macronutrients (per 100 liters of water):

• Nitrogen (N): 120-150 ppm
• Phosphorus (P): 30-40 ppm
• Potassium (K): 150-200 ppm
• Calcium (Ca): 150-180 ppm
• Magnesium (Mg): 50-60 ppm
• Sulfur (S): 50-60 ppm

Micronutrients:

• Iron (Fe): 2.5-3.5 ppm
• Manganese (Mn): 0.5 ppm
• Zinc (Zn): 0.2 ppm
• Copper (Cu): 0.05 ppm
• Boron (B): 0.3 ppm
• Molybdenum (Mo): 0.05 ppm

Mixing Instructions:

1. Start by filling the reservoir with clean water.
2. Add macronutrients in the following order: Calcium nitrate, Magnesium sulfate, then Potassium sulfate.
3. Add micronutrients last, stirring each thoroughly.
4. Adjust pH to stay within the 5.5-6.5 range.
5. Check EC to ensure it’s within the 0.8-1.2 mS/cm range.

Sowing and Transplanting

• Seed Germination: Sow seeds in a germination medium like rockwool cubes and maintain the temperature at 25-30°C. Seeds should germinate within 3-4 days.
• Transplanting: Once seedlings reach 2-3 weeks old with a few true leaves, transplant them into the NFT channels at a spacing of 15-20 cm.

Irrigation and Flow Management

• Flow Rate: Maintain a thin, consistent film of nutrient solution to cover root tips without causing waterlogging.
• Oxygenation: Ensure proper oxygenation of the nutrient solution for healthy root growth.

Pest and Disease Control

• Aphids: Check plants regularly for pests like aphids. Use organic insecticides or biological controls such as ladybugs.
• Downy Mildew: Prevent by maintaining airflow and moderate humidity. Use resistant varieties and clean equipment.
• Mosaic Virus: Use disease-free seeds and sterilize tools to avoid spreading.

Harvesting and Post-Harvest Handling

1. Harvesting Time: For loose-leaf varieties, start harvesting leaves when they reach marketable size (around 45 days). For head varieties, harvest the entire plant once the heads are fully formed.
2. Harvesting Method: Cut leaves or heads early in the morning for maximum freshness.
3. Storage: Store at 4-5°C with 95% relative humidity to keep lettuce fresh for up to three weeks.

Advantages of NFT Hydroponic Lettuce Cultivation

• Faster Growth: NFT systems accelerate growth rates, allowing for yields 20-30% faster than soil-based farming.
• Resource Efficiency: NFT systems use up to 90% less water than traditional farming methods.
• High Quality: Consistent nutrient supply leads to uniform growth and higher-quality lettuce.

Conclusion

Growing lettuce in an NFT hydroponic system offers several advantages, including faster growth, higher yields, and superior quality. By following this guide and using INHYDRO’s food-safe NFT systems, you can cultivate vibrant, nutrient-rich lettuce year-round. Visit INHYDRO’s website to explore our NFT hydroponics systems and access expert support for your hydroponic journey.