Technological development in Sri Lanka's agriculture

 Soil-less culture/Hydroponics culture.....

What is the Soil-less culture/Hydroponics culture?

Soilless cultivation is cultivation using solid, liquid and gaseous media other than soil.

importance of soil-less culture

• Suitable for urban cropland and home garden cultivation where large cultivation area is not required.
• Soil borne diseases will decrease.
• Due to fewer diseases, the use of chemical pesticides is less. This will reduce environmental pollution.
• This method can be used even on land that cannot be used for cultivation.
• More efficient use of water and nutrients increases the quantity and quality of crop yields

Types of soil-less culture/ Hydroponics culture

1. Solution culture or Liquid hydroponics

-Circulating methods (closed system)

• Nutrient film technique (NFT)
• Deep flow technique (DFT)

-Non-circulating method (open systems)

• Root dipping technique

         1. Root dipping technique for non-root tuber crops

         2. Root dipping technique for root tuber crops

• Floating technique
• Capillary action technique

2. Solid media culture (Aggregate systems) –These can be open systems or closed systems.

• Hanging bag technique
• Grow bag technique
• Trench or trough technique
• Pot technique

3. Aeroponics

• Root mist technique
• Fog feed technique

1. Liquid or Solution Culture

Circulating Methods

The nutrient solution is pumped through the plant root system and excess solution is collected, replenished and reused in these methods.

• Nutrient Film Technique (NFT)

The Nutrient Film Technique (NFT) is a hydroponic system used for growing plants without soil. In NFT, a thin film of nutrient-rich water continuously flows over the roots of the plants, providing them with the necessary nutrients. This method is particularly popular for growing crops like lettuce, herbs, and other leafy greens.

Channel System:

NFT systems typically consist of sloping channels or gullies through which a thin film of nutrient solution flows.

These channels are usually made of lightweight and inert materials like PVC or plastic.

Support Structure:

Plants are placed in small containers or net pots, and these containers are set in the channels, allowing the roots to be in direct contact with the nutrient film.

Continuous Flow of Nutrient Solution:

A nutrient solution, containing essential minerals and nutrients dissolved in water, is continuously pumped from a reservoir to the highest end of the channels.

The solution then flows along the channels, creating a thin film that bathes the roots of the plants.

Gravity Return:

At the end of the channel, the nutrient solution is allowed to drain or flow back into the reservoir by gravity.

The process repeats in a continuous cycle.

Oxygenation of Roots:

The thin film of nutrient solution provides oxygen to the roots as it flows over them. This oxygenation is crucial for the health of the plants.

Key features and advantages of the Nutrient Film Technique include:

Water Efficiency: NFT systems are known for their water efficiency as they use less water compared to traditional soil-based agriculture.

Nutrient Control: The nutrient solution can be precisely controlled, allowing for optimal nutrient levels for plant growth.

Space Efficiency: NFT systems are often used in vertical farming or in situations where space is limited, as the plants can be arranged in a compact manner.

Rapid Growth: Plants in NFT systems often experience faster growth rates because they have easy access to nutrients and oxygen.

Suitability for Certain Crops: NFT is commonly used for growing leafy greens and herbs, but it may not be as suitable for larger plants with extensive root systems.

Proper monitoring and control of factors such as pH, nutrient concentration, and temperature are essential to ensure the success of the Nutrient Film Technique.

• Deep Flow Technique (DFT)– Pipe System

The Deep Flow Technique (DFT) – Pipe System is a hydroponic growing method that shares some similarities with the Nutrient Film Technique (NFT). Like NFT, DFT involves a continuous flow of nutrient-rich water over the roots of plants, but there are some key differences in the system design.

In a Deep Flow Technique – Pipe System:

Growing Channels:

Similar to NFT, DFT uses channels to contain the plants. However, in the DFT – Pipe System, these channels are typically pipes or tubes.

The pipes are often inclined or laid horizontally to allow a thin, continuous film of nutrient solution to flow over the roots.

Plant Support:

Plants are typically placed in individual containers or net pots, and these containers are positioned in the pipes. The roots extend into the nutrient solution flowing through the pipes.

Continuous Flow:

A nutrient solution is continuously pumped from a reservoir to the highest end of the pipes.

The solution flows along the pipes, providing a continuous film that bathes the roots of the plants.

Gravity Return:

At the end of the pipes, the nutrient solution is allowed to drain or flow back into the reservoir under the influence of gravity.

This creates a continuous cycle of nutrient solution flow.

Oxygenation of Roots:

The thin film of nutrient solution also serves to oxygenate the roots as it flows over them, promoting healthy plant growth.

The Deep Flow Technique – Pipe System shares advantages such as water efficiency, nutrient control, and space efficiency with other hydroponic systems. It allows for precise control over the nutrient environment, promoting optimal plant growth.

As with any hydroponic system, careful monitoring of factors like pH, nutrient concentration, and temperature is crucial to ensure the health and productivity of the plants. The suitability of the Deep Flow Technique depends on the specific needs of the crops being grown and the available resources for system maintenance and control.

Non-Circulating Methods

The nutrient solution is not circulated but used only once. When its nutrient

concentration decreases or pH or EC changes, it is replaced.

• Root dipping technique

Root dipping is a technique commonly used in agriculture to treat the roots of seedlings or cuttings before transplanting. This method is employed to stimulate root growth and enhance the establishment of plants in their new environment. While the term "root tuber crops" typically refers to crops that store energy in their enlarged underground roots (such as potatoes, sweet potatoes, and yams), the root dipping technique can be applied to various types of crops.

• Preparation of Root Dip Solution:

• A solution is prepared to dip the roots of seedlings or cuttings before transplanting. The composition of the solution may vary based on the specific needs of the crops.
• Root dip solutions often include water, nutrients, rooting hormones, and sometimes fungicides or beneficial microbes.

• Dipping Process:

• The roots of the seedlings or cuttings are immersed or dipped into the prepared root dip solution for a specified period.
• The goal is to coat the roots with the solution, providing them with essential nutrients, promoting root development, and potentially protecting against diseases.

• Transplanting:

• After the roots have been dipped, the seedlings or cuttings are transplanted into the soil or growing medium.
• The treated roots are expected to benefit from the nutrient boost and hormonal stimulation, helping the plants establish more quickly in their new environment.

• Advantages of Root Dipping for Root Tuber Crops:

• Enhanced Root Growth: Root dipping is believed to encourage the development of a strong and healthy root system, which is crucial for root tuber crops.
• Faster Establishment: Treated plants may establish more quickly in the field, leading to earlier and more vigorous growth.

• Applicability to Root Tuber Crops:

• Root dipping is commonly used for crops that produce tubers, as it helps in the establishment of a robust root system, which is essential for tuber development.
• The technique is particularly relevant for crops propagated from seedlings or cuttings.

It's important to note that the specific composition of the root dip solution and the duration of the dipping process can vary based on factors such as crop type, local conditions, and specific goals of the treatment. Growers often tailor the root dipping technique to suit the needs of their particular crops and production systems.

It is of 2 types :

                 1. Root dipping technique for non-root tuber crops

                 2. Root dipping technique for root tuber crops

• Floating Technique

The "Floating Technique" can refer to a hydroponic or aquaponic method where plants are placed on floating platforms or rafts that float on a nutrient-rich solution or water. This technique is commonly known as the "Floating Raft" or "Deep Water Culture" (DWC) system. Here's an overview of the Floating Technique in hydroponics:

1. Floating Raft System:

   • In a Floating Raft or DWC system, plants are placed in net pots or containers that are supported by floating rafts made of materials such as foam.
   • These rafts float on the surface of a nutrient solution in a shallow tank or channel.

2. Nutrient Solution:

   • The nutrient solution is oxygenated to provide the necessary nutrients to the plant roots. Air stones or diffusers are often used to maintain oxygen levels in the solution.

3. Root Submersion:

   • The plant roots dangle through the net pots into the nutrient solution, which allows them to absorb both nutrients and oxygen directly.

4. Benefits of the Floating Technique:

   • Oxygenation: The floating technique ensures that plant roots receive ample oxygen, promoting healthy root development.
   • Nutrient Uptake: Plants have continuous access to nutrients in the solution, leading to robust growth.
   • Ease of Harvest: Harvesting is simplified as the plants are easily accessible on the floating rafts.

5. Common Crops:

   • The floating technique is often used for growing leafy greens, herbs, and other plants that don't have extensive root systems.

6. Maintenance:

   • Regular monitoring of nutrient levels, pH, and oxygen levels in the nutrient solution is essential for maintaining optimal growing conditions.

This hydroponic technique is particularly popular for its simplicity and efficiency. It's well-suited for smaller plants and is commonly used in educational settings, research, and by hobbyists. Additionally, variations of the floating technique are employed in aquaponics, where fish waste provides nutrients to the plants in a symbiotic system.

• Capillary action technique

The Capillary Action Technique, often referred to as capillary matting or capillary watering, is a method used in horticulture and gardening to provide a consistent and controlled water supply to plants. This technique takes advantage of capillary action, which is the ability of a liquid to flow in narrow spaces without the assistance of, or against, external forces such as gravity.

1. Materials:

   • Capillary matting or capillary wicks are commonly used. These materials have a high capacity for water absorption and can transport water through capillary action.

2. Setup:

   • A capillary mat or wick is placed in contact with the growing medium or soil of potted plants. One end of the mat is usually immersed in a water reservoir, while the other end is in contact with the soil or growing medium.

3. Capillary Action:

   • Water moves through the capillary mat from the reservoir to the soil or growing medium due to capillary action.
   • The matting transports water efficiently, ensuring that the soil remains consistently moist.

4. Advantages:

   • Consistent Watering: Capillary action provides a continuous and uniform supply of water to the plants.
   • Reduced Watering Frequency: This technique can reduce the frequency of manual watering, making it particularly useful in situations where consistent moisture is essential.

5. Applicability:

   • Capillary action is often employed in greenhouse settings, nurseries, and indoor gardening situations.
   • It is suitable for a variety of container plants, including potted flowers, herbs, and vegetables.

6. Considerations:

   • The water reservoir needs to be periodically refilled to ensure a continuous water supply.
   • It's important to monitor moisture levels to prevent overwatering or underwatering.

The Capillary Action Technique is an effective and low-maintenance method for providing water to plants, especially in situations where regular attention to watering may be challenging. It is commonly used in professional horticulture settings and can be adapted for use in home gardens or indoor plant care.

2. Solid media culture (Aggregate systems)

• Hanging bag technique

• Grow bag technique

The "Grow Bag Technique" typically refers to a method of container gardening where plants are grown in bags filled with a suitable growing medium. This technique is commonly used for growing various crops, including vegetables, herbs, and flowers. Here's an overview of the grow bag technique:

1. Container Bags:

   • Grow bags are typically made of lightweight and breathable materials such as fabric or plastic.
   • Fabric grow bags are popular because they allow for good aeration and drainage, preventing issues like overwatering and promoting healthy root development.

2. Growing Medium:

   • The grow bags are filled with a well-balanced and nutrient-rich growing medium. Common growing mediums include a mix of peat, coir, perlite, vermiculite, and other organic materials.
   • The choice of growing medium depends on the specific requirements of the plants being grown.

3. Planting:

   • Seeds or seedlings are planted directly into the grow bags. The number of plants per bag depends on the type of crop and its space requirements.

4. Watering and Fertilization:

   • Grow bags require regular watering, and the frequency may vary depending on the climate, plant type, and growing medium.
   • Fertilizers can be added to the growing medium or applied as needed, depending on the nutritional requirements of the plants.

5. Advantages of the Grow Bag Technique:

   • Portability: Grow bags are lightweight and easy to move, making them suitable for patios, balconies, or small gardens.
   • Aeration: Fabric grow bags provide good aeration to the roots, preventing issues like root circling and promoting a healthier root system.
   • Space Efficiency: Grow bags can be arranged closely together, maximizing the use of available space.
   • Less Soil-Borne Diseases: Since grow bags use a controlled growing medium, the risk of soil-borne diseases is reduced.

6. Common Crops:

   • Grow bags are suitable for a wide range of crops, including tomatoes, peppers, herbs, flowers, and more.

7. Disposal and Reuse:

   • At the end of the growing season, the growing medium can be emptied from the bags, and the bags can be folded for easy storage. Some growers choose to reuse the bags in subsequent growing seasons.

The grow bag technique is popular among home gardeners, especially those with limited space or challenging soil conditions. It provides a flexible and portable solution for cultivating plants in a controlled environment.

• Trench or trough technique

The "Trench or Trough Technique" typically refers to a method of cultivation where crops are planted in elongated, shallow depressions or trenches in the soil. This technique is commonly used in agriculture for various crops, and it can offer specific advantages in terms of water management, root development, and overall crop health.

1. Trench Preparation:

   • Trenches are dug into the soil, creating elongated furrows or depressions where crops will be planted.
   • The depth and width of the trenches can vary depending on the specific crop requirements and local growing conditions.

2. Planting:

   • Seeds or seedlings are planted along the bottom of the trench. The distance between plants and rows is typically determined by the specific crop's recommended spacing.

3. Water Management:

   • Trenches can help manage water efficiently. Rainwater or irrigation water tends to collect in the depressions, providing a consistent water source for the plants.
   • In arid regions, trenches can be used to capture and retain rainwater, promoting more efficient water use.

4. Root Development:

   • Trenches allow for improved root development as plant roots have more space to spread out horizontally.
   • Deeper root systems can help plants access nutrients and moisture more effectively, contributing to overall plant health and resilience.

5. Soil Aeration:

   • The loose soil in the trench provides good aeration to the roots, preventing issues such as waterlogging and promoting oxygen uptake.

6. Advantages:

   • Water Efficiency: Trenches can help conserve water by directing and retaining water where it's needed.
   • Root Development: The elongated shape of the trenches encourages lateral root growth.
   • Soil Aeration: Loose soil in the trenches facilitates better aeration, supporting healthy root systems.

7. Crop Rotation:

   • Trenches can be adapted for crop rotation, allowing farmers to plant different crops in different seasons.

8. Crop Types:

   • The trench or trough technique can be applied to a variety of crops, including vegetables, grains, and even some fruits.

This technique is particularly relevant in regions with specific water management challenges or where the topography of the land is conducive to trenching. It can be an effective and practical method for optimizing water use and promoting healthy crop growth.

• Pot technique

3. Aeroponics

This method involves suspending plant roots in air and periodically misting them with a nutrient-rich solution. The roots are exposed to both air and the nutrient mist.

• Root mist technique

• Fog feed technique

Benefits of Soil-less Culture/ Hydroponics Culture 

• Water usage is greatly reduced. The water that comes out of this is recirculated and used again for the plants.
• Plants thrive when water is mixed with the nutrients they need.
• There is no disease caused by flying insects when grown in green houses. Organic farming can be done without pesticides and chemicals.
• It does not need to be watered separately. Easy to maintain. No large space required. 
• Chemical free vegetables can be produced multiple times in less space.
• No workers are required.
• Cost of production is very low compared to other farming methods
• This method does not require weeding in agriculture.
• It can be harvested very quickly in less days.
• All types of vegetables and fruits can be cultivated throughout the year.