Unit 3 - Hi-Tech Horticulture
Syllabus: Micro irrigation systems and their components; EC, pH-based fertilizer scheduling.
Micro irrigation systems and their components
Micro-irrigation: Micro-irrigation is the slow application of Continuous drips, tiny streams or miniature sprays of water above or below the soil surface.
Micro irrigation is a type of irrigation system that delivers water to plants in small, controlled amounts through a network of pipes, tubing, and emitters.
The main advantage of micro irrigation is that it delivers water more precisely to plants, reducing water loss due to evaporation or runoff. This is particularly important in areas where water is scarce or expensive. Micro irrigation systems can also be used to apply fertilizers or other chemicals directly to the root zone of plants, reducing waste and environmental pollution.
There are two main types of micro irrigation systems: drip irrigation and micro-sprinklers.
- Drip irrigation is a type of micro-irrigation system that delivers water directly to the roots of plants through small, low-pressure emitters. The water is delivered slowly and steadily, which allows for efficient use of water and reduces water waste due to evaporation and runoff. Drip irrigation systems are typically installed underground or above ground, and the emitters are spaced out along the drip lines to ensure the even distribution of water to each plant. Drip irrigation systems can be used for a wide range of crops and can be adjusted to deliver varying amounts of water based on the needs of the crop. Types:- Surface, Subsurface, family, inline, online.
- Micro-sprinklers, on the other hand, are another type of micro-irrigation system that delivers water through small, low-pressure sprinklers that are typically installed above ground. The water is sprayed out in a fine mist or spray pattern, which allows for more even distribution of water over a larger area than drip irrigation. Micro-sprinklers are typically used for larger crops that require more water, such as fruit trees and vineyards. They can also be used to provide frost protection by applying water during periods of cold weather, which can help prevent damage to crops. Types:- centre pivot, rain gun 🔫, impact sprinkler, pop-up sprinkler etc.
- Bubbler irrigation: In this system water is applied to the soil surface in a small stream or fountain. Bubbler are used to irrigate bigger areas and apply water on 'per plant' basis.
- Spray irrigation: In this system, jets, foggers or misters also called as spitters are used. Water is applied to a fraction of the ground surface. Instead of dripping water from narrow orifice emitters, micro-sprayer system efjects fine jet that fan out from of nozzles. a series.
Both drip irrigation and micro-sprinklers have their advantages and disadvantages, and the choice of which system to use will depend on the specific needs of the crop and the conditions of the environment in which it is grown. However, in general, micro-irrigation systems like drip irrigation and micro-sprinklers are more efficient and effective than traditional irrigation systems, and they are an important tool for hi-tech horticulture to optimize water use and crop productivity.
Micro irrigation systems can be designed to be either above ground or below ground. Above-ground systems are typically more affordable and easier to install, but they are also more susceptible to damage from the environment, animals, or human activity. Below-ground systems are more expensive and require more planning and installation, but they are less vulnerable to damage and can be more aesthetically pleasing.
Overall, micro irrigation systems offer a more efficient and sustainable method of delivering water to plants, reducing waste and improving crop yields. They are particularly useful in arid and semi-arid regions, where water resources are limited, but can also be used in a variety of other agricultural and horticultural settings.
Components
The following are the essential components of a micro-irrigation system:
- Water source: A reliable water source is necessary for an irrigation system. The water source can be a well, borehole, dam, or municipal water supply.
- Pumping system: A pump is required to lift water from the source and deliver it to the irrigation system. Pumps can be electric, diesel, or solar-powered, depending on the availability of energy sources.
- Filters: Filters are used to remove impurities such as sand, debris, and algae from the water before it is delivered to the irrigation system. Filters can be sand, screen, or disc filters, depending on the water quality.
- Mainline: The mainline is the primary pipe that carries water from the pumping system to the irrigation system. The size of the mainline depends on the flow rate required and the distance between the pump and the irrigation system.
- Submain: The submain is a secondary pipe that distributes water from the mainline to the lateral lines. The size of the submain depends on the flow rate required and the distance between the mainline and the lateral lines.
- Lateral lines: Lateral lines are small-diameter pipes that deliver water to the plants. These pipes are fitted with emitters or drippers, which release water and nutrients directly to the root zone of the plants.
- Emitters or drippers: Emitters or drippers are devices that control the flow rate of water and nutrients to plants. These devices can be pressure-compensating or non-pressure-compensating, depending on the water pressure and the topography of the field.
- Fittings and accessories: Fittings and accessories are used to connect and secure pipes, emitters, and other components of the irrigation system. These include connectors, tees, elbows, couplers, valves, and pressure regulators. All of these components work together to provide a reliable and efficient irrigation system for modern horticulture practices.
EC
In the context of hi-tech horticulture, EC refers to Electrical Conductivity, which is a measure of the ability of a substance to conduct an electrical current. In the field of agriculture, EC is commonly used as a measure of the salt concentration in soil or irrigation water.
In soil, EC can be used as an indicator of nutrient availability, soil structure, and salinity levels. High EC levels in soil can indicate a build-up of salts, which can lead to reduced plant growth and yield. However, some crops are adapted to high salt environments and can tolerate higher EC levels.
In irrigation water, EC can also be used to measure the salt content. High EC levels in irrigation water can have a negative impact on plant growth and yield, as well as increase the risk of soil salinization over time. Therefore, it is important to monitor EC levels in irrigation water and adjust management practices accordingly, such as by using reverse osmosis to remove excess salts from the water or by selecting crops that are better adapted to high salinity conditions.
EC is commonly measured using a handheld EC meter, which works by passing a small electrical current through a sample of soil or water and measuring the resistance. The EC value is then converted to an estimate of the salt concentration in the sample.
Maintaining the correct EC level is important because:
1. It ensures that the plants receive the correct amount of nutrients: If the EC is too low, the plants may not receive enough nutrients, which can lead to stunted growth and poor yields. If the EC is too high, the plants may receive too many nutrients, which can lead to fertilizer burn and other problems.
2. It helps prevent nutrient imbalances: An imbalanced nutrient solution can cause nutrient deficiencies or toxicities, which can negatively impact plant growth and health. Monitoring and adjusting EC helps ensure that the nutrient solution is properly balanced.
3. It helps prevent salt buildup: Over time, salts can accumulate in the growing medium and cause problems for plant growth. By monitoring and adjusting EC, growers can prevent salt buildup and ensure that the growing medium remains healthy.
Overall, maintaining the correct EC level is essential for the success of hi-tech horticulture, and it requires careful monitoring and management of the nutrient solution.
pH-based fertilizer scheduling
pH-based fertilizer scheduling is a technique used in hi-tech horticulture to optimize the nutrient uptake by plants based on the pH level of the soil. The technique involves the measurement of pH levels in the soil and the application of fertilizers accordingly.
The pH level of the soil determines the availability of different nutrients to the plants. For example, when the soil pH is acidic, the availability of some essential nutrients such as phosphorus, calcium, and magnesium decreases. Similarly, in alkaline soil, the availability of other nutrients such as iron, manganese, and copper decreases. Therefore, it is important to adjust the pH level of the soil to ensure that plants can access all necessary nutrients for growth and development.
Fertilizer scheduling based on pH involves adjusting the pH level of the soil to a specific range that is optimal for the plant's growth and development. This is achieved by the application of soil amendments such as lime or sulfur. Once the pH level of the soil is within the optimal range, fertilizers are applied based on the plant's nutrient requirements and the pH level of the soil.
For example, if the pH level of the soil is low (acidic), lime is applied to raise the pH level and improve the availability of nutrients such as phosphorus, calcium, and magnesium. Once the pH level is adjusted, fertilizers are applied based on the plant's nutrient requirements and the pH level of the soil.
By using pH-based fertilizer scheduling, farmers can optimize the nutrient uptake by the plant, reduce fertilizer waste, and improve the efficiency of the fertilization process. Additionally, this technique can help in reducing the risk of nutrient leaching and contamination of groundwater. Overall, pH-based fertilizer scheduling is a sustainable and effective technique in hi-tech horticulture for managing plant nutrition.