Fertigation system in micro irrigation
presentation on :-
Subject: -
Micro irrigation system design
Presented by: -BARIA DIPAK ( PAGEN-091-2012 )
KAUSHAL .V. GADARIYA (PAGEN-097-2012)
CHETAN CHAUHAN (PAGEN-092-2012)
CONTENTS• INTRODUCTION
• ADVANTAGES AND DISADVANTAGES OF FERTIGATION
• OBJECTIVES OF FERTIGATION IN MICROIRRIGATION
• DOSIFICATION
• FERTILIZER INJECTION METHODS
- PRESSURE DIFFERENTIAL
- VACUUM INJECTION
- PUMP INJECTION
INTRODUCTION
Fertigation is a process in which fertilizer is dissolved, diluted and
distributed along with water in your drip or sprinkler irrigation
system.
Or, in other word, fertigation is the process of application of water
soluble solid fertilizer or liquid fertilizers through micro irrigation
system.
Fertigation advantages and limitations
• Advantages- Relatively uniform fertilizer applications- Flexibility in timing of application- Less fertilizers used- Reduced costs
• Disadvantages- Potential contamination hazard from equipment malfunctions- Backflow prevention devices required- Careful handling of liquid fertilizer required
Objectives of fertigation in micro irrigation
• Maximize profit by applying the right amount of water and
fertilizer.
• Minimize adverse environmental effects by reducing leaching
of fertilizers and other chemicals below the root zone.
Dosification
There are two types of fertigation, the type of fertigation chosen
depends on the crop grown, the soil type and the farm
management system.
- Quantitative fertigation
- Proportional fertigation
Quantitative fertigation• It is the application of the plant nutrients in predetermined
concentrations to the irrigation system.
• The fertilizer is applied in a pulse after a certain water sheetwithout fertilizer using a fertilizer tank.
• The advantages of this method are the low cost and the lowrequired maintenance.
• Disadvantages
- the system is affected by water pressure changes
- the concentration of the fertilizer varies during its applicationand it does not adapt to work with automation.
Proportional fertigation• the nutrients are is applied in a constant and proportional ratio to
the water sheet, so that the irrigation water takes a fixedconcentration of the applied fertilizer.
• In this case the fertilizers are applied by direct injection throughfertilizer pumps.
• Advantages
- precise control of the dosification and the injection moment, isnot affected by the water pressure changes, and it can be easilyautomated.
• Disadvantages
- high cost and maintenance and complicated operation.
Fertilizer injection method
• Modern fertigation equipment should be able to regulate:
- quantity applied
- duration of applications
- proportion of fertilizers
- starting and finishing time
• It is important to select an injection method that best suits the irrigation system and the crop to be grown.
• Each fertilizer injector is designed for a specified pressure and flow range.
1. Pressure differential (by-pass tank)
• This system works on the principle of apressure differential created by valve,pressure regulation, pipe friction in themainline.
• The pressure difference forces the waterto enter through a by-pass pipe into apressure tank which contains thefertilizer, and to go out again, carrying avarying amount of dissolved fertilizer.
• The application of nutrients is quantitative and inaccurate,
therefore is adapted for perennial crops like citrus, fruit
trees and/or crops grown on heavy soil.
Advantages:
• Very simple to operate, the stock solution does have not to be pre-mixed
• Easy to install and requires very little maintenance
• Easy to change fertilizers
• Ideal for dry formulations
• No electricity or fuel is needed
Disadvantages:
• Concentration of solution decreases as fertilizer dissolves
• Accuracy of application is limited
• Requires pressure loss in main irrigation line or a booster pump
• Proportional fertigation is not possible
• Limited capacity
• Not adapted for automation
• Inlet valve
2. Vacuum injection (Venturi)
• This method uses a venturi device to cause a reducedpressure (vacuum) that sucks the fertilizer solution intothe line.
Advantages:
• Very simple to operate, no moving parts
• Easy to install and to maintain
• Suitable for very low injection rates
• Injection can be controlled with a metering valve
• Suitable for both proportional and quantitative fertilization
Disadvantages:
• Requires pressure loss in main irrigation line or a booster pump
• Quantitative fertigation is difficult
• Automation is difficult.
3. Pump injection
• Pumps are used to inject thefertilizer solution from asupply tank into the line.Injection energy is provided byelectric motors, hydraulicmotors (diaphragm andpiston).
Advantages:
• Very accurate, for proportional fertigation
• No pressure loss in the line
• Easily adapted for automation
Disadvantages:
• Expensive
• Complicated design, including a number of moving parts, so wear andbreakdown are more likely