The application of nutrients through irrigation systems is called "fertigation," a contraction of fertilization and irrigation. The most common nutrient applied by fertigation is nitrogen.
Elements applied less often include phosphorus, potassium, sulfur, zinc and iron.This technique can reduce fertilizer application costs by eliminating high operational requirement. It may also improve nutrient efficiency by applying them closer to when the plant needs them. Also, it could conceivably reduce leaching or denitrification (gaseous) losses of nitrogen and lower the luxury uptake of nutrients by plants.
The first reported application of commercial fertilizer through a sprinkler irrigation system was in 1958.Today, we routinely inject fertilizer solutions and suspensions into irrigation systems via calibrated injection pumps that insure precision over both space and time. Fertigation has increased dramatically in the past 15 years, particularly for sprinkler and drip systems.
Fertigation system was designed and installed to supply optimum water containing nutrients directly to vegetable root inside Naturally Ventilated Crop Protection Structure. The system is an integration of irrigation controller, nutrient tank, electrical water pump, filter, gate valve, pressure meter, connectors, high density polyethylene distribution pipes ( main, secondary and tertiary ), adapters, dripper nozzles and stop ends.
A controller is an integral part of an irrigation system. It is an essential tool to apply water in the necessary quantity and at the right time to sustain agricultural production and to achieve high levels of efficiency in water, energy and chemical uses. Irrigation controllers have been available for many years in the form of mechanical and electromechanical irrigation timers. These devices have evolved into complex computer-based systems that allow accurate control of water, energy and chemicals while responding to environmental changes and development stages of the crop.
Fertilizer can be provided in different frequencies--daily, every other day, several times each week, or weekly, depending on irrigation needs, soil type, and other factors. Normally, it requires 5 times a day. Don't hesitate to irrigate if irrigation is needed other than during the normal schedule.
This is the heart of fertigation. This is where the fertilizer are kept, measurement of EC and pH are made. The size of the tank will depend on the number of polibegs. The nutrient can either be irrigate to the field either using the pump or by gravity
This technology required a pump to irrigate the fertilizer from the nutrient tank up the polibeg.
Naturally, the system will clogged over time if the water supply to the field is not clean. Filters are required to avoid the dripper from clogging hence will obstruct the flow to the plant. The filter need to be inspected and cleaned frequently
The pipe mainly consists of 3 major elements:1. Main lineThe main line is size depend on the size and location2. Sub lineThe sub line are located along each row of polibegs. This is where a micro dripper line will be installed to ensure the fertilizer reached it location
3. DripperThis is where the quantity of fertilizer are controlled. Normally it will dripped at the rate 2 liters/hours. The tendency to clog at the tip are very high so frequent check and cleaning of the dripper are required.
Polibeg is filled up with cocoa peat. This will be the medium where the plant are feed with the fertilizer. A good media will hold the moisture and water content at 60%
5 Major Elements:
There are 5 major element to monitor during the crop cycles.
a. Flushing of mediaCoco peat was added and compacted in the polibegs known as growth media. The growth media must flushed before adding with the coco peat.
b. Polibegs arrangementOnce the media in the polibegs, it is can be arranged. It is best to arrange the dripper and the microtubes at one side for ease for maintenance and inspection. The space between polibegs must be right to avoid overcrowded and ensure adequate light are equally distributed among the polibegs.
c. SeedingThe seed are cultivated using trays. Prior to seeding, the seed are treated to ensure healthy growth of the plant. Depends on the types of vegetables, normally it will stay in the tray from 10 days to 2 weeks. Ensure you only use high quality F1 seed only.
d. Tree trainingAs the plant grows, the tree are need to be trained to ensure the fruits/vegetables are easily harvested and strong. The tree training will also provide high quality vegetables. It can be done by using ropes or net. Some of other activities includes cutting, spraying, pest control and monitor pH and EC level.
e. HarvestThis is the best time of the year. The harvest time will affect the fruit gred standard and market price. The harvest are done manual to ensure the fruits are not damaged.
CommercialFertigation method allowed high yields compare to traditional method. Below are some of the comparison:Vegetable Fertigation (Tonne/ha) Traditional Yield (Tonne/ha)
Onion 9.5 2.8
Broccoli 5.7 3.0
Chilli 30 10
Bell Pepper 24 6
Shallot 33.9 27.6
Cabbage 38 16.1
Cauliflower 12 2.9
Rock Melon 30 10
Tomato 120 35.3
Celery 11.2 6.7