DRIP IRRIGATION FOR POTTED PLANTS

CULTIVATION CLASSIFICATION

In the horticultural sector, both seed plants and those derived from rooted cuttings are bred and marketed in containers, commonly called pots, in order to facilitate their handling, movement and mechanisation during the different phenological phases.

Species of interest may be herbaceous plants and flowering or fruit trees, mainly for ornamental purposes but also for commercial-productive purposes.

AGRONOMIC ASPECTS

Potting often involves special conditions that alter the correct growth process of plants, first and foremost the small area available to the roots, which often leads to water and nutritional imbalances. An important aspect in the potted plant sector is also linked to the cultivation substrate, which is the medium (natural or artificial) in which the root system of the plant develops and from which it absorbs water and mineral elements. Thus, the main two aspects for sizing and choosing the most correct type of irrigation system depend not only on the
species under consideration, but also and above all on the size of the pot and the physical characteristics of the cultivation substrate.

It is very important to know, for example, its water retention capacity, a parameter on which the saturation and drainage times of the pot itself depend: small pots tend to reach saturation sooner (risking becoming asphyxiated) than larger ones, which instead enjoy faster drainage. The water retention capacity must be such to ensure that the substrate moisture levels are consistent and optimal for the crops, without the need for overly frequent irrigation; it must not be too large in order to prevent root asphyxia and cooling of the culture medium.

IRRIGATION SYSTEM FOR POTTED PLANTS

Irritec offers different solutions for irrigation of potted crops. The Capillar System™ localised irrigation system, for example, designed by Irritec for the nursery, floral and protected crops sectors, consists of a polyethylene tube and a capillary: The water is conveyed into the cultivation vessels via a rod inserted at the end of the capillary.

The tube, made in diameters of 16 mm, 20 mm, and 25 mm, is drilled to the required spacing; the capillary, with a diameter of 3.2 mm, is inserted into the tube, and at the end of the capillary the rod is inserted, which is placed in the soil near the plant.

The laminar flow generated by the extremely fine diameter of the capillary allows a constant flow rate to be achieved, relative to the length of the capillary and the operating pressure.

It is a reliable and economical irrigation system. For soilless cultivation, Irritec recommends the on-line self-compensating drip heads with Drop Stop technology, which are capable of interrupting the flow at the end of the irrigation cycle, avoiding the emptying of the line and standardising the time and volume of supply for each plant.

The best solution is the pre-assembled kit (K-Drop System) which includes iDrop line drip heads and related accessories (manifold, micro tubes/capillary tubes and rods): the kit is offered pre-assembled with standard or modular sizes (choosing manifold and dipstick) according to the specific farming needs.

For cultivations under protective coverings Irritec also recommends polyethylene tubing (for the laterals), microtubes and white coloured rods, to reduce overheating of the nutrient solution and water supplied.

New from Irritec is iCircle, an ideal solution for irrigation of potted crops as it allows the flow rate delivered by an iDrop model drip head to be evenly distributed at 8 different drip points within the cultivation pot. The more uniform distribution of water and nutrients promotes homogeneous wetting of the cultivation medium and thus better development of the root system. iCircle is simple to install and easy to remove at the end of the growing cycle.

FILTRATION

Regardless of the type of distributor chosen, it is important to consider an efficient upstream filtration system, ensuring high performance across the entire irrigation system in the short and long term; selecting the most suitable filter depends on the source of the water supply: the type of filter will therefore be different if the water comes from a well, lake, reservoir, consortium, etc.

FERTIGATION, AUTOMATION AND SENSORS

In order to maximise the use of water and nutrient resources in potted crops, it is important to apply short and frequent irrigation shifts that allow the substrate to be kept moist at all times, and not to subject plants to water and nutritional stress.

This also achieves the goal of reducing the drainage from the pot and thus the leaching of water and nutrients as much as possible.

In this respect, Irritec recommends the use of highly professional fertigation benches such as the Shaker SET that allows the injection of up to 4 fertilisers + 1 acid into the pipeline at pH and EC targets, offering the possibility of being able to set multiple fertigation recipes and activate one or more irrigation programs according to ambient temperature demands or solar radiation by equipping the system with the related probes.

In addition, the use of sensors that are able to provide information on the state of humidity, temperature and electrical conductivity of the substrate is considered very useful.