HYDROPONICS III BHT319

Take your Hydroponics Knowledge to the Next Level

Learn How to Manage Hydroponic Systems 

Gain more knowledge in hydroponic management by building on the knowledge you already have; this course has been developed to complement Hydroponics I and II, it is intended for people who already have some experience and understanding of hydroponics.
Study the Management of Hydroponic Systems
 
This course has been developed to complement Hydroponics I and II; and is intended for people who already have some experience and understanding of hydroponics.
  • Start any time, study at your own pace
  • 100 hour course
  • Access to a team of qualified horticulturists and internationally distinguished hydroponic experts 
 
Course Content and Structure
There are eight lessons in this course as follows:

1. Options for Managing Plant Culture - different approaches to cultural operations in hydroponics. Organics vs. hydroponics:Nutrient differences in food products. Is hydroponic food more or less healthy than organic? How feasible is organic hydroponics?

2. Planning a Hydroponic Operation - site and crop selection; matching a system with a crop, materials, resources & services required.

3. System Design Components - pumps, hardware, media, pipes, size, type, and so forth. Components for different types of culture.

4. Managing a Hydroponic System in Hot, Humid Conditions - tropical and subtropical climates or summer in temperate areas.

5. Water Management - water quality measures, treatments, run-off testing, purifying water, water in recirculating and run-to-waste systems.

6. Nutrient Formulation - standard formulations, detecting toxicities & deficiencies.

7. Controlling Nutrient Levels - using EC and pH measures of concentration levels, solution temperatures, and maintaining nutrient levels.

8.Pest & Disease Control - nutrient and pH manipulation for control of pests & diseases, integrated pest management, common pests and diseases.

Aims

  • Describe different approaches to cultural operations
  • Demonstrate an awareness of similarities and differences between organic and hydroponic production techniques
  • Describe how to plan a hydroponic operation through site and crop selection, matching a specific crop, materials, resources and services required, and site layout; for different specific crops.
  • Discuss system design components such as pumps, grow beds, solution tanks, media and pipes in terms of size, type, and options for different cultures and specific crops.
  • Provide details of how to manage a hydroponic system in hot, humid conditions such as in tropical or subtropical areas, or in summer, in temperate areas, for specific crops.
  • Explain options for water management such as water sources, quality, testing, treatments, and use in recirculating and non recirculating systems.
  • Recommend awareness of natural and other methods of pest and disease control such as biological controls, as part of IPM and nutrient and pH manipulation for different pests and diseases.
  • Explain and recommend different standards of nutrient formulation, and advanced methods of detecting toxicities and deficiencies in specific crops.
  • Recommend methods to control nutrient level concentrations by taking EC, pH and temperature measurements, and maintaining nutrient levels for different specific crop


MANAGING A HYDROPONICS OPERATION IN HOT, HUMID CONDITIONS

In tropical and subtropical regions the summer temperatures can be quite excessive and prolonged. Spring and summer is also the wet season when plentiful rainfall causes high humidity levels. Although the days are longer during the wet season compared to the dry season (autumn and winter), there is little variation in the number of hours of sunlight. This is because the extra rainfall during the wet season is in short and intense spells. The clouds clear up very quickly afterwards to reveal sunny blue skies. Therefore, the stage of plant growth has more impact on nutrient solutions than sunlight in these climates.

Many of the countries in these regions around the world are developed countries where the inhabitants demand food crops which are ideally suited for growth in temperate regions. Other problems faced by agriculturists in these regions include the fact that land in valleys, which has traditionally been developed to grow crops due to the richer supply of water, is often polluted by runoff from neighbouring towns and so crop diseases can become widespread. Warmer temperatures all year long also boost insect pest populations. Pests can also be a big problem in outdoors hydroponics systems.

In temperate climates, hotter and longer summers coupled with intermittent rain and an already moister atmosphere, can also cause problems for growing outdoor temperate climate crops. In hydroponics systems, diseases in water can be controlled by applying appropriate treatments to the nutrient solution and through using filtration techniques.

 

WATER

In tropical and subtropical climates there is considerably more rainfall during the wet season than the dry season. In some regions, this makes growing crops impossible because there is simply too much water. Conversely, the rainfall during the dry season can be so low that the only way to grow crops is to do it during the dry season using irrigation.

These conditions mean that there is a shortage of certain crops at certain times of the year and so pave the way for hydroponic growers to fill the void.

As outlined in lesson 2, plants require a steady supply of water so that their moisture content does not drop to fatal levels. In tropical and subtropical regions there may not be sufficient surface water available, but sufficient underground water may be present. This can be extracted using bore holes. If it is not known whether underground water exists then a resistivity meter can be used to test for its presence.

On sites located close to large populations and industry, the quality of underground water will need to be tested for purity. Contaminated water cannot be used unless it is treated and purified before use.

 

CHILLING

Another problem in hot climates is that the temperature of water in the storage tanks may become too high, especially if they are not insulated or located underground. Even the solution passing through the system can become too warm.

In pioneering research, Dr. Atomic Leow (1993) used a thin film of chilled nutrient solution and chilled nutrient mists to successfully grow temperate climate vegetables in the topics. He used aeroponics and NFT to grow strawberries, cabbages and lettuces, as well as flowers such as tulips and carnations. Others have grown iceberg and butterhead lettuce using this technology.

In an advancement Dr Leow invented a chilling system that could significantly reduce power usage and costs and be easily introduced into different types of hydroponics systems. Water coolers or chilling units are also used in aquariums. They help to keep the water in the desired range of 21-23°C. This helps to prevent bolting (rapid growth and production of seed without producing much vegetative and root growth) of crops such as lettuce. In fact, chilling the water can enable some temperate climate crops to be grown in tropical and subtropical climates even when the ambient temperatures exceed the optimal growing conditions, since root temperatures are more important for growth.

Some plants are more sensitive to root chilling than others, and it is better to consult data with regards to which crops are more or less sensitive before using this technique on a large scale. Trial and error using small numbers of crops is also useful. Over-chilling can affect root and plant development by inhibiting the uptake of water and nutrients, particularly in those plants which are most sensitive. It can also damage plant cells and interfere with normal stomatal operation; often inducing excess water loss through the stomata and ultimately wilting and death.

 

HUMIDITY & TEMPERATURE

Temperate climate crops cannot tolerate high humidity levels and temperatures, so in order to grow them outdoors in tropical and subtropical regions it is necessary to seek out areas where humidity and temperatures are lower. Usually, this means choosing sites in mountainous regions. Even in these areas, the daytime and night time temperatures are likely to be at the optimum level for temperate climate plants.

During a heatwave, or a long spell above the usual temperatures, plants may die and whole crops fail. The higher the altitude, the less the risk that crops will fail due to fluctuations in temperature.

However, higher altitude can often mean steeper sites. Such steep locations are less favourable for traditional agriculture methods since there is a greater degree of soil erosion and the fertility of the soil is quickly depleted with successive cultivations. Also, soils may have high salt levels. In addition, these sites are not easy to navigate with machinery and so generally require more labour than flat sites.

In these environments, hydroponics may be a better choice. Certainly, if the soil is infertile there may be no other option. Steep sites can be terraced if necessary to enable the establishment of equipment and grow beds. However, it may prove problematic finding enough skilled staff to work in such a venture. It may also be necessary to store spare parts, nutrients, and equipment on site since deliveries may be slower. In developing countries this may be a necessity since most parts might have to be imported.

Another option in hot, humid environments is to grow seedlings in hydroponic propagation systems, such as in cubes of coir, and then plant them out into open fields of soil. This way, they have a greater chance of survival since in soil culture many seeds are killed by soil-borne disease before they have a chance to germinate. Nevertheless, this would still prove unviable in areas of extreme heat and humidity.

In temperate climates, hydroponic growers have used other methods to reduce the chance of plants bolting from long days of hot temperatures. These include planting crops in wide rows with dense plantings to keep the root systems cooler. However, less ventilation between the plants can lead to increased humidity and the spread of fungal diseases. Perhaps a better solution is to plant the crops later so that there is less risk of a cold snap followed by hot weather which may stimulate bolting of plants.

In tropical and subtropical climates, evaporative cooling techniques can be used within greenhouse environments to reduce excessive temperatures making it possible to grow temperate climate crops. For example, misting will reduce temperatures - but again, moisture on leaves can trigger fungal infestations or sun scorch. Another method, the fan-and-pad technique involves pumping water via pipes over porous pads from one end of the greenhouse and exhaust fans at the opposite end.

 

HOW CAN THIS COURSE HELP MY CAREER?

This course has been designed for those who have a sound background or knowledge of general hydroponics - you may have studied Hydroponics 1 and 11 with ACS or you may have worked in the field for some time. If you want to take your career to the next level then learning about the management of hydroponic systems is definitely the next learning step to undertake.It will help in career advancement or help you to further your hydroponics business pursuits.