For plant production the availability of good water is of vital importance
This article was published first in The Indian Nursery Association
A plant exists for more than 90% out of water; the rest is organic and inorganic material. This is partly made by the plant itself and partly taken up from the environment. As you probably know, a plant creates organic material such as sugars, carbohydrates and proteins from H2O (water) and CO2 (Carbon dioxide). This is done in the green parts of the plant and is directly influenced by temperature and light. So, no water means no growth.
All aspects of water
During my visits to growers all around the world I usually raise the following questions related to influencing the plant production:
The first question What is the quality of the water?
And related to this: What is the EC level (conductivity or salt content)? What is the pH, (acidity level)? And how much buffer capacity (bicarbonate HCO3) is in the water?
These levels need to be adjusted to make a controlled and balanced fertilizer schedule.
The second question: What about the hygiene level of the used water?
Water can contain quite a lot of biological contamination as algae, or - even worse - bacteria and fungi spores. The water can transport this quickly through the whole production area. Therefore, sanitation and disinfection are a must. Especially when we go to recirculation.
The third question: What is the consistency of the available water, and how can this be controlled?
When you as a grower are uncertain of the consistency of available water, think of the best alternatives for your production. What is affordable? In some highly developed markets, an investment in reverse osmosis is within reach, but this is certainly feasible for all markets.
The final questions: Are we sure we have no dangerous elements in the water? Here you can think of too much Chlorine, Sodium or too high levels of Iron and Zinc?
My conclusion: A grower must know all the relevant aspects of water quality before he starts a production. Based on this info we can calculate the best recipe for the fertilization of our crops. This is the basis for plant quality. Especially now chemical treatments become more and more difficult, we have to focus on plant health, using the right water quality, and the adjusted fertilization.
Water: a secret of success
The quality of your water can make a big difference to the quality of your production. It has an impact on fertilizer optimization and plant growth. It seems obvious but many growers underestimate how important water quality is to plant growth. That is why we recommend all growers to have their water supply analyzed. There is a huge difference between rainwater, bore hole water, tap water, ditch or canal water and recirculated water. When water quality is out of balance, or contains unknown elements, it can cause major negative effects on plant quality. Therefore, I offer three practical tips to Indian growers.
Three practical tips
- Know the quality of your water source by analysing it on all relevant elements. This requires help from a specialized laboratory but is quick and inexpensive. This is a list of elements which need to be analysed: pH, EC, NH4, NO3, P, K, Ca, Mg, SO4, HCO3, Na, Cl, Fe, Mn, Zn, B, Cu, Mo.
Influence of pH on availability of elements in the substrate
- Be sure the quality is consistent and controllable.
- If water quality cannot be guaranteed, find a reliable local alternative.
By ensuring good water quality, growers can expect higher quality plants; the balance of elements in the fertilizer is optimized and other plant health issues are avoided, such as when elements like chlorine or sodium are present or when water pH varies. To give your plants the best chances of success, give them only good clean water.
Water: storage, disinfection and recirculation
More and more the Indian horticultural sector, like in other parts of the world, must deal with reduced water supply and implementation of regulations to reduce environmental impacts. For that, growers have to reduce water use and loss of nutrients and residues of chemicals to natural water bodies. That’s why growers have to recycle more used water if possible, and to protect against diseases, the water needs to be disinfected and stored in a controlled system. That is own storage equipment in outdoor basins or, even better, in indoor tanks.
Discuss with a specialist company which techniques are required in the specific situation, because there are several options. Water from different sources can have different treatment requirements. As there are for instance: 1) adjusting pH and/or chemical composition, 2) particle and algae removal, and after recirculation 3) disinfection. Of course, we should recirculate nutrient solutions as well.
Water: Solving water quality issues
If you find a problem with your water quality, you will need specialist support to correct it. What are the two most common quality issues and how should they be addressed? The first step is to identify the problem correctly. Knowing the real cause of the problem is the only way to find the best solution. Sometimes the process is simple but at other times it can be challenging.
Here are the two most common problems and their solutions:
High alkaline (pH) or Electrical Conductivity (EC) levels:
Add clean water from a better source to minimize the problem or add calculated amounts of acid to lower the pH level. Reverse osmosis (RO) is an effective solution when there is no clean or affordable water source nearby. Although not cheap, RO is a stable and long-term solution. Note, however, that it increases the need for drip irrigation above sprinklers to avoid unnecessary waste.
Fungal spores, viruses or bacterial contamination, so called ‘waterborne pathogens’
This can happen when using ditch water or your own recirculated water. It requires a complete clean of the water by, for instance, one of the following – Chlorination; sand filter; heating; UV treatment or hydrogen peroxide (H2O2); Ozone (O3) in combination with UV light, or whatever your installation can combine. Installations nowadays are also able to remove chemical residues from the water as a condition for discharging any water into the environment. These solutions should be provided by a specialist water treatment company. They will develop the correct technique, based on your particular problem and geography, and ensure treatment complies with local regulations.
As the water quality is the basis of growth, a controlled and sustainable quality is the basis of a healthy crop, which also contributes to a higher % of saleable plants, and less diseases, means less chemicals. So, in all cases a profitable action.
Too high pH = Iron lack in Petunia.
This article is written by Ben Geijtenbeek, senior technical crop expert Syngenta Flowers as a service for Indian growers that use Syngenta Flowers genetics. Are you interested in Syngenta Genetics, please contact one of the contacts in the Syngenta Flowers India Distributor Network.