Water is one of the most important issues for the coming years, also for growers. In recent years, many countries have been experiencing more and more dry periods. Since water is the 'oil' of the horticultural sector, it is a crucial theme, and precisely around this theme, many challenges will present themselves in the coming years. Erfgoed, a supplier of water systems and cultivation floors for growers, 'discusses' a number of them in this article.
Several issues are important to growers when it comes to water. First of all, guaranteed availability, the certainty that good quality water is always available and can be delivered to the plants. In addition, flexibility is important. And when smart technologies can help save costs, that's a good thing. Furthermore, it is important that the watering is easily regulated and that not too many actions are required to provide the plant with the right amount of water.
For good water management, it is important to know exactly how much water is needed.
The water needed on your farm can be stored in various ways: in silos, water basins, concrete basements, or ponds (basins in the ground). According to Corné Verduijn, Heritage, the available space in particular often determines the choice that is made. "If there is sufficient space, we recommend choosing a basin. This is because it is cheaper than a silo, which you have to rely on when the available space is limited."
It is important to ensure that the clean and dirty water do not come into contact with each other. This can be done by working with multiple silos.
From the silo or basin, the water reaches the plants through the pumping unit. It may be obvious that it is crucial that this system always works. The way the water eventually gets to the plant does differ.
Although reusing water is far from commonplace throughout the world and in all crops, it is, of course, wise to do so where possible.
It is also important to prevent water discharge by cleverly switching between water basins and silos. Always provide a 'drain water storage,' which can be either in the form of a silo or a basin. This is where the water that has already been used once ends up and is used again after disinfection. Together with clean water from the clean water basin, this is mixed for a new watering.
A horticultural company uses water not only for crop growth but also for other activities. Think, for example, of watering the greenhouse roof. Cock van Bommel, Business Development Manager at ErfGoed, challenges growers to take a closer look at these water flows as well. "Clean, high-quality water is used for many activities when it is not always necessary. It is crucial that we use this clean water primarily for plants. Indeed, other activities can easily be carried out with 'gray' water. This is the water of lesser quality but excellent for spraying the greenhouse roof, for example, or replacing the water in the heating system. There is still a lot of profit to be made in this area."
Guessing is missing
Water is a decisive success factor for cultivation. It is, therefore, essential to have sufficient and good-quality water available throughout the cultivation period.
Some tips and points of attention to keep the water quality up to standard:
Rainwater is often of good quality. It often has an EC between 0.1 and 0.2 and a pH between 5.5 and 7. In addition, in dry periods, the water is often supplemented with ditch water. This is often of much lower quality and can have a higher EC. By means of caustic soda, you can get the pH back to the right level.
To ensure good water quality, it is crucial to keep the water cool. This is because water with a lower temperature has a better oxygen content than warm water. Oxygen-rich water is important for good plant growth. In addition, cool water slows the growth rate of algae and bacteria.
Cock van Bommel advises growers to take regular water samples anyway. "In general, there are no major problems with the water in the water storage, but it is good to measure the quality. Sometimes small deviations can have long-term consequences. In other words, measuring is knowing, guessing is missing."
Nevertheless, it is important to monitor the physical quality even then. After all, the water of high physical quality is much easier to disinfect and creates less contamination on the floor."
Purifying and monitoring water quality
The water that plants do not absorb ends up in a return water silo. It is very important to monitor the amount of contamination in the water and, if necessary, to use cleaning agents such as hydrogen oxide or chlorine.
These agents should be added at the final stage, just before watering. It is important to measure the number of agents at the intake, during watering, and in the return silo. If there is still some agent in return watering silo, then you know you have added enough agents.
In addition to using cleaning agents, you can also purify the water using filters, sieve bends, UV, or ozone. Here too, the rule is: measuring is knowing, guessing is missing.