“As a water board, we manage the water quality and the quantity of rainwater in the region. This applies to our entire area in West Brabant, from Tilburg to Bergen op Zoom and from Moerdijk to the Belgian border, including Zundert,” says Angelien Hagenaars, a member of the executive board of Waterschap Brabantse Delta and a resident of the region herself.

Our first question to the water board was: How is the quality of surface water in this region?

Quality

“The water board works closely with tree growers in Zundert. This collaboration has been in place since 2006. At that time, we first examined the impact of the tree nursery industry and the use of crop protection products on the quality of surface water (water in ditches, streams, and rivers). Since then, we have collaborated on various projects to improve water quality. In the initial years, we saw a significant decline in the number of exceedances of crop protection product limits. However, in recent years, that decline has levelled off. The number of exceedances now remains steady, with approximately three to four exceedances per year. We aim to further reduce this figure in cooperation with the industry. The rise of mechanical weed control has played a significant role in reducing the use of crop protection products.”

Quantity

We are currently experiencing a wet period. Overall, the amount of rainfall across the Netherlands is significantly higher than in an average year. However, this could change in the upcoming growing season. For instance, 2018 saw a historically dry period, while 2024 experienced a historically wet one. The role of the water board is becoming increasingly challenging, and collaboration, in this case with growers in Zundert, is more crucial than ever. We need to temporarily store water during wetter periods and introduce it into the soil to replenish groundwater reserves for use during drier periods.

To strike the right balance, the program ‘Water in Balance’ has been developed. This program, consisting of 10 underlying projects, addresses these challenges with a joint approach to find solutions. More information about ‘Water in Balance’ can be found on the website ‘Zundert Floreert.’ For example, one of the initiatives focuses on creating more space for water in low-lying areas.

What, in your opinion, can growers do in order to manage water as best as possible?

“The collaboration with the agricultural industry is visibly yielding results. Two awards have already been won: the ‘Aan de Slag’ trophy, presented by then-Minister Hugo de Jonge, for the pilot project ‘Vital Countryside,’ and the Water Innovation Award from the Association of Water Boards for the project ‘Zicht op Water’ (Water in Sight). In short, it’s a visibly successful collaboration that continues to evolve.

What measures can growers and residents take to address climate change (drought/excessive rainfall)?

Growers can introduce surplus water into the soil to ensure that water reserves are sufficiently replenished for irrigation during summer. For example, they can install a weir in ditches to prevent water from flowing away, allowing it to infiltrate into the soil. This method has already been successfully applied in various locations. Residents can disconnect their rainwater downpipes from the sewer system, allowing rainwater to flow directly into their gardens. This has several advantages: homeowners and their immediate surroundings experience less flooding during heavy rainstorms, pressure on the sewer system is reduced, and groundwater levels on residential properties remain stable. The municipality of Zundert supports this initiative with the ‘Brickey.’ This is the term Zundert uses for a tile placed beneath disconnected rainwater drainage systems to help distribute water more evenly.

Residents can take additional measures in their gardens. A green, water-friendly garden helps mitigate water issues during heavy rainfall. Conversely, during extended warm and dry periods, concrete and paved surfaces retain heat, making the environment feel even hotter. Plants and greenery, on the other hand, retain water and help keep the garden significantly cooler on hot summer days. Trees and plants in a green garden provide shade, which lowers temperatures. More tips for creating water-friendly gardens can be found at www.brabantsedelta.nl/tuintips.”

Good water policy is essential for tree nursery industry

Water is a basic necessity. No living being can survive without water, yet despite days of rain, water remains a scarce resource. To prevent or address this scarcity, water as a resource must be conserved and managed efficiently, both in terms of quantity and quality. This applies to the government, businesses, and individual citizens alike. The question is: how can we use it as efficiently as possible?

For this article, KwekersBode consulted two specialists in water management within the tree nursery industry: PlantoSys Nederland b.v. and Aqua Sifra. Water is not only essential but can also pose a threat, whether due to shortages or an overflow of rainwater. On this subject, we also spoke with the Water Board Brabantse Delta. Even in private gardens, it is crucial to handle water with care.

Practical solutions

PlantoSys Nederland B.V., based in Lochem, is a relatively new player in the tree nursery market. Since its establishment in 2010, the company has become active in over 30 crop types across more than 20 countries. “We are an innovative company that translates knowledge, experience, and fresh insights into practical solutions for agriculture and horticulture, while continuously investing in research,” says Alwin Scholten, director and tree nursery advisor. “Our focus is on products composed of natural ingredients.”

In the context of water management on nurseries, maintaining a stable pH level is crucial. Additionally, it is essential to keep irrigation pipes and drippers clean and free from blockages.

A commonly used solution for preventing pipe contamination is hydrogen peroxide. However, growers using hydrogen peroxide cannot simultaneously add organic products, such as bio stimulants and organic fertilisers, through the fertiliser tank. Research based on these challenges led to the development of two products: Blue Bac-1 and Blue Bac-2. These are 100% natural water maintenance products designed to eliminate organic contamination in irrigation systems. Both products are based on specifically targeted bacteria.

Blue Bac-1 competes with algae for organic nutrients in the water and aids in breaking down dead algae. Blue Bac-2 creates a very smooth natural coating on the inside of the irrigation system, preventing organic contamination, sand, and deposits such as phosphate residues from adhering to the pipes. Alwin Scholten explains, “Another significant advantage of Bac-2 is that it helps stabilise the pH level of irrigation water, and its positive effects are also noticeable in the substrate. This product has already been successfully implemented in strawberry cultivation, and we are seeing growing interest in the tree nursery industry as well.”

Water plants are important for great water management

Aqua Sifra from Boskoop/Hazerswoude-Dorp has been founded in 1994. Initially at the location on Compierkade in Boskoop, it later expanded to a site on Burgemeester Smitsweg in Hazerswoude-Dorp. Owner Piet Bakhuijzen has grown with the business from the very beginning and inherited his passion for water plants. “Our way of working comes from years of practical experience, not from a textbook,” says Piet.

His large water plant nursery offers a diverse, primarily native range of more than 320 different species of water and riparian plants. With approximately 10 employees and a total area of 12,000 square meters, Aqua Sifra is one of the largest water plant nurseries in the region. “We supply our plants to a wide range of customers, including garden centres, landscapers, green contractors, fellow nurseries, and government bodies in both the domestic and international markets.”

“Water and riparian plants are crucial for good water management,” says Piet. “They keep the water clear by absorbing nutrients such as nitrogen and phosphate and releasing oxygen.” In terms of their importance for public surface water, water plants stabilise the soil and trap floating particles while absorbing nutrients. Due to improved water quality and the presence of plants, (blue) algae have little chance to grow. Furthermore, water plants provide shelter and spawning grounds for aquatic animals and young fish. A major problem, however, is the presence of crayfish, which have become a significant pest, particularly for plants. Both for planting in and around private garden ponds, as well as for public surface waters, choosing the right plants is essential.

On behalf of trade fair GrootGroenPlus: Didier Hermans, member of the board

“ Tree nursery plots ensure good water infiltration. Every drop counts, which is why we, and and with us many participants at GrootGroenPlus, collect rainwater from our greenhouses and container fields.”