The Role of Silicon in Hydroponics: Insights From Prof. H. L. Darshani Weerahewa
I love to learn from experts. It’s the best way I know to gather knowledge faster.
I recently had the opportunity to meet with Professor H.L. Darshani Weerahewa from the Department of Botany, The Open University of Sri Lanka, a well-known academic in horticulture and post-harvest technology.
Although she didn’t start her career specializing in hydroponics, her journey into the field and her subsequent research have been enlightening. It was fascinating to hear about her experiences, challenges, and how her work impacts agricultural practices in Sri Lanka.
Our conversation offered a deep dive into hydroponics, particularly her research on using silicon in plant cultivation systems and the unique challenges and opportunities in Sri Lanka’s agricultural landscape.
Here’s what I learned.
An Unexpected Start in Hydroponics
During our chat, Professor Weerahewa shared how she began her journey in hydroponics. Surprisingly, hydroponics was not initially her primary focus.
Her specialization is post-harvest technology, which deals with maintaining the quality of fruits and vegetables after harvest. However, her role at the Open University, where she teaches a course on horticulture, provided the opportunity to explore the application of hydroponics in maintaining and enhancing crop quality while reducing diseases and post-harvest losses.
“I realized there was a gap in the existing knowledge and practices in Sri Lanka regarding hydroponics. There were few resources available, and even those engaged in commercial hydroponic farming were hesitant to share their methodologies and findings.”
Prof. H. L. Darshani Weerahewa
This observation motivated her to integrate hydroponics into her horticulture curriculum. The course was developed in collaboration with the Agriculture Department, using expert insights from various fields. It became one of the country’s few structured educational resources available on hydroponics.
Bridging the Knowledge Gap with Practical Research
One of the most exciting aspects of our conversation was Professor Weerahewa’s research on using rice husks in hydroponics.
In a country like Sri Lanka, where rice is a staple crop, rice husks are an abundant by-product. Typically, they are burned or discarded, with minimal understanding of their potential value as a horticultural substrate.
Professor Weerahewa explored the use of rice husks as a substrate to improve crop quality, focusing specifically on the presence of silicon in rice husks.
“Silicon is an essential micronutrient that can enhance plant resilience against diseases and improve the quality of fruits and vegetables.”
Prof. H. L. Darshani Weerahewa
However, it is often overlooked in traditional farming practices. Her research uncovered how this nutrient can be utilized effectively in hydroponic systems.
The professor’s enthusiasm was palpable as she described how she discovered that partially burned rice husks are an excellent source of silicon. While silicon is widely used in countries like Japan for rice crops, its application in fruit and vegetable cultivation is relatively new, even more so in Sri Lanka.
She experimented with various crops, such as tomatoes, Salad cucumbers, Capsicum, and pineapples, using different mediums like aggregate systems, soil, and hydroponics. The results were promising, showing significant improvements in both yield and quality.
Challenges and Breakthroughs in Research
While the findings were encouraging, Professor Weerahewa pointed out that applying silicon isn’t as simple as adding it to the soil or hydroponic nutrient solution.
“The form of silicon matters. Plants can only absorb specific forms of silicon, just as they can only absorb specific forms of nitrogen.”
Prof. H. L. Darshani Weerahewa
This means that not all silicon-rich materials are suitable for enhancing crop quality. Her research involved determining the optimal form and concentration of silicon that various plants can absorb.
Another significant hurdle was identifying the correct application method. Professor Weerahewa tested both root and foliar applications and experimented with using rice husks in hydroponic aggregate systems and mixing them with soil.
“It’s not just about adding silicon, but about how we add it and in what quantity.”
Prof. H. L. Darshani Weerahewa
Her trials revealed that partially burned rice husks were the most effective form, as entirely burned husks primarily contain potassium, which doesn’t provide the same benefits for disease resistance and quality improvement.
Silicon’s Impact on Crop Quality and Disease Resistance
One key benefit of using silicon in hydroponics is its ability to reduce disease incidence. Professor Weerahewa observed a marked reduction in diseases when crops were treated with silicon, whether through hydroponic nutrient solutions or soil amendments.
“Most farmers use pesticides without understanding the diseases they are dealing with. Applying silicon can naturally strengthen plants, reducing the need for pesticides and improving the overall quality of produce.”
Prof. H. L. Darshani Weerahewa
Moreover, silicon-treated crops had superior post-harvest qualities. She explained that factors such as visual appearance and texture were noticeably enhanced and reduced the rate of ripening in silicon-treated fruits and vegetables. This is particularly important for fruits like tomatoes and cucumbers, susceptible to quality degradation during transportation and storage.
Overcoming Barriers to Adoption
Despite the promising results, significant barriers exist to adopting these techniques on a broader scale. Rice husks, although abundant in certain parts of Sri Lanka, are not readily available throughout the country.
“We need to find a way to make rice husks available as a consistent resource for farmers, especially in regions where they aren’t produced locally.”
Prof. H. L. Darshani Weerahewa
She also mentioned that farmers are unaware of the benefits of using rice husks and silicon.
To address these challenges, the Open University has initiated training programs for farmers.
“We have been conducting workshops and demonstrations in areas like the Adikarigama and Ragala in Nuwara Eliya districts, teaching farmers how to incorporate partially burned rice husks into their farming practices.”
Prof. H. L. Darshani Weerahewa
The response has been positive, but widespread adoption is still far off.
Developing a Hydroponic Nutrient Solution
One of Professor Weerahewa’s ongoing projects involves developing a customized hydroponic nutrient solution incorporating silicon. Most commercial nutrient solutions in Sri Lanka do not include silicon, limiting their effectiveness in enhancing crop quality and disease resistance.
“I’m working with a team of chemists to formulate a nutrient solution that includes silicon in a form that plants can easily absorb,” she revealed.
Prof. H. L. Darshani Weerahewa
The goal is to create a solution for various hydroponic systems, from small-scale setups for hobbyists to extensive commercial operations. This could be a game-changer for hydroponic farming in Sri Lanka and beyond.
Looking Ahead: Hydroponics as a Pathway to Sustainable Agriculture
As we concluded our conversation, Professor Weerahewa shared her vision for the future of hydroponics in Sri Lanka.
“Agriculture in Sri Lanka is at a crossroads. We need to move towards more sustainable and efficient methods of cultivation. Hydroponics, coupled with the right research and resources, can play a crucial role in this transition.”
Prof. H. L. Darshani Weerahewa
She believes integrating advanced research findings, like her work on silicon application, into practical farming practices can lead to a more resilient agricultural sector.
“It’s not just about growing plants; it’s about growing them better, smarter, and more sustainably,” she remarked.
Prof. H. L. Darshani Weerahewa
Final Thoughts
Talking to Professor H.L. Darshani Weerahewa was an enriching experience that shed light on the potential of hydroponics to revolutionize agriculture in Sri Lanka. Her research on silicon application and the innovative use of local resources like rice husks provide valuable insights into how traditional farming practices can be enhanced using modern techniques. With dedicated professionals like her leading the way, the future of hydroponics in Sri Lanka looks bright and full of promise.
If you’re interested in exploring hydroponics or want to learn more about integrating innovative techniques into your cultivation practices, following Professor Weerahewa’s work is a great place to start.
Discover more about Professor Weerahewa’s groundbreaking research on ResearchGate. You can connect with the professor through LinkedIn, too.
