Azolla pinnata growth performance in different water sources

Area of Science:

• Aquatic Botany
• Environmental Science
• Agronomy

Background:

• Azolla pinnata is a globally significant aquatic fern with potential applications in agriculture and aquaculture.
• Water quality and nutrient availability are critical factors influencing the growth and propagation of aquatic plants like Azolla.
• Understanding the optimal water conditions for Azolla growth is essential for maximizing its biomass production.

Purpose of the Study:

• To evaluate the growth performance of Azolla pinnata R.Br. in various water sources with differing nutrient profiles.
• To identify the specific water source and associated nutrient concentrations that promote the highest Azolla biomass.
• To determine the relationship between water nutrient content and Azolla pinnata growth rates.

Main Methods:

• Azolla pinnata was cultivated in four distinct water sources: wastewater, drain water, paddy field water, and distilled water (control).
• Plant biomass and daily growth rates were monitored over a period from May to July 2011.
• Nutrient analysis (nitrate, nitrite, phosphate) of water sources was conducted, and BVSTEP analysis (PRIMER v5) was used to assess nutrient impacts.

Main Results:

• All water sources supported an increase in Azolla pinnata biomass, with drain water showing the highest growth (up to 133.3% increase) and daily growth rate (19.04%).
• Drain water exhibited higher concentrations of nitrate (0.035 mg L⁻¹) and nitrite (0.044 mg L⁻¹), alongside available phosphate (0.032 mg L⁻¹), correlating with superior growth.
• Biomass increases fluctuated but were consistently higher in drain water compared to other sources, indicating its favorable conditions.

Conclusions:

• Drain water, characterized by elevated nitrate and nitrite levels, provides the most favorable conditions for Azolla pinnata growth and propagation.
• The observed increases in Azolla biomass are significantly influenced by the combined effect of multiple nutrients present in the water sources.
• These findings highlight the importance of nutrient management in water sources for optimizing Azolla cultivation for various applications.