Urea intercalated encapsulated microalgae composite hydrogels for slow-release fertilizers

Area of Science:

• Agricultural Science
• Materials Science
• Biotechnology

Background:

• Hydrogels are crucial in agriculture for water management and controlled fertilizer release.
• They enhance soil nutrient availability, boost plant growth, and minimize water and fertilizer consumption.
• Developing sustainable soil conditioners is vital for efficient agricultural practices.

Purpose of the Study:

• To prepare a novel hydrogel composite using microalgae, chitosan, and starch.
• To evaluate its potential as an effective soil conditioner.
• To investigate its water retention and fertilizer release capabilities.

Main Methods:

• Hydrogel composite preparation using microalgae, chitosan, and starch.
• Characterization via FTIR, XRD, and SEM.
• Assessment of swelling, biodegradability, water-holding capacity, and urea fertilizer loading/release.

Main Results:

• The hydrogel composite demonstrated excellent water-holding capacity, increasing soil's capacity by 99.4-101.5%.
• Urea loading ranged from 99-440% with kinetics fitting the Freundlich model.
• Urea release was 78-95% over 30 days, following zero-order, Higuchi, and Korsmeyer-Peppas models.

Conclusions:

• The microalgae-based hydrogel composite shows significant potential as a soil conditioner.
• It effectively improves water retention and nutrient availability in soil.
• This sustainable material can reduce water and fertilizer usage in agriculture.