Hey there Engr. Md Sabbir Hosen! So, diving into chitosan-based hydrogels for moisture absorption and fertilizer release experiments is a smart move. To kick things off, I'd definitely want to consider some key tests to ensure I am covering our bases:

1. **Swelling Ratio Test**: This helps us understand how much the hydrogel can swell in different moisture conditions. It's crucial for gauging its absorption capacity.

2. **Mechanical Strength Test**: Assessing the hydrogel's mechanical properties under moist conditions gives us insights into its durability and suitability for real-world applications.

3. **Moisture Absorption Kinetics**: This test provides valuable data on how fast the hydrogel absorbs moisture over time, helping us optimize its performance.

4. **Fertilizer Release Profile**: You'll need to study how effectively the hydrogel releases fertilizer under various moisture levels, ensuring it delivers nutrients efficiently to plants.

5. **Biodegradability Test**: Since you're aiming for an eco-friendly solution, understanding how the hydrogel degrades over time is essential for assessing its environmental impact.

By covering these bases, you can gain a comprehensive understanding of the chitosan-based hydrogel's moisture absorption capabilities and its potential as a fertilizer carrier. Let's dive in and uncover some groundbreaking insights!