Properties of paper-based biodegradable pots for growing seedlings

The disadvantageous properties of plastic and plastic wastes have resulted in biodegradable products and seedling pots gaining popularity. Agents of different strengths and sizes agents are usually mixed in the paper pulp to enhance the strength of paper-based seedlings pots. In this study, three types of paper-based seedling pots, with 0%, 3% and 5% of additives, named N0, N3, and N5, respectively, were tested to determine their physical, mechanical and biodegradation properties. Water absorption test results showed that the absorption rate was higher in N0, followed by N3 and N5; a similar pattern was observed in the maximum water absorption, thickness and solubility tests. The tensile test showed the highest strength in N3 (3.9 MPa), followed by N0 (3.8 MPa) and N5 (3.1 MPa) at 0% moisture absorption. However, at 100% moisture absorption, tensile strength dropped the most for N0 (82%), followed by N3 (67%) and N5 (65%). Hybrid broccoli seeds germinated inside the plant factory showed that 95% germinated within 13 days. Temporal data showed that germination time was most delayed in N5. No significant difference was found in seedling height; however, a significant difference was found in the root to shoot height ratio. N0 showed maximum weight and tensile strength loss on the biodegradation test, followed by N3 and N5. At the end of the fourth week, the tensile strength of N0, N3 and N5 was found to be 0.25 MPa, 0.69 MPa and 0.79 MPa, respectively, which was reduced by 94%, 81%, and 79%, respectively, compared to their initial strength. In conclusion, pots containing water repellent additives showed different properties than those without additives, except for germination and seedling growth. This experiment confirms that using additives will increase the strength of paper-based seedling pots in wet conditions without affecting the germination and growth of seedlings.