# Changes in Soil Moisture Improved by High-Performance Ester Materials under Dry-Wet Cycles
## 3 Results and Discussion
### Improvement on Soil Ecological Performance from High-Performance Ester Materials  
High-performance ester materials can enhance the ecological performance of soil. Soil samples that have undergone 0, 10, and 22 dry-wet cycles were used for planting tests (as illustrated in Figure 9). As shown in Figure 9, these results demonstrate that as the dry-wet cycle progresses, the plant growth conditions of the soil sample become worse. Comparing plant growth after different times throughout the dry-wet cycles in the same test group, it was found that after multiple dry-wet cycles, plants' germination ratios and heights will decrease. Therefore, in ecological greening applications, it is generally necessary to cultivate loose soil before sowing. However, even after multiple dry-wet cycles, the plants planted in the improved soil samples still had a higher germination ratio and plant height than the CK group without materials. Therefore, high-performance ester materials can improve the germination rate and height of plants and enable the soil to maintain a good plant growth environment after multiple dry-wet cycles. The group with the best growth conditions was always test group 6, which had the highest plant height and germination rate. This soil improvement experiment shows that Test group 6 also had the highest water holding capacity and high EC. Figure 8: Response of high-performance ester materials to dry–wet cycles: soil EC improvement: (**a**) CK and test group 1–9: two polymer materials were added to the soil sample; (**b**) CK and test group 10–15: soil sample added with one polymer material. Figure 9: Improvement of soil ecological performance by high-performance ester materials under dry–wet cycling conditions: (**a**) Planting results of soil sample after 0 dry–wet cycles; (**b**) Planting results of soil sample after 10 dry–wet cycles; (**c**) Planting results of soil sample after 22 dry–wet cycles. Observing the test groups 1-3, 4-6, and 7-9, it was found from the graph that with a certain quantity of polymer adhesive material mixed, plant germination rates increased as the quantity of polymer water-retaining material added increased; the more polymer water-retaining material mixed, the higher the soil's moisture content was, which made the soil more conducive to plant sprouting. The plant's height also increased from the addition of polymer water-retaining materials. As the added quantity of polymer water-retaining materials was invariant, the added quantity of polymer adhesive materials increased the germination rate and plant height, which first increased and then decreased. This indicates that using excessive polymer adhesive materials will have a negative effect on the plant's germination and growth. Water-retaining materials and adhesive materials interact with each other in soil. Water-retaining materials play a role in increasing soil porosity and permeability. Adhesive materials can also affect the water holding capacity and EC of soil to a certain extent, but excessive adhesive materials can lead to strong soil particle adhesion, limit the expansion and water absorption of water-retaining materials, and lead to soil hardening and solidification. Based on the above research, a conclusion can be drawn that high-performance ester materials can enhance soil's water holding capacity and EC, improve the soil's plant growth conditions, and increase plant's germination and height. An optimal proportion of the high-performance ester material addition was also found. Changes in Soil Moisture and Soil Ecological Performance Improved by High-Performance Ester Materials under Dry-Wet Cycling Conditions  
Figure 10 shows the response of polymer water-retaining materials to dry-wet cycles. After four dry-wet cycles, the water absorption performance of the water-retaining materials had decreased to a certain extent, but after multiple dry-wet cycles, the water absorption showed a tendency to stabilize and maintain a high level.