## 3 Results
### Experiment 3: Evaluation of the CAIS with Multiple Irrigation Points
The next adjustment raised the moisture level and the 4 h irrigation interval was continuously applied until the end of the experiment. Figure 10: _Cont._  
The duration over which the CAIS adjusted the moisture levels of these three areas to 590 was about 24 h, as shown by the experimental results between Day 2 p.m. 04:00 and Day 2 p.m. 06:00 in Figure 9(a)-c. The average sampled moisture levels computed from Day 2 p.m. 04:00 to the end of the experiment on Day 4 a.m. 04:00 for these three areas were 595, 594, and 595, respectively. The average error bias was \(\pm\)5 moisture levels. The results proved that the CAIS maintained a constant moisture level by changing the irrigation interval of each VPA. Dividing the experimental plot into multiple areas efficiently reduced the impacts of soil density on soil moisture. The water was evenly distributed and retained a balanced moisture value over the whole experimental plot. An experiment with high air temperature, which is 30 \({}^{\circ}\)C-34 \({}^{\circ}\)C, is evaluated. The experimental platform is placed under the air conditioner vent. The surrounding humidity of this experiment is 58-68%. Figure 10(a)-c is the moisture levels of VPA#0, VPA#1, and VPA#4, respectively. The selectable irrigation intervals are also 2, 3, and 4 h. We also started the first irrigation on Day1 p.m. 04:00. The object is also to maintain the moisture level at 590 for all 3 cm depth layer of soil of these three areas. The first sampled moisture levels of these three VPAs were 653, 655, and 657. CAIS applied the 4 h irrigation interval for all of these VPAs to reduce their soil moisture levels. Their moisture levels changed to 582, 588, and 598. In Figure 10(a), CAIS adapted the irrigation interval of VPA#0 to 2 h At Day 2 a.m. 00:00, and the moisture level of VPA#0 continuously increases. At Day 2 04:00, CAIS changed the interval to 3 h because the increasing rate of the moisture level is too fast. At Day 2 a.m. 07:00, the moisture level reduced to 581. CAIS changed the interval to 2 h and the irrigation interval did not alter until the end of this experiment. The high air temperature increases the evaporating rate that the planting media at VPA#0 cannot hold water. Thus, the distance between the sampled moisture level and the required one gradually draws apart. For the VPA#1, CAIS adapted the irrigation interval 2 h and 3 h alternatively within the interval Day 2 a.m. 00:00 and Day 3 a.m. 05:00 shown as Figure 10(b). The high evaporating rate caused by the high air temperature also influences the planting media at VPA#1. Thus, the 2 h irrigation interval is almost applied to the end of this experiment after Day 3 a.m. 05:00 at VPA#1. Because VPA#1 has one more neighboring VPA than VPA#0, it can absorb the contained water from neighboring fields to balance the soil moisture. Figure 10: The moisture levels of the sensors at the 3 cm depth layer in different VPA. The moisture level is ranged from 0 to 1023. (**a**) the moisture level of the VPA#0. This VPA is located at the corner of the experimental plot. Similar VPAs are VPA#2, VPA#6, and VPA#8. (**b**) the moisture level of the VPA#1. Similar VPAs are VPA#3, VPA#5, and VPA#7. (**c**) the moisture level of the VPA#4, which is at the center location of the experimental plot. Figure 11: The moisture levels of the sensors at the 3 cm depth layer in different VPA with high air temperature (30 \({}^{\circ}\)C-34 \({}^{\circ}\)C). The moisture level is ranged from 0 to 1023. (**a**) the moisture level of the VPA#0. This VPA is located at the corner of the experimental plot. Similar VPAs are VPA#2, VPA#6, and VPA#8. (**b**) the moisture level of the VPA#1. Similar VPAs are VPA#3, VPA#5, and VPA#7. (**c**) the moisture level of the VPA#4, which is at the center location of the experimental plot. VPA#4, which locates at the central position of the experimental plot, has its moisture level close to the required 590. More than one sampled value of the moisture level is higher than 590 before Day 3 a.m. 05:00.