MSAVI2 and NDVI
The MSAVI2 vegetation index obtained from Sentinel 2 images showed values between 0.023 and 0.096 (Fig. 5). The maximum values were found in November and the minimum in May. The GAM fitted to the data had a significant treatment effect (Table 4). During the analyzed period, MSAVI2 in +W was not different from C except during summer when it was higher than in C (Fig. 5A). MSAVI2 in +N and +NW was higher than in C throughout the year (Fig. 5A).
The ground based daily NDVI values recorded from July 2019 to July 2020 ranged from 0.05 to 0.32, showing the maximum value in November and the minimum value in June (Fig. 6A). The results of the GAM fitting throughout the period (Table 4, Fig. 6A), as well as the results of the ANOVA tested with all daily values (Table 3, Fig. 6B), indicated significant effects of the treatments on NDVI. The treatments significantly increased NDVI compared to the control (p <0.0001), the effect being higher in +NW (p <0.0001). It should be noted that the maximum difference in NDVI between +W and C occurred in spring while it was much lower in autumn and winter (Fig. 6A).