Key techniques for controlling mobile dunes and grassland restoration in a desertified grassland of Gannan: Take the first bending of the Yellow River as an example

We established an experimental area on the windward slope of mobile dunes in the first bending of the Yellow River, as part of a pilot project to test sand controlling and grassland restoration techniques. The experiment was designed as 3 randomized block groups, exposed to 6 different treatments as follows: Dung (sheep dung), Dung + protect (sheep dung + protective species), Dung + mat + protect (sheep dung + fiber grid sand barrier + protective species), Dung + soil (sheep dung + peat soil), Dung + soil + protect (sheep dung + peat soil + protective species), and CK (control). The same formula of grass seeds was used in all treatments, and the germination and seedling density, growth height, projection coverage of grass, and the degree of wind-sand erosion accumulation were observed. The results showed the following: 1) In the six treatments, the treated sand surfaces were relatively stable, and grass seeds successfully settled, germinated. Seedlings grew in both Dung + mat + protect and Dung + soil + protect treatments. Wind severely eroded the sand surfaces and the seeds were consequently not planted for the other four treatments. There were no significant differences in average heights and the densities of grass except for projection coverage (P > 0.05). The averages of all other indicators in Dung + mat + protect and Dung + soil + protect were significantly higher than those of the other four treatments (P < 0.05). 2) The mean values of wind erosion were small for Dung + mat + protect and Dung + soil + protect, and there were no significant differences between them (P > 0.05). These values was significantly lower than those for the other treatments, except for Dung + soil (P < 0.05). In addition, there were no significant differences in the mean values of aeolian production for all treatments (P > 0.05). These findings suggested that Dung + mat + protect and Dung + soil + protect performed well in sand-fixing and promoting grassland restoration. These findings can be implemented as novel complex technologies to successfully address the sand-fixing concerns and improve grassland restoration in this area.