yes my dear can  using that soil for work 

My guess is top photo was when plots were installed, below photo taken later, after a period of erosion.  Although grass can hide surface irregulatories, the small trail at the base of the plots in above photo is gone as near as I can tell in bottom photo.  I used similar plots in coastal Oregon in 1978.  I have on my researchgate the paper that begins with title Hazel Pistol Erosion Plots ...  I would like to know if this study represented in photos was documented and appreciate a copy if available.  

The problem of closed erosion plots, especially on slopes as steep and eroded as the photo, is their short useful life. In these plots, from about five years on, the characteristics of the interior soil begin to be different from those of the exterior and stop serving to model the erosion processes. So, these plots should be used mainly to estimate erosion with different crops or soil cover, with different degrees of slope or precipitation intensity, or to test erosion control measures, such as different soil treatments.

Some examples of the use of plots:

 Https://www.researchgate.net/publication/39434933_Effects_sobre_la_cubierta_vegetal_la_escorrentia_y_la_erosion_del_suelo_de_la_alternancia_cultivo-abandono_en_excelesales_experimental

Https://www.researchgate.net/publication/27338827_Optimo_de_cobertura_vegetal_en_relacion_a_las_perdidas_de_suelo_por_erosion_hidrica_y_las_perdidas_de_lluvia_por_interceptacion

Https://www.researchgate.net/publication/265848807_Changes_in_the_physical_and_chemical_properties_of_the_soil_in_confined_erosion_plots_Murcia_Spain

regards

Article Efectos sobre la cubierta vegetal, la escorrentía y la erosi...

Article Óptimo de cobertura vegetal en relación a las pérdidas de su...

Chapter Changes in the physical and chemical properties of the soil ...

Dear all

Thanks for your explanation on my question from your point of view.

The study area is as enclosure site about 15 years ago. In above photo (about 10 years ago) sheep grazing and creating micro-terrace is incredible. However, after the stopping sheep grazing, rill erosion has been created in the region.

There are no rill erosion in the past, but now they were seen. In your opinion, what is the reason?

HI Hamzeh,

Good question ~ thanks for raising the issue ~ it is one that challenged me for years until I engaged complex open geosciences methods, You will  find the detailed answer to your question in my recently published chapter on Ecogenesis of the Huang He.

Briefly stated, grazing by hard hoof animals results in a reversal of the rainfall recharge/runoff ratio. Healthy rangeland ecosystems without grazing will recharge over two thirds of rainfall events into aquifers. By comparison, grazing by hard hoof herds results in soil and subsoil compaction resulting in over two thirds of rainfall events running over the land creating increased flooding hazards and various erosion patterns, including rill and sheet erosion.  These outcomes are now included as ecological indicators of pastoral desertification in rangeland watersheds...

You will not find these outcomes by applying the methods of closed system sciences using linear cause and effect logic and statistical sampling ~ It is necessary to map and model complete watersheds in detail (using accurate and reliable orthophoto mapping with 1 meter contours). The methodology requires a comprehensive watershed iGiS to map habitats and regoliths ~ with suites of peizometers to measure aquifer recharge and groundwater flows continuously... this methodology is explained in my UNESCO EOLSS chapter Habitat and Riparian Management in Rangeland Ecosystems..