Principles of sand dune fixation with straw checkerboard technology and its effects on the environment

The straw checkerboard technique is used for fixing sand dunes. Straw of wheat, rice, reeds, and other plants is placed in the shape of a checkerboard. Half is buried and the other half is exposed. Scientists at the Shapotou Desert Research Station, Chinese Academy of Science, devised this technique in 1957. Because of its success in fixing dunes, it is widely used in the desert regions of China. However, despite its wide use, little research has been done on its fixation and windbreak mechanisms, and its effects on the environment are still not clear. The objectives of this study were to investigate these factors. We used field experiments and simulation with a computational fluid dynamics model. We found that 10–20 cm is a reasonable height for the straw: it has a substantial effect on dune fixation and a relatively low cost. The practicable size of the checkerboard is 1 m×1 m; this has remarkable wind break and dune fixation effects and is easy to build. The straw can greatly increase the roughness length of the sand dune surface, decreasing the intensity of sand flux by as much as 99.5%. Where the sand is fixed, soil formation can begin; fine particles are accumulated and a hard soil crust is formed on the dune surface, improving both the microenvironment and the stability of the dune surface. The straw checkerboard can significantly increase the content of organic matter of the surface soil. The technique has several advantages: remarkable effect of dune fixation, ease of construction, rapid results, and no pollution of the environment. However, labor cost and replacement after 3–5 years are problems. The straw checkerboard can be regarded as a very effective technique, with wide application for sand dune fixation both in China and around the world.