Kennedy soil soil phosphorus, nickel element content detection Young workers -18,028,719,370, online QQ: 1448179206 firm soil, this soil is soft and medium dense clay, heavy clay, gravel soil, dry loess, containing pebbles of gravel loess, clay, compacted fill, solid coefficient is between 0.8 to 1.0, with an average bulk density of between 17.5-19.0, excavation method is mainly used picks, shovels rarely used, hoes and other ways to tap For part with a crowbar to dig. [3] the time factor in soil formation in a variety of soil forming factors mentioned above, the parent material and topography is relatively stable factors, the climate and biological factors are more active, their role in soil formation over time evolve constantly changing. Therefore, the soil is experiencing a changing natural entity and its formation process is quite slow. In the heat, cold, drought and floods and other extreme environments, as well as the residual parent material formed on the hard rock, you may need thousands of years to form a layer of soil occurs, for example, in the dunes soil, especially in the forest, a typical gray developmental needs of soil from 1000 to 1500. But more moderate on changing environmental conditions, as well as soil formation processes in favor of loose soil parent material, soil profile development much faster. Customers are welcome to inquire to know, we have a professional attitude to provide you with the best quality service!