In nature, any kind of soil originates from the evolution of rock. Firstly, the rock composing the earth crust has be changed into the parent material forming soil through physical, chemical and biological erosion. The nutritional element in the parent material forming soil is dispersive and can be lost easily with flowing water, and nitrogen, the most required element for plant growing, does not exist in the parent material forming soil. Secondly, autogenous bacteria begin to appear in the parent material forming soil. The autogenous bacteria do not need organic nutrition, they only need water , air and mineral nutrition as well as a certain temperature for growth and reproduction. Thirdly, Lower-grade plants such as lichen, bryozoan etc. begin to grow. Along with the accumulation of living beings is going more and more, the amount of organic matter in the parent material forming soil is going more and more, Then higher-grade plants gradually replace lower-grade plants, and through strong and extensive root system, the dispersive and soluble nutrition can be concentrated. After the death of organisms, and through decomposition of microbes, one part of the remains of the organisms becomes nutrients for plants, and another part of the remains turns into humus. The humus plays an important role in terms of generating fertility for the parent materials forming soil. On the one hand, it can keep nutrition, on the other hand, it can change the physical properties of the parent materials forming soil and make the parent materials forming soil possess structure and fertility. After all these steps, the parent materials forming soil has turned into soil, and the evolution from rock to soil has been accomplished.
The basic principle of artificial soil and the mechanism of naturally-generated soil are almost the same, the difference is that time and process for generating artificial soil have been shortened greatly.
The essential materials of artificial soil can be divided into three types. The first type is different kinds of rocks including sedimentary rock, metamorphic rock and volcanic rock among which black mudstone, black shale, clay, slate, phyllite, granite, basalt, andesite and volcanic ash are the best except some chemically depositional rock such as salt rock, gypsum, limestone. The second type is solid wastes from industry, mining and construction, including waste rock, tailings, waste slag, gangue, coal cinder, brick and tile, ceramics, cement component, sand and waste plastic except some harmful substance such as container with agricultural chemical, poisonous compound, wastes of over-standard? heavy metal and radioactive substances. The third type is different kinds of organisms, including straw, peels and core of melons and fruits, vegetables, weed, remains of animals, algae, manure of humans and animals, house-hold rubbish, meat, fibre, waste cloth, leather, waste? wood, silt of river and lake, silt from sewer and sewage treatment plant, peat and brown coal except harmful chemicals, organic matter containing over-standard mercury, benzene and heavy metal. The technological process of artificial soil can be divided into five steps ﹙see F-036 Fig. 1﹚. Firstly, Collected raw materials for artificial soil have been classified and classified further. Secondly, Classified inorganic materials have been crushed and abraded to make a lot of powder and store them separately. Thirdly, Organic material ﹙the solid organic matter needs to be crushed ﹚ and inorganic material powder have been mixed in certain proportion and put into ferment workshop under medium-high temperature condition to ferment and make the compost manufacturing soil. Fourthly, The compost manufacturing soil and inorganic materials powder﹙also as：the parent materials manufacturing soil﹚ have been mixed in certain proportion to make artificial soil with properties of water-retaining, heat-retaining, permeation and fertility, and essential condition for growing of plants. Fifthly, artificial soils have been checked and evaluated comprehensively according to standards of soil for green food production base, then experiment of growing crops has been conducted. Only after the soil is tested to be qualified, it can be put to the market.