The design of ACL includes two parts: one the design of the soil profile and the other the design of the worksite of ACL.
It has been officially proposed by the International Association of Soil Science that the standard profile of soil should include: dirt bed(A-horizon) (0) , humus layer (A), eluviate layer(E), illuvial layer(horizon B) (B), parent material (horizon C)(C) and bedding course ( R ) . In terms of the growth of crops, the most related layers include the dirt bed (A-horizon) (0) and humus layer (A).Generally speaking, the purpose of ACL is to grow crops and produce grain, so it is only necessary to design the cultivation layer, i.e. the dirt bed (A-horizon) (0) and humus layer (A) in the standard profile of soil. Then according to the crops to be planted, artificial soil of different kinds and qualities is selected.
As for the design of the cultivation layer, we can refer to the quality standards of the black soil in the northeastern plain in China . The black soil in the northeastern plain is 30-60 cm thick with the max. of 100-130 cm. It is slightly acid to neutral with the content of organic material up to 5-10%. The surface layer of the black soil is well-structured, air and water-permeable and easy to cultivate. The black soil can be used for a long time with relatively greater viscosity at its bottom layer to preserve water and fertilizer.
Many factors need be taken into consideration when the engineering agricultural technique is used to design the sites of ACL, such as prevention of salinization of soil, water-saving cultivation, prevention of soil erosion, ensuring pollination, prevention of droughts and floods as well as plant diseases and insect pests and so on. |