The invention relates to a land transformation method, in particular to a
saline and alkali
land improvement method. The method comprises the following steps: the
saline and alkali land to be improved to is changed into an alternant land for a trench land and ridges; a layer of fine flowing sand or sandy
loess with thickness of 3-3.5 cm is evenly laid on the trench land, the saw
powder and the chopped grass with thickness of 1-1.5 cm are laid, and the plowing depth is 5-15 cm and is not excessively deep; the trench land is filled with water during the watering process and the
ridge cannot be filled with water as possible; the
saline and alkali tolerant high-quality corn variety is selected and planted or the agropyron elongatum can be planted; after the young seedlings grow out, the traditional intertillage management is carried out; after the seeds are harvested, the
straw returning is carried out; as for the land
tillage in the second year, the sand with thickness of 2-5 cm is laid, the saw
powder and the chopped grass with thickness of 1-3 cm are laid, then a certain amount of
farmyard manure is applied and the rest is the same as the
tillage in the first year; as for the land
tillage in the third year, the ridges on both sides of the land are respectively taken as the lands with one eighth width during the
tractor-ploughing process, so the trench land is increased, and other parts are repeated according to the tillage in the second year; as for the land tillage from the fourth year to the sixth year, the tillage method in the third year is repeated; and the improvement of the whole saline and alkali land is finished after six years. The invention can enable the saline and alkali land to be changed into a fertile land, thereby thoroughly harnessing the saline-alkali land.