| Biological improvement of saline and alkaline land mainly combines crop production and livestock raising in a proper manner to improve land fertility and then raise economic benefits of saline and alkaline land. Where soil salt content is high, 67.3% salt can be desalinized in 040 cm soil after salt-tolerant cereal grasses have been planted for three years; 78.7% salt can be desalinized after medlar that belongs to taproot plants has been planted for 3 three year. But the desalinization through irrigation to improve saline and alkaline land would consume a great amount of water, 1.6 times as much as through biological methods. Where soil salt content is higher than 1.5% the land improved through biological ways has a higher crop yield than the land improved through irrigation. Biological improvement of saline and alkaline land is a model, which can produce good ecological, social and economic benefits. In the arid regions with saline and alkaline land dominated by sulfates, the improvement of saline and alkaline land through the combination of planting salt-tolerant grasses with irrigation is practical and feasible. |