Improved Effect Study Of The Salt-tolerant Plants In The Mining Area

With the rapid development of the global economy,the mining industry has been forced to explore ceaselessly.However,disordered and excessive exploitation has resulted in serious destruction of ecosystem and native vegetation in mining area.The environmental issues and ecological restoration study in the mining area has been widely concerned at home and abroad.The vegetation restoration has to be settled urgently.At present,there are many problems in vegetation restoration in mining area,such as single treatment technology,unreasonable utilization of water resources,unreasonable selection of vegetation,single type of vegetation,high treatment cost and so on.It is of great significance to carry out mining area restoration scientifically and reasonably for maintaining mining area production safety,ecological safety and miners’residence safety.Therefore,in the ecological management,it is very important to study the mechanism of soil amelioration in mining area by rational planting of salt-tolerant plants.This article will take Dananhu Coal Mine restoration area in Hami as an example,select three typical salt-tolerant plants as study subjects,like arbor（Elaeagnus angustifolia,Hybrid Willows）,shrub（Haloxylon ammodendron,Tamarix ramosissima,Lycium chinensis）,and herb（Medicago Sativa,Glycyrrhiza uralensis）,respectively analyze and study the dynamic characteristics of total salt and base ions in soil,growth physiological response characteristics of salt-tolerant plants and amelioration effect of salt-tolerant plants on soil salinity in restoration area during June,August and October,the most important period of plant growth.The main results obtained in this paper are as follows:（1）Compared with the undisturbed soil,the p H value of the vegetation-free soil in the restored area increased and the soil electrical conductivity decreased with the increase of irrigation frequency.With the increase of irrigation frequency,the total saltness of the soil showed a trend of decrease,and the decreasing amplitude was the largest in October,which decreased 40.71 g/kg compared with the previous period.And the content of Ca²⁺decreased 0.33 g/kg,the content of SO₄^2-decreased 0.20 g/kg,and the content of Na⁺+K⁺decreased 42.55 g/kg.In the spatial range,with the increase of soil depth,the total salt content of the soil increased first and then decreased.Compared with the topsoil,the salt content of the soil in60-80cm layer was the largest which increased 116.80 g/kg,the content of Mg²⁺increased 0.05 g/kg,the content of Cl^-increased 8.491 g/kg and the content of Na⁺+K⁺increased 125.60 g/kg.（2）Under the condition of plant cultivation in the restoration area,with the extension of cultivation time,the total salt content of soil in each layer in 2019 was higher than that in each layer in 2020,and the total salt content in each layer of 0-10 cm,10-20 cm,20-40 cm,40-60 cm and 60-80 cm decreased.The salt content decreased by 3.76 g/kg,0.96 g/kg,10.41 g/kg,45.38 g/kg,28.67 g/kg,respectively,and the salt content decreased most significantly in 40-80cm layer.In two years,the content of base ions had significantly decreased and varied.The content of Mg²⁺decreased 0.21 g/kg,the content of Ca²⁺decreased0.69 g/kg,the content of Cl^-decreased 4.06 g/kg,the content of SO₄^2-decreased 0.80 g/kg,the content of Na⁺decreased 121.50 g/kg and the content of K⁺decreased 17.46 g/kg.In comparison,by growing plants,the control of potassium and sodium ions in soil is the most obvious.（3）The growth situation of these five plants（Elaeagnus angustifolia,Hybrid Willows,Haloxylon ammodendron,Tamarix ramosissima,Lycium chinensis）showed that haloxylon ammodendron had the best growth and Elaeagnus angustifolia had the worst growth.The growth profile is characterized by Haloxylon ammodendron>Tamarix ramosissima>Lycium chinensis>Hybrid Willows>Elaeagnus angustifolia.Among the planted arbors,the Tamarix ramosissima comparatively had better absorption of the Cl^-、Ca²⁺、Mg²⁺in the soil,the Elaeagnus angustifolia absorbed SO₄^2-、Na⁺in the soil,and both of them could not absorb k⁺.Under the same planting conditions of the three shrubs,Haloxylon ammodendron had better absorption of salt,followed by Hybrid Willow,Haloxylon ammodendron was the weakest,but Haloxylon ammodendron had better absorption of K⁺than Hybrid Willow.The saline ions in haloxylon ammondendron,Hybrid Willow and Haloxylon ammodendron was significantly different.Among the two herbs,Glycyrrhiza uralensis had a more significant absorption effect on salt ions in the soil,while Medicago Sativa did not absorb salt ions in the soil but would release excess salt ions into the soil.The contents of Cl^-,SO₄^2-,Ca²⁺and K⁺in Glycyrrhiza uralensis and Medicago Sativa were significantly different.（4）Soil salt decreased significantly under two years’planting,and soil salt content changed from severe salinization to moderate salinization.After planting,the contents of Cl^-,Mg²⁺and Na⁺in soil decreased by 48.99 g/kg,4.59 g/kg and 251.74 g/kg,respectively.Under the condition of planting arbors,the soil salinity after planting Hybrid Willows and Elaeagnus angustifolia decreased significantly,and the Hybrid Willows had better salinity change than Elaeagnus angustifolia.In shrub planting,there was no significant difference in soil salinity at 0-10 cm layer,but soil salinity at 10-20 cm,20-40 cm,40-60 cm and60-80 cm layers all decreased,and the difference was significant.The salinity change of Tamarix ramosissima was significantly better than that of Lycium chinensis and Haloxylon ammodendron.The soil salinity of Medicago Sativa increased at 0-10 cm,but decreased significantly at 10-20cm and 20-40cm with significant difference.Soil salinity in Glycyrrhiza uralensis was significantly decreased.In conclusion,in the experiment,all the plants can absorb the salt in the soil,and the plants can reduce the salt content in the soil.Among the three kinds of plants,Hybrid Willows,Haloxylon ammodendron,Tamarix ramosissima and Glycyrrhiza uralensis are more suitable for cultivation in Damanhu No.2 Mine.The results showed that the combination of Hybrid Willows,Haloxylon ammodendron,Tamarix ramosissima and Glycyrrhiza uralensis had better improvement effect in mining area.