| Sulfur was one of the important elements of farmland soil and had an important influence on the growth and metabolism of vegetation.Sulfur in the soil had many forms,divided into two parts:organic sulfur and inorganic sulfur.Among them,inorganic sulfur accounted for only a small part.Sulfate was an essential sulphur element for plant growth and plays a vital role in plant metabolism.In order to study the spatial distribution characteristic and influencing factors of sulfate in soil of Linhuan mining area in Huaibei,a total of 34 soil samples were systemic collected.The sequential extraction method was used to test and analyze the sulfur content of different forms in the samples,and combined with the correlation of physical and chemical properties to discuss the distribution characteristics of soil sulfate content and its relationship with environmental factors.And its relationship with environmental factors in order to make scientific recommendations for Acid sulphate soil.The main research results were as follows:（1）The overall level of soil organic matter content in the Linhuan subsidence area was relatively high（42.61 g/kg）,and the organic matter was at the first level of soil nutrient classification.The distribution of organic matter in the study area was significantly different.The soil organic matter content in the solid wasted accumulation area（57.23 g/kg）and the soil organic matter content in the farmland soil area（40.69 g/kg）were respectively 2.10 times and the soil organic matter content in the control area（27.27 g/kg）1.49 times;the low soil p H value（6.24）,indicating that the soil in the study area was in a weakly acidic environment,and the regional distribution difference was also significant.Among them,the soil p H in the solid waste accumulation area was the lowest at 5.92,followed by the soil p H in the farmland soil area at6.21,and the soil p H in the control area was the highest at 6.85.（2）The variation range of total sulfur content in the study area was 60.70～447.90 mg/kg,the average value was 162.52 mg/kg,and the higher coefficient of variation was 59.36%,indicating that total soil sulfur was highly susceptible to external environmental interference.Among them,the organic sulfur content varied from 45.58 to 386.34 mg/kg,with an average value of 133.34 mg/kg,accounting for 82.05%of the total sulfur,and the inorganic sulfur content varied from 15.12 to 61.56 mg/kg,with an average of 29.18 mg/kg,Accounting for only 17.95%of total sulfur.（3）The variation range of soil sulfate content was 11.08～59.18 mg/kg,with an average value of 25.38 mg/kg;In terms of spatial characteristics,the distribution of soil sulphate content dispiayed the order solid waste accumulation area>farmland soil area>control area;indicating that the coal gangue,fly ash and other sulfur-containing solid wastes piled up in the solid waste accumulation area have undergone leaching or weathering processes after entering the soil,it had a direct or indirect impact on soil sulfate,resulting in an increase in soil sulfate.（4）There was a significant positive correlation between soil sulphate and organic matter,which was mainly due to the fact that coal gangue and other sulfur-containing minerals in the study area were mainly green shale and coal shale,which was related to contain more carbon,and the surface soil organic matter contains nitrogen and sulfur functional groups.Soil sulfate was negatively correlated with p H,which was low in soil p H in the study area.It contains more iron-aluminum oxides and kaolin,and its absorption of sulfur was stronger;the soil C/S value was higher Low（average value of 108.15）,indicating that the soil sulfur in the study area was in the process of mineralization and the sulfur content in the soil of the mining area was relatively high.（5）Acid sulphate soil has low p H and high sulphate as the main obstacles,while manganese toxicity and aluminum toxicity were secondary obstacles.In this study,the acid sulfate soil was repaired by adding a certain amount of lime and self-made soil amendment.The experimental results showed that after treating the soil with lime and self-made amendments,the content of available manganese,available iron,exchangeable H+and exchangeable Al3+in the soil decreased,and the total calcium,total magnesium and total iron contents of the root system were increased.The internal environment of the soil has been improved to some extent,and the production level was higher,which was conducive to plant growth. |
