Study On The Relationship Between The Types Of Abandoned Grassland Development Projects And Soil Properties In Tangxian County

Under the background of balance between construction land and cultivated land,the development of new arable land has become an effective way to solve this problem.The research of other grassland development projects was born under this background.It is a product of a certain period of economic and social development and an objective requirement for the transformation of land use from extensive to intensive.Since the developed land is used for crop cultivation,research on the relationship between engineering development and soil quality has become particularly important.In the past,research on land project development focused on the impact of the overall project on soil quality.It does not involve single engineering elements and cannot be treated locally.In view of this,this study started with soil thickening and soil tending methods to study the changes in soil properties.Tang County is one of the representative counties in the low mountain and hilly areas of the Taihang Mountains.Because there are more development projects in the county,the area is selected as the research target.In the study area,four typical project areas with complete types,large scales,and representative projects were selected and a detailed survey of the project implementation in each project area was conducted.Based on the changes in soil properties before and after the development of the project area,the relationship between soil thickening and soil tending methods was studied.The results are as follows:(1)Summarized the trends of each soil properties after development.After carrying out development projects on other grasslands,the soil bulk density of the four project areas generally increased,with the added value ranging from 0.05 to 0.13 g/cm~3,and the maximum rate of change was 48.15%.Organic matter increased or decreased by half,the added value was about 11.00 g/kg,the reduction value was between 7.78~14.94 g/kg,and the rate of change was between 60.45%and 135.20%.The increase of available phosphorus was mainly at 0.22~6.73 mg/kg,and the maximum rate of change was 55.57%.The available potassium content increased all the time,and the added value ranged from20.03 to 119.86 mg/kg,with the maximum growth rate of 133.62%.The total nitrogen content increased or decreased by half,the increase value was between 0.08 and 0.68 g/kg,the decrease value was between 0.38 and 0.43 g/kg,and the change rate was between11.94%and 75.56%.(2)Analysis of changes in soil properties under different soil-thickening projects and soil tending methods.When the soil thickening works are all deep and the soil tends to be organic fertilizer+fertilizer and single organic fertilizer,organic fertilizer+fertilizer has better effect on quick-improving phosphorus and quick-improved potassium,and organic fertilizer is only applied to organic matter.When the soil thickening project is deep pine+guest soil and the soil tending method is organic fertilizer+chemical fertilizer and single organic fertilizer,organic fertilizer+chemical fertilizer has better effect on quick-improved phosphorus and quick-improved potassium,and single organic fertilizer is applied.Improved effect on organic matter and total nitrogen.When the soil tending method is organic fertilizer+fertilizer,and the soil thickening works are deep loose and deep pine+custom soil,the deep pine has better effect on the bulk density,organic matter and available phosphorus,and the deep pine+custom soil is effective.Potassium and total nitrogen improve the effect.When the soil tending method is single application of organic fertilizer and the soil layer thickening works are deep and loose soil+guest soil,the effect of deep pine+guest soil on bulk density,organic matter,available phosphorus,available potassium,and total nitrogen is better.(3)Aiming at the different underlying surfaces,the study of matching between soil thickening and soil tending methods.In the study of different soil thickening projects and different soil tending methods,based on the analysis of the changes in soil properties,combined with the type of underlying surface,we initially explored:When the underlying surface is shale and calcareous cinnamon soil,and the soil thickening project is deep,the soil tending method is preferred to apply single organic fertilizer.When the underlying surface is gneiss+calcareous cinnamon soil,and the soil thickening project is deep pine+home soil,the soil tending method is preferably single application of organic fertilizer.In summary,this study analyzed the changes of soil properties in the four typical project areas in Tangxian County,and compared soil condition changes with the combination of different soil thickening projects and soil tending methods.Finally,the underlying surface under various conditions was defined to make the research results more specific.In terms of improving soil properties,the results of this study provide a reference for the selection of other types of grassland development projects in low hilly areas.