Effects Of Land Reclamation Models On Soil Nutrient Status In Jining City

Based on the present research situation of land reclamation in the mining area,this paper studied the soil chemical fertility traits in the reclamation area of Jining mining area,and explored the effects of different reclamation methods on the soil Nitrogen,available phosphorus,available potassium,organic matter and soil fertility,and the changes of soil organic matter,available potassium,available phosphorus and organic matter after different reclamation years were analyzed.The results were analyzed and evaluated for the soil fertility and environmental restoration to provide theoretical basis,the results show that:(1)Taking the reclamation plots filled with fly ash?coal gangue?the Yellow River sediment?lake sediments and the plots prepared for reclamation as the research object in Jining,this research was conducted to explore the influence on the soil nutrient and the total level of soil fertility with different reclamation modes.The results showed that the available nitrogen?available phosphorus?and organic matter which were 28.07mg/kg?45.15mg/kg and 1.14% increased significantly at 0-30 cm depth of the plot filled with coal gangue.The content of available potassium for the plot filled with the Yellow River sediment was the highest.Fly ash filling had the worst effect on the content of the available nitrogen.Pre-reclamation had the least influence on the available phosphorus?available potassium and organic matter.At the 30-50 cm depth,fly ash filling had the biggest influence on the soil fertility.The available nitrogen?available phosphorus?available potassium and organic matter were 68.5%?89.0%?71.4%?177.3% higher than the Control plot.The influence on the total level of soil fertility of five reclamation modes was in sequence of the plot filled with fly ash > the plot filled with coal gangue > the plot filled with the Yellow River sediment > the plot filled with lake sediments > the plot prepared for reclamation,at the 30-50 cm depth,the sequence was the plot filled with lake sediments > the plot filled with fly ash > the plot prepared for reclamation > the plot filled with the Yellow River sediment > the plot filled with coal gangue.Comprehensive consideration about soil nutrient and the total level of soil fertility,fly ash filling and lake sediments filling had the best effect on the recovery of soil fertility in Jining,and should get further popularization.(2)Changes of Soil Nutrients with same Reclamation Modes under Different YearsThe contents of soil organic matter were 10.34 mg / kg,13.28 mg / kg and 12.11 mg / kg,respectively,and the soil organic matter content was lower than that of the control.The content of organic matter in the land was 3.48 mg / kg,0.33 mg / kg and 0.83 mg / kg,which was close to that of the control plot.In the early stage of reclamation,the contents of available N were 57.29 mg / kg,59.67 mg / kg and 60.14 mg / kg,respectively,which was lower than that of the control plot 27.313 mg / kg,25.782 mg / kg,27.41 mg / Kg,but with the extension of the reclamation period,the content of soil alkali-hydrolyzable nitrogen increased gradually.Although the content of alkali-hydrolyzable nitrogen in the soil was still lower than that in the control land for five years,but with the development of the reclamation years,the contents of available N raises fastly,basically can reach the normal farmland level.The results showed that the available phosphorus contents in the 1 year,3 years and 5 years were significantly lower than those in the control plot.The soil available phosphorus was 11.810 mg / kg,10.536 mg / kg,11.479 mg.The soil available phosphorus content was 6.34 mg / kg,6.21 mg / kg,5.93 mg / kg,and 5.91 mg / kg,respectively accounting for 60% of the available phosphorus content in the control plot,although the available phosphorus content in the reclamation after 5 years only 60% of the control plot,but the overall is still on the rise.The soil available potassium content in the soil was lower than that in the control plot.The soil available potassium increased with the extension of the reclamation period.The soil available potassium in 0-20 cm,20-40 cm,40-60 cm soil The content was 110.28 mg / kg,122.39 mg / kg,118.49 mg / kg.The content of available potassium in 0-20 cm and 40-60 cm soil layer was still lower than that in control plot,but the content of available potassium in 20-40 cm soil layer was similar to that of control plot.(3)The recovery trend of reclaimed land with yellow river sedimentThe soil bulk density of yellowing can be restored after 7 years.After 5 to 6 years,the contents of organic matter,alkali-hydrolyzable nitrogen and available potassium can be restored to the level of cultivated land.The recovery time of available phosphorus is relatively long,to 15 years.May be appropriate to increase the application of phosphate fertilizer.