Soil Phosphorus In Larix Gmelinii Plantation Forest And The Research Of Phosphate-solving Bacteria

Phosphorus is an important nutrient element in the soil.Together with nitrogen and potassium,it is an indispensable nutrient element in the soil.However,the form of Phosphorus in the soil is difficult to be absorbed by the soil,and it is difficult to be absorbed by the soil.Therefore,Phosphorus utilization is low in many places,and plant growth is in a state of Phosphorus deficiency.Nowadays,the method of applying Phosphorus fertilizer is widely used to change the Phosphorus deficiency in the soil.However,this method cannot solve the problem of low Phosphorus utilization rate of the plant from the root.It also produces river eutrophication and soil Phosphorus pollution.side effect.The environment of the burned area is relatively fragile,and it is even more unsuitable to use a large amount of phosphate fertilizer.In this paper,the Larix olgensis plantation planted on the severely burned ground in the Greater Xing'an Mountains is used as the research object.Through the maximum adsorption amount of soil Phosphorus,adsorption intensity factor,maximum buffer capacity,isothermal adsorption curve,Phosphorus form,type and activity of Phosphorus-resolving microorganisms The determination and analysis of soil Phosphorus were studied in the Daxinganling severely burned soil during the process of vegetation restoration and the characteristics of adsorption and desorption of soil Phosphorus.Research indicates:The results show that in non-rhizospHere soils of 0 to 20 cm,the isothermal adsorptioncurve of soil Phosphorus at different levels in the non-rhizospHere soil profile of natural secondary forests fits the Langmuir equation to the highest degree,showing similar adsorption mechanisms;In soil,the maximum range of soil Phosphorus adsorption(Qm)ranges from 672.49 to 700.77 mg/kg;in the natural secondary forest,the Phosphorus supply capacity in the soil of 0 to 20 cm is higher than that of Larix olgensis plantations with different recovery years.In different soil layers,the desorption amount and desorption rate of Phosphorus in the soil layers of 0?10cm and 10?20cm are not very different.In different restoration years,the non-rhizospHere soil of the Larix olgensis plantation has a restoration period of 29 years.The range of the maximum Phosphorus absorption(Qm)of?20cm soil is 2105.77?2200.06mg/kg;the maximum Phosphorus absorption(Qm)of 0?20cm soil layer in non-rhizospHere soil of the larch plantation with a recovery period of 23 years The variation range was 2000.28?2105.36 mg/kg;in the larch plantation with a recovery period of 8 years,the maximum adsorption amount(Qm)of Phosphorus in non-rhizospHere soil from 0 to 20 cm ranged from 1800.81 to 2005.17 mg/kg.In a larch plantation with a recovery period of 18 years,the maximum Phosphorus absorption(Qm)in the non-rhizospHere soil from 0 to 20 cm varied from 1300.49 to 1700.59 mg/kg.In non-rhizosphere soils,the adsorption intensity factors(K)of natural secondary forests were higher than those of Larix olgensis plantations with different recovery years.Natural secondary forest soil adsorption intensity factor is 0.017 L/mg,recovery of 29 years larch plantation soil adsorption intensity factor is 0.013 L/mg,recovery of 23 years larch plantation soil adsorption intensity factor is 0.011 L/mg,recovery of 18 years The soil adsorption intensity factor of the larch plantation was 0.005 L/mg,and the soil adsorption intensity factor of the larch plantation after recovery for 8 years was 0.009 L/mg.In different ages of Larix gmelinii plantations,different Phosphorus forms are also related to the use efficiency of Phosphorus by vegetation.In the burned areas of the Greater Xing'an Mountains,the content of active Phosphorus in the soil of Larix olgensis plantations with different recovery years accounted for 0.5%to 7.4%of the total Phosphorus;.intermediate active Phosphorus content accounted for 11.6%to 39.3%of the total Phosphorus;low active Phosphorus content accounted for the total Phosphorus 3.0%?47.1%.There are significant differences in Phosphorus forms in different regions.Among Phosphorus-resolving microorganisms,they are divided into organic Phosphorus-resolving bacteria and inorganic Phosphorus-soluble bacteria.In natural secondary forests,plantations in 1995,plantations in 2000,and plantations in 2010,the number of Phosphorus-dissolving bacteria in rhizospHere soil is generally higher than that in non-rhizospHere soils.The most is the rhizospHere soil in the natural secondary forest,the number is 23.32(cfu/g);the least is the non-rhizospHere soil in the larch plantation in 2000,the number is 3.02(cfu/g).Among the inorganic Phosphorus-soluble pHospHate bacteria,the largest number was the rhizospHere soil in the natural secondary forest,the number was 6.72(cfu/g);the smallest number was the non-rhizospHere soil of the larch plantation in 2000,the number of which was 1.71(cfu/g).