Research On The Response Mechanisim Of Soil Protozoa Colpoda Inflata To Nitrogen And Phosphorus

Soil protozoa are the third largest soil group,which is an essential link in material and energy cycles in soil ecosystems.The community structure of soil protozoa is greatly affected by regions and seasons,and it is also closely related to the vegetation types.Soil protozoa are numerous,and play an important role in soil carbon,nitrogen mineralization and phosphorus conversion.This paper explored the main characteristics of protozoan communities in winter in agricultural soil,soil with weeds and five typical plants at Northeast near the 45°north latitude of China.The protozoan abundance,the diversity and the correlation between the abundance,the diversity and the soil physicochemical properties,the plant types were analyzed to select a representative protozoa Colpoda inflata.Then,this paper mainly focused on the effects of nitrogen and phosphorus on Colpoda inflata and the effects of Colpoda inflata on the cycle of nitrogen and phosphorus.To further explore the response mechanism of protozoa to nitrogen and phosphorus.The conclusions are as follows:1.Describe and compare protozoan community structure in agricultural soil and soil with weeds in winter in Northeast China.According to the correlation between the abundance,the diversity and the soil physicochemical properties,the plant types,representative protozoa were selected and identified as Colpoda inflata.Protozoan diversity was mainly affected by the positive effects of the ammonia nitrogen and the nitrate nitrogen and the negative effects of the total nitrogen and the organic matter.2.The effects of nitrogen and phosphorus on the growth rate of Colpoda inflata were studied.Compared with the control group,nitrogen and phosphorus were added separately,it had inhibition on Colpoda inflata.Under the combined action of nitrogen and phosphorus,the cell density of Colpoda inflata increased significantly.After adding sufficient carbon,the population growth rate of Colpoda inflata significantly increased,and the best ratio of carbon/nitrogen/phosphorus was proposed.3.The response mechanism of Colpoda inflata to nitrogen and phosphorus were analyzed,and the effects of Colpoda inflata on nitrogen and phosphorus cycle were discussed.Colpoda inflata is directly involved in the nitrogen cycle through reductionreaction and nitrification.Phosphorus are accumulated in Colpoda inflata under certain conditions,and at the same time it plays an important role in the nitrogen metabolism.Adequate carbon can improve the efficiency of nitrogen and phosphorus metabolism.