Study On Soil Microbiological Characteristics In Improved Salinized Soil In TEDA

Soil microorganisms, mainly bacteria, actinomyces and fiingi and soil biochemical activities, including respiration, ammoniation, invertase, proteinase, urease in salinized and improved soil were investigated during 2001 in Tianjin Economic and Technological Development Area (TEDA).It was shown that both Guest Soil and New Soil could be used to lift the land level and improve the original salinized soil. The microorganism numbers and the biochemical activities of improved soil were higher than that of salinized soil.The mean annual amount of soil microorganism are in order of New Soil improved earth, Guest Soil improved earth, Original Salinized Soil. The amount of microorganism in topsoil was about 3 times higher than that in subsurface soil. The dominant genera of Bacillus were B.cereus, B.subtilis, B.licheniformis and B.alvei. The dominant genera of actinomyces were Glaucus, Griseofuscus and Albosporus . The dominant genera of fungi in Original Salinized Soil were Penicillium and Asergillus, while in improved soil were Thamnidium and Pythium.In improved soil the amount of cellulose decomposing bacteria was increased by 100~500 times, denitrobacteria amount increased more than SOOtimes, amino-bacteria amount increased more than 1000 times. Azotobacter and nitrobacteria were new inhabitants in improved soil.After the soil improvement, the mean annual respiration intensity was improved by about 1.5 times, the activity of invertase was raised by about 5~10 times, the activity of proteinase was raised by about 2~4 times, and the activity of urease was raised by about 2~5 times.ANONA shows that the amount of bacteria and the boichemical activities in improved soil is higher than that in original salinized soil significantly. The biochemical activities were higher under the earth improved by Guest Soil, while under the New Soil improved earth the microbe amount was higher.The correlation analysis shows that the correlation is significant between biochemical activities and organic matter content hi the soil, it also shows that biochemical activities and the salt content correlated negatively. That is to say after soil improvement the salt content was controlled and the organic matter was increased.High organic matter and low salt content were favorable to microbial reproduction and biochemical process. After the soil was unproved by either way, the salt content decreased and the organic matter content increased. The New Soil unproved earth is more favorable to microorganism.