Impact Of Alternative Technologies To The Use Of Methyl Bromide On Soil Protozoa Community In Greenhouses

The effects of the tomato varieties and soil disinfestations(MB, MB+VIF, MS, MS+VIF and SS+BCA) on soil protozoa with three level ten-fold dilution methods were studied. The results show that:1.The total abundance of protozoa was 15.11 millions/g.soil. Flagellate was about 5.44 millions/g .soil (36.00% of total abundance); Amoeba was about 7.49 millions/g. soil (49.57% of total abundance); Infusorian was about 2.09 millions/g . soil (14.43% of total abundance ). Therefore, flagellate and amoeba were dominant species.2.Grafted maofen significantly increased the abundance of protozoa. Because the amount and varieties of root exudates were different on different growth stages of tomato, the promoting effect was different. On the tomato seedling stage, the root was undeveloped, and root exudates were low and hadn't significant effect on soil protozoa. With tomato's growth, the root exudates were high and the abundance of flagellate was significant between tomato varieties. So did amoeba. At the end of tomato, part of plants died, and root exudates were low and there was not significant effect on flagellate and amoeba. The effect of tomato varieties on infusorian was significantly only on February and April. Therefore, the effect of tomato species on dominant species was higher than the other species.3. AH measures of soil disinfestation significantly inhibitted abundant of soil protozoa. The inhibition of methyl bromide on the amoeba was stronger and longer than the metham-sodium. After treated, the abundance of amoeba greatly decreased, then rebounded quickly, and the abundance was higher than CK.4. Results showed that tomato varieties didn't change the rate of flagellate, infusorian and amoeba. But the measures of soil disinfestation changed the community structure of soil protozoa, and the effect of all measures on flagellate and amoeba was same: All five measures decreased the percent of flagellate, and increased that of amoeba.5.Result showed that there was significantly correlation between soil protozoa and soil nitrogen. Therefore, soil protozoan is important among the alteration of soil nitrogen.