Study On Soil Physical And Chemical Properties,Microbial And Enzyme Activities In Greenhouse Tomato

Tomato(Lycopersicon esculentum Mill)as one of China's major vegetables,has been widely cultivated in China.The tomato biomass,soil physical and chemical properties,microorganism and enzyme activities in a field tomato and a potted tomato were studied in this paper.Main results are as follows: 1.Effects of continuous cropping years on soil physical and chemical properties,microorganism and enzyme activity :Results show that,with the increasing of continuous cropping years,tomato soil pH value decreased gradually,and tomato soil conductivity,organic matter,soil total N,available K,available P content increased gradually in the first 6 years,and then decreased year by year;With the increase of continuous cropping years,the number of microorganisms increased first and then decreased,and the number of bacteria reached the highest value in sixth years(2.5×108 CFU.g-1),and the number of fungi reached the highest value in 7 years of continuous cropping(2.4×105 CFU.g-1).However,the ratio of bacteria to fungi had been decreasing.The content of soil catalase and urease content increased first and then decreased,catalase reached the maximum value in the continuous cropping 6 years(0.87 m L.g-1),urease in continuous cropping 5 years reaches the maximum value(2.52 mg.g-1).Continuous cropping had a deep effect on soil microbial biomass,soil physical and chemical properties and soil enzyme activity,especially for 6-7 years,the soil had an extreme value in all aspects.the obstacles of continuous cropping were obvious.2.Effects of different planting patterns on soil physical and chemical properties,microbial activities and enzyme activities in Greenhouse Tomato: 2.1 Effects of different planting patterns on soil physical and chemical propertiesThe relationship between soil pH was intercropping?crop rotation> continuous cropping,effects of different planting patterns on soil organic matter was not significant,intercropping,crop rotation pattern was slightly higher than that of continuous cropping pattern.The relationship between soil electrical conductivity and intercropping model was slightly lower than that of continuous cropping pattern.The soil available nutrients was intercropping?crop rotation> continuous cropping.2.2 Effects of different planting patterns on soil microbesThe number of different planting patterns of soil bacteria relationship was intercropping>crop rotation>continuous cropping,the ratio of bacteria to fungi was the intercropping>crop rotation>continuous cropping.The relationship between soil bacterial species was ntercropping>crop rotation>continuous cropping,the relationship between soil fungi intercropping was intercropping?crop rotation>continuous cropping.2.3 Effects of different planting patterns on soil enzyme activitiesThe urease content of intercropping and crop rotation models was significantly higher than that of continuous cropping model,the relationship was intercropping>crop rotation>continuous cropping,and the relationship between the content of soil catalase and continuous cropping>crop rotation>intercropping.2.4 Effects of different planting patterns on Greenhouse TomatoThe relationship between tomato yield was intercropping>crop rotation>continuous cropping.2.5 The relationship among soil physical and chemical properties,soil microorganwasms and greenhouse tomato in preplantThe number of soil bacteria before tomato planting had a significant effect on tomato yield,the effect of bacterial / fungal ratio before tomato planting on root fresh weight and root dry weight was significant,and the effect of fresh weight on stem and leaf weight was significant.2.6 The relationship among tomato and soil physical and chemical properties and soil microorganwasmThe yield of tomato was negatively correlated with soil available nutrient.There was a significant positive correlation between soil catalase and tomato root fresh weight,while soil urease content was negatively correlated with the root freshness.Soil fungi and bacteria were negatively correlated with soil catalase content,but positively correlated with soil urease content.2.7 Relationship between soil physical and chemical properties and soil microbesSoil fungi were significantly correlated with available potassium,and soil catalase was negatively correlated with soil pH,and negatively correlated with organic matter content.There was a significant negative correlation between soil urease and soil organic matter percentage,and negatively correlated with soil pH.