Effects Of Different Crop Stubbles On Tomato Growth And Development And Rhizosphere Soil Micro-environment Incontinuous Cropping Soil

It is true that continuous cropping obstacle has been a burden on the developing ofChinese vegetable industrial system. With Chinese greenhouse vegetable industryincreasing markedly, continuous cropping obstacle in many vegetables, such as tomato, isbecoming widespread in most part of China. At present, there is less research about effectsof crop stubble on continuous cropping vegetables, especially in the mechanism behind howthe crop stubble influence continuous cropping soil environment and vegetable growth.In this experiment, eight treatments had been included under greenhouse potted plantconditions: normal soil treatment (CK), continuous cropping tomato obstacle soil (8years)treatment (CS), continuous cropping tomato soil mixed with different weight ratio maizestubble treatments (CSM1means0.5%, CSM2means1.0%and CSM3means2.0%) andcontinuous cropping tomato soil mixed with different weight ratio soybean stubbletreatments (CSS1means0.5%, CSS2means1.0%and CSS3means2.0%). In thisexperiment, the effects of different crop stubbles on soil enzyme activities, soilmicroorganism community structures, character of soil physical and chemical properties,plant growth, fruit quality and yield were evaluated. Results are shown as follows.1. Mixing continuous cropping soil with soybean or maize stubble treatments candramatically increase plant growth and tomato yield, and meanwhile decrease fruit hardnessand vitamin C. And some treatments in those can increase contents of fruit soluble sugarand organic acid. CSM1and CSS1had better performances in improving plant growth.Tomato yield of CSM2and CSS2increased separately9.68%and8.27%.2. Mixing continuous cropping soil with soybean or maize stubble treatments canimprove soil pH value and soil electrical conductivity, which were obvious in CSM2andCSS2. Soybean stubble treatments were better than maize stubble treatments in those twoindexes. Mixing either soil or soybean stubble with maize stubble can increase soil nutritioncontents. Maize stubble played a better role in increasing soil available P and available K contents. Meanwhile, soybean stubble had a better performance in improving soil NO3--Ncontents.3. Soil microbiological community analysis showed that mixing continuous croppingtomato soil with maize or soybean stubble had increased the bacterial quantity,actinomycetes quantity and total microbiological quantity. In summary, those treatmentschanged soil microorganism community structure from “fungi dominant” to “bacteriadominant”, and maize stubble treatments were better in this part.4. What’s more, compared with CK, rhizosphere soil catalase activity, urease activity,sucrase activities decreased in CS, but phosphatase activity also increased at the same time.Increases of soil catalase activity, urease activity, phosphatase activity and sucrase activitywere detected in all maize stubble and soybean stubble treatments. And CSM3, CSS2werethe best at those areas. Compared to soybean stubble treatments, maize stubble treatmentshad a better performance in improving urease activity, phosphatase activity and sucraseactivity. Mixing continuous cropping soil with soybean stubble really did well in increasingsoil catalase activity.In conclusion, it was detected that both mixing continuous cropping soil with1.0%soybean and1.0%maize had the best performance in improving soil environment ofcontinuous cropping tomato and increasing fruit quality and tomato yield. Maize stubbleshowed its ability which could release nutrition steadily and slowly. Meanwhile, soybeanstubble released nutrition quickly, therefore it could improve soil environment and plantgrowth at early stage of tomato growth.