Effects Of Treatment Agent On Soil Properties And Root Knot Nematodes In The Continuous Cropping Soil Of Protected Tomato

Five soil treatment agents Paecilomyces lilacinus(T1),Fuqiduo(T2,10%fosthiazate),liquid chlorine dioxide(T3),Calcium cyanamide(T4)and 1,3-D(T5)were studied in the soil of seriously harmed by root knot nematode in the greenhouse planting tomato for about 10years,their effects on the dynamic accumulation characteristics of soil nutrient,the soil enzyme activity,the root knot nematode disease and the yield of tomato were analyzed,and the main results were as follows:1 Five different treatment agents has no effect on soil pH;Paecilomyces lilacinus,Calcium cyanamide,1,3-D can effectively reduce the soil EC value;Fuqiduoand chlorine dioxide also can reduce the soil EC value at seedling stage obviously,thus reduce the damage of soil salt ion on the tomato root.2 Paecilomyces lilacinus can delay the decreasing of organic matter in the soil,organic matter content is significantly higher than control during the whole growth period of tomato,while changes of soil organic matter are larger in other four chemical treatment The effect on content of alkaline hydrolysis nitrogen in soil is less;Paecilomyces lilacinus can significantly maintain total nitrogen content in shallow soil layer soil;Soil available phosphorus and available potassium content showed a trend of W in the whole growth period of tomato;Paecilomyces lilacinus can significantly increase the levels of available potassium and available phosphorus in the shallow soil.3 All the five treatments can promote the activities of urease,invertase and phosphatase,and Fuqiduo and 1,3-D had the most obvious influence on the three soil enzyme activity;while little effect was found on the activity of hydrogen peroxide enzyme.4 All the five treatments can increase the yield of tomato to more than 27%,and chlorine dioxide perform best,it can increase tomato yield 35.6%higher than CK,Paecilomyces lilacinus can increase tomato yield 31.6%higher,the lowest is Fuqiduo,which can reach tomato yield 27%higher.5 Five soil treatment can effectively restrain root knot nematodes infection and reproduction,although there is no significantly decreased in the rate of root knot nematode infected seedlings,but the nodules are small and less,prevention effect is more than 72%,chlorine dioxide perform best to control root knot nematode over 85.6%,and Calcium cyanamide controling effect was 72%the lowest.