اثرات کوتاه مدت ورمی کمپوست بر ویژگیهای خاک و کیفیت برگ سبز چای در اراضی چایکاری

There is no scientific report, as an out put of field study, related to short or long effect of vermicompost on soil properties and quality of tea green leaves with the aim of replacement of chemical fertilizers with organic manures and producton of organic tea, but in trade level this activity has been started in small scale in Guilan province. In order to study short time effects of different levels of vermicompost on soil properties and quality of tea green leaf with the aim of investigation posibility of organic tea production, this research has been counducted in one tea garden with 30 hectares area, located in the side of Foman–Maklavan road, in Guilan province, in a completely randomized design with 3 treatments and replications. First of all, prune floor has been done in the part of this garden and plots were separated with 20 square meter area. Then soil samples were taken from surface and combined and primary experiments have been done, in the end of winter, 2013. Then, vermicompost, with suitable size (<4mm), were provided and its important characterictics were determind and then according to statistical design, were added to soil surface of each plot in three levels (0, 0.5 and 2%) and mixed with soil, thoroughly by surface plow. During spring and summer, weed growth has been controed between the rows and raini irrigation has been done. In the end of summer, soil samples were collected by uger again and tea green leaf includes a bud plus two youngest leaves and also third leaf, picked up by mashin and immidiatly samples were shifted to the tea research center laboratory. Immidiatly in plant sample, third leaf separated from bud pluse two youngest leaves, by hand. Then soil and plant samples preparation and then soil test and plant samples analysis include third leaf and bud plus two youngest leaves has been done, seperatly. Results indicated an increase in electrical conductivity, cation exchange capacity, organic carbon, respiration, porosity and moisture content, in soil by adding vermicompost in both levels (0.5 and 2 %). The amount of nitrogen, phosphors and potassium in soil samples increased in treated plots by vermicompost as compare to treatment witout vermicompost, significantly, but there was no different between treatments of 0/5 and 2 percent. Organic manure application in both levels (0.5 and 2 %) deccreased bulk and particle density in soil. In treatment with 0.5 % vermicompost, potassium content and in treatment with 2 % vermicompost, in addition of K, N and P content improved in third leaves. In bud plus two youngest leaves, caffeine content increased but poliphenoles, total ash and water extract, decreased. According to the results of this research, it could be concluded that within six months after application of vermicompost in the soil of tea garden, it improved soil properties and quality of tea green leaf especially in 2 % level and it could provide major part of macronutrients for tea plant growth. These results, in short time, could be earned, if first class of vermicompost used, secondly, organic manure mixed with soil thouruly in application time, in this sitioation, it is possible to produce organic tea green leaf, witout application of chemical fertilizers. According to the availability of agricultural and natural waste in Guilan, scientifically and practically, production of organic tea green leaf is possible, in north of Iran.