THAI NGUYEN UNIVERSITY UNIVERSITY OF EDUCATION VU NGOC TU STUDY THE VARIATIONS OF BENEFICIAL MICROORGANISMS IN SOIL AND PESTS ON LDP1 TEA PLANTS IN PHU THO PROVINCE UNDER THE IMPACT OF MICROBIAL ORGANIC FETILIZER AND SOME FARMING TECHNIQUES Speciality: Ecology Code: 9420120 DISSERTATION SUMMARY THAI NGUYEN - 2019 The dissertation was finished at: THAI NGUYEN UNIVERSITY - UNIVERSITY OF EDUCATION Supervisors: Assoc Prof Dr Nguyen Van Toan Assoc Prof Dr Le Tat Khuong Reviewer 1:……………………………………………… Reviewer 2:……………………………………………… Reviewer 3:……………………………………………… The dissertation will be defended in the university committee: THAI NGUYEN UNIVERSITY - UNIVERSITY OF EDUCATION At ……………… , 2019 The dissertation can be read at: - National library of Vietnam; - Thai Nguyen University - Learning Resource Center; - Library of University of Education LIST OF PUBLICATIONS RELATED TO THE THESIS Tran Dang Viet, Vu Ngoc Tu (2015), "Research on mechanic harvesting technology for tea variety LDP1 on the mature ages" Vietnam journal of agricultural science and technology, Vietnam Academy of Agricultural Science Vol 5(58): 33-38 Vu Ngoc Tu, Nguyen Van Toan (2017), "Effects of Microbial Organic Fertilizer and Mulch to Population and Bioactivity of Beneficial Microorganisms in Tea Soil in Phu Tho, Viet Nam" International Journal of Agricultural Technology 2017 Vol 13(4): 469-484 Available online http://www.ijat-aatsea.com ISSN 1686-9141 Vu Ngoc Tu, Nguyen Van Toan (2018), "Impact of organic micro-fertilizers on main pests population on Phu Tho tea" Journal of Science and Technology, Thai Nguyen University Vol 180(04): 181 - 186 Vu Ngoc Tu, Nguyen Van Toan, Le Tat Khuong (2018), “Effects of multiple-purpose shading trees on some main pests of Phu Tho tea” Vietnam Journal of Agricultural Science and Technology, Vietnam Academy of Agricultural Science Vol 12(97)/2018: 82-88 PREAMBLE The urgency of the thesis Tea is one of the most consumed beverage in the world and produced from the leaves of Camellia sinensis Applying organic fertilizer, especially microbial organic fertilizer, will provide nutrients for plants and supply soil microorganisms The development and activity of soil microorganisms greatly affect soil quality and plant growth Using organic fertilizer increases organic matter and microbial activity, releases gradually nutrients, not increasing nitrogen levels in plant tissue In addition to fertilizing, farming measures such as mulch, plucking and planting shade trees also affect the growth of tea plants and affect the quality of tea shoots Soil cover or mulch is to cover organic or inorganic materials on the soil surface in order to reduce weed growth, to protect soil moisture, to protect soil from erosion, to speed up the infiltration, and to reduce fluctuations in soil temperature, thus increasing the growth of plants Plucking of tea is both a harvesting operation and a technical measure that greatly affects the yield and quality of tea shoots Besides, planting shade trees helps tea plants grow better, increase tea production, improve soil and limit pests and diseases LDP1 is a tea cultivar with good growth, relatively high shoot yield, ability to tolerate adverse conditions and pests well Shoots of LPD1 are used for processing both green tea and black cover with good quality In order to improve the quality of tea products towards a sustainable tea production and to enhance the value of the tea industry, "Study on the effect of microbial organic fertilizer and some farming measures on variation of soil beneficial microorganisms and pests on LDP1 tea in Phu Tho" is essential to be able to propose positive solutions for tea production in Phu Tho in particular and the country in general Objectives of the study - Determining the impact of microbial organic fertilizer on the variation of some beneficial microorganisms in soil and the development of some pests on tea which used as a basis for proper fertilization - Determine the effect of some technical measures to the variation of some beneficial microorganisms in soil and pests to improve the yield and quality of tea and to reduce the development of pests New contribution of the thesis From the obtained research results, the thesis has some new contributions to science those are: (1) Provide specific information on the variation of microorganisms and increasing the quality of tea soil under the impact of microbial organic fertilizer; (2) Using Guot to mulch for tea plants, the number of bacteria has increased rapidly, mulching material has been quickly decomposed, thus helping to improve the soil in a short time; (3) Applying tea plucking method by machine helps to increase tea yield and reduce the harmful effects of some pests on tea such as green leaf hoppers, thrips and tea mosquito bugs The layout of the thesis The main content of the thesis is shown in 134 pages, including preamble pages, 41 overview pages, 11 pages of materials, contents and research methods, 79 pages of research results, discussion, references The whole section consists of 36 tables, 10 figures and graphs The appendix includes the tea production, tea consumption in Vietnam and in the world and other contents related to the thesis Chapter OVERVIEW In this chapter, the thesis summarizes the research results and outlines the general assessment of the content of the researches as follows: - Using organic fertilizer, especially microbial organic fertilizer and the application of farming measures all affect soil quality, growth, development and crop yield, from annual crops to perennials, as well as the generation of some pests - For the tea plants, the research results show that use of organic fertilizer increases the growth of tea plants and increases tea yield Applying of organic fertilizers leads to diverse microbial populations and also increase the number of soil microorganisms - Mulching by organic materials (straw, grass, sawdust, crop residues, ) help to moisturize soil, regulate soil temperature, improve organic matter in soil, change the population of microorganisms and enzyme activity in the soil, thereby increasing soil fertility and increasing crop yield and quality The technique of tea plucking is one of the most important factors which is interested in tea harvest, because it is related to the yield and quality of fresh tea leaves The research results show that different tea plucking techniques lead to different yield and quality - Using "muong la nhon" (Indigofera zollingeriana Miq.) or mondo grass (Ophiopogon japonicus Wall) as shade trees in tea fields to decrease problems with some pests is reported The research results show that shade trees affect the generation of different tea pests - Although studies on the effect of organic fertilizer on tea plants has been performed, the deep researches on the effect of organic fertilizer, especially microbial organic fertilizer on the population of soil microorganisms, in particular, pointing out the change in the number of microorganism groups such as bacteria, actinomycetes or bioactive microorganisms when applying these fertilizers on tea soil in Vietnam is still very limited Similarly, studies of the effect of organic fertilizer on the variation of pests to tea plants over the time of the year are also not popular - The effects of shade trees on the tea yield and quality and some pests have also been studied However, this research direction on LDP1 tea plants (> 5-years old plants) in Phu Tho has not been implemented Chapter MATERIALS, CONTENTS AND RESEARCH METHODS 2.1 Research materials Tea cultivar: LDP1 tea cultivar grown in 2000 was used in the experiments Other materials: - Microbial organic fertilizer used in the study is composted from straw, green-manure plants, microbial products containing Actinomycetes decomposing cellulose, Bacillus and Azotobacter converting organic matter Quality of product: moisture content of 26%, organic content of 24%, total N content of 3.8%, density of microorganisms decomposing cellulose 2.1 x 108 CFU/g; density of Bacillus and Azotobacter 3.09 - 5.12 x 108 CFU/g - Song Gianh microbial organic fertilizer produced by Song Gianh Corporation has components: moisture of 30%, organic of 15%, P2O5 of 1.5% , humic acid of 2.5%, medium components (Ca , Mg, S), beneficial microorganisms: Aspergillussp., Azotobacter, and Bacillus - Mulch: Guot and tea tree wastes have been used as mulching materials - Shade trees: "Muong la nhon" aged 4-5 Chinaberry were planted along the border with the distance between plants from 710m (trees with a height of 5-7m) Research subjects: - Microorganism groups in soil are interested in research: bacteria, actinomycetes, fungi - Some pests on tea plants including red spider mite, tea mosquito bugs, green leaf hoppers, thrips 2.2 Location and time of study - Location: Northern Mountainous Agriculture and Forestry Science Institute (Phu Ho commune, Phu Tho town, Phu Tho province) - Time for monitoring experiments: From December 2012 to December 2015 2.3 Research contents Content 1: Study the effect of the amount of microbial organic fertilizer on the variation of beneficial microorganisms in soil and pests on tea plants in Phu Tho Content 2: Study the effect of mulch materials on the variation of beneficial microorganisms in soil Content 3: Study the effect of harvesting methods on the variation of pests on tea plants and the yield, quality of tea Content 4: Study the effect of shade trees on the variation of pests on tea plants and the development of tea plants 2.4 Research methods 2.4.1 Experiments: * Experiment 1: Effect of the amount of microbial organic fertilizer on the variation of beneficial microorganisms in soil * Experiment 2: Effect of replacing mineral fertilizer by microbial organic fertilizer (calculated by amount of fertilizer) on the variation of pests on LDP1 tea cultivar * Experiment 3: Effect of replacing mineral fertilizer by microbial organic fertilizer (calculated by value of fertilizer) on the variation of pests on LDP1 tea cultivar * Experiment 4: Effect of mulch materials on the variation of beneficial microorganisms in soil * Experiment 5: Effect of harvesting methods on the variation of pests on tea plants and the yield, quality of tea * Experiment 6: Effect of shade trees on the variation of pests on tea plants and the development of tea plants 2.4.2 Methods * Study the effect of microbial organic fertilizer on the variation of beneficial microorganisms in soil + Research methods of microorganisms in soil: - Soil sampling method: Soil samples were taken at a depth of - 15 cm, after removing about cm of soil and plant residues - Methods of isolation and determination of microbial cell numbers - Method of determining strains of microorganisms which are able to decompose cellulose, phosphate and free nitrogen fixation + Experimental layout method: experiments were arranged in a completely random block, replicates, each experiment had an area of 45 m2 + Adding organic fertilizer: - Adding once at the beginning of the year (in February), at the time of rain, moist soil Fertilizer was added into a hole which is close to the stump (15-30cm far from the stump, 10-15cm deep hole) * Study the effect of the amount of microbial organic fertilizer on the variation of pests on tea plants + Methods of investigating the composition and popularity of pests: Conducting the survey every 7-10 days, randomly surveying at diagonal points, each point takes small points, each small point on a tea line is 1.0m long (equivalent with tea plants), use a large plastic bag to cover the tea plant and vibrate for all organisms to fall in and then conduct counting and classification Determine the frequency of encountering each pest * Study the effect of mulch materials on the variation of beneficial microorganisms in soil Mulching method: evenly spread mulch materials along the tea row, close to the tea stump For tea leaves and branches after cutting, they were removed from the surface and mulched immediately to the stump * Study the effect of harvesting methods on the yield, quality of tea and the variation of pests on tea plants - Monitoring of agronomic indicators: shoot density, mass of shoot, productivity of fresh tea shoots, ratio of tea with A+B quality, indicators of pest density, 2.5 Data analysis Statistical analysis was performed by using R software In order to determine whether the experimental formulas which were statistically different, Tukey (P