In order to improve the quality of tea products towards asustainable tea production and to enhance the value of the teaindustry, "Study on the effect of microbial organic fertilizer and
Trang 1VU 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
Trang 21 Assoc Prof Dr Nguyen Van Toan
2 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
Trang 31 Tran Dang Viet, Vu Ngoc Tu (2015), "Research on mechanicharvesting 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
2 Vu Ngoc Tu, Nguyen Van Toan (2017), "Effects ofMicrobial Organic Fertilizer and Mulch to Population andBioactivity 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://
4 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
Trang 41 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 providenutrients for plants and supply soil microorganisms Thedevelopment and activity of soil microorganisms greatly affectsoil quality and plant growth Using organic fertilizer increasesorganic matter and microbial activity, releases graduallynutrients, not increasing nitrogen levels in plant tissue Inaddition to fertilizing, farming measures such as mulch, pluckingand planting shade trees also affect the growth of tea plants andaffect the quality of tea shoots
Soil cover or mulch is to cover organic or inorganic materials onthe soil surface in order to reduce weed growth, to protect soilmoisture, 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 technicalmeasure that greatly affects the yield and quality of tea shoots.Besides, planting shade trees helps tea plants grow better, increasetea production, improve soil and limit pests and diseases
LDP1 is a tea cultivar with good growth, relatively high shootyield, ability to tolerate adverse conditions and pests well Shoots ofLPD1 are used for processing both green tea and black cover withgood quality
In order to improve the quality of tea products towards asustainable tea production and to enhance the value of the teaindustry, "Study on the effect of microbial organic fertilizer and somefarming measures on variation of soil beneficial microorganisms andpests on LDP1 tea in Phu Tho" is essential to be able to proposepositive solutions for tea production in Phu Tho in particular and thecountry in general
2 Objectives of the study
- Determining the impact of microbial organic fertilizer on thevariation of some beneficial microorganisms in soil and the
Trang 5development of some pests on tea which used as a basis for properfertilization.
- Determine the effect of some technical measures to thevariation of some beneficial microorganisms in soil and pests toimprove the yield and quality of tea and to reduce the development
of pests
3 New contribution of the thesis
From the obtained research results, the thesis has some newcontributions to science those are: (1) Provide specific information
on the variation of microorganisms and increasing the quality of teasoil under the impact of microbial organic fertilizer; (2) Using Guot
to mulch for tea plants, the number of bacteria has increasedrapidly, mulching material has been quickly decomposed, thushelping to improve the soil in a short time; (3) Applying teaplucking method by machine helps to increase tea yield and reducethe harmful effects of some pests on tea such as green leaf hoppers,thrips and tea mosquito bugs
4 The layout of the thesis
The main content of the thesis is shown in 134 pages, including
3 preamble pages, 41 overview pages, 11 pages of materials, contentsand research methods, 79 pages of research results, discussion,references The whole section consists of 36 tables, 10 figures andgraphs The appendix includes the tea production, tea consumption inVietnam and in the world and other contents related to the thesis
Chapter 1 OVERVIEW
In this chapter, the thesis summarizes the research results andoutlines the general assessment of the content of the researches asfollows:
- Using organic fertilizer, especially microbial organic fertilizerand 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 organicfertilizer increases the growth of tea plants and increases tea yield
Trang 6Applying of organic fertilizers leads to diverse microbial populationsand also increase the number of soil microorganisms.
- Mulching by organic materials (straw, grass, sawdust, cropresidues, .) help to moisturize soil, regulate soil temperature,improve organic matter in soil, change the population ofmicroorganisms and enzyme activity in the soil, thereby increasingsoil fertility and increasing crop yield and quality The technique oftea 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 tealeaves The research results show that different tea pluckingtechniques 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 Theresearch results show that shade trees affect the generation ofdifferent tea pests
- Although studies on the effect of organic fertilizer on tea plantshas been performed, the deep researches on the effect of organicfertilizer, especially microbial organic fertilizer on the population ofsoil microorganisms, in particular, pointing out the change in thenumber of microorganism groups such as bacteria, actinomycetes orbioactive microorganisms when applying these fertilizers on tea soil
in Vietnam is still very limited Similarly, studies of the effect oforganic 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 somepests have also been studied However, this research direction onLDP1 tea plants (> 5-years old plants) in Phu Tho has not beenimplemented
Chapter 2 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 compostedfrom straw, green-manure plants, microbial products containingActinomycetes decomposing cellulose, Bacillus and Azotobacter
Trang 7converting organic matter Quality of product: moisture content of26%, organic content of 24%, total N content of 3.8%, density ofmicroorganisms decomposing cellulose 2.1 x 108 CFU/g; density ofBacillus and Azotobacter 3.09 - 5.12 x 108 CFU/g.
- Song Gianh microbial organic fertilizer produced by SongGianh Corporation has components: moisture of 30%, organic of15%, 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 mulchingmaterials
- Shade trees: "Muong la nhon" aged 4-5 Chinaberry were
planted along the border with the distance between plants from 10m (trees with a height of 5-7m)
2.2 Location and time of study
- Location: Northern Mountainous Agriculture and ForestryScience Institute (Phu Ho commune, Phu Tho town, Phu Thoprovince)
- Time for monitoring experiments: From December 2012 toDecember 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 andpests 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:
Trang 8* Experiment 1: Effect of the amount of microbial organicfertilizer on the variation of beneficial microorganisms in soil.
* Experiment 2: Effect of replacing mineral fertilizer bymicrobial organic fertilizer (calculated by amount of fertilizer) on thevariation of pests on LDP1 tea cultivar
* Experiment 3: Effect of replacing mineral fertilizer bymicrobial organic fertilizer (calculated by value of fertilizer) on thevariation of pests on LDP1 tea cultivar
* Experiment 4: Effect of mulch materials on the variation ofbeneficial microorganisms in soil
* Experiment 5: Effect of harvesting methods on the variation ofpests on tea plants and the yield, quality of tea
* Experiment 6: Effect of shade trees on the variation of pests ontea 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 6
- 15 cm, after removing about 5 cm of soil and plant residues
- Methods of isolation and determination of microbial cellnumbers
- Method of determining strains of microorganisms which areable to decompose cellulose, phosphate and free nitrogen fixation+ Experimental layout method: experiments were arranged in acompletely random block, 3 replicates, each experiment had an area
of 45 m2
+ Adding organic fertilizer:
- Adding once at the beginning of the year (in February), at thetime of rain, moist soil Fertilizer was added into a hole which isclose 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 5diagonal points, each point takes 2 small points, each small point on a
Trang 9tea line is 1.0m long (equivalent with 3 tea plants), use a large plasticbag to cover the tea plant and vibrate for all organisms to fall in andthen conduct counting and classification Determine the frequency ofencountering each pest.
* Study the effect of mulch materials on the variation of beneficial microorganisms in soil
Mulching method: evenly spread mulch materials along thetea row, close to the tea stump For tea leaves and branches aftercutting, they were removed from the surface and mulchedimmediately 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 ofshoot, 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 werestatistically different, Tukey (P <0.05) comparison was used to testthe difference between average values
Chapter 3 RESULTS AND DISCUSSION
3.1 Effect of the amount of microbial organic fertilizer on the variation of beneficial microorganisms in soil and pests on tea plants in Phu Tho
3.1.1 Physical and chemical properties of tea soil
The results show that soil used in the experiments is acidic andpoor nutrient pHKCl fluctuates in the range of 3.6-4.6, total anddigestible phosphate (P2O5) are low, organic matter (OM), potassium(K2O) and protein at average level Low CEC, from 4.12 to 6.69 meq/100g soil; low Ca and Mg, 1.59 and 0.72 meq/100g soil, respectively.These results are consistent with previous studies
Trang 103.1.2 Effect of the amount of microbial organic fertilizer on the variation of beneficial microorganisms in soil
3.1.2.1 Effect of microbial organic fertilizer on total microbial composition
Effect of microbial organic fertilizer on total bacterial density
Figure 3.1: Effect of microbial organic fertilizer on total bacterial density (unit: 106CFU/g soil) Different lower case letters indicatesignificant differences among treatments at the same day and different uppercase letters indicate significant differences among days at P < 0.05 CT1(control): No organic fertilizer; CT2: adding microbial organic fertilizer at1.0 tons ha-1 year-1; CT3: adding microbial organic fertilizer at 2.0 tons ha-1
year-1; CT4: adding microbial organic fertilizer at 3.0 tons ha-1 year-1
During the 60 days after applying fertilizer, the total bacterial density
in soil at the experiments began to increase, with the highest density in CT4.After 240 days, the total bacterial density continued to increase in allexperimental treatments, the highest density in CT4 (reaching 14.3 x
106CFU / g soil) but an increase of total bacterial density in CT2 and CT3was slowed down, gradually stabilized at over 9.80 x 106CFU / g soil
Trang 11Effect of microbial organic fertilizer on total actinomycetes density
Figure 3.2: Total actinomycetes density in soil (Unit: 10 5 CFU/g soil).
Different letters indicate significant differences among treatments at the
same day at P < 0.05The results showed that the density of actinomycetes in CT2,CT3 and CT4 increased after 120 days of applying microbial organicfertilizer and increased compared to control Particularly in CT4, thedensity of actinomycetes increased faster, only after 60 days After
240 days, in the treatments adding large amounts of fertilizer (CT4),the density of actinomycetes significantly increased, reaching 10.67 x105CFU / g soil, while the density of actinomycetes in the controldoes not change In the treatments applied lower microbial organicfertilizer, such as CT2 and CT3, the density of actinomycetes wasalso increased compared to the control but still lower than that ofCT4 after 240 days
Effect of the amount of microbial organic fertilizer on the density
of bioactive microorganisms
Of the 10 tested strains of bacteria in CT4, up to 46% of strainshad cellulose decomposing activity; the number of the strainsdecomposing insoluble phosphates, starch and mucous membranewas 32%, 22% and 15%, respectively The number ofmicroorganisms decomposing cellulose, insoluble phosphates in CT2and CT3 was lower, even many strains which are not able todecompose starch and mucous membrane were also detected in thesetreatments
3.1.2.2 Assession of the diversity of microorganisms in soil under the impact of microbial organic fertilizer
Trang 12Table 3.1: The diversity of microorganisms in soil after applying
microbial organic fertilizers (240 days)
Treatments Genus total
Bacteria Filamentous fungi Lipomyces Actinomycete Number % Number % Number % Number %
Table 3.2: Soil microbial composition and their distribution
in treatments applying microbial organic fertilizer
(after 240 days)
Groups Composition of varieties
Frequency of occurrence of strains
T1 (control )
-Total 18
Trang 13Note: So many: (++++), many: (+++), relative: (++), less: (+), and none: (-)
Table 3.2 shows that applying more microbial organicfertilizers (CT4) in soil leads to appear many strains ofbacteria decomposing organic matter, cellulose, andinsoluble phosphates such as Pseudomonas, Bacillus,Azotobacter, Nitrosomonas and Nitrobacter
3.1.3 Effect of the amount of microbial organic fertilizer on the variation of pests on tea plants
3.1.3.1 Investigation of the composition of pests and natural enemies
on tea plants in Phu Tho
The composition of pest on tea plants in Phu Tho
The survey results show that there are 29 pest species on teaplants in Phu Tho, belonging to 9 orders of insects and spiders,including:
- Order Acarina: There are 5 species of 4 families, of which the
main harm species is Oligonyclus coffeae Nietner.
- Order Coleoptera: There are 2 species of 2 different familiesCurculinidae and Scarabacidae, notably dor-beetles that damage tea roots
- Order Diptera: 1 species of Chloropidae family
- Order Hemiptera: there are 5 species of 4 families, notably tea
mosquito bugs Helopeltis theivora Waterhouse seriously harms tea.
- Order Homoptera: There are 4 species of 4 families, of whichEmpoasca flavescens Fabr belongs to Ciadellidae which accountsthe largest number, then to the mealybug
- Order Isoptera: 1 species Odontotermes formosanus Shiraki
belongs to Termitidae family
- Order Lepidoptera: There are 8 species of 7 families
- Order Orthoptera: 2 species of 2 families, these species of thisorder do not cause significant harm
- Order Thysanoptera: 1 species Physothrips setiventris Bagnall of
Thripidae family
The composition of natural enemies of pests on tea in Phu Tho
Trang 14In the beginning of 2013, investigation and evaluation of naturalenemies of pests on tea in Phu Tho has obtained 19 species of insects,prey spiders and parasites, belonging to 8 different orders.
Table 3.3: The composition of natural enemies of pests on tea in
2 Nhen gap la Clubiona japnicollaBoes et Str. Clubionidae Green leafhoppers +
3 Nhen ham dai Tetragnatha maxilloxa Thorell Tetragnathidae Green leafhoppers ++
4 Nhen linh mieu Oxyopes javanus Thorell Oxyopidae
Green leaf hoppers, larva of Lepidoptera
++
5 Nhen lun Atypena formosana sp. Linyphiidae Green leafhoppers +
Pardosa pseudoannulata
Boes et Str.
7. Nhen van lunghinh mac Argipe catenulataDoles chall Araneidae hoppers, thripsGreen leaf +
Order Coleoptera
8. Kienkhoang ba Paederus fuscipes Curtis Strophylinidae Aphids, larva ofLepidoptera ++
9 Bo rua do Micrapis discolor Fabr. Coccinellidae Aphids, larva ofLepidoptera ++
10 Bo rua nho Stethorus sp. Coccinellidae green leafAphids,
hoppers
+
11 Bo rua 6 van
Menochilus sexmaculatus
Fabr.
Coccinellidae Aphid, green leafhoppers +
12. Bo rua chuanhan Coccinella transversalis Coccinellidae Aphids, theireggs +
15. Ongtrang nhoken Apanteles sp. Braconidae coffearia Niet. Homona +