Effect of some foliar fertilizers on the growth, development and yield of dt51 soybean in winter season, 2020 gia lam, ha noi

ABSTRACT Research on the effects of some foliar fertilizers on the growth, development and yield of soybeans in winter season 2020, Gia Lam, Ha Noi.. Since then, contributing to the sele

SOYBEAN IN WINTER SEASON,

2020 GIA LAM, HA NOI

Student code : 611757

Supervisor : PhD NUYEN VAN PHU Department : PLANT PHYSIOLOGY

HANOI-2021

DECLARATION

I declare that the undergraduate thesis is the result of my research The data and results mentioned in this thesis are honest and not used in any published thesis, dissertations, and scientific research projects previously

I hereby commit that the information cited in the thesis ensuring cited as prescribed I bear full responsibility for these reassurances

Hanoi, February 24, 2021

Student

Le Linh Chi

ACKNOWLEDGEMENT

After a long period of studying in the university, the undergraduate thesis

is the most important time for me to improve and have more knowledge to research the reality with teachers and staff in the Faculty of Agronomy, especially teachers in the Plant Physiology Department During the internship and undergraduate thesis, not only my efforts but also I received a lot of help from teachers, family and friends

First of all, I would like to express my deep gratitude to PhD Nguyen Van Phu who dedicated guidance and helped me during the study process and complete thesis

Specially thanks to the Dean Of Faculty and all the teachers in the Faculty

of Agronomy, especially the teachers in Plant Physiology who helped me complete this undergraduate thesis

I would also like to thank the staff of the Department of Plant Physiology for helping, sharing valuable experiences as well as creating the best conditions for me to do this undergraduate thesis

Finally, I would like to thank my family and friends who are always there

to care for and encourage me throughout the undergraduate thesis process

Sincerely!

Hanoi, February 24, 2021

Student

Le Linh Chi

ABSTRACT

Research on the effects of some foliar fertilizers on the growth, development and yield of soybeans in winter season 2020, Gia Lam, Ha Noi Since then, contributing to the selection, creation and construction of cultivation methods to determine the most effective foliar fertilizers for high yield and high quality soybean of varieties soybean in Vietnam

The pot experiment was carried from September 2020 to January 2021 at the Faculty of Agronomy, Vietnam National University of Agriculture, Trau Quy commune, Gia Lam district, Hanoi The experiment was arranged is arranged in the randomized complete block (RCB) repeat time times Five treatments included T1 (H2O), T2 (Dau Trau 501), T3 (Grow More 30-10-10+TE), T4 (Profarm- n29) and T5 (Seaweed 95%) Monitoring criterias: height, number of leaves, number of flowers, leaf area, leaf area index Using Excel software and IRISSTAT 5.0 biological statistical software to process data

The results showed that foliar fertilizer has good effects on criterias of growth and development of DT51 soybean in which T5: Seaweed 95% helped the plant to grow best, reached the highest of yield 19.64 quintals/ha and got the highest net profit 91.75 million VND/ha Meanwhile, no significant difference

in the growth, development and yield among foliar fertilizers

CONTENTS

DECLARATION i

ACKNOWLEDGEMENT ii

ABSTRACT iii

CONTENTS iv

LIST OF ABBREVIATIONS vii

LIST OF TABLES viii

LIST OF FIGURES ix

PART 1 INTRODUCTION 1

1.1 Introduction section 1

1.2 Research objective and requirement 2

1.2.1 Objective 2

1.2.2 Requirement 3

PART 2 LITERATURE REVIEW 4

2.1 Valuations of soybean 4

2.1.1 Economic value of soybean 4

2.1.2 Agricultural value of soybean 5

2.2 Soybean production in the world and Vietnam 5

2.2.2 Soybean production in Vietnam 7

2.3 Function and requirement of some basic mineral nutrients elements for soybean 9

2.3.1 Role of Nitrogen 9

2.3.2 Role of Phosphorus 10

2.3.3 Role of Potassium 10

2.3.4 Role of Magnesium 11

2.3.5 Role of Iron 11

2.3.6 Role of Manganese 11

2.3.7 Role of Copper 12

2.3.8 Role of Bo 12

2.4 Mechanic of uptake foliar nutrition and advantages, disadvantages of foliar application 12

2.4.1 Mechanic of uptake foliar nutrition 12

2.4.2 Advantages and disadvantages of foliar application 14

2.5 Research of foliar application for crops, soybean in the world and Vietnam 15

2.5.1 Some results of foliar application in the world 15

2.5.2 Some results of foliar application in Vietnam 17

PART 3 RESEARCH CONTENT AND METHOD 20

3.1 Materials of research 20

3.2 Location and time research 21

3.3 Research content 21

3.4 Method of research 21

3.4.1 Experimental design 21

3.4.2 Map of experiment 22

3.4.3 Cultivation techniques 22

3.5 Tracking and method criteria 23

3.5.1 Growth criteria 23

3.5.2 Physiological criteria 23

3.5.3 Yield criteria 24

3.5.4 Processing data 25

PART 4 RESULTS AND DISCUSSION 26

4.1 Effect of foliar fertilizers on plant height of DT51 soybean 26

4.2 Effect of foliar fertilizers on number of leaves of DT51 soybean 29

4.3 Effect of foliar fertilizers on branching ability of DT51 soybean 31

4.4 Effect of foliar fertilizers on leaf area and leaf area index of DT51

soybean 33

4.5 Effect of foliar fertilizers on nodule formation of DT51 soybean 35

4.6 Effect of foliar fertilizers on dry matter of DT51 soybean 37

4.7 Effect of foliar fertilizers on flower formation of DT51 soybean 39

4.8 Effect of foliar fertilizers on SPAD index of DT51 soybean 41

4.9 Effects of foliar fertilizers on yield components of DT51 soybean 42

4.10 Effect of foliar fertilizers on yield of DT51 soybean 45

4.11 Economic efficiency when using foliar fertilizer for DT51soybean in Gia Lam-Hanoi, winter season 2020 47

PART 5: CONCLUSION AND RECOMMENDATION 49

5.1 Conclusion 49

5.2 Recommendation 49

PART 6: REFERENCE 50

APPENDIX 1: ECONOMIC ACCOUNTING 52

APPENDIX 2: SOME PICTURES OF THE RESEARCH 55

APPENDIX 3: RESULTS OF DATA PROCESSING WITH IRRISTAT SOFTWARE 59

LSD Least significant different

No

RCB

Number The randomized complete block

LIST OF TABLES

Table 2.2.1a Soybean production in the world 2010-2019 6

Table 2.2.1b Soybean production of some countries 2017 - 2019 7

Table 2.2.2 Soy bean production in Vietnam from 2009–2019 8

Table 4 1 Effects of foliar fertilizers on plant height of DT51 soybean 27

Table 4 2 Effects of foliar fertilizers on number of leaves of DT51 soybean 29

Table 4.3 Effect of foliar fertilizers on branching ability of DT51 soybean 31

Table 4.4 Effects of foliar fertilizers on leaf area and soybean leaf area index of DT51 soybean 33

Table 4.5 Effect of foliar fertilizers on nodule formation of DT51 soybean 36

Table 4.6 Effect of foliar fertilizers on dry matter of DT51 soybean 38

Table 4.7 Effect of foliar fertilizers on number of flowers and flowering time of DT51 soybean 40

Table 4.8 Effect of foliar fertilizers on SPAD index of DT51 soybean 41

Table 4 9 Effects of foliar fertilizers on yield constituent factors of DT51 soybean 42

Table 4.10 Effect of foliar fertilizers on yield of DT51 soybean 45

Table 4.11 Economic efficiency when using foliar fertilizer for DT51soybean 47

LIST OF FIGURES

Figure 4.1 Growing dynamic of plant height of DT51 soybean 28 Figure 4.2 Growing dynamic of leaf number of DT51 soybean 30 Figure 4.3 Growing dynamic of number of branches 32 Figure 4.10 Effect of foliar fertilizers on theoretical yield and actual yield of

DT51 soybean 46

PART 1 INTRODUCTION

1.1 Introduction section

The soybean or soya bean (Glycine max) is a species of legume (Fabaceae),

a native species to East Asia As one of the four important crops ( corn, rice, wheat, soybean) provides 43% of the nutritional energy and 40% of protein so soybeans are used for many purposes, food for human and cattle which is used largely as a supplement to cereal seeds in feed domesticated livestock such as dairy cows, cattle, pigs, goats, sheep, horses and poultry For agricultural production, soybean is a significant crop in the farming system, crop rotation and soil improvement (Duong Hong Dat, 2012)

In terms of food value, soybean seeds have a high nutritional ingredient Nguyen Thi Hien and Vu Thi Thu (2004) said that the average protein content of soybeans ranges from 35.5 to 40 % Besides, soybean seeds also contain lipids 15-20%, carbohydrates15-16% and many vitamins such as Vitamins B1, B2, C,

D, E, K and minerals important for life (Quotes from Tran Van Dien, 2007) Protein in soybean is good quality and can completely replace animal oil in human die that is used in medicine to help avoid malnutrition among children in poor countries and helps to limit goiter

In recent times, the demand for soybeans domestically as well as for export has been increasing, while natural disasters occur frequently and agricultural land is shrinking In order to increase soybean yield, people use new varieties with high yield, suitable planting season, reasonable fertilizers, watering in which special attention is paid to fertilizers techniques for soybean plants In addition to traditional fertilizers, foliar fertilizers for soybean have been applied

in recent years (Vu Quang Sang et al, 2015) Currently, in the market, there are many types of nutritional preparations for leaves, but their effect on plants as well as the most effective fertilizers technique for the user needs to be studied

Foliar fertilizers overcome nutritional deficiencies, prevent nutrient deficiencies due to limited absorption of the root system and limited internal transport within the plant, replace or supplement the root-based fertilizers method, increase resistance to pests and diseases, increase resistance to cold Moreover, foliar fertilizers help to protect the environment, overcoming the pollution problem caused by fertilizing the soil

DT51 soybean variety was selected by Legumes Research and Development Center- Field Crops Research Institute from the hybrid combination between LS17xDT2001 According to the assessment, DT51 has outstanding advantages: high yield can be planted 3 farming seasons/year, the rate of 3-seeds reaches over 30% In Vietnam, DT51 soybean variety is planting to develop a concentrated soybean-producing region towards commodity to meet market demand with the conventional fertilizing process, not using foliar fertilizer There have not really been many studies on the effect of foliar fertilizer on the growth of this soybean variety

Therefore, in order to contribute quickly to the use of foliar fertilizer and to find the best foliar fertilizer to be put into production, on that basis, we studied

the topic: “Effect of some foliar fertilizers on the growth, development and yield of DT51 soybean variety in the winter season, 2020 Gia Lam, Ha Noi” 1.2 Research objective and requirement

1.2.1 Objective

Research the effects of some foliar fertilizers on the growth, development and yield of soybean that is grown in the winter season 2020, Gia Lam, Ha Noi, determinate the most effective foliar fertilizers for high yield and high quality of soybean

PART 2 LITERATURE REVIEW

2.1 Valuations of soybean

2.1.1 Economic value of soybean

The economic value of soybean mainly depends on the nutritional content

of soybean seeds Essential nutritional ingredients that can replace products from animals, soybean seeds are used a lot in the food processor for humans such as tofu, soy milk, vegetarian food, ice cream, confectionery, etc In industry, soybean oil accounts for about 50% of total vegetable oil From soybean oil, people can produce hundreds of other products: paint, candles, soap, ink, plastics, artificial rubber

In the 1970s of the XX century in Brazil, black soybean have produced the highest profit on a unit of agricultural land area for farmers that compared to other seed crops (Duong Hong Dat, 2012)

In terms of medicine, soybean has a very important significance, the use

of soybeans helps to cure several diseases: cardiovascular disease, anti-cancer, aging prevention and osteoporosis of old age Soybean enhances immune function due to its high content of vegetable protein which has been referred to

as "plant meat" Using beans not only adds protein to the body but also avoids the increase in cholesterol Soybeans contain a large amount of lecithin, isoflavones, which play a big role in improving the mind, whitening teeth, skincare and preventing cancer

There are two types of isoflavones in soybeans, daidzein and genistein which have a chemical structure as the female hormone estrogen, also known as

a phytoestrogen Phytoestrogens have similar effects to natural estrogens but weaker and soybeans consist of four chemical structures, aglycones, daidzein, genistein and glycitein Many studies show that soybeans contain isoflavones and are considered a food to increase femininity and protect women from many

diseases, so soybeans are also known as the "miracle" of women Many clinical studies in humans and animals are being studied precisely answering these precious effects

2.1.2 Agricultural value of soybean

According to research, the soybean plant is an important crop in the Vietnamese cropping system, being intercropped, pillow growing and increasing crops in agriculture (Tran Van Lai, 1999) Soybeans, like all other legumes, play

a very important role in soil improvement because they can accumulate free nitrogen in the air for self-use and enrich the soil nitrogen through the symbiosis

of Rhizobium Japonicum in the root system Under favorable conditions, these

Rhizobium can synthesize a nitrogenous amount equivalent to 20-25 kg/ha (Pham Van Thieu, 2009) In the crop rotation system, if the arrangement of crops is appropriate with soybean plants, it will reduce the fertilizer costs significantly Soybean’s leaf and stem are also used as green manure and replace organic fertilizer because the N content is about 0.05% in stem and in leaves accounts for about 0.19% (Nguyen Danh Dong, 1982)

Soybeans are an important source of food in livestock, especially bred cattle The soybean plant can be used either as direct food or dried mashed as a complete feed Industrial by-products such as soybean meal which contain quite high nutritional components are used a lot in livestock production

2.2 Soybean production in the world and Vietnam

2.2.1 Soybean production in the world

According to the Food and Agriculture Organization of the United Nations (FAO), soybean production in recent years in the world has been increasingly expanded and developed

In 2019, the USA was the country with the largest soybean production in the world (120.51 million tons), quite different from 104.54 million tons compared to the fourth-ranked country, China (15.97 million tons) Soybean is

the 2nd largest crop in the USA after corn and valid annual is about 4 billion dollars (According:Statista.com)

Currently, in the world, there are about 98 soybean-growing countries With a high nutritional value and can be processed into many different products for human consumption and animal feed Soybean production has been continuously increased over the years

Table 2.2.1a Soybean production in the world 2010-2019

Year Area (million ha) Yield (ton/ha) Quantity (million ton)

Source: FAO Statistic Database (2020)

The worldwide soybean’s area in 2019 was 124.5 million hectares, an increase of 21.73 million hectares compared to 2010 Along with the increase in area and yield, the total soybean quantity of the world in 2019 also increased by 68.58 million tons compared to 2010 In general, the annual soybean area in the world increased by an average of around 1 million hectares

Table 2.2.1b Soybean production of some countries 2017 - 2019

Source: FAO Statistic Database (2020)

Currently, the top 4 soybean-growing countries in the world are the USA, Brazil, Argentina and China (Table 2.2.1b) These countries account for about

76% of the world's soybean area and about 84.53% of the world's soybean

quantity In 2019, the three countries America, Brazil and Argentina have

soybean yield that was higher than the world, the USA’s soybean yield was

3.4(tons/ha) higher than the world, Brazil was 3.39 (tons/ha) and Argentina was 3.33 (tons/ha) The strong growth of soybeans in these countries was the result

of adopting techniques, mechanization in agricultural production, high-yielding transgenic varieties and pest resistance

2.2.2 Soybean production in Vietnam

In Vietnam, soybean is the type of old crop, suitable for many different climate zones Until now, soybean has become an important crop in the agricultural system of the country, but soybean production area tends to decline

Soybean has imported to Vietnam increased in recent years In March

2020, soybean imported to Vietnam reached 211.3 thousand tons, worth 85.8 million USD, up 63.1% in quantity and 59.9% in value over to the previous month, an increase of 88.2% in quality and 89.4% in value compared to March

2019 Generally in the first quarter of 2020, soybean’s import quality reached

430 thousand tons, worth 176.4 million USD, risen 2.1% in quality and 5.6% in value over the same period in 2019

According to the Food and Agriculture Organization of the United Nations (FAO), soybean production in recent years in Vietnam has fluctuated as shown in the table below

Table 2.2.2 Soy bean production in Vietnam from 2009–2019

Year Area (thousand ha) Yield (ton/ha) Quantity ( million ton)

Source: FAO Statistic Database (2020)

Through the above statistics table, we can see that the area, yield and quality of soybean in Vietnam fluctuate unevenly over the years From 2009 to

2019, the soybean area tended to decrease overall, but from 2013 to 2015, the area planted was gradually increasing Soybean’s yield has been stable over the years and is gradually increasing, with the highest yield of 1.61 tons/ha in 2016 Quality increased sharply from 2017-2018 up to 711.62 thousand tons but then decreased (53.47 million tons) in 2019

With the local market advantage of reducing transport and circulation costs, the good quality of fresh seeds, suitable for human food, Vietnam’s soybeans will be able to compete with imported soybeans, competing with other crops: rice and maize

Soybean is widely grown throughout Vietnam but still has some limitations and has not fitted the domestic market demand due to many reasons such as lack of good seeds, lack of investment in fertilizers and materials, small scale It is forecasted that in the coming years, Vietnam will have a shortage of about 4-6 million tons of soybeans with 2-3 billion USD, exceeding the current rice export and becoming a country of soybean importer

Currently, Vietnam is in a strategy to develop 350-700 thousand hectares

of soybean production with a yield of 20 quintals/hectare to increase production efficiency, increase competitiveness, reduce imports, and strive to reach 0.7 million tons soybeans/year, self-sufficient 20-30% of annual consumption, soil improvement, environmental protection It can be seen that soybean is a crop with great output, bringing economic efficiency to farmers as well as improving the efficiency of land use and soil improvement in the current period

2.3 Function and requirement of some basic mineral nutrients elements for soybean

2.3.1 Role of Nitrogen

- Nitrogen is present in many important organic compounds that play a decisive role in metabolism and energy as well as physiological activities of the plant

- N is involved in the structure of Protein - is an important structural component of protoplasts and enzymes

- N participates in the structure of nucleic acid - the nucleus of the cell, which determines the genetic nature of the plant

- N is also a component of chlorophyll, synthesizing organic compounds

of the plant body

- N is a component of important vitamins such as B1, B2, B6

With these important roles above, N determines the whole life and yield

of plants However, N also has two faces on plants If the excess or lack of N are harmful to plants

2.3.2 Role of Phosphorus

-A component of the protoplasm and nucleus, has a direct influence on the process of cell division, affects the growth and growth of plants Young organs with a strong meristem are always in high demand for P

- As a subdivision of the protoplasm, it affects the permeability of the cells, affects the ability to absorb nutrients as well as the plant's resistance to resistance P increases cold tolerance in plants, promotes the development of the root system and meristem tissue

- Participating in building ADP, ATP are compounds rich in cell bioenergy, affecting biological processes of plants such as respiration, photosynthesis, water absorption and mineral salts

2.3.3 Role of Potassium

- Has a great influence on the exchange of carbohydrates K promotes the exchange, transport and metabolism of carbohydrates in the plant, thus helping the plant to harden, clear, and limit falling

- K profoundly affects the protoplasmic state, K increases the hydration of the protoplasm of cells, reduces viscosity, increases the ability of cells to retain water Therefore, K increases the cold tolerance and disease resistance of the plant

- Promote the synthesis of vitamins

- Promote respiration and affect the activity of enzymes: amylase, saccharase promoting the synthesis of sugar and ripening process of plants

- Potassium also promotes the iron absorption of plants

2.3.4 Role of Magnesium

- Magnesium is an important component of the chlorophyll molecule, so it determines the photosynthetic activity of the plant This is also the activator of many enzymes that are important for the respiration and metabolism of the plant Mg is essential for short-term crops such as rice, corn, beans, potatoes

Mg will increase the starch content in the product

- Magnesium plant in the form of Mg2+ Magie ions in plants are concentrated in young parts

- Mg deficiency slows flowering, plants often have yellow leaves due to lack of chlorophyll The typical symptom is that the veins are green while the pulp has turned yellow The appearance of necrotic tissue is usually from the lower leaves, mature leaves to young leaves, because Mg is a flexible element, plants can be reused from older leaves

2.3.5 Role of Iron

- The most important role of iron is activating enzymes of photosynthesis and respiration It does not participate in chlorophyll composition but has a decisive effect on chlorophyll synthesis in plants The iron content of leaves is closely related to the chlorophyll content in them

- Fe deficiency usually occurs on soils with limestone, phosphorus, lime fertilizers and high pH The iron-deficient leaves will change from green to yellow or white in the flesh, while the veins will remain green Iron deficiency symptoms appear first on young leaves, then to old leaves, because Fe does not move from old leaves to young leaves

on leaf flesh and develop necrotic spots on leaves If insufficient, leaves will be dry and dead Mn deficiency symptoms can manifest in old or young leaves depending on the plant

2.3.8 Role of Bo

- Bo is one of the most effective trace elements in plants B has a direct impact on cell differentiation, hormone metabolism, N exchange, water and other minerals, the most obvious effect of B is on meristem at the apical growth and flower differentiation, pollination, fertilizers, fruit formation

- When B is deficient, shoots and growth peaks die, lateral buds decrease gradually, flowers do not form, fructification rate is poor, fruit falls easily, roots grow poorly, leaves are thickened Symptoms of B deficiency often manifest in the anterior immature parts

2.4 Mechanic of uptake foliar nutrition and advantages, disadvantages of foliar application

2.4.1 Mechanic of uptake foliar nutrition

Normally, the leaves are responsible for photosynthesis, CO2, O2 and dissolved minerals are easily assimilated in the form of ions from solution through stomata However, this uptake is highly dependent on the cutin layer of the leaves The cuticle layer can be thick and thin depending on the type of plant and the age of the plant Minerals can completely penetrate through microscopic

pores in the cutin layer, cell wall and membrane system The diameter of these holes is larger than 1mm and the density is very high 1010 holes/dm2 of leave (Horst, M 1996) With such a small-diameter, solutes can easily pass but larger molecules such as organic molecules, chelates are difficult to pass

Temperature and weather conditions also affect the efficiency of foliar nutrition, when using foliar nutrition, people often incorporate the spray leaf surfactants at cool and it’s not (Nguyen Van Phu, 2002) The process of nutrient uptake by leaf cells is essentially passive, the rate of absorption depends much

on the physiological status of the leaves and plant nutrition

The process of nutrient uptake through leaf cells, like the uptake of nutrients through the roots It is the transport of minerals across the biological layer, which is a mode of active transport Absorption of nutrients through leaves is rapidly effective under nutrient-poor soil conditions and the uptake of nutrients through the roots is limited This is considered as a supporting method

to supplement nutrients in periods of nutritional imbalance when plants switch from nutritional growth to real growth with macronutrients Because minerals are heavily concentrated in the formation of reproductive organs, root growth is greatly reduced that impaired absorption of minerals Therefore, the supplement

by foliar spray method will overcome the nutritional imbalance of the plant at that stage, helping the plant to grow and develop better (Nguyen Van Phu, 2002) According to Horst, M (1996), the foliar absorption of mineral ions is stronger than the anion

On the surface of the leaves are stomata, nutrients dissolve into cells through stomata Stomata is a microscopic hole in the surface of the leaf, helping the plant evapotranspiration to stabilize the plant's temperature, opening for CO2 to participate in photosynthesis

Some ions also penetrate directly through the leaf epidermis, this path depends on the structure of the leaves, cutin layer,

Nutrition penetrates vacuoles, vacuole is considered as the repository of nutrients before being absorbed into cells

The absorption of ions at night is usually more active and intense when the stomata are open Older leaves absorb less than young leaves When the concentration of the off-leaf solution is too high, the uptake of nutrients is also limited

The process of absorption of nutrients through the roots is mainly, foliar fertilizers cannot replace the original fertilizers

2.4.2 Advantages and disadvantages of foliar application

a Advantages of foliar application

According to Tluto et al (1999), Nguyen Van Phu (2003), the foliar fertilizers method is particularly effective in the following cases:

- The soil layer is poor in nutrition and drought, making the root's ability

to absorb nutrients limited

- Foliar nutrition is particularly effective and popular with elements such

as Mg, S and especially trace elements

- Foliar nutrition has a high utilization rate of 95% compared to only 50% of nutrients in the soil, thus saving fertilizer and reducing soil pollution

40 Adjust the imbalance of plants when plants switch from nutritional growth to real growth At this time, the growth of the root system is greatly reduced, causing impaired mineral absorption Therefore, the supplement by foliar spray method will overcome the nutritional imbalance of the plant at that stage

- Foliar nutrition is very effective when the soil has an ionic antagonism phenomenon According to Vu Quang Sang et al (2015), in conditions of soil rich K+ greater than 300mg/kg of soil and Mg2+ greater than 160 mg/kg of soil, the absorption of Mg2+ will be prevented due to the phenomenon of plant ion antagonism with lack of Mg2+, applying Mg2+ to the soil will cause the plant to

lose nutritional balance and die due to Mg2+ poisoning Meanwhile, fertilizing with Mg2+ through leaves helps plants grow well The plants are fertilized through the leaves grow stably, have fewer pests and diseases and resistant to unfavorable conditions such as inundation, drought, salinity

- Apply foliar fertilizers to increase product quality such as increasing sugar content in sugarcane, increasing fruiting, firm seeds, early ripening, good appearance, increasing commercial value, increasing content of trace elements

b Disadvantages of foliar application

The method of foliar fertilizers is highly effective but still needs to overcome some of the following disadvantages:

- A small number of minerals that can be absorbed through the leaves with trace elements, N, P, and K are only about 10%, so this method is not popular with macronutrients

- Easily washed away from leaves when it rains and leaves is burned when spraying at high temperature Therefore, using foliar fertilizers should be combined with surface adhesives and pay attention to the weather when spraying

- Foliar nutrition does not apply to all plants For leaves with a thick cuticle layer on the surface that are waterproof, foliar fertilizers will not be effective (Nguyen Van Phu, 2002)

2.5 Research of foliar application for crops, soybean in the world and

Vietnam

2.5.1 Some results of foliar application in the world

Foliar fertilizer is effective fast, effective up to 90% nutrients According

to Nguyen Van Phu (2001), it showed that the combination of spraying Mg and

N increases the yield of dry matter and especially the combination of N+Mg, N+Mg+Mn, N+Mg+Zn increase the yield of wheat 30-30.9% If Mg, N+Mg is applied it will increase chlorophyll content in leaves, increase dry matter

accumulation of wheat, increases yield of the plant under two soil conditions

Mg++ poor and K+ rich Lam and Morahan (1993) found that the yield and sugar content of beetroot under nitrogen deprivation was increased when using a nitrate-sprayed mixture but was not increase yield under sufficient nitrogen conditions

The elements Mg++ and K+ have an antagonistic relationship in soil If the

K+ and Mg++ content are both high, then Mg++ can become the missing element

in plants But applying Mg++ to the soil can cause ionic imbalances and poisoning the plant, and foliar application of Mg++ is the best method to get nutritional imbalances and improve plant growth ( Borkert, 1994)

According to Smit (1988), on the pH <5.5, the addition of Mo will increase soybean's yield to a significant level But according to author Dave Mengel (1987), a soil expert at Kansas State University, acidic soils often lack

Mo and liming can not overcome this deficiency completely Mo will work well

in combination with P The use of fertilizers contain a lot of S will reduce the absorption of Mo In soils with a pH above 6.5, Mo application is not necessary With soil pH <6, Mo can be fixed with hydroxides of Fe(OH)3, Al(OH)3; Fe2O3

Mo is toxic, so use is usually foliar spray If Mo is applied for seeds, labor protection equipment is required

Floral and Foliar Application of Plant Growth Promoting Rhizobacteria strains significantly increased yield per trunk cross-section area, fruit weight, shoot length and shoot diameter in 'Starkrimson' apple and yield per Trunk Cross-Sectional Area and fruit weight in 'Granny Smith' apple in the province of Karaman, Turkey (Lutfi Pirlak et al, 2007) The results of this study suggest that Pseudomonas BA-8 and Bacillus OSU-142 alone or in combination have the potential to increase the yield, growth, and nutrition of apple plants

Foliar application of potassium (K), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) increased their corresponding concentrations in the leaves of aquaponic-treated plants On the other hand, foliar spray of K, Fe, Mn, Zn, and Cu caused a significant increment of applied element concentrations in the fruits of hydroponic-grown plants These findings indicated that foliar application of some elements can effectively alleviate nutrient deficiencies in the leaves of tomatoes grown on aquaponics (Hamid R Roosta &Mohsen Hamidpour, 2013)

The efficiency of the foliar application is mainly controlled with the characterization of plant leaves, agrochemicals, and environmental conditions including weather factors Therefore, the proper timing of foliar applications mainly also depends on these previous factors No doubt that foliar application has several benefits including the quality of harvested crops during pre and post-harvest, production of biofortified food crops and plant nutrition as well as its protection Day by day, there are new tasks for foliar applications that will be discovered like nano foliar application (T Alshaal, 2017)

2.5.2 Some results of foliar application in Vietnam

Foliar fertilizers have been widely used in many localities with positive results There are many popular foliar fertilizers on the Vietnamese market such

as Dau Trau 502, Comix, HB101, Bio fact, BK104, Pomior, Seaweed 95%, Atomix, Luc Thuy section, Open all, Use foliar fertilizers have been seen that rapid growth of the plant, large stems, thick leaves, bright green color, fewer pests and diseases than without spraying The number of fill pod per plant was not significantly different, the number of two seeds per plant increases significantly On the other hand, fertilizing helps plants in drought or flood conditions, plant in decline, this is the only way to help plants recover quickly

According to Ha Thi Thanh Binh et al (1998), micro-spraying soybean and peanuts on Mai Son-Ha Son Binh soil at stage 3, 5 and 7 leaves had a good effect on the environment, development and increased yield from 13.8 - 20.2%, quality was also increased

According to the author Manh Ha (2012), during the winter season, when spraying organic Perti Amino product for DT2008 soybean in the 2-3 leaves, it began to flower With the amount of spraying 270 420 1/ha, the yield increased 4.38 quintals/ha compared to the water spray control

Foliar fertilizer is a technical advance that has been used a lot in recent years but cannot be 100% substitute for soil fertilizers, foliar fertilizer is a safely strategic solution for the crop (Vu Cao Thai, 1996) When using foliar fertilizers for crops in the Mekong Delta, it showed that: quickly responding to the nutritional needs of plants, plants are grown stable, healthy, less pest, resistant to adverse conditions and increased commercial value such as, sugar cane, beans (Nguyen Van Uyen, 1995) Nguyen Tan Le (1992) used Mo and Bo to treat peanuts grown in Quang Nam-Da Nang, the average yield of 3 crops increased

by 6.2-11.1% compared to the control

According to Trinh An Vinh (1995), in terms of a sustainable and healthy environment, compost fertilizers, foliar organic fertilizers and other similar fertilizers should be encouraged to research and put into agricultural production

to get great significance in developing sustainable agriculture

Foliar fertilizer Pomior can promote plant growth and, in effect, the foliar yield increased in the Spring - Summer cropping season Foliar fertilizer Pomior also increased the quality of mulberry leaves as evidenced by increased cocoon yield in the Spring - Summer cropping season, Gia Lam, Ha Noi (Tran Thi

Ngoc, 2011)

According to Nguyen Duc Tuan (2020), the number of sprays and foliar concentrations had a significant effect on the growth and development of LDP1

tea plants in Thai Nguyen province Applying composted manure combined with foliar fertilizer application 3 times at a concentration of 0.1% gave the highest yield, the sensory, tannin and flavonoid contents were similar to Tan

Cuong green tea

PART 3 RESEARCH CONTENT AND METHOD

3.1 Materials of research

• DT51 soybean variety

- Origin: DT51 soybean variety was selected by Legumes Research and Development Center- Field Crops Research Institute from the hybrid combination between LS17x DT2001.The variety was recognized by the Ministry of Agriculture & Rural Development for production in the Northern provinces, according to Decision No 218/QD-TT-CCN dated June 15, 2012

- Author agency: Legumes Research and Development Center- Field Crops Research Institute

- Growth characteristic: belong to the group of early middle ripening, growing time 84 days in winter, 88-92 days in spring and summer

- Resistance: Good resistance to heat and spillage, infection is mild to moderate with some major diseases, good resistance to spillage and drought

• Foliar fertilizer “Dau Trau 501”

- Origin: Binh Dien - Mekong Joint Stock Company, Viet Hoa Industrial Park - Duc Lap Ha - Duc Hoa - Long An

- Ingredient: N: 30%, P2O5: 15% K2O5: 15%, Cao: 0.05%, MgO: 0.05%, TE: 1.859ppm; B,Cu,zn: 1.850ppm, NAA: 200ppm, Ga: 100ppm,

Humidity:<=1%

- Dosage: Mix 20g/1 liter of water

• Foliar fertilizer “Grow More 30-10-10+ TE”

- Origin: Grow More manufacturer’s product

- Ingredient: N: 30%; P2O5: 10%; K2O: 10%; Ca: 0.05%; Mg: 0.1%; S: 0.02%; B: 0.02%, Fe: 0.1%; Zn: 0.05%; Cu: 0.05%

- Dosage: Mix 5-10g/8 liter of water, use periodically 7-10 days/time

• Foliar fertilizer “Profarm- n29”

- Origin: imported from Belgium

- Ingredient: : N: 29%; P2O5: 10%; K2O: 10%; Mg: 1.8%; S:2.4%; B: 0.01%, Mn: 0.01%; Fe: 0.02%; Zn: 0.01%; Cu: 0.01%

- Dosage: Mix 15-20g/16-20l water in 360m2

• Foliar fertilizer “Seaweed 95%”

- Origin: Acaduan Seaplants Limited (Canada)

- Ingredient: Organic matter:36%, N: 0.63%, P2O5: 0.18% , K2O5: 15.3%, Mg: 0.18%, Ca: 0.18%,pHH2O: 10, humidity: 10%

- Dosage: Mix 10g/16-32l water

3.2 Location and time research

- Location: Field Experimental region in Faculty of Agronomy- Vietnam National University of Agriculture, Trau Quy-Gia Lam-Hanoi

- Time: from September 2020 to January 2021 winter season

- The experiment consisted of 5 treatments with 3 replications, a total of

15 experimental plots, area of a plot is 5m2

+ Treatment 1 (T1) : ( Control) spraying H20

+ Treatment 2 (T2): Spaying Dau Trau 501

+ Treatment 3 (T3): Spraying Grow More 30-10-10+ TE

+ Treatment 4 (T4): Spraying Profarm- n29

+ Treatment 5 (T5): Spraying Seaweed 95%

- Experimental factor: foliar fertilizer

- The total number of experimental beds is 15 beds

- Acreage of each bed = 1m x 5m = 5m2

- Total acreage = 75m2 does not count 30-40cm beds distance

- Moisture: Soil before sowing, soil moisture reaches about 75%

- Planting density: 40 plants/m2

- Planting distance: 2 seeds/hole, 30 x 10cm

- Fertilizer techniques:

+ Basal fertilizer for 1 ha: 200kg lime eggshell + 30kg N + 90kg P2O5

+ Top dressing for 1 ha: Divide into 3 phases

+ Phase 1: When the plant has 2-3 real leaves, fertilize 50% N + 50% K2O, combine with weeding and stirring

+ Phase 2: After finishing phase 1 about 15 days (5-6 real leaves), combine weeding, stirring and cultivating

- Spraying foliar fertilizers are divided into three stages:

+ Spraying time: spraying when plants grow and thrive: Start branching - Start flowering - 7 days after flowering

+ Spraying dose: (depending on growth stage) from 600l/ha - 1000l/ha (600l/ha at the beginning of branching; 600l/ha at the beginning of flowering; 1000l/ha after flowering 7 days) Carry out spraying when it is cool, not sunny (usually spray in the evening)

3.5 Tracking and method criteria

3.5.1 Growth criteria

- Plant height (cm): In each plot take 5 plants (follow the 5-point diagonal method) when the plant has 3 real leaves, periodically every 7 days and then calculating the average

- Leaf number (leaves/plant):

In each plot, take 5 plants (follow the 5-point diagonal method), count the number of compound leaves on the plant, periodically every 7 days and then calculate the average

- Plant height (cm/ plant) = ∑Plant height of each plant (cm)

∑Number of plants tracking

- Number of leaves/plant (number) = ∑Number of leaves of each plant

∑Number plant tracking

3.5.2 Physiological criteria

- Leaf area (dm2 /plant):

In each bed, take randomly 3 plants to calculate the area of leaves, we use the fast weight method Take all the fresh leaves on the plant to weight (P1), cut 1dm2 of leaves to weight (P2) Follow up at 3 stages: start bloom, flowering, fruit formation

Leaf area (dm2/plant) =

2

1

P P

P1: Mass of fresh leaves of the whole plant

P2: Mass of 1dm2 fresh leaves

- LAI (Leaf Area Index) (m2 leaves/m2 of land)

- SPAD index (chlorophyll index in leaves): An assessment of chlorophyll content in leaves The higher the SPAD index, the higher the chlorophyll content

in the leaves and vice versa

- The formation of nodules (nodule/plant):

In each bed, take randomly 3 plants, wash them Count the total number

of nodules on the root, the number of the effective nodule (EN) Weigh the total number of EN then calculate the average Follow up at 3 stages: flowering, full bloom, fruit formation

Number of nodules = ∑Number of nodules in each plant

∑Number of plants tracking

Rate of effective nodules = ∑Number of effective nodule in each plant

Mass of nodules = ∑Number of effective nodules

- Dry matter (g/plant):

In each bed, take randomly 3 plants, wash them and dry at 90oC Then weigh to determine the dry mass

- Flowering time, the total number of flowers:

In each bed take 5 plants (follow the 5-point diagonal method), counting the number of flowers per day From there, know the total number of flowers on the plant and the time to flower

3.5.3 Yield criteria

Take 10 plants randomly and observe:

- Total fruits per plant (C), Total plant tracking (B)

Rate of fruits =

B

C

*100

- Total number of fill pod (D)

Rate of fill pod = * 100

C D

- Rate of 1 seed, 2 seeds, 3 seeds, 4 seeds (compared to% of fill pod)

- Mass of 1000 seeds (g)

- Individual yield (g/plant)

- Theoretical yield (quintal/ha) = Individual yield (g) x Density

PART 4 RESULTS AND DISCUSSION

4.1 Effect of foliar fertilizers on plant height of DT51 soybean

For plant growth, plant height is one of the important criterias that reflect the growth status of a cultivated variety under certain conditions If the soybean

is grown in good, warm soil conditions and a favorable climate, it will grow well and taller The stem is the framework that supports all the above-ground parts of the plant, transporting water and substances from the roots to other parts such as flowers, fruits, seeds and also transporting the resin from the leaves to the roots

The stem not only determines the height of the plant, but also affects the number of leaves, the number of branches, flowers, and fruit, thereby directly affects the yield of the plant Another characteristic of soybean is that it is different from other crops, the vegetative life continues along with the biological life, but in the first stage, soybean grows in height very quickly, maximum when the plant flowers, starting to produce fruit, starting at this stage, the plant height

is very slow (some plants may not increase in height) but focuses on vegetative growth

The dynamics of height growth represent growth, care regime and natural conditions where the plant is grown In other words, the dynamics of height growth of the variety expresses genetic traits, extracellular conditions, technical conditions and support measures

Therefore, research on soybean plant height growth is very important and necessary In this research project, I study the effect of foliar fertilizers on the growth of soybean plants which were monitored When the plants start to have 2-3 true leaves and the repetition time was 7 days Monitoring results are presented in Table 4.1

Table 4 1 Effects of foliar fertilizers on plant height of DT51 soybean

Unit (cm)

Treatment

Day after sowing

T1:H2O (control) 21.67 27.61 32.21 38.23 45.87 T2: Dau Trau 501 22.77 29.42 32.35 41.08 53.95

T4: Profarm-n29 24.03 30.93 36.33 40.77 50.32 T5: Seaweed 95% 22.58 30.13 33.43 41.63 54.14

The table above shows that on the same basal fertilizer and care regimen when using different foliar fertilizers, the first has a different impact on the height growth dynamics of DT51 soybean The height increases gradually with the growing stage and stops at the flowering stage

Considering each treatment:

In T1 (control): plant height ranges from 21.67 to 45.87 cm and increased

24.2 cm This is the treatment with the lowest growth in height among the 4

treatments of the experiment

In T2 (Dau Trau 501): stem height was second highest after T5,

increased 31.61cm when ranging from 22.77 to 54.16 cm

In T3 (Grow More 30-10-10+ TE): the growth of plants was only slightly

higher than the T1 control treatment, ranging from 25.3 to 50.89 cm, and the growth was 25.59 cm

In T4 (Profarm- n29): plant height ranged from 24.03 to 50.32 cm

During the process of growing, the plant increased 26.29 cm

In T5 (Seaweed 95%): the height of the plant had the largest height in the

treatments with 31,56 cm when plant height ranged from 22.58 cm – 54.14 cm

Comment: In 39 days after sowing with Statistical Significance at 95%

confidence level, the difference of T3 is significant In 46 days after sowing, the difference of T5 is significant and in 53 days after sowing, the difference of T2, T5 are significant at the 95% confidence level Meanwhile, other treatments also gave stem height higher than T1 but this difference was not significant

Figure 4.1 Growing dynamic of plant height of DT51 soybean

Thus, the following process can conclusions that: on the same ground, climatic conditions, the same conditions of care, using foliar fertilizer affected to the height of the main stem

4.2 Effect of foliar fertilizers on number of leaves of DT51 soybean

Leaf plays an important role in the physiological life of the plant The leaf

is the main organ that converts solar energy into chemical energy (with most higher plant species) that determines the existence, growth and development of the plant The number of leaves in soybean plants determines photosynthesis and respiration, so it determines the plant's yield The leaves of the plant will thrive until the plant forms flowers, creat fruit to help the plant accumulate enough organic matter in the fruit and seeds For plants to have a high yield, people often apply appropriate technical measures to optimize the photosynthesis of the leaves, helping the plant to grow big and strong to create more hardly fruits The development of the leaf set is also very important, if from the beginning the set

of leaves is big, stable green, well developed, the plant will give high yield

Table 4 2 Effects of foliar fertilizers on number of leaves of DT51 soybean

Unit (number of leaves/plant)

the control treatment Specifically, treatment T2: Dau Trau 501 had the highest

rate of leaves and ranged from 3.47 to 36.87 leaves/plant with increasing 33.4 leaves after the whole growth process, an average of 0.69 leaves per day Treatment T3, T4 and T5 increased by an average of 0.67; 0.65 and 0.68 leaves/day Control treatment T1 had the smallest number of leaves in 5 treatments, increased from 3.47 to 33.53 leaves/plant, increased 30.06 leaves during the whole follow-up stage

Comment: at the 95% confidence level, in all treatments, the difference

was not significant at 25DAS, 32DAS and 39DAS Meanwhile, in 46 days after sowing, this is a period of growth and development so the leaves thrived, the difference of T3, T4, T5 are significant In 53 days after sowing, the difference

of T2, T5 are significant

Figure 4.2 Growing dynamic of leaf number of DT51 soybean