(Luận văn) effects of nitrogen types on yield performance and no3 content in mustard in thai nguyen

THAI NGUYEN UNIVERSITY THAI NGUYEN UNIVERSITY OF AGRICULTURE AND FORESTRY lu an TRAN DIEU LY n va gh tn to TOPIC TITLE: EFFECTS OF NITROGEN TYPES ON YIELD p ie PERFORMANCE AND NO3 d oa nl w CONTENT IN MUSTARD IN THAI NGUYEN v an lu BACHELOR THESIS m ll fu an : Full-time Major : Environmental Science and Management Faculty : International Training and Development Center Batch : 2010 - 2015 oi Study mode nh at z z @ om l.c gm an Lu n va Thai Nguyen, 23/01/2015 a th c si Thai Nguyen University of Agriculture and Forestry Degree Program Bachelor of Environmental Science and Management Student name Tran Dieu Ly Student ID DTN1053110388 an lu Thesis Title Effects of Nitrogen types on yield performance and NO3- content in Mustard in Thai Nguyen Supervisor Dr Nguyen Duc Nhuan n va gh tn to Abstract: p ie The production of vegetables has been a key sector for the economy of the w households in Thai Nguyen City Safety vegetable production has been the Plant d oa nl Protection Department attention which opened the training for farmers However, v an lu until now effect of the program is not high because growers are not consciousness fu an with food safety but profit The farmers not fully follow the safe vegetable oi m ll production model Therefore, there is no assurance of quality and safe vegetables to consumers that is the reason why consumption is very low Content of NO3- in nh at mustard in Thai Nguyen City: The results of analysis of mustard grow in winter z z @ 2014 at Thai Nguyen areas are shown that On the average, the nitrate content of gm non exceeded safe levels when applied l.c vegetable samples from treatment om fertilizers: Urea 46%, Superphosphate 16% P2O5, potassium sulphate 58% K2O5, Lu (NH4)2SO4 21%, NH4Cl 26% follow treatment 70N + 60 P2O5+ 35 K2O5 Mustard an n va isn't excess of the permitted standards this is for mustard The accumulation of a th c si nitrate in vegetables after harvest ascending doses nitrogen, lowest in control treatment is 52.60 mg / kg fresh and the highest in the treatment Urea 46% N / is 301.28 mg/kg fresh, the treatment (NH4)2SO4 21% is 272.62 mg/kg fresh, the treatment NH4Cl is 256.46 mg/kg fresh Nitrate tends to decrease when the last time dressing as far as the day of harvest Land used for vegetable production in Thai Nguyen City are of alluvial soil or sandy rich soil with pH 5.2 – 5.7 (acid lu an soil) and humus, N, P2O5, K2O contents are low The content of NO3- in the soil va before planting is 0.36 mg NO3- /kg soil At harvest, NO3- content accumulated n gh tn to lowest in the soil at control treatment 0.55 mg/100g soil, highest in treatment p ie and (Urea and (NH4)2SO4 are 0.71 mg/100g soil, the treatment NH4Cl is 0.60 d oa nl w mg/100g soil The study suggested some recommendations specifically suitable for study areas in order to improve sustainable quality and quantity of vegetables oi m ll Keywords: fu an v an lu consumed in Thai Nguyen nh at z om l.c gm 15/01/2015 @ Date of Submision : pages z Number of pages: an Lu n va a th c si Acknowledgements I would like to express deepest gratitude to my advisor Dr Nguyen Duc Nhuan for his full support, expert guidance, understanding and encouragement throughout my study and research Without his incredible patience and timely wisdom and counsel, my thesis work would have been a frustrating and overwhelming pursuit an lu In addition, I express my appreciation to teachers in Faculty Resource n va Management Their thoughtful questions and comments were valued greatly gh tn to I would also like to thank Dr Tran Thi Pha, engineer Phan Tien Hung, MSc Duong Thi Minh Hoa for helping me complete the experiment p ie Thanks my classmates at Thai Nguyen University of Agriculture and Forestry and w d oa nl staff of advanced education program Special thanks go to my numerous friends who helped me throughout this academic exploration v an lu Finally, I would like to thank my parents and brother for their unconditional love fu an and support during the last time: I would not have been able to complete this thesis m ll without their continuous love and encouragement oi nh at z z @ om l.c gm an Lu n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 Table of Contents an lu n va p ie gh tn to Acknowledgements CHAPTER 1: INTRODUCTION 1.1 Introduction 1.2 Background of the Study 1.3 Theoretical Framework of the Study 1.4 Conceptual Framework of the Study 10 1.5 Statement of the problem 11 1.6 Hypothesis 12 1.7 Objectives 12 1.8 Definition of Terms 12 CHAPTER 2: REVIEW OF RELATED LITERATURE AND STUDIES 14 2.1 Related Literature 14 2.2 Related Studies 27 CHAPTER 3: RESEARCH METHODOLOGY 27 3.1 Research Materials 27 3.2 Experimental approach 28 CHAPTER 4: RESULTS, ANALYSIS AND INTERPRETATION OF DATA 30 4.1 The current vegetables productivity of Thai Nguyen City 30 4.2 Actuality of soil and fertilizer in vegetables production area of Thai Nguyen City 33 4.2.1 Soil 33 4.2.2 Situation of using fertilizers 34 4.2.3 Situation of using pesticides to vegetables 36 4.3 Effect of different nitrogen types on yield performance and residual of NO3- in mustard 37 4.3.1 Effect of nitrogen on yield performance of mustard 37 4.3.2 The effect of nitrogen types to NO3 - variation in mustard 39 4.3.3 The effect of nitrogen types to changes of NO3- in the soil 40 CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS 43 5.1 Conclusions 43 5.2 Recommendations 44 References 45 d oa nl w oi m ll fu an v an lu nh at z z @ om l.c gm an Lu CHAPTER INTRODUCTION n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 1.1 Introduction Vegetables are essential to human health since they are good source of vitamins, minerals and biologically active substances However, vegetables also contain nitrate and nitrite Nitrate itself is relatively non-toxic but its metabolites, nitrite, is associated with methaemoglobinaemia (commonly known as Blue Baby Syndrome) Nitrite might also react with amines to form carcinogenic nitrosamines in the stomach According to the Agency for Toxic an lu Substances and Disease Registry, the chemicals used in the making of commercial n va gh tn to fertilizers create high concentrations of nitrate compounds within the soil Nitrates are naturally occurring ions that form when organic nitrogen materials decompose p ie in the soil Nitrate ions act as chemically charged molecules that offset the natural w balance within a soil environment Nitrates can have the same effects on the d oa nl human body as well as in plant and animal bodies, according to Pest Management v an lu at the Crossroads Over time, nitrates can accumulate inside the body and fu an eventually disrupt normal functions within the body's endocrine, neurological and m ll immune systems Nitrates pose a particularly dangerous threat to fetal oi nh development and infant health in terms of brain and immune system development at z (http://www.ehow.com) z @ gm Thai Nguyen City is an economic, political and cultural center in the North om l.c of Vietnam For many years, the city has established food manufacturing belt in which vegetables are considered the most important products With the growth of Lu an agriculture, vegetable production in Thai Nguyen has met the demand in quantity, n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 slowly overcoming the shortage of food before rice harvest, many kinds of high quality vegetables in the meals have been added to people's daily diet However, the intensive vegetable production technology now reveals the downside is that the massive application, lack of selection of technical advances such as fertilizers, growth stimulant, plant protection drugs not only cause cultivation environmental pollution but also make vegetables contaminated there by affecting the health of lu an users va In cruciferous plants, mustard has a short growing time from 20 to 40 days, n gh tn to high yields of 20-40 tons/ha, Nutrient composition of mustard is also quite p ie high.etc Currently there are many safe vegetable production areas to create safe d oa nl w products meet human needs In order to mustard growth and development - the highest yield with nitrate residue levels permitted requiring provide a sufficiently v an lu logical Therefore need to be more research on nutrition for vegetables in general fu an and mustard in particular Stemming from the above problems to meet the m ll requirements of actual production, to contribute to the understanding improve the oi efficiency of fertilizer nitrogen in general and in particular I proceed to implement nh at the project " Effects of Nitrogen types on yield performance and NO 3- content z z @ in Mustard in Thai Nguyen " om l.c gm 1.2 Background of the Study an Lu Unlike many arid and semi-arid countries where urban wastewater is sought after using extensively, the underlying reason for its agricultural use in Vietnam is n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 the unplanned discharge of wastewater into natural watercourses, drainage canals or irrigation canals However, intentional wastewater use occurs in some instances due to inadequacy of irrigation systems particularly at the end of source (http://web.idrc.ca/en, 2011) In the process of promoting industrialization - modernization, in many localities in the country, environmental pollution in Thai Nguyen is a serious lu an problem affecting production and quality of people’s life, etc, So, confronting va n the problem posed is to have the right solution to fit the production development, gh tn to investment attraction, but must ensure the ecological balance of the environment, p ie stability and improved living environment of communities, especially in urban w areas, and industrial sites in the area (http://www.monre.gov.vn) d oa nl Besides soil, surface water in the city of Thai Nguyen has been heavily v an lu contaminated by toxic chemicals from industrial waste of factories such as Iron fu an and Steel Thai Nguyen Company, Paper- mill Hoang Van Thu, Cao Ngan factory; m ll waste from agriculture and urban centers, etc, They are the causes for reducing oi nh fresh vegetable growing areas of the city at z z According to statistics of the Department of Environmental Protection, @ gm there are hundreds of establishments mainly engaged in mining and ore discharge om l.c of wastewater into the Cau River basin In addition, most wastewater discharged from 200 villages located along the Cau River have not been treated, the use of an Lu chemicals and plant protection agents in agriculture, sand and mass gravel n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 extraction has raised large amounts of pollution, erosion that changed the flow of the river (www.tnmtthainguyen.gov.vn, 2010) To increase crop yields, farmers use pesticides and chemical fertilizers more and more Currently, all areas of agricultural production in Cau River basin extensively used chemical fertilizers estimated at around 500,000 tons per year, the excess flowing into the basin is about 33% In the vegetable areas, the lu an percentage of pesticides and fertilizers is higher than 3-5 times with the rice va n growing areas (www.tnmtthainguyen.gov.vn, 2010) p ie gh tn to The problem of soil and water pollution caused by industrial activities, agriculture, urban waste in the city of Thai Nguyen has been articulated by many w researches but only focusing on the assessment of soil pollution and water, and they d oa nl have not yet researched on the impact of pollution on the quality of agricultural fu an v an lu products This study was conducted to investigate the effects of Nitrogen types on m ll oi yield performance and NO3- content in Mustard, the results of which is expected in nh provide a contribution to solving the problems mentioned above at z z 1.3 Theoretical Framework of the Study @ Nowadays, food safety issues are the concern of everyone in every aspects of gm om l.c lives Vegetable is one of the foods that is used daily in all families In recent years, state and the agricultural sector have developed many local policy measures for an Lu producing safe vegetable to ensure users’ health n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 Although the authorities had a lot of efforts in the development of safe vegetable models, these models of safe vegetable production have not been used extensively Vegetable production areas according to technical processes are polluted by many causes Currently safe vegetable production areas is still sparse and it is too difficult for the organization, production, and testing consumers’ products lu an In Vietnam, the producers have abused nitrogen fertilizer use to increase va n productivity and profitability of their farms Using nitrogen fertilizer has increased gh tn to but the use of phosphate, and potassium are very low Rate of unreasonable p ie combination makes nitrate level in commercial products high w Studying the soil, water, and fertilizer contamination and their effects on d oa nl agricultural products is a pressing issue at present to contribute to decrease domestic v an lu waste and industrial materials as well as to provide useful measures to create safe fu an products m ll 1.4 Conceptual Framework of the Study oi nh Figure shows an overview of the conceptual framework where the at relationship between and among the inputs and the outputs of the study is being z z @ shown in two boxes: gm l.c The box to the left houses the inputs which are actually the independent an Lu Bed: (P2O5: 50kg/ha; K20: 35kg/ha) om variables: Nitrogen rate: bed + (0N, 70N Urea 46%, (NH4)SO4 21%, NH4Cl 26% ) n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 4.3.2 The effect of nitrogen types to NO3 - variation in mustard NO3 - accumulation in plants is due to the growth and development of plants absorbs nitrogen from the soil and from the air NO - accumulation in plants more or less depends on the ability to provide protein of soil more or less, the absorption capacity of the plant is strong or weak Also depends on the type of an lu vegetable (edible leaves, edible tubers, and fruit) n va The results of analysis of mustard grown in winter in 2014 average of four p ie gh tn to treatments and three replications are shown in Table w d oa nl Table The effect of nitrogen types to the variation in NO3 – through the growth period of the mustard (experiments in Thai Nguyen) days after days after oi Treatments m ll fu an v an lu Mean levels of nitrate (mg/kg fresh) days after days after second top- second top- dressing dressing 65.79 52.60 second top- dressing dressing T1 45.50 73.80 T2 76.72 492.28 T3 59.56 327.14 295.43 T4 54.75 325.18 288.52 nh first top- at z z @ gm 301.28 l.c 370.96 om 272.62 an Lu 256.46 n va a th c si 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37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 * Standard: 500 mg NO3 – /kg fresh In table shows that the accumulation of nitrate in vegetables after harvest ascending doses nitrogen, lowest in control treatment is 52.60 mg / kg and the highest in the treatment Urea 46% N / was 301.28 mg/kg Nitrate accumulation in plants is highest in 5th day after the second topdressing when the most powerful plant growth stage, due to nitrate nutrition also lu an increase the protein content of this phase trees also absorb the most nutrients va n (including N) In the treatment Urea 46%N/ha reached the highest was 492.28 gh tn to mg NO3 -/ kg fresh control and the lowest was 73.8 mg NO 3- / kg of fresh p ie vegetables but up to days after second top-dressing and days after second top- w dressing, the concentration of NO3- in the treatment are reduced, because the d oa nl nitrogen dressing last time influenced the variation of nitrate in plants Nitrate v an lu tends to decrease when the last time dressing as far as the day of harvest From oi m ll among all treatments fu an Table shows that the meaning of nitrate level in each period has significant nh at z 4.3.3 The effect of nitrogen types to changes of NO3- in the soil z @ Nitrate in the soil is easily digested protein supply for crops, it is formed in gm l.c the ground and go through the process of mineralization due to the operation of a om variety of microorganisms Cumulative NO3-N in soil more or less depending on Lu the activity of microorganisms and the ability to supply nitrogen to the soil an n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 Most of soil in Vietnam is poor in nitrogen and the fact shows that if only planted without proper nutrition plants would poorly developed Appling chemical nitrogen or other fertilizers containing nitrogen such as: manure and muck plant growth thrive (Bui and et al, 1996) Land used for vegetable production in Thai Nguyen City are of alluvial soil or sandy rich soil with pH 5.2 – 5.7 (acid soil) and humus, N, P2O5, K2O contents lu an are low The content of NO3- in the soil before planting is 0.36 mg NO3- /kg soil n va p ie gh tn to d oa nl w The effect of types nitrogen to changes of NO3- in the soil v an lu Table Content of NO3- in the soil before first top-dressing (mg/100g soil) (experiments in Thai Nguyen) fu an Replication Replication T1 0.37 0.36 T2 0.92 0.91 T3 0.73 0.73 0.71 T4 0.67 0.68 0.66 oi m ll Treatment Replication Average 0.36 0.36 nh at 0.90 0.91 z z @ 0.73 om l.c gm 0.67 Lu an Before the first top-dressing, NO3- content accumulated lowest in the soil at n va treatment is 0.36 mg/100g soil, highest at treatment is 0.91 mg/100g soil a th c si 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37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 Table 8: Content of NO3- in the soil before second top-dressing (mg/100g soil) (experiments in Thai Nguyen) an lu n va Treatment Replication Replication Replication Average T1 0.64 0.63 0.65 0.64 T2 1.42 1.42 1.43 1.42 T3 1.77 1.76 1.77 1.76 T4 1.21 1.21 1.20 1.20 gh tn to p ie The content of nitrate in the soil increase rapidly when nitrogen types is applied w Before second top-dressing, NO3- content accumulated lowest in the soil at d oa nl treatment is 0.64 mg/100g soil, highest at treatment is 1.76 mg/100g soil v an lu Table 9: Content of NO3- in the soil after harvest (experiments in Thai Nguyen) fu an Replication Replication T1 0.56 0.54 T2 0.71 0.71 T3 0.71 0.72 0.71 T4 0.61 0.60 0.60 oi m ll Treatment nh Replication Average 0.55 0.55 at 0.71 z 0.71 z @ l.c gm 0.71 0.60 om n va soil, highest is 0.72 mg/100g soil an Lu At harvest, NO3- content accumulated lowest in the soil at 0.54 mg/100g a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 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nitrogen content and nitrate va n accumulation in the soil after harvest and before planting Results indicated that in gh tn to the experimental conditions, when applied nitrogen types will increase the amount p ie of nitrate accumulation in the soil after harvest and will lead to increased risk of w water pollution from cropland d oa nl v an lu fu an CHAPTER CONCLUSIONS AND RECOMMENDATIONS This chapter summarizes the findings draws conclusions and gives m ll oi recommendations about the findings as gathered from the study nh at z z 5.1 Conclusions @ Based on the results of this study the following conclusions were drawn: gm is done properly and safe vegetable production processes om l.c Vegetables grown in Thai Nguyen City had not contaminated NO3- because it an Lu n va a th c si 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37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 Use water from the deep well to ensure water quality for vegetables, water from Cau River should be checked before irrigation to vegetables, water from muck to irrigation for vegetable have to ensure isolation time as chemical nitrogen fertilizer, using wastewater contaminated to irrigation for vegetable is cause contaminated to vegetables 3.Nitrate accumulation in plant, soil and total nitrogen have large fluctuations lu an over the growth period of the plant However, this variation tends to decrease at va n harvest p ie gh tn to d oa nl w m ll fu an v an lu 5.2 Recommendations oi In the light findings and conclusions of this study, it is recommended that: nh at The farmers should be to reduce the use chemical fertilizer, increase the use of z z @ compost, organic fertilizer, limit of use water from muck, nitrogen fertilizer to gm om l.c minimize the amount of NO3- and heavy metal residues in vegetables Soil and water for agricultural production to residues nitrate should be studied an Lu and treated by appropriate measures n va a th c si 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panel on contaminants in the food chain Eur Food nh at Saf Assoc J 689, 1–79 z z @ gm Tran et al, (2003), Techniques of Vegetable grow (Vegetable safety), om l.c Agricultural Publishing House in Hanoi an Lu Dang et al (2003) Study some measure of farming techniques for specialized areas reasonably safe vegetable production, Research project in 2003, Institute of Research Vegetable – Fruit, Hanoi n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 Venter F and P D Fritz (2007) “Nitrate contents of kohlrabi (Brassica oleracea L var Gongylodes Lam.) as influenced by fertilization”, Plant Food for Human Nutrition (Formerly Qualitas Plantarum), Springer Netherlands, pp 179 – 186 an lu Chung, J.C., Chou, S.S., Hwang, D.F, (2004) Changes in nitrate and nitrite content of four vegetables during storage at refrigerated and ambient temperatures Food Addit Contam 21, 317–322 n va gh tn to p ie B Periodicals d oa nl w Eustix, Mirjana (1991) “Nitrate accumulation in lettuce as related to nitrogen m ll fu an 49 – 56 v an lu fertilization levels”, Poljoprivredna znanstvena smotra 0370-0291, 1991, pp oi Hanafy Ahmed, A H Mishriky, J F and Khalil, M.K (2000) “Reducing nh at Nitrate accumulation in Lettuce (Lactica Sativa L.) plants by using different z z @ biofertilizers” Plant Physiology Section and Vegetable Department, gm Faculty of Agriculture, Cairo University, Giza, Egypt om l.c an Lu DU Lian-feng, ZHAO Tong-ke, ZHANG Cheng-jun, AN Zhi-zhuang, WU n va Qiong, LIU Bao-cun, LI Peng and MA Mao-ting, (2011) “Investigations a th c si 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37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 on Nitrate Pollution of Soil, Groundwater and Vegetable from Three Typical Farmlands in Beijing Region, China” Agricultural Sciences in China, 10(3) : 423-430 Dang et al (2003) Study some measure of farming techniques for specialized areas reasonably safe vegetable production, Research project in 2003, Institute of Research Vegetable – Fruit, Hanoi an lu va Dinh et al (2005) Assessing the social factors affecting food safety vegetable n 2004 p ie gh tn to production in the suburban area of Hanoi Subject independent state, 2000- d oa nl w Chung, J.C., Chou, S.S., Hwang, D.F, (2004) Changes in nitrate and nitrite v an lu content of four vegetables during storage at refrigerated and ambient m ll fu an temperatures Food Addit Contam 21, 317–322 oi Centre for Food Safety, Hong Kong, (2010) Nitrate and nitrite in vegetables nh at available in Hong Kong In: Risk Assessment Studies Report No 40 z z @ gm C.Unpublished thesis/ Dissertations om l.c an Lu n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.C.33.44.55.54.78.655.43.22.2.4.55.2237.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.66 Dang (2002) Research on the effects of fertilizers, contamination of soil and irrigation water to the level of nitrate and accumulation of heavy metals in some vegetables, Masters Thesis science, Hanoi University of Agricultural Pham (2001) Research on the effects of different fertilizers on the yield and volatility of nitrate in soil and mustard, Masters Thesis Agricultural lu an Sciences, University of Agriculture and Forestry Members Ho Chi Minh va City n gh tn to p ie Eustix, Mirjana (1991) “Nitrate accumulation in lettuce as related to nitrogen 56 d oa nl w fertilization levels”, Poljoprivredna znanstvena smotra 0370-0291, 1991, pp 49 – FAO start database – (2006) oi m ll fu an v an lu D Electronic sources nh at z www.agriculturesnetwork.org, (2007) z @ l.c gm www.tandfonline.com om http://www.ehow.com/list_7340687_dangers-fertilizershumans_.html an Lu http://www.ehow.com http://web.idrc.ca/en, 2011 n va a th c si 37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.55.77.77.99.44.45.67.22.55.77.C.37.99.44.45.67.22.99 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