T THE JOIINT ACADEMIC P PROGRAAM OF EXECUTIIVE MAS STER IN SCIENCES ANND MAN NAGEMENT OF THE T ENV VIRONMEENT BETWEEEN INDUSTRIAL ERSITY OF L UNIVE O HOCHHIMINH CITY AND L LIÈGE UNIVERS U SITY LE NH CHAU E THI MIN EFFE ECT OF O BIOOCHARR ON GREE G ENHOUUSE GA AS EM MISSIO ONS AN ND THHE GR ROWTH H OF PADDDY RIC CE M Major: EXECUTIVE E MASTE ER IN SC CIENCES AND MA ANAGEM MENT OF F THE ENVIIRONMENNT MASTER’S M S THESIS S HOCH HIMINH CIT TY, YEAR 2018 The project was completed at The Industrial University of Hochiminh City Supervisor’s name: Dr. Nguyen Thanh Binh The thesis was taken at The Industrial University of Hochiminh City date 23 month 06 year 2018. - Secretary DEAN OF INSTITUTE OF ENVIRONMENTAL COMMITTEE CHAIR SCIENCE, ENGINEERING AND MANAGEMENT ACKNOWLEDGEMENTS I would like to send my sincere thanks to the professors of University of Liege and IESEM, Industrial University of Ho Chi Minh City, who have imparted knowledge to me in recent years. It is very important for me to be able to successfully complete my dissertation.
I am highly indebted to my supervisors Dr. Nguyen Thanh Binh for his persistent effort in guiding, supervising and encouraging me throughout the course of study. I would like to thank Prof. HAUGLUSTAINE Jean-Marie, Dr.
Dinh Dai Gai, Dr. Luong Van Viet, Dr. Le Hoang Anh for their advice and encouragement. I would like to thank Industrial University of Ho Chi Minh City for securing funds for this study.
Finally, thanks a lot! AUTHOR LE THI MINH CHAU 1 ABSTRACT Agricultural practices affect the growth of rice and emission of methane (CH4) from the paddy field. The increased CH4 concentration in the atmosphere could be contributed from the flooded regime. The release of CH4 from soil is the largest source of carbon to the atmosphere. In order to examine the effect of biochar on rice growth and CH4 emission from paddy soil, an experiment was conducted with 6 treatments and 4 replicates.
Six treatments include (1) no manure – no biochar, (2) no manure – rice husk biochar, (3) no manure – rice straw biochar, (4) cow manure – no biochar, (5) cow manure – rice husk biochar, (6) cow manure – rice straw biochar. The experiment was conducted over three months at the Institute of Biotechnology and Food Technology, Industrial University of Ho Chi Minh City. Gas samples were collected and analysed with CH4 weekly. The biomass of rice crop and soil properties were determined at the end of the experiment.
The results showed that: − Application of cow manure increased CH4 emission from the paddy rice. Biochar reduced CH4 emissions from the treatments applied with cow manure. Specifically, CH4 emissions decreased by 58% with the addition of rice straw biochar, decreased by 17% with the addition of rice husk biochar. − Addition of biochar alone (no cow manure) on saline soil increased aboveground biomass of paddy rice and the influence level depending on the type of biochar.
In the current study, aboveground biomass increased to 346% with straw biochar, and to 174% with husk biochar. The addition of biochar and cow manure into saline soils also affected the nutrient content of the soil. 2 TABLE OF CONTENTS LIST OF TABLES. 4 LIST OF FIGURES.
5 LIST OF ABBREVIATIONS. The reason for choosing the topic. Objectives of the study. Subjects and scope of the study.
10 CHAPTER 1 LITERATURE REVIEW. Paddy rice production in Vietnam. Soils for paddy rice production. Greenhouse gas emission from paddy fields.
Biochar with crop production. Biochar with paddy rice production. Current problems of paddy rice production in Vietnam and biochar solutions. 18 CHAPTER 2 MATERIALS AND METHODS.
Materials and methods. Measurements and analyses. 27 CHAPTER 3 RESULTS AND DISCUSSION. Basic characteristics of experimental materials.
Variations in CH4 effluxes during experiment. Soil properties of six treatments after experiments. Exchangeable concentrations of PO43-, NH4+, NO3-, and Cl-. Soil pH and EC.
Soil exchangeable concentrations of Ca, K, and Mg. Soil CEC, Na, and non-Na, exchangeable Na. For CH4 emissions:. For the growth of paddy rice.
For soil nutrients. 50 3 LIST OF TABLES Table 1. 1 The paddy rice cultivated area and yield of Vietnam from 2000 to 2013. 1 Details of treatments.
1 Basic properties of experimental materials. The numbers in the parenthesis are the standard deviation of the mean. 2 Average CH4 emission of each treatment through observations. SD = standard deviation of the mean.
In the same column of data, different letters indicated statistically significance with probability P <0. 3 Soil concentration of PO43-, NH4+, NO3-, and Cl- of 6 treatments after the experiment. SD = standard deviation of the mean. 4 Soil pH of six treatments after the experiment.
5 Soil EC of six treatments after the experiment. 43 4 LIST OF FIGURES Figure 1. 1 Distribution of national rice area in Vietnam. 2 Salinity intrusion in the Mekong Delta.
3 CH4 emission mechanism. 4 Methane formation and emission in paddy field. 1 Measure EC of the soil. 2 Collected the saline soil samples.
3 Rice husk biochar. 4 Rice straw biochar. 7 Experiment Pots when appling rice. 1 Trends of CH4 emissions in no manure treatments.
2 Evolution of CH4 emissions in manure treatments during experiment. 3 Evolution of CH4 emissions. On the same measuring day, the data with the same number are not significant. The statistically significant dates are represented by the letters a, b.
4 CH4 emissions from 6 treatments during the experiment. Within the same measuring day, data attached with the same letter were statistically significant from the others. 5 Total methane emitted for 90 days from experimental treatments. Error bars are the standard deviation of the mean.
Bars attached with the same letters are not significantly different from the others at P ≤ 0. 6 Aboveground biomass of paddy rice after 90 days from sowing. Error bars are the standard deviation of the mean. Bars attached with the same letters are not significantly different from the others at P ≤ 0.
40 5 LIST OF ABBREVIATIONS ANOVA Analysis of variance Institute of environmen Science and Environmental IESEM Management IPCC Intergovernmental Panel on Climate Change ISO International Organization for Standardization GHG Green house gas SD Standard deviation TCVN Standard of vietnam 6 INTRODUCTION 1. The reason for choosing the topic Global warming has been studied and reported quite frequently in recent years and is forecasted to continue for coming decades [1]. Global warming in recent years, mainly caused by the continuous accumulation of greenhouse gases, such as CH4 and N2O in the atmosphere, resulted in many negative impacts to all countries in the world. In developed countries, greenhouse gas emissions (GHG) are mainly derived from industrial and energy activities, while in developing countries these could come mainly from agricultural production [2].
Currently, agricultural production was reported to emit up to 1/3 total gases, which cause greenhouse effect [3]. Annually rice cultivation emitted about 60 million tons of greenhouse gases (ranging from 20 to 100 million tons) in the world, equivalent 5 - 20% of total anthropogenic greenhouse gases [1]. In Viet Nam, agriculture annually emitted 43% of total national greenhouse gases (about 65 – 150 million tons CO2) from paddy rice production and improper handling of byproducts of some crops such as straw, bagasse, coffee pods, stems and leaves of corn, peanuts, and soybeans. In 2000, paddy rice production emitted 57,5 % of total greenhouse gases from the agricultural activity of the country [4].
Thus, rice production in Vietnam is emitting a large amount of CH4, N2O annually due to the flooded growing environment, creating anaerobic conditions for metabolic processes within the soil. This phenomenon contributes to increasing the concentration of greenhouse gases in the atmosphere with time. The soil is also the issue of rice production in Vietnam. In Vietnam, it is estimated that saline soils have nearly 2 million hectares, accounting for nearly 6% of the total natural land.
Saline soil is studied to improve paddy rice yield and greenhouse gas emissions [5]. Biochar is the residue after an incomplete combustion (pyrolysis) of organic substances such as wood, leaves, plant remnants in anoxic conditions. It is 7 the organic carbon - rich materials, which have lots of important features. For agronomy, biochar can increase fertility of the soils and the growth of crops by (a) reducing soil acidification, (b) enhancing soil’s ability to hold nutrients [6], (c) enhancing soil texture, and (d) increasing soil nutrient contents of N, P and K [7].
For environment, paddy rice soil added with biochar may limit methane emissions, through three mechanisms, including (1) limiting the activities of methane metabolizing bacteria (2) increasing the activity of methane oxidation process, and (3) enriching the gene pmoA of the methane using bacteria [8]. After carbon dioxide, methane emissions provide the second largest contribution to historical warming, but it has the radiative forcing causing global warming as much as 25 times higher than that of CO2 [9]. Human activity causes methane emissions, a major source of greenhouse gas accounting for 20% of global warming [10], and paddy rice production is a primary source of methane emissions. Zhang (2012) undertaking studies on biochar, which was produced from straw for paddy rice, reported an effective improvement of soil fertility (pH, total protein, total C and density) and an increase in the crop yield.
The results of these authors also showed that biochar has a potential of reducing N2O emissions, but increasing emissions of CH4. However, another study of Pratiwi and Shinogi (2016) showed that biochar, produced from rice hulls can reduce CH4 emissions, and increase the growth of paddy rice. However, there is almost no study in Vietnam and other countries all over the world reporting greenhouse gas emissions and growth of paddy rice cultivated on saline soils affected by biochar produced from by - products from rice production. As a result, the current study "Effects of biochar on greenhouse gas emissions and the growth of paddy rice" is set up and conducted.
The main purpose of this study is to evaluate the effect of biochar on GHG emissions and the growth of paddy rice on saline soil. The findings from the current study could be useful domestically and internationally. This knowledge could serve 8 as a basis for sustainable development of paddy rice. The results of this experiment may provide an overview about the impact of biochar on GHG emissions and the growth of paddy rice, suggesting a direction for the optimal utilization of by - products, which are abundant natural resources of the country.
Moreover, it is the basis for further studies in the selection of organic amendments to improve soil properties, enhance paddy rice yield and contribute to reducing greenhouse gases in the atmosphere. Objectives of the study This thesis is set out to address the gaps in knowledge outlined in the problem statement. It aims at: − Assessing the effect of biochar on greenhouse gas emissions from paddy rice production; − Assessing effect of biochar on the growth of paddy rice; 3. Subjects and scope of the study a.
Research subjects The research subject is the growth of paddy rice from saline soil and Quantity of greenhouse gases emissions when paddy rice is produced. Research scope A pot experiment was set up in a net house at the Industrial University of Ho Chi Minh city. The experimental soil had EC of 6 mS. The paddy rice was grown for 3,5 months.
This study examined the growth of paddy rice and greenhouse gases emissions from saline soil. Soil properties were also measured to examine the active mechanisms of biochar.
