In the transition from a fossil to a bio-based economy, it has become an important challenge to maximally recycle valuable nutrients that currently end up in waste streams. Nutrient resources are rapidly depleting. Significant amounts of fossil energy are required for the production of synthetic fertilizers, whereas costs for energy and fertilizers are increasing.
The goal of this thesis was to evaluate the impact of bio-amendments instead of synthetic fertilizers. It aims to i) identify the impact of the different scenarios on the soil fertility ii) the influence of bio-amendment substitutes on the soil quality and iii) the impact of the applied amendment on the plant nutrient contents. Eleven scenarios were designed from liquid manure, digestates and scrubber water.
Their application resulted in no nitrate pollution according to the Flemish Manure decree in the top 90 cm of the soil. Also there was no negative impact on the soil quality and soil fertility though soil degradation needs to be monitored in the long term. Moreover, the nutrient status of the experimental field was already quite high to begin with. However, the lack of a reference treatment precluded the real evaluation of the potential of the bio-amendments on soil quality and crop yields. Meanwhile, biogas production through anaerobic digestion produces nutrient rich digestates, which could potentially be reused as green fertilizers in agriculture, thereby providing a sustainable substitute for synthetic fertilizers.
Table of Contents
CHAPTER ONE
1.1 BACKGROUND OF STUDY
1.2 PROBLEM STATEMENT
1.3 SUBJECT JUSTIFICATION
CHAPTER TWO
2.1 INTRODUCTION
2.3 DIGESTATE PRODUCTION AND THEIR NUTRIENT CONTENT
2.4 DIGESTATE SEPARATION
2.5 NUTRIENT ELEMENT NITROGEN RECOVERY
2.5.1 AMMONIA STRIPPING
2.5.2 AIR SCRUBBER
CHAPTER THREE
3.1 SOIL SAMPLE PREPARATION
3.2 CHEMICAL ANALYSIS
3.2.1 NITRATE
3.2.2 SOIL pH
3.3 ELECTRICAL CONDUCTIVITY (EC)
3.4 TOTAL NITROGEN
3.5 MAJOR NUTRIENTS
3.6 AVAILABLE MAJOR NUTRIENTS
3.6.1 SOIL ANALYSIS
3.6.2 PLANT ANALYSIS
3.7 STATISTICAL ANALYSIS
CHAPTER FOUR
4.1 SOIL QUALITY
4.2 SOIL NUTRIENT STATUS
4.3 PLANT NUTRIENT CONTENT
CHAPTER FIVE
5.1 IMPACT OF BIO-BASED AMENDMENT ON SOIL FERTILITY AND SOIL QUALITY
5.1.1 SOIL QUALITY
5.1.2 SOIL FERTILITY
5.2 IMPACT OF BIO-BASED AMENDMENT IMPACT PLANT NUTRIENT CONTENT
5.3 CONCLUSION
Research Objectives and Core Themes
The primary research objective is to evaluate the viability of utilizing bio-based amendments, such as digestates and scrubber water, as sustainable substitutes for conventional fossil-based mineral fertilizers in agriculture. The study investigates how these amendments influence soil fertility, soil quality parameters, and plant nutrient uptake through a controlled field experiment.
- Nutrient cycle closure via bio-based waste recycling.
- Impact of digestate separation and ammonia recovery on soil health.
- Comparative analysis of synthetic versus bio-based fertilizer efficacy.
- Monitoring of soil chemical properties including pH, salinity, and nitrate content.
- Assessment of plant nutrient accumulation under varying amendment scenarios.
Excerpt from the Book
1.1 BACKGROUND OF STUDY
Manure can be used to improve the nutrient status of agricultural fields. In the Flemish agricultural sector, the manure policy is one of its most important environmental policies (Van der Staeten & Buysse, 2009). Biodegradable waste management, has become one of the main target fields in this progression. Manure can be utilized as a substitute for inorganic fertilizers. Fossil fuel energy is needed for the production of inorganic fertilizers. It is usually expensive. In 2011, 10.2 million tons of nitrogen (N), 2.2 million tons of phosphate (P2O5) and 2.4 million tons of potash (K2O) were applied to 134.4 million hectares of farmland in the European Union per season (EFMA, 2011). By 2020/21, Fertilizers Europe forecasters expect that these fertilizer consumption figures will reach 10.8, 2.6 and 3.2 million tons respectively, applied to 133.7 million hectares (EFMA, 2011). Minerals such as P and K now extracted via mining, are rapidly becoming limited (EFMA, 2000).
Intensive livestock and agriculture is been practised in Belgium and other European countries. The practice of intensive animal agriculture in some areas has resulted in excessive manure production for the available land base (Ippersiel et al., 2012). In line with the cradle-to-cradle approach, the consideration of biodegradable waste as a secondary resource for the production of green fertilizer substitutes for fossil-based mineral fertilizers has become an important course in the path to sustainability (Vaneeckhaute et al., 2011). Livestock manure is an important source of calcium (Ca), magnesium (Mg), potassium (K), sodium (Na) and nitrogen (N) for crop production. It decreases the need for mineral fertilizer use, particularly in intensive livestock production (Alitalo et al., 2012). Intensive livestock and arable crop production contribute substantially to the economy of European countries in terms of employment and export to other countries (Melse & Timmerman, 2009). This is also true for the Belgian economy. However, animal manure production is connected to a number of environmental effects, especially when poorly managed. Nutrient leaching, mainly nitrogen,
Summary of Chapters
CHAPTER ONE: Provides an overview of the environmental and economic context surrounding manure management, the need for fertilizer substitutes, and the research objectives.
CHAPTER TWO: Reviews existing literature on nutrient recovery, anaerobic digestion, and various technologies like ammonia stripping and air scrubbing for waste processing.
CHAPTER THREE: Details the site location, field experimental design with eleven different treatment scenarios, and the analytical methods used for soil and plant analysis.
CHAPTER FOUR: Presents the experimental results regarding soil quality parameters such as nitrate residues, pH, electrical conductivity, and soil nutrient status.
CHAPTER FIVE: Discusses the findings, assesses the impact of bio-amendments on soil fertility and plant nutrient content, and provides conclusions regarding the sustainability of these practices.
Keywords
Bio-based amendments, Anaerobic digestion, Digestate, Nutrient recovery, Ammonia stripping, Soil fertility, Sustainable agriculture, Mineral fertilizer, Field experiment, Nutrient leaching, Nitrogen management, Phosphorus availability, Manure policy, Circular economy, Soil quality.
Frequently Asked Questions
What is the core focus of this research?
The research focuses on the transition toward a bio-based economy by utilizing nutrient-rich residues from anaerobic digestion, such as digestates and scrubber water, as sustainable alternatives to fossil-based synthetic fertilizers.
What are the primary thematic areas addressed?
The study addresses nutrient recycling, the environmental impact of livestock manure management, the application of innovative extraction technologies (stripping and scrubbing), and the assessment of soil and plant nutrient status.
What is the main research question or goal?
The goal is to determine if bio-based amendments can effectively substitute mineral fertilizers without compromising soil quality, soil fertility, or crop yields, while also complying with regional environmental regulations.
Which scientific methodology is employed?
The research utilizes a controlled field experiment involving eleven distinct scenarios with different bio-based product combinations, followed by chemical laboratory analysis of soil and plant samples using standardized methods (e.g., Kjeldahl, ICP-OES).
What is covered in the main body of the work?
The main body covers the literature review on waste processing technologies, the detailed materials and methods of the field trial, an extensive presentation of results for various soil and plant nutrients, and a discussion on the ecological and agricultural implications.
Which keywords best characterize the study?
Keywords include bio-based amendments, anaerobic digestion, nutrient recovery, sustainable agriculture, manure policy, and soil fertility management.
Why are standard deviations particularly relevant in this field experiment?
They are essential for evaluating the consistency of the results across the different subplots, accounting for the inherent variability of soil conditions in field trials.
What role does the Flemish Manure Decree play in this research?
It serves as a regulatory benchmark, specifically regarding the maximum allowed nitrate levels in the soil, to ensure that the experimental applications remain environmentally safe.
- Citation du texte
- Bongaman Massimo Wongbi (Auteur), 2013, Closing the Nutrient Cycle by Using Bio-Based Amendments as Substitutes for Fossil-Based Fertilizers, Munich, GRIN Verlag, https://www.grin.com/document/304378
