개별 이온 및 작물 생육 센싱 기반의 정밀 수경재배 양액 관리 시스템

학위논문 (박사) -- 서울대학교 대학원 : 농업생명과학대학 바이오시스템·소재학부(바이오시스템공학), 2020. 8. 김학진.In current closed hydroponics, the nutrient solution monitoring and replenishment are conducted based on the electrical conductivity (EC) and pH, and the fertigation is carried out with the constant time without considering the plant status. However, the EC-based management is unable to detect the dynamic changes in the individual nutrient ion concentrations so the ion imbalance occurs during the iterative replenishment, thereby leading to the frequent discard of the nutrient solution. The constant time-based fertigation inevitably induces over- or under-supply of the nutrient solution for the growing plants. The approaches are two of the main causes of decreasing water and nutrient use efficiencies in closed hydroponics. Regarding the issues, the precision nutrient solution management that variably controls the fertigation volume and corrects the deficient nutrient ions individually would allow both improved efficiencies of fertilizer and water use and increased lifespan of the nutrient solution. The objectives of this study were to establish the precision nutrient solution management system that can automatically and variably control the fertigation volume based on the plant-growth information and supply the individual nutrient fertilizers in appropriate amounts to reach the optimal compositions as nutrient solutions for growing plants. To achieve the goal, the sensing technologies for the varying requirements of water and nutrients were investigated and validated. Firstly, an on-the-go monitoring system was constructed to monitor the lettuces grown under the closed hydroponics based on the nutrient film technique for the entire bed. The region of the lettuces was segmented by the excess green (ExG) and Otsu method to obtain the canopy cover (CC). The feasibility of the image processing for assessing the canopy (CC) was validated by comparing the computed CC values with the manually analyzed CC values. From the validation, it was confirmed the image monitoring and processing for the CC measurements were feasible for the lettuces before harvest. Then, a transpiration rate model using the modified Penman-Monteith equation was fitted based on the obtained CC, radiation, air temperature, and relative humidity to estimate the water need of the growing lettuces. Regarding the individual ion concentration measurements, two-point normalization, artificial neural network, and a hybrid signal processing consisting of the two-point normalization and artificial neural network were compared to select an effective method for the ion-selective electrodes (ISEs) application in continuous and autonomous monitoring of ions in hydroponic solutions. The hybrid signal processing showed the most accuracy in sample measurements, but the vulnerability to the sensor malfunction made the two-point normalization method with the most precision would be appropriate for the long-term monitoring of the nutrient solution. In order to determine the optimal injection amounts of the fertilizer salts and water for the given target individual ion concentrations, a decision tree-based dosing algorithm was designed. The feasibility of the dosing algorithm was validated with the stepwise and varying target focusing replenishments. From the results, the ion-specific replenishments formulated the compositions of the nutrient solution successfully according to the given target values. Finally, the proposed sensing and control techniques were integrated to implement the precision nutrient solution management, and the performance was verified by a closed lettuce cultivation test. From the application test, the fertigation volume was reduced by 57.4% and the growth of the lettuces was promoted in comparison with the constant timer-based fertigation strategy. Furthermore, the system successfully maintained the nutrient balance in the recycled solution during the cultivation with the coefficients of variance of 4.9%, 1.4%, 3.2%, 5.2%, and 14.9%, which were generally less than the EC-based replenishment with the CVs of 6.9%, 4.9%, 23.7%, 8.6%, and 8.3% for the NO3, K, Ca, Mg, and P concentrations, respectively. These results implied the developed precision nutrient solution management system could provide more efficient supply and management of water and nutrients than the conventional methods, thereby allowing more improved water and nutrient use efficiencies and crop productivity.현재의 순환식 수경재배 시스템에서 양액의 분석과 보충은 전기전도도 (EC, electrical conductivity) 및 pH를 기반으로 수행되고 있으며, 양액의 공급은 작물의 생육 상태에 대한 고려 없이 항상 일정한 시간 동안 펌프가 동작하여 공급되는 형태이다. 그러나 EC 기반의 양액 관리는 개별 이온 농도의 동적인 변화를 감지할 수 없어 반복되는 보충 중 불균형이 발생하게 되어 양액의 폐기를 야기하며, 고정된 시간 동안의 양액 공급은 작물에 대해 과잉 또는 불충분한 물 공급으로 이어져 물 사용 효율의 저하를 일으킨다. 이러한 문제들에 대해, 개별 이온 농도에 대해 부족한 성분만을 선택적으로 보충하고, 작물의 생육 정도에 기반하여 필요한 수준에 맞게 양액을 공급하는 정밀 농업에 기반한 양액 관리를 수행하면 물과 비료 사용 효율의 향상과 양액의 재사용 기간 증진을 기대할 수 있다. 본 연구의 목적은 자동으로, 그리고 가변적으로 작물 생육 정보에 기반하여 양액 공급량을 제어하고, 작물 생장에 적합한 조성에 맞게 현재 양액의 이온 농도 센싱에 기반하여 적절한 수준만큼의 물과 개별 양분 비료를 보충할 수 있는 정밀 수경재배 양액 관리 시스템을 개발하는 것이다. 해당 목표를 달성하기 위해, 변이하는 물과 양분 요구량을 측정할 수 있는 모니터링 기술들을 분석하고 각 모니터링 기술들에 대한 검증을 수행하였다. 먼저, 작물의 물 요구량을 실시간으로 관측할 수 있는 영상 기반 측정 기술을 조사하였다. 영상 기반 분석 활용을 위해 박막경 기반의 순환식 수경재배 환경에서 자라는 상추의 이미지들을 전체 베드에 대해 수집할 수 있는 영상 모니터링 시스템을 구성하였고, 수집한 영상 중 상추 부분만을 excess green (ExG)과 Otsu 방법을 통해 분리하여 투영작물면적 (CC, canopy cover)을 획득하였다. 영상 처리 기술의 적용성 평가를 위해 직접 분석한 투영작물면적 값과 이를 비교하였다. 비교 검증 결과에서 투영작물면적 측정을 위한 영상 수집 및 분석이 수확 전까지의 상추에 대해 적용 가능함을 확인하였다. 이후 수집한 투영작물면적과 기온, 상대습도, 일사량을 기반으로 생육 중인 상추들이 요구하는 물의 양을 예측하기 위해 Penman-Monteith 방정식 기반의 증산량 예측 모델을 구성하였으며 실제 증산량과 비교하였을 때 높은 일치도를 확인하였다. 개별 이온 농도 측정과 관련하여서는, 이온선택성전극 (ISE, ion-selective electrode)를 이용한 수경재배 양액 내 이온의 연속적이고 자율적인 모니터링 수행을 위해 2점 정규화, 인공신경망, 그리고 이 둘을 복합적으로 구성한 하이브리드 신호 처리 기법의 성능을 비교하여 분석하였다. 분석 결과, 하이브리드 신호 처리 방식이 가장 높은 정확성을 보였으나, 센서 고장에 취약한 신경망 구조로 인해 장기간 모니터링 안정성에 있어서는 가장 높은 정밀도를 가진 2점 정규화 방식을 센서 어레이에 적용하는 것이 적합할 것으로 판단하였다. 또한, 주어진 개별 이온 농도 목표값에 맞는 비료 염 및 물의 최적 주입량을 결정하기 위해 의사결정트리 구조의 비료 투입 알고리즘을 제시하였다. 제시한 비료 투입 알고리즘의 효과에 대해서는 순차적인 목표에 대한 보충 및 특정 성분에 대해 집중적인 변화를 부여한 보충 수행 실험을 통해 검증하였으며, 그 결과 제시한 알고리즘은 주어진 목표값들에 따라 성공적으로 양액을 조성하였음을 확인하였다. 마지막으로, 제시되었던 센싱 및 제어 기술들을 통합하여 NFT 기반의 순환식 수경재배 배드에 상추 재배를 수행하여 실증하였다. 실증 실험에서, 종래의 고정 시간 양액 공급 대비 57.4%의 양액 공급량 감소와 상추 생육의 촉진을 확인하였다. 동시에, 개발 시스템은 NO3, K, Ca, Mg, 그리고 P에 대해 각각 4.9%, 1.4%, 3.2%, 5.2%, 그리고 14.9% 수준의 변동계수 수준을 보여 EC기반 보충 방식에서 나타난 변동계수 6.9%, 4.9%, 23.7%, 8.6%, 그리고 8.3%보다 대체적으로 우수한 이온 균형 유지 성능을 보였다. 이러한 결과들을 통해 개발 정밀 관비 시스템이 기존보다 효율적인 양액의 공급과 관리를 통해 양액 이용 효율성과 생산성의 증진에 기여할 수 있을 것으로 판단되었다.CHAPTER 1. INTRODUCTION 1 BACKGROUND 1 Nutrient Imbalance 2 Fertigation Scheduling 3 OBJECTIVES 7 ORGANIZATION OF THE DISSERTATION 8 CHAPTER 2. LITERATURE REVIEW 10 VARIABILITY OF NUTRIENT SOLUTIONS IN HYDROPONICS 10 LIMITATIONS OF CURRENT NUTRIENT SOLUTION MANAGEMENT IN CLOSED HYDROPONIC SYSTEM 11 ION-SPECIFIC NUTRIENT MONITORING AND MANAGEMENT IN CLOSED HYDROPONICS 13 REMOTE SENSING TECHNIQUES FOR PLANT MONITORING 17 FERTIGATION CONTROL METHODS BASED ON REMOTE SENSING 19 CHAPTER 3. ON-THE-GO CROP MONITORING SYSTEM FOR ESTIMATION OF THE CROP WATER NEED 21 ABSTRACT 21 INTRODUCTION 21 MATERIALS AND METHODS 23 Hydroponic Growth Chamber 23 Construction of an On-the-go Crop Monitoring System 25 Image Processing for Canopy Cover Estimation 29 Evaluation of the CC Calculation Performance 32 Estimation Model for Transpiration Rate 32 Determination of the Parameters of the Transpiration Rate Model 33 RESULTS AND DISCUSSION 35 Performance of the CC Measurement by the Image Monitoring System 35 Plant Growth Monitoring in Closed Hydroponics 39 Evaluation of the Crop Water Need Estimation 42 CONCLUSIONS 46 CHAPTER 4. HYBRID SIGNAL-PROCESSING METHOD BASED ON NEURAL NETWORK FOR PREDICTION OF NO3, K, CA, AND MG IONS IN HYDROPONIC SOLUTIONS USING AN ARRAY OF ION-SELECTIVE ELECTRODES 48 ABSTRACT 48 INTRODUCTION 49 MATERIALS AND METHODS 52 Preparation of the Sensor Array 52 Construction and Evaluation of Data-Processing Methods 53 Preparation of Samples 57 Procedure of Sample Measurements 59 RESULTS AND DISCUSSION 63 Determination of the Artificial Neural Network (ANN) Structure 63 Evaluation of the Processing Methods in Training Samples 64 Application of the Processing Methods in Real Hydroponic Samples 67 CONCLUSIONS 72 CHAPTER 5. DECISION TREE-BASED ION-SPECIFIC NUTRIENT MANAGEMENT ALGORITHM FOR CLOSED HYDROPONICS 74 ABSTRACT 74 INTRODUCTION 75 MATERIALS AND METHODS 77 Decision Tree-based Dosing Algorithm 77 Development of an Ion-Specific Nutrient Management System 82 Implementation of Ion-Specific Nutrient Management with Closed-Loop Control 87 System Validation Tests 89 RESULTS AND DISCUSSION 91 Five-stepwise Replenishment Test 91 Replenishment Test Focused on The Ca 97 CONCLUSIONS 99 CHAPTER 6. ION-SPECIFIC AND CROP GROWTH SENSING BASED NUTRIENT SOLUTION MANAGEMENT SYSTEM FOR CLOSED HYDROPONICS 101 ABSTRACT 101 INTRODUCTION 102 MATERIALS AND METHODS 103 System Integration 103 Implementation of the Precision Nutrient Solution Management System 106 Application of the Precision Nutrient Solution Management System to Closed Lettuce Soilless Cultivation 112 RESULTS AND DISCUSSION 113 Evaluation of the Plant Growth-based Fertigation in the Closed Lettuce Cultivation 113 Evaluation of the Ion-Specific Management in the Closed Lettuce Cultivation 118 CONCLUSIONS 128 CHAPTER 7. CONCLUSIONS 130 CONCLUSIONS OF THE STUDY 130 SUGGESTIONS FOR FUTURE STUDY 134 LIST OF REFERENCES 136 APPENDIX 146 A1. Python Code for Controlling the Image Monitoring and CC Calculation 146 A2. Ion Concentrations of the Solutions used in Chapter 4 (Unit: mg∙L−1) 149 A3. Block Diagrams of the LabVIEW Program used in Chapter 4 150 A4. Ion Concentrations of the Solutions used in Chapters 5 and 6 (Unit: mg∙L−1) 154 A5. Block Diagrams of the LabVIEW Program used in the Chapters 5 and 6 155 ABSTRACT IN KOREAN 160Docto

Vegetable Crops

In ancient times, people benefited from ingesting different parts of various weeds (root, stem, shoot, leaf, flower, fruit, seed, etc.) to maintain a healthy life. People have obtained the vegetables we grow today by succeeding in cultivating these weeds. This book explains the health benefits of vegetable crops, organic vegetable growing, greenhouse management, and principles of irrigation management for vegetable crops

Novel toxigenic species on maize kernels in Southeastern Europe

In recent years, global climate changes have caused the variability of agro-climatic conditions, which could contribute to the synthesis of higher concentrations of mycotoxins in cereal grains during the growing season and could result in economic losses in the production, as well as in increased risk to human and animal health. These reasons and the fact that new toxigenic species have been identified in Serbia and its neighbouring countries in a few past years, indicate the need for permanent monitoring of mycopopulations on cereals. In Serbia, 30 different species of the genus Aspergillus have been identified, isolated mainly from cereal grains. The uncommonly high frequency and incidence of Aspergillus infestation of maize grain in the last few years were caused by extremely stressful agrometeorological conditions, high temperatures and drought over the period from flowering to waxy maturation of maize. Molecular detection of Aspergillus species collected from different samples of cereal kernels was done by using PCR-RFLP analysis of aflR-aflJ intergenic spacer (IGS). Restriction digestion of PCR products with BglII enzyme gave profiles specific for A. parasiticus - two fragments of 363 and 311 bp, which confirmed the presence of this species in the samples subjected to analysis. Characterization of Fg comlex species was done by DNA sequence-based analysis using primer pairs ef1/ef2. Specific genome fragments were sequenced and analized. Sequences were compared to the data from GeneBank. Most of the tested isolates appeared to represent F. graminearum sensu stricto species, while only two of them were identified as Fusarium boothii and Fusarium vorosii

Contamination of maize kernels with mycotoxins after harvest

The species of the genus Fusarium and Aspergillus are the most common pathogens of maize kernels worldwide. The most common species among them are F. verticillioides, F. graminearum and A. flavus. These fungi produce a wide spectrum of mycotoxins, among which the most common are fusariotoxins: trichothecenes-deoxynivalenol (DON), fumonisins (FBs) and aflatoxins: aflatoxin B1 (AFB1). The aim of this study was to examine the mycopopulation on maize kernels after harvest, as well as the concentration of their mycotoxins in kernels. Standard mycological examinations of maize kernels revealed the presence of toxigenic species of fungi from three genus, Fusarium, Aspergillus and Penicillium. In the examined samples, the species F. verticillioides was most often isolated in majority of hybrids, with a maximum incidence of 32%, while the presence of Aspergillus spp. was from 0 to 17%. Mycotoxicological analysis of maize kernels was performed by the ELISA method using a commercial kit (Tecna S.r.l., Italy). All analysed samples were positive for the presence of at least one mycotoxin. The differences between the examined hybrids in the concentration of mycotoxins in the grain were statistically significant (P <0.001) for DON and FBs, but not for the content of AFB1. Likewise, the interaction between hybrids and localities was statistically significant (P <0.001) for DON and FBS content, while it was not statistically significant for AFB1 concentration. The average DON concentrations were 127,55 µg kg–1 , FBs 3050,21 µg kg–1 , and AFB1 2,98 µg kg–1

Effects of bacteria and enzyme mixture inoculants on quality of high-moisture maize grain silage

The objective of this study was to evaluate the effect of applying lactic acid bacteria (LAB) and enzymes mixture inoculants (Sil-All and Silaprilis) on the chemical composition and fermentation of high-moisture grain silage of two maize hybrids Zenit and ZP 735. Maize hybrids were harvested at 68-72% of dry matter. Commercial inoculants were prepared and sprayed following the manufacturer's specifications. Silages were stored in glass jars with a special valve filled with water in the middle of the lid. Significant differences between hybrids were found for ash, crude protein, pH, and acetic acid. The hybrid Zenit had significantly higher ash (14.9 g kg-1 dry matter (DM)), pH (4.03), and acetic acid (6.3 g kg-1 DM), and significantly lower crude protein (89.0 g kg-1 DM) than hybrid ZP 735 (12.5 g kg-1 DM, 3.98, 5.1 g kg-1 DM and 101.2 g kg-1 DM, respectively). Compared to control, LAB+enzymes mixture inoculants stimulated ensiling of high-moisture maize grain. Inoculants decreased the contents of ammonia nitrogen and acetic acid, and pH value, and increased the contents of dry matter, ash, crude protein, crude fat, and lactic acid during silage fermentation than control. Accordingly, the application of LAB+enzymes mixture inoculants is justified and they can be recommended for high-quality silage production in feeding livestock

Achieving effective traceability systems for the domestic fresh produce industry in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master in Food Technology at Massey University, Albany Campus, New Zealand

Figures 2.1 (=Bosona & Gebresenbet, 2013 Fig 2) & 2.2 (=Fan et al., 2019 Fig 1) were removed for copyright reasons. Figure 2.7 is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives International License (CC-BY-NC-ND).A reliable and effective traceability system is important to the food industry especially when a foodborne illness outbreak occurs. In particular, fresh fruit and vegetables are highly perishable, fragile, seasonal, diverse products with relatively short shelf life, thereby making their value chain complex and fast-paced. Hence, the traceability system in the fresh produce industry becomes critical in the event of a food crisis where products need to be tracked and traced in a timely manner. The objective of this study was to investigate current traceability systems in the fresh produce industry in New Zealand and also to explore potential improvement in the traceability system along the domestic supply chains. There were four different methods applied in this study: observation of traceability information available on fresh produce products, interviews with industry participants using a questionnaire, survey strategy by means of a questionnaire that was sent to growers, and a pilot study using GS1 technology to examine a modelled traceability system in two supply chains of strawberries. There were 336 fresh produce samples observed for traceability information analysis throughout the supply chain. Four growers, three wholesalers and one retailer from the fresh produce industry participated the face to face interviews. The questionnaire developed in the survey was sent to 578 growers with 40 of them responded and answered. Two pallets of strawberries were selected and GS1 (Global Standards One) barcodes and systems were used in the pilot study to track and trace each strawberry punnet throughout the supply chains. Qualitative and quantitative data were collected from produce traceability data samples, interviewed industry stakeholders, surveyed growers, and the pilot study to generate empirical information on traceability systems along fresh produce supply chains in New Zealand. Subsequently, data were analysed using quantitative tools such as frequency distributions, Chi-Square test (X2) and Fisher’s Exact test, and qualitative descriptions in this study. The findings show that fragmentation of product traceability information, lack of standardisation in data format and information asymmetry exist in the domestic fresh produce industry. As only a ‘one-up, one-down’ traceability system for food businesses is required by regulators in New Zealand, industry players intend to solely focus on their own or internal needs without recognising the importance of an industry-wide traceability system in the fresh produce supply chain. The findings pose a question mark as to whether or not the ‘one-up, one-down’ traceability requirement is sufficient for the fresh produce industry. The findings also indicate that an effective and efficient external traceability system throughout the fresh produce value chain in New Zealand is feasible to implement by industry-wide cooperation from growers, packers, transporters and receivers/buyers. This study fills the gap found in the literature where few academic papers focused attention on traceability systems in the fresh produce industry in New Zealand

XVI Agricultural Science Congress 2023: Transformation of Agri-Food Systems for Achieving Sustainable Development Goals

The XVI Agricultural Science Congress being jointly organized by the National Academy of Agricultural Sciences (NAAS) and the Indian Council of Agricultural Research (ICAR) during 10-13 October 2023, at hotel Le Meridien, Kochi, is a mega event echoing the theme “Transformation of Agri-Food Systems for achieving Sustainable Development Goals”. ICAR-Central Marine Fisheries Research Institute takes great pride in hosting the XVI ASC, which will be the perfect point of convergence of academicians, researchers, students, farmers, fishers, traders, entrepreneurs, and other stakeholders involved in agri-production systems that ensure food and nutritional security for a burgeoning population. With impeding challenges like growing urbanization, increasing unemployment, growing population, increasing food demands, degradation of natural resources through human interference, climate change impacts and natural calamities, the challenges ahead for India to achieve the Sustainable Development Goals (SDGs) set out by the United Nations are many. The XVI ASC will provide an interface for dissemination of useful information across all sectors of stakeholders invested in developing India’s agri-food systems, not only to meet the SDGs, but also to ensure a stable structure on par with agri-food systems around the world. It is an honour to present this Book of Abstracts which is a compilation of a total of 668 abstracts that convey the results of R&D programs being done in India. The abstracts have been categorized under 10 major Themes – 1. Ensuring Food & Nutritional Security: Production, Consumption and Value addition; 2. Climate Action for Sustainable Agri-Food Systems; 3. Frontier Science and emerging Genetic Technologies: Genome, Breeding, Gene Editing; 4. Livestock-based Transformation of Food Systems; 5. Horticulture-based Transformation of Food Systems; 6. Aquaculture & Fisheries-based Transformation of Food Systems; 7. Nature-based Solutions for Sustainable AgriFood Systems; 8. Next Generation Technologies: Digital Agriculture, Precision Farming and AI-based Systems; 9. Policies and Institutions for Transforming Agri-Food Systems; 10. International Partnership for Research, Education and Development. This Book of Abstracts sets the stage for the mega event itself, which will see a flow of knowledge emanating from a zeal to transform and push India’s Agri-Food Systems to perform par excellence and achieve not only the SDGs of the UN but also to rise as a world leader in the sector. I thank and congratulate all the participants who have submitted abstracts for this mega event, and I also applaud the team that has strived hard to publish this Book of Abstracts ahead of the event. I wish all the delegates and participants a very vibrant and memorable time at the XVI ASC