Greenhouse Climate Control: Sensors & Control Strategies

Effective greenhouse management requires good understanding of sensors and climate control strategies. Recent technological advancement in CEA expanded the range of sensors available for greenhouse growers and the access to more sophisticated algorithms such as artificial intelligence (AI). This symposium will provide participants with foundational information about sensors and control strategies for crop production in greenhouses. The presenters will review common sensors used to measure key environmental parameters including light, temperature, humidity, carbon dioxide, and root zone conditions. In addition, participants will learn how the sensor readings can be used to provide optimum growing conditions for crops grown in greenhouses. Two additional lectures will be presented that cover novel environmental control strategies based on crop growth models and AI. Industry professionals (beginners) in greenhouse and indoor farms are encouraged to register.

tHRIve Symposium Schedule

8:00 AM - Welcome

8:05 AM - Measuring and Controlling Light – A.J. Both (Rutgers University)

Light is one of the most important environmental variables for growing plants. Participants will be introduced to key light measurements such as PPFD, ePAR, DLI, solar radiation, and net radiation. Some strategies to control light and radiation in plant production systems will be explained.

8:40 AM - Measuring and Controlling Temperature – Murat Kacira (University of Arizona)

Temperature is a critical factor affecting all living organisms; however, it is also most difficult measurement to obtain accurate data. This lecture provides an overview of types of sensors for measuring air and leaf temperatures together with tips for measurement accuracy using aspirated radiation shield. Strategies to control temperature in plant production systems will be introduced.

9:15 AM - Measuring and Controlling Humidity and CO₂ – Peter Ling (Ohio State University)

While humidity and CO₂ are critical factors affecting plant transpiration and photosynthesis, these factors are often overlooked by growers who have limited understanding of plant physiology. The lecture defines “relative humidity”, “vapor pressure deficit”, and “vapor pressure difference” and how these factors affect plants. Strategies to control humidity and CO₂ concentrations in plant production systems will be discussed.

9:50-10:05 AM - Break

10:05 AM - Measuring and Controlling EC, pH, DO, and other Rootzone Parameters – Chieri Kubota (Ohio State University)

Controlled environment agriculture often employs soilless or hydroponic cultivation systems where rootzone conditions can be maintained for optimum plant growth. This lecture will review various types of sensors for measuring electrical conductivity, pH, and dissolved oxygen. Precision control of moisture content in the soilless substrate is critical for food crops, and a typical practice of controlling rootzone conditions using a lysimeter setup will be described. A unique strategy to improve fruit quality by rootzone management will be introduced.

10:40 AM - Integrating Sensor Measurements with Advanced Crop Growth Models for Optimum Climate Control – Niels van der Geest (Delphy, The Netherlands)

Crop growth models can predict plant growth and yield under a selected set of environmental conditions. Use of crop models is an advanced climate control strategy. Case studies of successful applications of using crop growth models for optimum greenhouse climate control will be discussed.

11:15 AM - Using Artificial Intelligence for Greenhouse Climate Control – Ken Tran (Koidra, Inc.)

This lecture will explain the basic concept and some benefits of artificial intelligence for greenhouse climate control. Case studies of successful applications of using artificial intelligence for optimum greenhouse climate control will be discussed.

11:50AM Closing

Meet Our Speakers

A.J. Both (Rutgers University, New Brunswick, NJ)

Dr. A.J. Both is a Professor and Extension Specialist in Controlled Environment Engineering in the Department of Environmental Sciences at Rutgers University. His research focuses on methods and systems to provide the optimum growing environment in protected plant production facilities and includes topics such as hydroponics, supplemental lighting, crop modeling, and the use of energy in agricultural systems. He teaches undergraduate and graduate classes at the School of Environmental and Biological Sciences. He serves as an associate/consulting editor for publications by the American Society of Agricultural and Biological Engineers and the American Society for Horticultural Science. He is involved in the development of professional standards that address the design and operation of commercial and research plant production facilities.

Murat Kacira (University of Arizona, Tucson, AZ)

Dr. Murat Kacira is the Director of UA Controlled Environment Agriculture Center and a Professor of the Department of Biosystems Engineering, University of Arizona. Dr. Kacira has over 20 years of experience in CEA research and teaching, with a focus on efficiency of systems through integrated crop and production system sensing, monitoring, environmental control, and alternative energy applications. He actively interacts with stakeholders through technical consultations, hands-on educational workshops, and short courses.

Peter Ling (The Ohio State University, Wooster, OH)

Dr. Peter Ling is an Associate Professor/Greenhouse Engineer Extension Specialist at the Department of Food, Agricultural, and Biological Engineering, The Ohio State University. Dr. Ling has a well-established greenhouse engineering extension program, The annual Greenhouse Management Workshop offers different themes from year to year that has attracted 50-164 attendees every year. Under Dr. Ling’s leadership, The Ohio State University, Rutgers University, and University of Arizona have collaboratively published 52 horticultural engineering technology learning modules on YouTube with more than 61,000 views.

Chieri Kubota (The Ohio State University, Columbus, OH)

Dr. Chieri Kubota is the Director of the Ohio Controlled Environment Agriculture Center and a Distinguished Professor of Food, Agricultural and Environmental Sciences, Department of Horticulture and Crop Science, The Ohio State University. With an interdisciplinary greenhouse training background, Kubota research and extension efforts focus on the intersection of horticultural sciences and engineering. She has worked on issues in CEA crop production such as lighting technologies, water, and nutrient management, and introducing new crops for CEA. Kubota is very active in training professionals through online courses, hands-on training, and consultations. She also regularly communicates with stakeholders through social media (e.g. Facebook), webinars, science cafes, and presentations at grower conferences. Dr. Kubota is the project lead faculty for the newly developed Controlled Environment Agriculture Research Complex at OSU. 

Niels van der Geest (Delphy, Bleiswijk, The Netherlands)

Niels van der Geest graduated for the master Biosystems Engineering at the University of Wageningen and is now a Cultivation Engineer at Delphy in the Netherlands. As Cultivation Engineer he develops data-driven cultivation management tools which support growers by making decisions based on data. He aims to support growers by optimizing their strategical decisions based on data and taking into account the local conditions. Delphy stands for Worldwide Expertise for Food & Flowers. Through this, Delphy is the company in knowledge and expertise for their partners in plant sectors, worldwide. The knowledge experts of Delphy contribute to the success of partners thus creating their own success. Niels’s expertise is data driven cultivation management, tomatoes, and cucumbers. 

Kenneth Tran (Koidra Inc., Seatle, WA)

Dr. Ken Tran is the Founding CTO of Koidra. Koidra is a tech startup with a mission of making manufacturing smarter and more efficient, via innovations in industrial IoT and AI. Koidra has received numerous awards for the application of its tech in autonomous greenhouses. Before Koidra, Kenneth was a Principal Applied Scientist in the Machine Learning Group, Microsoft Research. His research expertise and experience include Reinforcement Learning, Deep Learning, Optimization, and Distributed Computing. At Microsoft, he led the research and development for strategic AI projects such as Deep Reinforcement Learning for real-world control problems, Computer Vision API for Cognitive Services, Autonomous Greenhouses.