Source: UNIVERSITY OF ALASKA submitted to
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
Funding Source
Reporting Frequency
Accession No.
Grant No.
Project No.
Proposal No.
Multistate No.
Program Code
Project Start Date
Dec 28, 2020
Project End Date
Sep 30, 2023
Grant Year
Project Director
Karlsson, M.
Recipient Organization
Performing Department
Agriculture and Horticulture
Non Technical Summary
Food security is a major issue for Alaska. Short field seasons and challenging climatic conditions result in variable and often limited supplies of locally grown products resulting in high dependency on food brought into Alaska. Enhancing local production to reach some degree of self-sufficiency is therefore desirable. Greenhouses, controlled environment vertical farms, hydroponics and other indoor growing facilities offer opportunities to expand and extend the growing season or to produce food in areas with no or limited access to suitable land for crop production. The most appropriate crops still need to be identified for this type of a production system and assessed as to crop turnaround, scheduling, yield estimates, markets, labor commitments and production costs.Greenhouses and indoor cropping systems often require significant energy inputs in form of heat and power. Light emitting diodes (LEDs) convert electric energy more efficiently compared to earlier lighting technologies, while also offering more control over the generated light in form of spectrum and quality. Many types of LEDs are commercially available but their energy efficiency varies widely. Information is needed to establish guidelines for efficient adaptation and use of LEDs in controlled environment production at northern latitudes. In addition to the extended life expectancy, high output and ability to customize the light, LEDs allow for innovative and non-conventional design configurations to more effectively utilize the horizontal and vertical indoor growing space. In this project, the use of LEDs as the sole light source or as a supplement to natural light conditions in a greenhouse will be studied and documented.
Animal Health Component
Research Effort Categories

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
Goals / Objectives
Objective 1. To evaluate and develop strategies to improve energy efficiency in controlled environment agriculture. Objective 3. To train growers and students to utilize emerging controlled environment agriculture technologies.
Project Methods
Evaluate and develop strategies to improve energy efficiency in controlled environment agricultureStudies using several approaches will be conducted to improve energy efficiency in controlled environment agriculture, with a focus on lighting and air quality (temperature and humidity). Several commercially available horticultural LEDs are on the market but their energy efficiency varies widely. The best fixtures are twice as efficient as the lowest efficiency fixtures. LED fixtures also vary in their light spectrum with two typical approaches: 1) primarily red/blue light in different ratios and 2) broad spectrum (white) light (obtained from phosphor-coated blue LEDs). The ratio of red/blue can impact plant height and yield. Data on crop yield, installation, maintenance, ongoing energy costs, and life expectancy will be used to identify and determine the efficiency and economics of LED adoption.Several strategies formakinglighting decisions to supplement sunlight will be comparedincludingtime clocks (lights on for a fixed number of hours daily), light threshold (lights turn on/off when instantaneous light reaches a set threshold level), daily light integral (DLI, coordinated control of light and shade curtains to reach a target DLI). We will then compare crop uniformity/quality in the variousfloriculture and leafy green cropping systems. Data on crop yield/quality, control system costs, and energy costs will be used to compare the suitability of the control strategies.Most research has focused on characterizing plant responses when exposed to a single light recipe (static spectrum). We will develop dynamic light recipes to improve growth rate and quality (morphology and phytochemical content) in indoor production systems for leafy greens such as lettuce and spinach. We will attempt to match spectrums to different plant growth stages (lag, log, and plateau) to maximize output (nutrient, flavor, growth) and improve system energy efficiency.Train growers and students to utilize emerging controlled environment agriculture technologiesUndergraduate students will be involved in independent research related to this project as the future of the industry depends on highly-qualified professionals. Training and involvement of graduate students will also be significant and integral components in this project.The AFES greenhouse on the UAF campus is a versatile facility with opportunities to design various types of production systems such as horizontal and vertical hydroponic methods along with traditional pot-and-media based systems. This facility will be used for training, demonstrations, instructional, outreach and research activities.