Performing Department
Horticultural Science
Non Technical Summary
This project will improve sustainability in horticulture by addressing three key areas: 1) Assess the current energy efficiency of horticulture by evaluating energy inputs and energy outputs of different production systems and present possible solutions to improve energy efficiency. 2) Research the responses of specialty crops to light quality using energy efficient lighting technology such as light emitting diodes in order to improve production, nutritional content, and economics. 3) Research organic based production under controlled environment to improve production and economics of crops produced in greenhouses and vertical farms.
Animal Health Component
0%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
The research goal is to develop and establish sustainability in horticulture locally, nationally, and globally. The US farm bill official definition of sustainability has five parts: emphasizing productivity, environmental quality, efficient use of nonrenewable resources, economic viability, and quality of life. The five parts of sustainability are greatly affected by the system's energy inputs/outputs and an energy efficient horticultural system can yield a sustainable horticultural system. The main goal is to improve sustainability in horticulture by improving horticultural energy management.In order to improve energy management, the actual energy inputs an environmental contribution of different growing systems have to quantified and evaluated (objective 1). Also more energy efficient lighting technologies such as light emitting diodes (LEDs) have to be evaluated and adopted in innovative ways for the production of horticultural crops (objective 2). Furthermore, current sustainable and organic production techniques under controlled environment have to be improved (objective 3).Objectives1.- Evaluation and modeling of energy conservation strategies in horticultural production systems.The objective is to evaluate the energy efficiency of current production practices and technologies in horticulture in order to optimize energy conservation and increase sustainability. Current production practices are diverse and require different farming technologies. For example, field production commonly requires heavy machinery for tillage, seeding, weeding, and sometimes harvesting. In contrast, controlled environment (CE) production requires climate control equipment such as lighting, heating, cooling, and CO2 supplementation, among others. Independent of the growing system, energy inputs have to be made in order to produce a crop. Currently in the US, the agrifood system accounts for about 19% of the energy dissipated in all economic sectors (Pimentel and Pimentel, 2008). With the proper use of technology and farming practices, energy input can be minimized. In collaboration with the Center for Environmental Farming Systems (CEFS), energy conservation strategies and technologies in different horticultural systems will be evaluated and, where needed, more sustainable strategies implemented. This technology evaluation program will evaluate new technologies' efficiencies and capital costs and consider specific farm needs and objectives in order to generate decision-making information.2.- Light-plant interactions: Light environment manipulation to improve plant production systemsThe objective is to use alternative technologies to manipulate horticultural light environments in order to increase production, improve plant quality, reduce energy consumption, and increase profitability of horticultural systems. LEDs can have a customized spectral output that can improve plant production, desirable plant morphology, and growing energy efficiencies. The electrical efficiencies of LEDs (µmol·J-1) are higher than the current horticultural lighting technology and are expected to increase 20x and decrease in cost 10x in the next 10 years (Haitz & Tsao, 2011). I plan to design a problem-solving research program focused on the manipulation of light to improve horticultural systems sustainability. For example, optimal light recipes are needed in order to optimize plant growth under protected horticulture. As part of my research program, I would like to investigate plant responses to different light qualities. This research will generate important and critical information for the scientific and commercial sector. Among the crops that will tested are transplants (vegetables and ornamentals), leafy greens, small fruiting crops, medicinal plants, and plant-based pharmaceuticals, among others.3.- Sustainable and organic horticultural production of specialty crops under controlled environmentThe organic market now represents 4+ percent of total food sales in the US and consumer demand for certified organic products continues to show double-digit growth (USDA Organic Market Overview). The increasing market-demand in conjunction with stable high-price-premiums are incentives for specialty crop farmers to modify conventional growing techniques to organic growing techniques when economically feasible.Most commercial organic crop production is based in open field cropping systems. Producers using controlled environment such as high-tunnels, greenhouses, and vertical farms (VF) have an interest in producing crops organically in order to capitalize in the premium market prices. However, organic production in controlled environments is limited due to several challenges such as; lack of comprehensive organic nutrient plans, sometimes lower yields under organic production, challenges in biofilm management, and lack of the crop specific optimal growing systems. In collaboration with CEFS, the objective for this research will be to evaluate current organic nutrient delivery strategies (substrate based-organics and organic hydroponics) for the production of specialty crops such as leafy greens (baby lettuce, microgreens, leaf lettuce) and vegetable and ornamental transplants (high density plug production) under controlled environment production systems.Summary of goals1) Evaluate the energy efficiency of current production practices and technologies in horticulture.2) Manipulate horticultural light environments in order to increase production, improve plant quality, and reduce energy consumption in specialty crop production.3) Improve organic production under controlled environment agriculture.
Project Methods
1) Evaluate the energy efficiency of current production practices and technologies in horticulture.Development of an energy budget model. This model will be capable of calculating the Energy Return on Energy Input (ERoEI) of a particular horticulture operation including community farms, conventional farms, organic farms, greenhouse production system, and plant factories, among others. This model will operate by factoring direct (human labor, liquid fuels, natural gas, electricity, etc.) and indirect (energy input to produce natural gas, energy input to produce electricity, fertilizers, machinery, materials, etc.) energy inputs. The model will then use conversion factors (i.e. 40 MJ/kg to produce N fertilizer, 48 MJ/kg of diesel fuel) to calculate the total energy input of the farm (MJ). Later, the model will calculate the energy output in terms of MJ/kg of harvested crop. This model will then give an ERoEI for the specific growing practice modeled. The model will also provide the total energy inputs (direct and indirect) and outputs by category allowing the user to see where improvements can be made.2) Manipulate horticultural light environments in order to increase production, improve plant quality, and reduce energy consumption in specialty crop production.Screening plant responses to LED lighting (with focus on B:R ratio, spectral deficit lighting)Hypothesis: There will be a range of B:R ratios that assure acceptable growth and development for most (if not all) crop species. There may be a few exceptional "over-sensitive" responses (such as a cultivar of tomato rootstock identified as problematic under LEDs recently). Approach: two types of screening will be applied: a) Examine combinations of red and blue light at varied B:R ratios, and b) Examine spectrally deficit light using B, G, R, and FR LEDs. [This is a similar approach to a biological study using knock-out genes.]Crop species to examine will be selected from a wide range of families relevant to CEA plant production. Based on the outcomes, the plants will be classified into three groups of light quality sensitivity. A recommendation will be made of target B:R ratio that is likely to work for the majority of crop species without largely reducing the growth and quality. Criteria for this "acceptable reduction in growth and quality" will be developed based on the plant response.Apiaceae: cilantro, parsleyAsteraceae: lettuce (butterhead, red leaf, and green leaf)Brassicaseae: arugula, kale, mizuna, and pakchoiCucurbitaceae: cucumber, watermelon, and their rootstocksLamiaceae: basil and mintRosaceae: strawberry (vegetative stage)Solanaceae: tomato, bell pepper, eggplant, and their rootstocks3) Improve organic production under controlled environment agriculture.Evaluate current organic nutrient delivery strategies (substrate based-organics and organic hydroponics) for the production of specialty crops such as leafy greens (baby lettuce, microgreens, leaf lettuce), vegetable and ornamental transplants (high density plug production) under CE.The evaluation will consist of comparing the organic systems in terms of productivity, environmental sustainability, and profitability.Hypothesis: The optimal fertility will depend on the type of crop and cost for production (organic fertilizer amount and type, application method, re-circulation, etc.).Several specialty crops suitable for CE (leafy greens and vegetable/ornamental plug transplants) will be selected.Several substrate-based-organic recipes and several organic-hydroponic recipes and potential combinations will be compared in terms of productivity (i.e. yield, plant quality), sustainability (i.e. amount of fertilizer and water usage), and profitability (cost of fertility program). Treatments will be developed in collaboration with active research in the field.The best organic recipe will be selected per crop.