[2024] In-depth Comparison of Three Types of Plant Factories and Open-Field Cultivation

Hello everyone! I’m Shohei.

You’ve probably been hearing the term “plant factory” more and more lately, haven’t you?
But many of you may be wondering, “What types are there?” “What’s the difference between them?” “How do they compare to open-field cultivation?”
Indeed, it’s difficult for those who aren’t familiar with the details to understand the fine distinctions.

So, in this article, we’ll explain the following four cultivation methods in an easy-to-understand way:

• Sunlight-type plant factory
• Combined-type plant factory
• Artificial light-type plant factory
• Open-field cultivation

We’ll thoroughly compare the advantages and disadvantages of each, considering profitability, future potential, and concrete data.
By reading this article, you should gain insight into the possibilities and challenges of each cultivation method. Please read through to the end, deepen your understanding of plant factories, and find the cultivation method that’s best for your business.

If you’re wondering what a plant factory is in the first place, please also refer to the following article:

Four Cultivation Methods: Plant Factories and Open-Field Cultivation

To summarize, we’ll classify and compare the four main types based on factors like the type of light source and the presence or absence of environmental control.
Below, we’ll discuss the characteristics, advantages and disadvantages, and suitable plants for each type in detail.

1. Sunlight-type Plant Factory
2. Combined-type Plant Factory
3. Full Artificial Light-type Plant Factory
4. Open-Field Cultivation

1. Sunlight-type Plant Factory

Characteristics

As the name suggests, a sunlight-type plant factory utilizes sunlight as its primary light source. The facility is typically a greenhouse-like structure with a roof and some side walls covered in transparent materials like glass or vinyl.

Maximizing the use of sunlight provides the significant advantage of reducing running costs like electricity.

Advantages

• Low Initial Costs: Due to the absence of artificial light equipment, initial costs are lower compared to other types.
• Low Running Costs: Using sunlight as the primary light source significantly reduces electricity costs.
• Low Environmental Impact: Not using artificial light reduces CO2 emissions and environmental impact.

Disadvantages

• Vulnerability to Weather: Sunlight irradiation is affected by weather, making it difficult to achieve stable production. Continuous periods of low sunshine or cloudy days can lead to poor growth and decreased harvesting yields.
• Requires Large Land Areas: Although not as much as open-field cultivation, these factories still require relatively large plots of land.
• Pest Risk: Compared to fully sealed plant factories, the risk of pests is higher.

Suitable Plants

These factories are well-suited for cultivating fruit vegetables like tomatoes, eggplants, and peppers that thrive in sunlight.

2. Combined-type Plant Factory

Characteristics

A combined-type plant factory uses both sunlight and artificial light. It utilizes sunlight when it’s available, supplementing with artificial light during periods of low sunshine and at night.

This type combines the advantages of sunlight-type and full artificial light-type factories but also comes with the drawback of potentially higher equipment costs.

Advantages

• Less Susceptible to Weather: Using both sunlight and artificial light makes production less dependent on weather, allowing for stable output.
• Cost Reduction Through Sunlight Utilization: Harnessing sunlight helps reduce electricity costs compared to full artificial light-type factories.
• Wide Range of Cultivable Plants: Using both sunlight and artificial light enables the cultivation of various plant varieties.

Disadvantages

• Potential for High Equipment Costs: The need for equipment for both sunlight-type and full artificial light-type factories can result in higher initial costs.
• May Not Fully Leverage Sunlight Advantages: Depending on location and season, it may be challenging to fully utilize sunlight.

Suitable Plants

This type is suitable for cultivating a range of plants, including those that thrive in sunlight and those that can also grow under artificial light.

3. Full Artificial Light-type Plant Factory

Characteristics

A full artificial light-type plant factory relies solely on light sources like LEDs without utilizing any sunlight. It enables the cultivation of plants in a fully controlled environment, unaffected by external factors.

Advantages

• Stable Production Unaffected by Weather: Production is unaffected by weather, allowing for consistent output throughout the year.
• Year-Round Cultivation: Plants can be cultivated year-round, regardless of the season.
• High Yield Per Unit Area: Employing multi-level cultivation maximizes yield in limited spaces, contributing to increased output.
• Suppressed Pest Risk: Cultivating in sealed spaces significantly reduces pest occurrence.
• Urban Production: These factories can be set up in urban areas where sunlight is limited, expanding production possibilities.

Disadvantages

• High Initial Costs: LED lighting, HVAC systems, and other equipment result in higher initial costs compared to other types.
• High Running Costs: Running costs, especially electricity, tend to be higher.

Suitable Plants

This type is best for growing leafy vegetables with low photosynthetic rates, such as lettuce and herbs.

4. Open-Field Cultivation

Characteristics

Open-field cultivation involves growing plants outdoors using natural sunlight, wind, and rain. It’s the oldest and most common method of cultivation but is susceptible to weather and carries a higher risk of diseases and pests.

Advantages

• Low Initial Costs: As no plant factory-like investments are required, initial costs are significantly reduced.
• Low Running Costs: Utilizing natural sunlight, wind, and rain lowers running costs.

Disadvantages

• Vulnerability to Weather: Production is significantly impacted by sunlight intensity, temperature, and rainfall, making stable output challenging.
• High Pest and Disease Risk: Compared to plant factories, the risk of pests and diseases is higher, requiring more effort and cost for mitigation.
• Requires Large Land Areas: Large land areas are necessary for large-scale production.
• Lower Yield: Yield per unit area is lower than in plant factories.

Suitable Plants

Various plants are grown in open fields, including rice, wheat, soybeans, vegetables, and fruit trees.

Comparing Types of Plant Factories and Their Characteristics

The table below compares the characteristics of the four cultivation methods: Sunlight-type, Combined-type, Full Artificial Light-type, and Open-field cultivation.

	Sunlight-type	Combined-type	Full Artificial Light-type	Open-field cultivation
Cultivation Proportion	44%	14%	42%	–
Main Light Source	Sunlight	Sunlight, LED 81%, Sodium Lamps, Fluorescent Lights, etc. 38%	LED 96%, Fluorescent Lights 8%. LEDs primarily adopted after 2013	Sunlight
Water Source	Well water 62%, Tap water 38%	Well water 60%, Tap water 33%	Tap water 78%, Well water 20%	Rainwater, Well water, Tap water, etc.
CO2 Application	83% with application	86% with application	89% with application	Natural CO2 concentration
Main Cultivated Crops	Tomatoes 71%, Strawberries 8%, Other Fruit Vegetables 8%, Non-lettuce Leafy Greens 6%	Tomatoes 27%, Lettuce 27%, Flowers 20%	Lettuce 91%	Diverse
Number of Employees (Full-time: Regular)	Under 110 34%. Average 9.8 per facility	Average 9.2 per facility	Average 8.0 per facility	Varies by management scale
Number of Employees (Full-time: Non-regular/Part-time)	20-50 35%, 50+ 24%. Average 44.0 per facility	20-50 31%, 50+ 31%. Average 46.3 per facility	20-50 19%, 50+ 21%. Average 28.3 per facility	Varies by management scale
Number of Employees (Temporary)	Excluding those without temporary employment, under 1-5 26%. Average 9.6 per facility	Average 16.4 per facility	–	Varies by management scale
Major Crop Work Ratios	Production (Especially Crop Management) Most Common at 35% or More	Production (Especially Crop Management) Most Common at 35% or More	Harvesting 27%, Shipping 24%, Transplanting/Final Transplanting 19%, Washing 10%	Varies by crop and cultivation scale
Settlement by Yield Per Labor Hour	Higher Yield Per Labor Hour Results in Lower Red Ink Ratio	–	Higher Yield Per Labor Hour Results in Lower Red Ink Ratio	–
Cost Ratio by Yield Per Labor Hour	Higher Yield Results in Lower Personnel Cost Ratio	–	Higher Yield Results in Lower Personnel Cost Ratio	–
Settlement by Yield	Higher Yield Results in Higher Profit/Balanced Ratio	–	Higher Yield Results in Higher Profit/Balanced Ratio	–
Recent Settlement	Profit/Balanced 73%	Profit/Balanced 60%	Profit/Balanced 45%	–
Annual Sales	Average 430 million yen	Average 460 million yen	Average 190 million yen	Varies by management scale
Settlement by Main Crop Cultivation Area	Larger Area Results in Higher Profit/Balanced Ratio	–	Larger Area Results in Higher Profit/Balanced Ratio	–
Cost Ratio by Cultivation Method	Personnel Costs Highest at 30%	Personnel Costs Highest at 30%	Personnel Costs Highest at 30%, Electricity Costs 27%	Varies by crop and cultivation scale
Cost Ratio by Settlement	Lower Electricity Costs and Depreciation Costs in Profitable Settlements	–	Lower Electricity Costs and Depreciation Costs in Profitable Settlements	–

1. Plant factory data is based on results from the “Large-scale Greenhouse Horticulture/Plant Factory Actual Situation Survey/Case Study” conducted by the Japan Facility Horticulture Association. The survey period was from November 2022 to January 2023, with an effective response rate of 25.7%.

2. Open-field cultivation conditions vary significantly based on weather, location, management scale, and crops, making it impossible to provide a general numerical comparison.

So, Which Business Should You Choose?

We’ve discussed the characteristics of plant factories and open-field cultivation. But ultimately, which one should you choose?
That’s the important question, isn’t it?

Deciding between a plant factory and open-field cultivation requires a comprehensive evaluation of factors like the type of plants to be cultivated, production scale, initial investment, running costs, and profitability.

• Those aiming to minimize initial costs and running costs: Open-field cultivation, Sunlight-type plant factory
• Those seeking weather-independent, stable production: Full Artificial Light-type plant factory, Combined-type plant factory
• Those wanting to supply high-quality produce year-round: Full Artificial Light-type plant factory, Combined-type plant factory
• Those looking to produce crops in urban areas: Full Artificial Light-type plant factory
• Those aiming for large-scale production: Open-field cultivation, Sunlight-type plant factory

Summary

There are three types of plant factories: Sunlight-type, Combined-type, and Full Artificial Light-type, along with Open-field cultivation, each with its advantages and disadvantages.

It’s crucial to choose the appropriate type based on production goals and budget.

Plant factories offer advantages like weather-independent stable production, year-round cultivation, high yield per unit area, and reduced pesticide usage, making them promising contributors to the future of agriculture.

On the other hand, open-field cultivation provides the benefits of lower initial costs and running costs while facing challenges like weather dependence and high pest and disease risks.

When considering plant factory implementation, choose the type that aligns with your needs, taking into account the features and selection points discussed in this article. It’s essential to make comprehensive assessments of initial investment, operating costs, the types of plants to cultivate, and other relevant factors. By leveraging economies of scale and managing running costs and depreciation expenses effectively, you can achieve high-profitability in agriculture.

Plant factories are expected to continue evolving in the future, thanks to advanced environmental control systems utilizing AI and IoT. It’s crucial to stay informed about the latest technological developments and explore the potential of agriculture.

What are the positive and negative aspects of plant factory cultivation?

The positive aspects of plant factory cultivation include the ability to achieve year-round and planned production, as well as the potential to produce high-quality vegetables consistently. On the other hand, the negative aspects include potentially high initial investments and operating costs. Full Artificial Light-type factories, in particular, tend to have higher running costs.

What types of plant factories are there?

There are three types of plant factories: Sunlight-type, Combined-type, and Full Artificial Light-type. Sunlight-type factories mainly use sunlight, while Combined-type factories utilize both sunlight and artificial light. Full Artificial Light-type factories rely solely on artificial light sources. Each type differs in its light source, environmental control methods, the types of plants that can be cultivated, production efficiency, and cost.

What are the different ways to cultivate vegetables?

There are several methods for cultivating vegetables: Open-field cultivation, greenhouse cultivation, and plant factories. Open-field cultivation is the traditional method conducted outdoors, while greenhouse cultivation takes place in structures like vinyl greenhouses and glasshouses. Plant factories are facilities that control environmental conditions optimally for vegetable production and are categorized into Sunlight-type, Combined-type, and Full Artificial Light-type.