Underground Pit Greenhouse for Sustainable Horticulture

 Underground Greenhouses: A Sustainable Agricultural Innovation

In light of global climate change and increasing environmental pressures, agricultural innovation is becoming urgent to face the future. Underground greenhouses are one pioneering and sustainable solution that could radically transform modern farming methods. This article comprehensively overviews this technology, its benefits, challenges, global applications, and potential roles in sustainable agricultural solutions.

Benefits of underground greenhouses:

1. Maintaining appropriate temperatures:

Underground greenhouses use the earth's thermal insulation to achieve year-round thermal stability. These systems can be designed using geothermal energy storage analysis to reduce dependence on external energy. The surrounding soil provides natural insulation of 10-20°C, allowing the houses to retain heat during the winter and dissipate it in the summer.

2. Managing water resources efficiently:

The close environment's high relative humidity significantly reduces water evaporation in these houses. Clever agriculture techniques can be applied, such as drip and sensor-controlled irrigation, where water is recycled and filtered using biological water treatment systems.

3. Resistant to harsh climate conditions:

Underground greenhouses include an architecture resistant to extreme weather conditions such as wind and rain. Geometric designs such as geodesic domes can provide a highly efficient, sustainable structure in terms of space and materials.

4. Year-round farming: 

Advanced lighting technologies, such as photovoltaic or high-efficiency integrated lighting (IEC) LEDs, can stimulate plant growth year-round. These technologies allow light spectrum modulation to enhance photosynthesis and improve crop yields.

1. Background on Sustainable Agriculture

Contemporary environmental challenges include climate change, water scarcity, and the loss of agricultural land due to desertification and urbanization. As a result, the need to find more efficient and sustainable farming solutions has become of utmost importance. Sustainable agriculture, including greenhouses, provides a means to increase productivity while reducing environmental impact.

2. The Concept of Underground Greenhouses

This innovation involves building underground agricultural facilities that extend to varying depths depending on the design and environmental needs. These houses benefit from the soil's natural insulation, which helps create a more stable and efficient agricultural environment.

Design and Structure

Underground greenhouses consist of holes or tunnels enclosed by glass systems. The ground can cover the greenhouses wholly or partially, and the depth varies depending on the type of crop and thermal insulation requirements. Glass or other transparent materials allow natural light to enter, and adequate ventilation systems provide the necessary oxygen and ventilation.

3. Environmental and Agricultural Benefits

3.1 Temperature Regulation

The soil's natural insulation provides a stable temperature environment, with temperatures typically ranging between 10 and 16 degrees Celsius at moderate depth throughout the year. These conditions eliminate the need for excessive spending on heating or cooling devices, significantly reducing energy consumption by up to 50%.

3.2 Water Efficiency

Underground greenhouses reduce water evaporation, and this technology is estimated to reduce water loss by up to 50% compared to traditional outdoor cultivation. Advanced drip irrigation systems can be adopted to increase water use efficiency, reducing water requirements by 80% in some cases.

3.3 Increased productivity

Studies indicate that underground greenhouses can increase crop productivity by 20% to 30%, thanks to the protection of crops from heat stress, pests, and sudden climate changes. Protected systems contribute to the continuation of the agricultural cycle throughout the year, significantly increasing annual production.

Technology used:

1. Ventilation and humidity control systems:

Underground greenhouses rely on advanced ventilation systems to maintain fresh air flow and control humidity levels.

2. Artificial lighting and LED technologies:

Modern lighting technologies such as LEDs provide the necessary light for plants, allowing for control of lighting hours and increasing plant growth efficiency.

3. Intelligent sensing and analysis:

Advanced sensors monitor environmental conditions inside greenhouses, such as temperature, humidity, and carbon dioxide levels, helping to improve agricultural growth accurately and sustainably.

4. Challenges and difficulties

4.1 Cost and Investment

The cost of building underground greenhouses varies greatly depending on the location and dimensions but can range from $120 to $200 per square meter. These houses require more expensive infrastructure trenches and high-quality insulation materials to prevent corrosion and moisture.

4.2 Infrastructure and Logistics

Underground greenhouses require tight ventilation and drainage systems to avoid moisture and the accumulation of toxic gases. This requires high maintenance and attention to ensure this infrastructure's efficient and long-term operation.

4.3 Research and development

This field still needs continuous development to improve the materials and technologies used. Investments in research and development are crucial to reducing costs and increasing efficiency. Continuous development requires an investment of $5–10 million annually.

5. Global applications and successes

5.1 Europe

The Netherlands has successfully used this technology to produce vegetables and fruits. Thanks to advanced technology, Dutch farmers have achieved stable and high-quality production, regardless of external climatic conditions, enhancing the country's food security.

5.2 Asia

In China, where extreme weather conditions can harm traditional crops, underground greenhouses have been used to grow tomatoes and cucumbers year-round. The results showed that the yield was twice as high as in conventional farming.

5.3 Middle East

In areas such as the United Arab Emirates, where dry and hot climatic conditions pose significant challenges to agriculture, pilot projects have been successfully implemented to provide sustainable crops of leafy vegetables.

6. Socio-economic impacts

Underground greenhouses are essential for food security, especially in land scarcity and poor climatic conditions. These houses promote job creation and support rural economies by increasing productivity and improving the quality of life in agricultural communities.

Feasibility Study for Underground Greenhouses

1. Market Study

Demand Analysis:

- Target Markets: Megacities, Harsh Climate Zones, Areas with Limited Water Resources.

- Agricultural Products: High-Value Organic Crops, Fresh Herbs, Medicinal Plants, Seasonal Vegetables and Fruits.

- Target Customers: Food Retailers, Fine Dining Restaurants, Organic Agricultural Markets, Local Governments.

Satisfaction and Competition:

Competitor Analysis: Underground greenhouses have limited Competition; Most Competitors Rely on Traditional Greenhouses or Conventional Agriculture.

- Market Gaps: There is a Growing Need for Sustainable and Effective Agricultural Solutions.

2. Technical Study

Project Phases:

1. Research and Development:

- Estimated Time: 6-12 Months

- Initial Cost: $100,000

2. Design and Engineering:

- Estimated Time: 3-6 Months

- Initial Cost: $150,000

3. Construction and Fit-out:

- Estimated Time: 12-18 Months

- Initial Cost: $1 Million to $2 Million, Depending on Project Size

Technology Used:

- Ventilation and Humidity Control Systems:

Integrated Ventilation System Cost: $200,000

- Artificial Lighting and LED Technologies:

Specialized LED Lighting Cost: $150,000

- Intelligent Sensing and Analysis:

Environmental Sensing and Analysis Systems Cost: $100,000.

Location and Infrastructure:

- Geological Analysis: Initial Cost: $50,000

- Land and Construction: Land Purchase Cost: Depends on Location (Can Range from $500,000 to $1 million)

- Infrastructure and technical support: Variable cost of $300,000 to $500,000.

3. Financial study

Fixed costs:

1. Research and development: $100,000

2. Design and engineering: $150,000

3. Construction and equipment: $1.5 million

4. Technology used: $450,000

5. Land and infrastructure: $1.5 million

Approximate total: $3.7 million.

Operating costs:

1. Annual salaries and wages: $200,000

2. Annual energy and maintenance: $100,000

3. Annual raw materials and agricultural supplies: $150,000

Annual total: $450,000

Expected annual revenue:

1. Annual production: 500 tons of organic agricultural products

2. Average selling price Per ton: $2,000

Total annual revenue: $1 million

Profitability and financial indicators:

1. Annual net profit: $1 million (revenue) - $450,000 (operating costs) = $550,000

2. Payback period: Fixed costs / annual net profit = $3.7 million / $550,000 ≈ 6.7 years

3. Return on investment (ROI): (Annual net profit / fixed costs) * 100% = ($550,000 / $3.7 million) * 100% ≈ 14.86%.

4. Environmental and social study

Environmental impact:

- Reducing water consumption by up to 50% compared to conventional agriculture.

- Reducing the use of pesticides and fertilizers thanks to the controlled environment.

- Reducing carbon emissions thanks to using renewable energy technologies such as solar panels.

Social Impact:

- Providing jobs for the local community in agricultural engineering and information technology.

- Raising awareness of sustainable agricultural practices through educational and training programs.

- Enhancing food security in urban and rural communities.

Advantages of creating a greenhouse to improve gardening