5 Subsurface Irrigation Methods You Need to Know

Subsurface irrigation is a highly efficient method for delivering water directly to the roots of crops. As the global demand for water increases and environmental concerns rise, subsurface irrigation offers a sustainable solution for farmers looking to optimize water use. By minimizing evaporation and runoff, this technique ensures that crops receive the right amount of water at the root zone, promoting healthier plants and higher yields.

In this guide, we will explore five key subsurface irrigation methods that every farmer should know to boost water efficiency, along with their benefits and practical applications. Understanding the differences between surface and subsurface irrigation, the advantages of sub-irrigation, and the best practices will help you choose the right method for your farm.

1. Introduction to Subsurface Irrigation

Subsurface irrigation is a method of watering plants where water is delivered beneath the soil surface directly to the root zone. It provides a more controlled and efficient irrigation solution compared to surface irrigation methods. By minimizing water evaporation and reducing runoff, subsurface irrigation helps conserve water, especially in areas facing water scarcity.

This irrigation method involves several techniques, each suited to different soil types, crop varieties, and farm conditions. Whether you’re looking to implement sub irrigation on a small farm or scale up on a commercial farm, understanding the different subsurface irrigation methods is essential.

Importance of Subsurface Irrigation

• Water Conservation: Subsurface irrigation uses water more efficiently, reducing waste and preventing over-irrigation.
• Enhanced Crop Growth: By ensuring water reaches the root zone directly, plants receive better hydration and nutrients.
• Reduction in Weeds and Disease: With water delivered below the soil surface, weed growth and plant diseases caused by excess surface moisture are minimized.

As farmers worldwide seek sustainable solutions, subsurface irrigation has become increasingly popular. In this blog, we will explore five of the most effective subsurface irrigation methods and how they can improve water efficiency on your farm.

2. Subsurface Irrigation Method #1: Drip Irrigation

Drip irrigation is one of the most widely used subsurface irrigation methods. It involves the use of flexible tubing with emitters that slowly release water directly to the soil near plant roots. These emitters can be placed along the rows of crops, allowing the water to drip in small amounts over an extended period.

Benefits of Drip Irrigation

• Precision Water Delivery: Drip irrigation allows water to be applied directly to the plant roots, ensuring that only the necessary amount of water is used.
• Reduced Water Loss: Since water is delivered to the root zone, evaporation and surface runoff are minimized.
• Fertilizer Efficiency: Drip systems can also incorporate fertilizers, enabling fertigation, which ensures nutrients reach the plant roots directly.

When to Use Drip Irrigation

Drip irrigation is ideal for crops like tomatoes, strawberries, and lettuce that require precise watering. It’s also effective for crops grown in rows, such as vine crops and trees. However, for large-scale applications, drip irrigation systems require careful planning and maintenance to avoid clogging and to ensure long-term efficiency.

For more insights into sustainable farming techniques, check out our Comprehensive Guide to Wheat Crop Cultivation and Importance.

3. Subsurface Irrigation Method #2: Perforated Pipe System

A perforated pipe system involves burying a network of perforated pipes beneath the soil surface. These pipes release water slowly into the soil, ensuring consistent hydration for plant roots.

Benefits of Perforated Pipe System

• Simple Installation: Unlike drip systems, which require emitters and flexible tubing, perforated pipes are easier to install in large fields.
• Even Water Distribution: The water is distributed evenly across the root zone, promoting uniform plant growth.
• Durability: Perforated pipes are often made from durable materials such as PVC or corrugated plastic, ensuring a long lifespan.

Applications of Perforated Pipe System

This method is most commonly used for tree orchards, vineyards, and other large-scale crops. It’s also suitable for areas where drip irrigation might be difficult to implement due to soil conditions.

For further information on intensive subsistence farming and effective irrigation techniques, take a look at 5 Key Insights into Intensive Subsistence Farming.

4. Subsurface Irrigation Method #3: Capillary Irrigation

Capillary irrigation works by utilizing the natural movement of water through the soil. A capillary system uses porous materials like clay or special soil additives to facilitate the upward movement of water from a water source beneath the soil.

Benefits of Capillary Irrigation

• Low Maintenance: Capillary systems require minimal maintenance once installed.
• Efficient Use of Water: Since water moves upward from below, there’s less evaporation and runoff.
• Suitable for Small-Scale Operations: This method is ideal for home gardens, greenhouses, and small-scale farming operations.

When to Use Capillary Irrigation

Capillary irrigation is most effective for smaller crops or greenhouse environments where water conservation is critical. It is not as widely used in large-scale farming due to the limitations in water delivery to large areas.

5. Subsurface Irrigation Method #4: Subirrigation with Open Trenches

Subirrigation using open trenches involves digging trenches beneath the soil surface, typically along the rows of crops. Water is delivered into these trenches, where it moves upward through the soil to the root zone via capillary action.

Benefits of Subirrigation with Open Trenches

• Cost-Effective: This method is relatively inexpensive compared to other subsurface irrigation systems.
• Water Conservation: Since the water is absorbed directly by the roots, there’s minimal water waste.
• Improved Soil Aeration: The open trenches allow for better air circulation around the roots, preventing soil compaction.

Ideal Crops for Subirrigation with Open Trenches

This method is ideal for shallow-rooted crops, such as leafy vegetables and small fruits. It’s also a great option for organic farming, as it minimizes the use of chemicals.

For more tips on growing healthy crops using organic farming techniques, explore our article on Top Tips for Growing Healthy Organic Natural Farming Crops.

6. Subsurface Irrigation Method #5: Subsurface Drip System (SDI)

The Subsurface Drip System (SDI) combines the principles of drip irrigation with subsurface watering. It involves burying drip lines beneath the soil surface, delivering water directly to the root zone. SDI is a more advanced version of drip irrigation, offering even more efficient water use.

Benefits of Subsurface Drip System (SDI)

• Maximum Water Efficiency: The water is applied directly where it’s needed, reducing evaporation and surface runoff.
• Adaptable to Different Soils: SDI systems can be tailored to suit various soil types, from sandy to clayey soils.
• Long-Term Savings: Though the initial installation cost can be high, SDI systems lead to significant water and labor savings in the long run.

Best Practices for SDI

• Regular Maintenance: SDI systems require regular monitoring to prevent clogging.
• Pre-Installation Soil Testing: Before installing an SDI system, it’s crucial to conduct soil testing to determine the best depth for the drip lines.

7. Key Differences Between Surface and Subsurface Irrigation

Understanding the difference between surface and subsurface irrigation is essential when choosing the right system for your farm. Let’s compare the two:

Surface Irrigation

• Common methods include flood, furrow, and basin irrigation.
• High water wastage due to evaporation and runoff.

Subsurface Irrigation

• Water is applied directly below the surface, targeting the root zone.
• Common methods include drip irrigation, perforated pipe systems, and subirrigation.
• Reduced water wastage and enhanced plant growth due to precise water delivery.

For an in-depth guide on the difference between surface and subsurface irrigation methods, check out our Step-by-Step Guide to Starting Your Own Organic Natural Farming Journey.

8. Choosing the Right Subsurface Irrigation Method for Your Farm

Selecting the best subsurface irrigation method depends on several factors, including the type of crop you’re growing, the soil condition, your water availability, and your budget. Here’s a simple guide to help you make the right choice:

• Drip Irrigation: Best for row crops like tomatoes and strawberries.
• Perforated Pipe System: Suitable for tree orchards and vineyards.
• Capillary Irrigation: Ideal for small-scale farms and greenhouses.
• Subirrigation with Open Trenches: Best for organic farms and shallow-rooted crops.
• Subsurface Drip System (SDI): Ideal for large-scale farms with varying soil conditions.

Conclusion

Subsurface irrigation is a game-changer for farmers seeking efficient water use. By using techniques such as drip irrigation, perforated pipe systems, capillary irrigation, and SDI, you can reduce water waste, promote healthy crops, and conserve valuable resources.

For more information on sustainable farming practices and water conservation techniques, explore our other articles, such as 5 Essential Soil Testing Methods for Effective Agriculture in 2025 and Why Yellowing of Leaves Is Due to Deficiency of Essential Nutrients.

By implementing the right subsurface irrigation system, you’ll be on your way to maximizing crop yield while conserving precious water resources.