Why is Subsurface Drip Irrigation Ideal for Challenging Fields?
NutraDrip began its journey on an oddly shaped, unconventional field where installing a center pivot system wasn’t an option. This is where drip irrigation technology—specifically subsurface drip irrigation (SDI)—proved to be the perfect solution.
What is Drip Tape?
Drip tape is small, black, plastic tubing buried 10 to 16 inches below the surface, depending on soil type and tillage practices. It’s typically spaced every 40 to 60 inches across the field, though in some cases, spacing can be as close as 30 inches. This underground network can deliver water, nutrients, and manure directly to the root zone of crops.
The Sweet Spot for Drip Line Depth
Achieving the right depth is crucial for optimal performance. Drip tape should be installed:
- No deeper than 16 inches: At greater depths, nutrients take too long to reach the crop’s root zone.
- At least 6 inches below your deepest tillage pass: This protects the tape from damage while ensuring its effectiveness.
Experience has shown that the sweet spot for drip line depth is between 10 and 16 inches. At this range, SDI systems function like an intravenous (IV) system for plants, efficiently delivering nutrients and manure where they are needed most. Installing the tape too deep reduces its effectiveness, delaying nutrient uptake and impacting crop growth.
Why Choose Subsurface Drip Irrigation?
SDI offers several advantages, particularly for areas facing water scarcity or irregular field shapes:
- Water Efficiency: With no evaporation or runoff, SDI ensures that every drop of water reaches the crop.
- Nutrient Delivery: Drip irrigation systems deliver nutrients directly to the root zone, improving uptake and reducing waste.
- Adaptability: SDI is ideal for fields where traditional irrigation systems like center pivots aren’t feasible.
NutraDrip’s approach to subsurface drip irrigation maximizes water and nutrient use efficiency while addressing the challenges of unique field conditions. By finding the right depth and spacing, SDI systems transform irrigation into a precise, sustainable practice that supports healthy crops and resource conservation.
How Does NutraDrip Handle Manure Separation?
For the past six to seven years, NutraDrip has been refining manure separation processes to achieve a highly effective system. This system begins with manure sourced from flush barns, or barns that scrape or vacuum manure, starting at 10-12 percent solids. Using a screwpress and microfilter with a 25-micron screen, liquids are separated from solids. The resulting liquid is a brown fluid with large particles removed, preventing potential clogs in the drip system.
This innovative separation technology, imported from Italy, is both efficient and cost-effective. It opens new possibilities for processing manure and allows the separated liquid to be delivered seamlessly through a subsurface drip irrigation system. By making manure separation affordable and practical, NutraDrip provides growers with an environmentally friendly and resourceful solution for nutrient management.
What Are the Community Benefits of Using SDI for Manure Application?
Subsurface drip irrigation (SDI) offers significant public relations benefits for dairies and farms, especially in neighborhoods and counties where they operate. One major advantage is the ability to virtually eliminate odor during manure application. By applying manure through SDI, farms can maintain better relationships with neighbors and local communities.
Another key benefit is the reduction in wear and tear on roads. Traditional manure application often involves trucks and trailers hauling manure, which can strain local infrastructure and raise concerns among county commissioners. With SDI, these trucks and trailers are no longer necessary, significantly decreasing road damage.
How Long Does a Subsurface Drip Irrigation System Last?
When properly maintained, SDI systems can last over 30 years. One system we service in Nebraska has been operational for 39 years. This does vary depending on water quality, as well.
How Does NutraDrip Handle Maintenance and Winterization?
NutraDrip offers a comprehensive in-house full-service program, as well as materials and training for those who prefer to manage their own system startups in the spring. This includes in-season monitoring support to ensure everything runs smoothly. For areas north of I-80, winterization is a critical step. NutraDrip simplifies this process with three large air compressors that allow us to blow out and winterize systems. A quick phone call is all it takes to schedule this essential service.
The rigidity of the tape, made from medium-density polyethylene, ensures it can expand and contract without issue. Interestingly, the primary reason for blowing out the system isn’t the tape but the PVC and HDPE pipe infrastructure. Water must be removed from the ends of the field, as well as the mainline components and valves, to prevent damage during freezing temperatures. The tape itself remains securely in the soil horizon, moving naturally with the soil as it freezes and thaws, ensuring long-term durability. Winterization is a crucial preventative maintenance step focused on protecting pipes, valves, and filters for continued system reliability.
How To Prevent Root Intrusion in Subsurface Drip Systems?
Root intrusion is rarely an issue with annual crops, but it can become a concern with perennial crops like alfalfa or when rye is left in the field and taken to forage. In such cases, NutraDrip recommends injecting a low rate of Treflan through the drip line. Treflan, applied at its labeled rate, effectively burns the roots away from the emitter, preventing them from growing backward toward the water source.
This issue is more likely to occur in situations where deficit irrigation is practiced—when there isn’t enough water to meet the crop’s demand, causing the roots to seek out additional water. To address this, injecting Treflan serves as a preventative measure to protect the system and ensure uninterrupted water flow to the crop.
How Can Technology Help Monitor and Maintain Your Irrigation System?
Each valve in our irrigation system is connected to a radio, which transmits telemetry data back to the cloud. This allows us to remotely control the system, turning it on or off, adjusting valves, and starting or stopping the pump. We can monitor pressure in every zone and track overall flow, ensuring the system is working as expected. If something goes wrong, like a valve not opening or closing properly, we can diagnose the issue quickly. We also monitor the system for potential blockages over time. For instance, if the flow rate drops or pressure rises beyond expected levels, we know there might be buildup in the drip line. In that case, we inspect the system and may use cleaning solutions like acid or hydrogen peroxide to clear any blockages. This proactive monitoring and maintenance process helps ensure that your system continues running smoothly for decades, with an expected lifespan of 30 to 50 years.
Manure Separation on Dairies
Manure separation systems can significantly reduce the cost of managing leachate, a liquid byproduct of manure. For dairies using drag lines to dispose of leachate, the costs can add up quickly. Leachate itself has minimal fertilizer value but must be treated like manure, particularly in states like Minnesota and the Dakotas.
For example, using a drag line typically costs about 1.2 cents per gallon. However, with manure separation systems in place, the operational cost (including depreciation, electrical, and other factors) drops to approximately 0.3 to 0.4 cents per gallon. This represents an 85% reduction in application costs. Even in scenarios with reduced leachate volumes, the cost might rise slightly to 0.7 cents per gallon, but it remains significantly less than the 1.2 cents per gallon for traditional methods.
These savings translate directly to lower production costs for dairies. For instance, applying 30,000 gallons of leachate annually at 0.8 cents per gallon results in a cost savings of approximately $250 per acre each year. Beyond financial benefits, this approach reduces soil compaction and transforms leachate and manure from liabilities into valuable assets.
Consider a dairy site with 500 acres and a manure separation system capable of processing 15 million gallons of leachate annually. Such a setup can address a substantial portion of manure management needs, solving logistical challenges and creating opportunities to apply nutrient-rich products efficiently.
