Turning Waste Into Value Through Subsurface Drip Irrigation

Turning Waste Into Value Through Subsurface Drip Irrigation

Contributed by Jim Hunt, Tim Wolf and Jim Ed Beach, Netafim USA

It started with a two-part question posed to us by farmers a few years ago: How can I cut the cost of removing manure waste, and how can I use the wastewater as fertilizer without breaking the bank?

The answer: our team’s award-winning subsurface drip irrigation (SDI-E) system, which we implemented to create the first drip irrigation system utilizing dairy effluent. This innovative system uses Netafim’s patented blending control technology to mix animal wastewater with freshwater, creating a natural fertilizer blend for farmers’ use.

DSC_0031First, the wastewater and manure from cows’ pens is pushed to a farm’s holding ponds or lagoons, where our filtration system separates out some of the solids. The mixture is then combined with fresh water to create a nutrient-rich fertilizer blend. The level of nutrients is controlled by monitoring the salt content through measuring and adjusting the electrical conductivity in real-time using Netafim’s digital farming controllers. Delivery to the crops from there is through a fully automated drip irrigation system. Another environmentally-friendly addition can be the incorporation of a methane digester system that generates natural gas that can be used to generate electricity among other uses.

Netafim Controller

At some farms, the harvested crops return right back to the cows whose manure fertilized the fields, creating a circular economy model. Even more, this manure-based fertilizer will meet the requirements needed to be a Certified Organic crop. 
This SDI-E process helped farmers’ bottom lines in several ways:

  • Reduced costs of removing wastewater
  • Reduced need for commercial fertilizer, as the recycling process creates a natural crop nutrient and soil builder
  • Improved crop uniformity and higher yields through drip irrigation, as water and nutrients are used more efficiently.
  • All field sizes and shapes can be accommodated
  • Reduced water loss through drip irrigation, as the system virtually eliminates evaporation, runoff, and deep percolation
  • Reduced time spent manually monitoring electroconductivity and salt levels of fertilizer mixtures

The environmental benefits are also significant. The system requires fewer water resources than traditional methods, which is especially critical in drought-impacted areas. Studies also show that approximately 70-90 percent fewer greenhouse gases were released when dairy effluent water was applied through an SDI system.

With a proven ROI period of 3-5 years for our subsurface drip irrigation system, the choice has been easy for many farmers to make the switch to this new model of sustainability.

Based on the success we've had with the dairy effluent system, our focus is shifting to utilizing swine effluent for a hog-farming industry that spends millions annually to remove waste. There is future potential beyond swine too, as Netafim is investigating the feasibility of entering markets with beef cattle and other CAFOs.

We know the challenges of swine farmers. Urban sprawl has led to new neighbors feeling as if the hogs’ smell is offensive, while farmers must pay significant fixed and variable costs every year to remove wastewater. Dragline pipes used to remove it cannot be used in the summer growing season or during spring soil prep, while many swine farming areas run the risk of high rainfalls, caused by spring storms or hurricanes that overflow wastewater lagoons and contaminate water resources.

While with swine effluent the task of separating the right amount of solids is more challenging, the potential benefits are well-worth the challenge. Although we are still in the very early testing stages with swine effluent, we see the potential to disrupt a billion-dollar industry, where hog prices have increased significantly over the past 12 months.  

Netafim Filters
Swine Effluent Innovation Is Underway
We are already on the ground in the Midwest, working with swine farmers to conduct effluent testing. Additional filtration options and technologies are being researched. Collaboration is underway with NutraDrip to test filters and filtration equipment, and with Centrol Crop Consulting to develop manure management plans that align with state soil regulations and localized crop needs. There are also plans to team up with national industry organizations and universities that are invested in sustainable farming practices.

Netafim has over 50 years of experience in producing forward-looking, practical solutions for farmers of all specialties, and plans to continue paving a new path for the utilization of dairy and swine effluent. 

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