NCR-SARE Grant

The goal of this project is to educate students about Sustainable Agriculture by teaching them about sustainable greenhouse production techniques.  Our primary focus will be on decreasing water usage and decreasing fertilizer needs.  Students will learn about the benefits of Ebb and Flood benches and other recirculating hydroponic systems for water conservation.  Students learn about the benefits of polyculture through the decreased nutrient inputs by recirculating between hydroponic systems and aquaculture tanks, utilizing the high-nitrogen fish waste for plant growth.  Students will be growing tomatoes and greens, which will be served in the school cafeteria, giving them the opportunity to be directly involved with the local Farm to School Program.

This project is a joint effort between my Aquaculture and Specialty Agriculture, Fish and Wildlife Management, and Plant Science and Greenhouse Management Classes and the Westby FFA, with financial support from a grant through the North Central Region Sustainable Agriculture Research and Education program (NCR-SARE), which is funded by the U.S. Department of Agriculture- National Institute of Food and Agriculture (USDA-NIFA). Students will have the opportunity to study and practice sustainable greenhouse production, with the end result of providing fresh tomatoes and greens for the school lunchroom.


Before the grant, we had an existing 300-gallon recirculating aquaculture system in which we were growing tilapia.  In addition to the existing 300-gallon system, Westby Co-op Creamery donated several 55-gallon drums and 5-gallon pails.  We are using the 55-gallon drums to create another recirculating aquaculture system.  Before the project, the nutrients that resulted from fish waste were lost in our effluent.  We have set up several hydroponic systems to make use of the nutrients in the fish systems. 

In our first hydroponic system, we have a sump pump on a repeat cycle timer pumping water from a bin filled with effluent from the 300-gallon aquaculture system into a series of twenty perlite-filled 5-gallon buckets growing tomatoes.  The buckets will drain by gravity back into the reservoir, ready for the next cycle.

  

In our second system, making use of the donated 55-gallon drums, water drains by gravity from a 55-gallon drum containing fish to another 55-gallon drum with a sump pump on a float switch.  When the sump pump is switched on, water is pumped through PVC pipes which distribute the water to four half-drums containing perlite that will be growing lettuce and other greens.  Those half-drums will drain by gravity back into the drum containing fish, and the cycle repeats itself.

  

In a third system, water is pumped from the 300-gallon fish tank to a Greens 2001 Small Leaf crop NFT system, which drains by gravity back into the fish tank.

  

In a fourth system, water fertilized with commercial fertilizer is used in a Ebb and Flood System.  Students will be able to compare and contrast the systems using fish effluent versus commercial fertilizer, and could switch the Ebb & Flood system over to fish effluent if they deem it to be a worthwhile switch.


Using floating aquaponics/hydroponics trays with Rockwool cube inserts, students are also growing plants in a floating bed in the 300-gallon aquaculture tank.

The plants in each of the systems above act as bio-filters for the systems, taking nutrients from the fish waste. 

Both the NFT System and the Ebb and Flood system water plants at the root zone, rather than from above, which consumes less water than traditional sprinkler or hand watering, has the potential to decrease labor costs, and should decrease instances of disease on the leaves.