Farm-Scale Application of Concentrated Urine-Derived Fertilizer: Evaluation of a Roller Pump for Precise and Consistent Side Dressing of Sweet Corn

Commodities

• Vegetables: sweet corn

Practices

• Crop Production: application rate management, nutrient cycling
• Sustainable Communities: local and regional food systems

This project builds upon two
previous SARE Partnership projects with John Janiszyn, who
operates Pete's Stand in Walpole, NH, with field sites in
Vermont.  In these previous projects, we designed a
gravity-fed method for applying sanitized urine fertilizer to his
sweet corn, followed by successful experiments using a urine
concentrate to increase application efficiency. This project will
give further attention to the method of dosing the urine onto the
field, addressing needs for both consistent dosing rates and
minimal ammonia volatilization. We will design a ground-driven
peristaltic (or "roller”) pump system to dispense urine
concentrate into crop rows, and we will evaluate its efficacy
through quantitative testing, farmer feedback, and leaf tissue
analysis of fertilized crops. The roller pump system design will
be documented in a short video and made accessible to farmers
interested in adopting urine-fertilization
technology. 

This project will evaluate the
ease of use, effectiveness, and consistency of a customized
fertilizer applicator using a ground-driven "roller pump" for
applying a sanitized, concentrated urine-derived fertilizer to
sweet corn. We will purchase a multi-tube roller pump and the
necessary auxiliary component parts to assemble a complete system
that can 1) consistently deliver the desired amount of urine
fertilizer per acre (adjustable by the farmer), 2) cover the
urine fertilizer with soil immediately upon application to
prevent ammonia loss, and 3) be easy to operate and maintain.
Furthermore, we will test the practical limits of the system’s
dosing rates and discover any mechanical weaknesses. We will
monitor urine-fertilized crops for signs of healthy development
(visually and through tissue analysis), and note any differences
in health from synthetically-fertilized crops. From this
assessment, we hope to determine the potential for this
applicator to be used for other crops and application contexts.
Desired outcomes of the roller pump system testing
include:

Deliver a consistent and correct
urine fertilizer volume per acre 

1. There is no variation in the
   quantity of fertilizer dispensed over a set distance when the
   tractor is driving at different speeds
2. The drive wheel consistently
   powers the pump as the tractor moves over the ground, even when
   encountering bumps, divots, etc.
3. The pump provides a practical
   flow rate for urine concentrate and delivers urine at the
   correct depth and location relative to row crops
4. There are no differences in
   plant development and overall health during the growing season
   between plants receiving urine fertilizer or synthetic
   fertilizer 

Ammonia volatilization is limited
during application

1. The urine fertilizer is
   immediately buried in soil upon application to the
   ground
2. Little to no ammonia odor is
   present following application

The roller pump system is easy to
operate and maintain and contexts for its potential use are
understood

1. The farmer-partner reports an
   easy-to-operate user experience with minimal challenges
2. There are no mechanical
   failures or signs of wear/weakness in any system
   components
3. The system is expected to be
   useful for other crops and application contexts besides sweet
   corn
4. The system limits are
   understood through a determination of the maximum and minimum
   practical dosing rates possible