Farm-scale Urine Fertilizer Implementation: Refining Application Methods, Gathering Buyer and Consumer Perspectives, and Producing Farmer Guide

Progress report for ONE22-426

Project Type: Partnership
Funds awarded in 2022: $29,998.00
Projected End Date: 06/30/2024
Grant Recipient: Rich Earth Institute
Region: Northeast
State: Vermont
Project Leader:
Abraham Noe-Hays
Rich Earth Institute
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Project Information

Project Objectives:

This project seeks to demonstrate the effect of urine-derived fertilizer on a variety of crops, while further honing application methods and fertilizer formulations chosen to meet plant needs while minimizing harmful nutrient migration into the wider environment. 


Objective 1: Scale up and refine fertilization and application methods for several new crops, including urine-derived fertilizer type and application methods. Conduct side-by-side demonstrations, comparing urine-derived fertilizer to typically-used fertilizer for each crop. Document farmer experiences and plant response, including soil and crop analyses as requested by farmers.  

Objective 2: Understand perspectives of potential wholesale buyers and consumers of produce grown using urine-derived fertilizer, to inform educational and marketing strategies for farmers.  

Objective 3: Develop a guide for farm application, including key findings from Objectives 1 and 2 as well as past field trials and social research.


Documenting the impact of urine fertilizer and effective application methods for a variety of crops will enable more farmers to become familiar with and adopt this practice. Farmers will benefit from an increased ability to effectively utilize a low-cost and sustainable source of nitrogen fertilizer.  Farmers will also better understand concerns of wholesale buyers and direct market customers, which will inform educational and marketing strategies.


By diverting human urine from the wastewater stream and transforming it into fertilizer, we are beginning to solve two major problems: pollution of sensitive waterways with nutrients from wastewater, and dependence of agriculture on unsustainable and expensive sources of fertilizer. The proposed project builds on previous work, improving methods for delivering urine fertilizer appropriately to meet plant nutritional needs and developing a farmer guide to support the adoption of this sustainable amendment. 


Surface waters throughout the Northeast are heavily impacted by nitrogen and phosphorus pollution due to both agricultural runoff, as well as wastewater effluent–primarily due to the urine it contains (70% of the nitrogen and 50% of the phosphorus in wastewater is from urine). Many wastewater plants and most septic systems are unable to control this nutrient pollution and are poorly suited to nutrient reclamation. 


Meanwhile, nitrogen fertilizer is derived from the Haber-Bosh process, which accounts for 1.2% of global energy use and associated greenhouse gas emissions (Dawson & Hilton 2011), while high-N amendments used by organic farmers are expensive and supplies are uncertain. Phosphate is a finite resource, subject to politically induced price swings, and the Global Phosphorous Research Initiative is predicting a shortage of high-quality rock phosphate within 40 years. Additionally, some fertilizer prices have increased more than 300% since 2021 (Myers & Nigh 2021). 


The potential of urine-derived fertilizer is immense. With 54.5 million people living in the Northeast SARE region, each producing 4 kg of nitrogen in their urine annually (Vinnerås & Jönsson, 2002), there is a maximum potential to source 218 million kg of nitrogen fertilizer each year, (plus P, K and trace nutrients,) which would nearly meet the region’s approximately 280 million kg demand for N fertilizer (US EPA, 2019). While nitrogen is the most significant nutrient that human urine could supply, Rich Earth has also successfully separated phosphorus from urine, producing struvite and a low-P liquid fertilizer. Rich Earth’s prior agronomic research and technological development has addressed a number of barriers to farmer adoption of the use of urine as a fertilizer (See Previous Work). 


The effectiveness of urine as a fertilizer has been demonstrated in pot and field trials with crops including amaranth (AdeOluwa & Cofie, 2012), cowpea (Lomeling & Huria, 2020), corn, bean, and cabbage (Shingiro et al., 2020). Rich Earth has conducted the only known field studies of human urine fertilizer in the Northeast region, including yield trials for hay which demonstrated that diluted and undiluted urine are both effective fertilizers, increasing yield in second cut hay on par with synthetic fertilizers (SARE ONE14-218). Rich Earth’s methods aim to integrate urine fertilization with existing practices and equipment, allowing for efficient application matched to crop needs and field conditions.


Although still uncommon, urine diversion is gaining traction. Laufen, a high-end porcelain company, is manufacturing a new urine-diverting toilet, and the National Fish and Wildlife Federation is funding urine diverting toilet installations to protect Long Island Sound. Rich Earth Institute’s LLC spin-off is now selling urine pasteurizers that will enable farms throughout Vermont to produce state-permitted urine fertilizer (whether through use of Rich Earth’s mobile pasteurizer or purchase of a pasteurizer unit to keep on-site). Charcoal filtration can remove pharmaceutical contaminants in urine (Solanki & Boyer, 2017), thereby addressing concerns of some farmers and stakeholders identified in prior research. Urine collection in Vermont is projected to increase substantially in the coming years due to the expansion of Rich Earth’s community collection program to Rockingham, VT, and the establishment of a new urine-collecting portable toilet company (wasted*) in Burlington, VT. These new developments, combined with the application guide we propose to create, have the potential to make urine fertilizer more practical, effective, and useful to farmers in the Northeast. 


Additionally, farmers have indicated a desire to better understand the perspectives of buyers and consumers prior to adopting urine fertilizer. Since urine is in a gray area for organic certification, farmers who practice "organic" methods but are not certified are prime early adopters for urine fertilizer. In our prior research with farmers in this category, they expressed a desire to understand the potential concerns about the use of this fertilizer on the part of buyers who purchase wholesale products from the farm. Additionally, farmers were interested in better understanding the perspectives of consumers who purchase agricultural products directly from farmers (i.e. CSA and/or farmstand customers). Through conducting social research with these groups - and characterizing key perspectives in the farmer guide, this work will help develop farmer education and marketing strategies. 


While significant research has demonstrated effectiveness of urine as a fertilizer for different contexts and methods (see Previous Work) there are few resources directed toward supporting farmer adoption of this practice. As access to urine fertilizer increases, the development of a farmer guide communicating both the agronomic and social findings of this project as well as key conclusions from Rich Earth’s work over the past ten years will enable farmers to make decisions about best practices for diverse crops and application methods.



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Materials and methods:

Drip Fertigation Trial 

To address issues observed in our 2020 SARE project (ONE20-375) (See Previous Work), this trial was designed to quantify the unevenness of urine distribution, identify factors causing it, and test methods for reducing it. The trial exclusively used drip tape, because it is the most common and economical drip irrigation method, and it performed well in the previous trial.

Quantify unevenness: We retested our previous experimental setup (center-fed ½” mainline with 10 tapes, each 10’ long), and captured fertigation water from emitters spaced throughout the system, over an entire fertigation run. We measured the electrical conductivity of the collected liquid to determine the amount of urine it contains, and calculated differences in urine concentration. Preliminary results confirm an uneven distribution of urine output from the drip tape line, with higher concentrations at the ends of the lines. 

Identify factors: We repeated the previous test, varying specific factors that could contribute to uneven distribution. These include 1) the slope of the drip irrigation system and 2) effects of depressurizing the system when switching between water and urine delivery. Another factor that we were not able to test was the difference in temperature between the urine and water; differences in the relative density of urine and water could cause the slightly denser urine to move along the bottom of the irrigation lines or preferentially pool in downhill portions of the drip tapes. 

Test mitigation strategies: We identified the relative density differences between urine and irrigation water as a likely factor influencing uneven distribution. In the spring we will use drip tapes 100’ long to test the effect of slightly diluting the urine, rather than using pure urine injected alternately with pure irrigation water. We expect this modification to result in a more even urine distribution, due to a more homogenous density of the liquid in the irrigation tubing. 


Fertilizing Annual Row Crops 

Our successful 2021 collaborative trials included fertilizing sweet corn with urine. The farmer, John Janiszyn, used a +/- 35 gallon urine tank mounted on a 3-point hitch, from which urine flowed through a hose to an opening just behind a center-mounted cultivator tine. This summer he wanted to fertilize a larger area of sweet corn with urine, but needed to reduce the labor of application. 

Extreme summer rains substantially impacted the farm and subsequent farm operations, which required a deviation from the original application plan in which we had planned to assemble a larger, 275-gallon applicator tank to minimize fill-ups and multiple application nozzles to fertilize more rows at once. Rather than deploy a new applicator, we applied a urine concentrate to achieve fewer trips and minimize labor using the same general rig that was used in a previous SARE Partnership with John Janiszyn. The urine concentrate was a novel fertilizer, which required some extra flow control for the system. Urine was applied through a hose running from the applicator tank to the corn hill, and the spider wheel hiller was easy to operate and effective; urine was buried in the soil with no apparent wet spots at the surface and limited odors, indicating minimized ammonia losses. Three fertilizer variations were applied to plots of corn (4 corn rows/plot) including urine, urine concentrate, urea, and a non-fertilized control. Corn leaf tissue samples were taken from the middle two rows and analyzed by Spectrum Analytics. We plan to do a test of the larger, multi-row application set up in the spring.

Additionally, John Janiszyn had planned to test urine fertilization of a vegetable crop grown under black plastic mulch, but this was not feasible due to time constraints. We plan to do this in the spring, time and weather permitting.


This image shows the urine application method used at Pete's Stand
The spider wheel hiller effectively buried the urine as it was applied to the corn hill at John Janiszyn’s farm.
This image shows the corn field where urine was applied as fertilizer
Urine is applied to sweet corn at John Janiszyn’s farm.


Composting Wood Chips

Jesse Marksohn (Yellowbud Farm) composts hardwood chips to make mulch and compost for growing nursery stock. He previously conducted an informal trial adding urine to chip compost piles, with encouraging results. We had planned to test four compost recipes with varying ratios of wood chips and urine, with the goals of accelerating the composting process and increasing the compost’s nitrogen content and overall quality. However, Yellowbud Farm decided not to compost wood chips this season and instead applied a large amount of urine directly to the soil where seedlings are grown (see Fertilizing Nursery Trees below). We did not run any wood chip composting trials as planned. 


Fertilizing Nursery Trees

Yellowbud farm conducted an experiment assessing the effect of urine fertilization on chestnut nursery stock planted in the ground. Urine was applied at a 2:1 dilution rate of water:urine using an applicator tank and boom. Yellowbud farm decided to apply urine at a consistent rate to all trees, and we therefore did not test different application rates or mycorrhizal effects as planned. Jesse Marksohn (Yellowbud Farm) reported exceptional results in seedling health and wants to fertilize with urine again next year. Yellowbud received urine for fertilization trials from the Rich Earth Institute and decided to fertilize all their tree saplings with it. Lacking a non-fertilized control, we cannot determine relative improvement in seedling quality from urine fertilization, only that the farmers reported that the urine-fertilized trees were of exceptional quality.


This image shows the chestnut trees used in field trials
Eric Cornell of Yellowbud Farm fertilizes a field of chestnut nursery stock seedlings.
This image shows the applicator used in Yellowbud field applications
Urine is applied to chestnut nursery stock using a tank and boom applicator


A smaller, controlled urine fertilization trial was also conducted in air pruning beds on hickory seedlings at Yellowbud Farm. Urine was applied before germination on June 21 and to seedlings on August 4 in three treatment groups: a low rate, a high rate, and a non-fertilized control. Air-pruned bed treatment groups did not include inoculation with mycorrhizae as planned. Four beds were each divided into six subplots, and each of the three treatment groups were randomly assigned to 2 subplots/bed for a total of 8 replicates/treatment. For both applications, beds were lightly watered to moisten the soil prior to fertilization, and urine was diluted and applied using a watering can. Beds were lightly watered again immediately following urine application. 

Germination was lower than expected in the air-pruned beds, likely because the hickory seeds were too dry at harvest. On November 17, all seedlings were collected and growth indicators of 1) stem diameter at base, 2) stem height, and 3) root diameter were measured. The combined wet mass for all seedlings in a plot was also recorded, and dry mass will be measured once seedlings have dried. Data has not yet been analyzed.


This image shows the air-pruning beds used in controlled urine application experiments at Yellowbud
Urine-fertilized hickory seedlings in air-pruning beds are dug and measured after one growing season at Yellowbud Farm


Farmer Qualitative Observations

Farmers were asked to observe and document crop responses to the urine fertilizer and comparison treatments, including observations of plant development, fruit set, pest and disease pressure, and any other indicators they felt were relevant. To assist with documentation of their observations, we conducted an interview/site visit at each farm at  the end of the season. (We had planned to do both mid and end of season interviews but due to farmers' schedules, it made more sense to just do one set of interviews/visits). We also documented the applications with photos and asked farmers to document plant responses. We are still in the process of collecting this documentation from the farmers. The audio recordings from these site visits are currently being transcribed and will be analyzed for key observations and recommendations. We had intended to bring farmers together for a final meeting with Rich Earth staff at the end of the season to share observations with each other, and generate ideas and recommendations for follow-up research. However, we have since determined that in lieu of the field days we were also planning, we will hold a webinar to which we will invite these farmers, to share their observations and experiences with a wider audience of farmers who may be unfamiliar with the use of urine fertilizer. That webinar will be held later this winter. See "Outreach" below. (Our letter requesting this change from field day to webinar  - which was approved - is attached.)


SARE 2022 Partnership change in plan request letter.docx


Buyer & Consumer Perspectives

To understand potential concerns of buyers, we are focusing on those who buy wholesale product from farmers who practice "organic" methods but are not certified, as these farmers are key constituents for urine fertilizer. To better understand consumer concerns, we will conduct three dialogue groups with consumers who purchase agricultural products directly from farmers (i.e. CSA and/or farmstands). Because this is a relatively small sample, we will not be conducting statistical analysis, but rather drawing out key themes and specific questions and concerns to inform ongoing research, and assist farmers with future educational and marketing materials. Some of the ideas gleaned from this research will also inform the guide.

  • Interview four wholesale buyers, addressing concerns such as pharmaceutical residuals. What would they need to know about treatment/processing (for example), to feel comfortable? 
  • Conduct three dialogue groups with CSA/Farmstand customers, including a range of backgrounds and experiences about their attitudes, motivations and concerns about fertilizer use
  • Transcription and analysis 

Progress to date: we attended farmers' markets this past summer, tabling and talking to consumers about this project. We gathered contact information from 32 individuals who said they would be interested in participating in dialogue groups. We are now in the process of contacting these individuals to see if they are still available/interested. We will then select 16 individuals randomly from the set of 32, for two dialogue groups made up of farmers' market customers which we plan to conduct in February, 2024.  We have also contacted a number of farmers with CSA to recruit potential participants in a third dialogue group made up of CSA customers. We will continue this until we have at least 16 potential participants, and then randomly select 8 of these for the third dialogue group which will also be held in February if at all possible.

We have contacted a number of wholesale buyers and are currently scheduling the four buyer interviews.


Co-developing Guide

To respond to farmer requests for an application guide, we are drawing on our previous ten years of research, literature review, and consultation with local farmers to create a urine fertilization guide featuring information about urine nutrient content, application methods for different crops, sanitation methods (including Rich Earth’s pasteurizer unit), buyer and consumer perspectives, and several case profiles of the experience of Rich Earth farm partners, from this project as well as previous partnerships. The steps involve: 

  • Review and compile prior research results 
  • Compile documentation of field trials from prior SARE-funded projects, and the current project, for case profiles of farm partners 
  • Write and edit the guide
  • Solicit feedback from additional farmers 
  • Edit, revise, graphic design

Progress to date: We have developed an outline for the guide and are in the process of compiling prior research results and documentation from our prior field trials. We are now in the process of writing and editing the guide content. The intention is to produce a guide of approximately 10 pages. We also plan to receive consultation of the guide from farmers, but have not yet identified the farmer consultants.


Research results and discussion:

Data analysis is in preliminary stages and there are no results yet to report.


Research conclusions:

Data analysis is in preliminary stages and there are no conclusions yet to report.

Participation Summary
3 Farmers participating in research

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

We will host a webinar in Burlington, VT this winter to facilitate connections of potential early adopter farmer partners into local urine diversion efforts. We will include as panelists for this webinar representatives from Wasted*, a urine-diverting portable toilet company based in Burlington, as well as the two partner farmers for this project (Yellowbud Farm and Pete’s Stand) to share their experiences, as well as several other farmers who have partnered with us on previous SARE projects. This will be an opportunity to reach new potential partners for urine applications, particularly those in near Burlington that could benefit from Wasted*’s urine supply. In addition to tailored outreach to farmers in the immediate region, outreach to this event will be targeted to farmers and agricultural educators via Vermont, Massachusetts and New Hampshire Extension personnel as well as farm listservs and associations such as the Vermont Releaf Collective, Northeast Organic Farming Association, Vermont Pasture Network, the Connecticut River Farmers Watershed Alliance, Food Solutions New England, the North American Food Systems Network, the National Sustainable Agriculture Coalition, and the Northeast Sustainable Agriculture Working Group. 

Additionally, we plan disseminate the guide to farmers through sharing with the aforementioned farmer networks, distributing print copies to farmers, and creating accompanying digital media to share key findings and increase online farmer engagement with the guide. The guide will be shared on Rich Earth’s website, newsletter (which currently includes 1,350 subscribers), and social media accounts (818 followers on Instagram, 1,865 followers on Facebook). By collaborating with wholesale buyers, direct farm consumers, and local farmers to develop the guide, we will expand Rich Earth’s existing network of stakeholders interested in urine fertilization. We will provide digital content for interested farm partners to share information about the guide via their newsletters, websites, and/or social media pages. The guide will also be disseminated to those who attended the webinar. 

We will gather further feedback on the guide, and farmer interest in urine fertilization, through a short survey which will accompany the guide. 

We will also present our project’s findings and the guide at one or more conferences, although these may occur after the end of this grant period, as we don't anticipate completion of the guide in time for this year's Vermont Organics Recycling Summit, or the NOFA-VT Winter Conference.


Learning Outcomes

Key areas in which farmers reported changes in knowledge, attitude, skills and/or awareness:

The three farmers (two at Yellowbud, one at Pete's Stand) have learned more about how their crops respond to urine treatment. At Yellowbud, a number of volunteers assisted with applications and documentation during the season so they became familiar with urine as a fertilizer and were able to observe crop responses. 



Project Outcomes

1 Farmers changed or adopted a practice
1 New working collaboration
Project outcomes:

So far, the farmer partners involved in the project have reported positive crop responses (or comparable responses as to their usual fertilizer in the case of Pete's Stand), and are enthusiastic about continuing this research. Dialogue groups and buyer interviews are still in progress so no outcomes to report yet. 


Assessment of Project Approach and Areas of Further Study:

This project is still in process, and therefore we have not yet made an assessment of project approach.


Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.