Effect of an Indigenous Soil Microbial Inoculant on Soil, Soil Microbial Community and Leaf Nutrient Density

Project Overview

Project Type: Farmer
Funds awarded in 2019: $12,323.00
Projected End Date: 03/31/2022
Grant Recipient: Endless Farm LLC
Region: Northeast
State: Rhode Island
Project Leader:
Rebecca Roberts
Endless Farm LLC

Information Products

Summarized Report (Fact Sheet)


  • Vegetables: greens (lettuces)


  • Crop Production: biological inoculants, fertilizers, foliar feeding, no-till, nutrient cycling, nutrient management, tissue analysis
  • Education and Training: on-farm/ranch research
  • Natural Resources/Environment: biodiversity
  • Production Systems: agroecosystems, organic agriculture
  • Soil Management: organic matter, soil analysis, soil microbiology, soil quality/health
  • Sustainable Communities: sustainability measures

    Proposal summary:

    Indigenous Microorganisms (IMO) is a soil microbial inoculant used by farmers as a low-cost method to increase yield, soil nutrient availability, and decrease pest pressure. Rice is incubated on an undisturbed soil in the forest and fermented, yielding a diverse microbial brew. Limited research suggests a positive to neutral effect on plant disease and yield, but little research has tested the impacts of IMO on more direct effects like microbial diversity, total microbial biomass, soil nutrient availability, and nutrient density of plant leaf tissue. We will compare the effects of single and multiple applications of IMO to these soil and plant health markers. Anecdotal evidence on IMO effects is widely disseminated among farmer networks, so peer-reviewed data on soil health and leaf nutrients could help academics and farmers understand the direct impacts of IMO, and help farmers make informed decisions about using IMO on their farms.

    We will publish in an open access journal and use social media networks and listservs popular with farmers and extension educators in the region to send both a summary of the research and a direct link to the article. We will also present this research at Southeast New England NOFA Conferences, where farmer interest in IMO is strong.

    Project objectives from proposal:

    This project seeks to investigate how application frequency of indigenous soil microbial inoculant may impact the size and diversity of the soil microbial community, soil nutrient availability, and yield, and leaf tissue nutrient density in lettuce production. If this method improves soil and plant nutrition by increasing soil microbial diversity, it will provide much needed evidence about how IMO works, give farmers additional information on how often to apply IMO, and allow farmers to make informed decisions about using IMO compared to other microbial amendments.

    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.