Efficacy and cost effectiveness of foliar nutrient applications to vegetable crops on a large Rhode Island farm

Project Overview

Project Type: Partnership
Funds awarded in 2017: $14,963.00
Projected End Date: 04/15/2018
Grant Recipient: University of Rhode Island
Region: Northeast
State: Rhode Island
Project Leader:
Andy Radin
University of Rhode Island Cooperative Extension


  • Vegetables: tomatoes


  • Crop Production: foliar feeding
  • Farm Business Management: budgets/cost and returns

    Proposal abstract:

    Rhode Island vegetable farmers need to maximize profits on limited cropland. Foliar nutrient application is a
    popular production practice. Extension publications recommend this practice only under conditions of stress or
    suspected deficiency, yet according to a recent informal survey in RI, it is routinely used as regular production
    practice on conventional farms. While positive results are sometimes observed, its cost-effectiveness is unknown,
    though it may be warranted in high tunnels where land is limited.

    Efficient input use is a key factor of economic sustainability. Qualified professionals can provide guidance towards
    this end. The objectives of this project are to: 1) test a set of foliar nutrient application practices recommended by
    a fertilizer company representative for a) efficacy and b) cost-effectiveness and 2) survey RI conventional growers
    on their fertilizer decision-making process in order to design effective educational programming.
    On Confreda Farm, three succession plantings of determinate tomatoes will be split, half receiving prescribed
    nutrient sprays, half without. Leaf tissue nutrient status and percent marketable yield will be measured. A field plot
    study at URI will duplicate the farm study. For both components, input costs and potential revenue per acre will be
    extrapolated for comparison. At a winter meeting in which the subject is discussed and results reported, growers
    will be asked to complete a survey on their fertilizer decision-making processes to assess educational needs. A
    ten-minute video on the subject of foliar nutrient application for vegetable growers will be created, along with an
    extension fact sheet.

    Project objectives from proposal:

    The aim of this investigation is to improve profitability and environmental sustainability among conventional Rhode Island vegetable growers through examination of fertilizer nutrient delivery to vegetable crops. Two hypotheses
    will be addressed:
    1) Routine applications of foliar fertilizers to field-grown determinate tomatoes provide significant return on
    2) Foliar nutrient applications can be used to correct deficiencies in field-grown determinate tomatoes, particularly
    of nitrogen and potassium
    Yield and leaf tissue parameter monitoring will determine if supplemental foliar-applied nutrients are necessary as
    routine production practice, or only useful when deficiencies have been diagnosed through tissue sampling. In
    particular, cost-effectiveness of the routine use of these products will be assessed.
    The issue of information sources and their quality will be addressed in a grower survey designed to answer the
    following question:
    3) How do growers arrive at their decisions to adjust inputs for vegetable crops which they have been producing
    as a part of their mix of crops?
    The objective of the survey component is to ascertain whether growers are being reached by professionally
    qualified purveyors of relatively unbiased, science-based information. If they are not, the survey will explore
    reasons for this disconnect.

    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.