Evaluating functional diversity in an organic intercropping system

Project Overview

Project Type: Graduate Student
Funds awarded in 2011: $10,000.00
Projected End Date: 12/31/2013
Grant Recipient: Texas A&M University
Region: Southern
State: Texas
Graduate Student:
Major Professor:
Dr. Astrid Volder
Texas A&M University

Annual Reports


  • Agronomic: peanuts
  • Fruits: melons
  • Vegetables: peppers


  • Crop Production: biological inoculants, cover crops, crop rotation, double cropping, intercropping, irrigation, multiple cropping, nutrient cycling, tissue analysis
  • Education and Training: demonstration, display, participatory research
  • Farm Business Management: community-supported agriculture
  • Natural Resources/Environment: biodiversity, carbon sequestration
  • Pest Management: biological control, competition, soil solarization
  • Production Systems: agroecosystems, holistic management, organic agriculture
  • Soil Management: nutrient mineralization, organic matter, soil analysis, soil chemistry, soil microbiology, soil quality/health

    Proposal abstract:

    Weed, pest and disease control are major challenges facing organic farmers in Texas. Pesticides approved for organic production are not always effective in controlling their intended target. Additionally, inputs in the form of pesticides, fertilizers, and irrigation reduce producer profit margin. This study will examine the effects of varying levels of functional diversity on ecosystem functioning, resource-use efficiency, pest suppression and yields in an intercropping system. To assess treatment affects on ecosystem functioning, soil moisture and soil fertility will be examined. Nutrient-, radiation-, and water-use efficiency will be assessed through measurements of plant tissue nutrient levels, light penetration and quality, plant photosynthesis and leaf water potential. Weed biomass and disease incidence and severity will be monitored to assess the ability of a functionally complex plant community to suppress weed growth and act as a physical and chemical barrier for the spread of disease. Yield and quality measurements will be taken in order to compare the potential profitability of each intercropping system. We hypothesize that by incorporating a system of functionally diverse species, organic producers can improve or sustain soil health while improving crop resource-use efficiency and enhance plant community pest resistance. This will reduce inputs and costs, increasing profits. Another outcome of this project will be to incorporate research into the Aggie Green Fund Organic Farm, a recently developed on-campus student-led farm whose goal is to increase involvement from and educate students about sustainable agriculture, which will then extend out to the community and the State.

    Project objectives from proposal:

    The short term goal of this project is to obtain a mechanistic understanding of functional diversity and its effects on ecosystem functioning, resource-use efficiency, pest resistance, and productivity.

    Our objectives are to:

    1. To examine the relationship between functional diversity and soil chemical (fertility, soil C) and physical properties (soil moisture, soil temperature)

    2. To examine the relationship between architectural complexity and nutrient-, radiation, and water-use efficiency

    3. To determine how incremental increases in functional diversity affect weed suppression and disease incidence and severity

    4. To evaluate the effectiveness of intercropping systems on sustaining or enhancing crop yield and quality

    5. To incorporate this research into the student-led Aggie Green Fund Organic Farm which is geared toward education and research

    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.