Best management practices for organic orchard nutrition

Best management practices for organic orchard nutrition

Summary

Management of ground covers, weeds, and nutrients for organic apple orchards in the southern region will be studied through surveys of organic growers and replicated research trials. A comparison of four ground cover management systems and three organic fertilizers will be studied in orchard trials to determine optimum nutrition management practices. Data will be collected on weed control, soil quality, chemistry, and biology, nutrient availability, nutrient uptake, tree growth and tree performance. As the project is only six months since its initiation, baseline soil information is the only data that has been collected and analyzed as of this report.

Objectives/Performance Targets

To develop an understanding of nutrient management and recommendations through the evaluation of seasonal nutrient content of soil and foliage in an organic production system with interaction treatments of ground cover management and organic nutrient source

A.Identify nutrient management practices currently being used by organic fruit growers in the South.
Results are being collected and compiled from a survey mailed to 40 organic and ecologically-based apple producers throughout the southern SARE region. The survey included questions on orchard nutrient management including: groundcovers, fertilizers, diseases, mulches, weeds, and orchard productivity.

B.Work with Southern region organic tree fruit growers to assess the impact of their nutrient management practices.
Producers have been identified to participate in a soil and foliar nutrition survey in which samples are collected, by producers, on a monthly basis to assess the nutritional status of the soil and trees.

C.Based on results of on-farm analyses, conduct a controlled, replicated study to further evaluate ground cover and nutrient management practices and develop locally-appropriate recommendations for organic fruit tree growers in the South.
An organic apple orchard has been planted at the University of Arkansas to examine the effects of 2 organic fertilizers and 4 groundcover treatments in a replicated study. Soil and foliar samples are being collected monthly for chemical, physical and biological assessment.

Accomplishments/Milestones

• The project is divided into two major components; 1) a survey of practices and nutrient status of organic orchards in Arkansas and the Southern Region, and 2) establishment of replicated trial to test the interaction of ground cover management system and nutrient source.

  1.Survey of Practices
  •A survey was developed by the project leaders and reviewed and approved for distribution by the Institutional Review Board (IRB) of the University of Arkansas which reviews all surveys and tests involving human and animal subjects.
  •A list of organic fruit producers and potentially organic fruit producers or sustainable producers in Arkansas and the Southern Region was developed form lists of certifying agencies, farmers markets, and internet sources. The growers on the list were mailed a copy of the survey titled, “Survey of Transition and Organic Apple Nutrient Management Practices”. A follow-up post card has been mailed, follow-up phone calls are being made increase the response rate.
  •A protocol for soil and foliage surveys was developed and distributed to grower participants in the project.

  2.Replicated Field Trial of Interaction of Ground Cover Management and Nutrient Source on Organic Orchard Nutrition and Performance.
  •Trees for the replicated trial ordered (Sept 05) and received.
  •Orchard training system (2-wire vertical axis trellis) established and irrigation installed.
  •Baseline soil analyses were collected and analyzed.
  •Orchard site was prepared with compost and lime applications and planted to a winter cover crop (wheat) and permanent in-row cover crop (K-31 fescue).
  •Trees planted and initial training implemented.
  •Treatments applied. Ground cover management treatments: 1) fescue cover crop, 2) white-paper mulch, 3) wood chip mulch, 4) municipal green compost. Nutrient source treatments: A) control (nutrients provided from the ground cover treatments), B) composted manure, C) pelletized organic poultry based fertilizer. Treatments were applied as a split-split plot design with six replications.
  •Measurement variables for the 2006 growing season will follow proposal protocols.

Impacts and Contributions/Outcomes

The impact of this trial should be several fold.
•Best practices used by organic producers for ground cover management and orchard nutrition management will be determined.
•The status of organic orchard nutrition in the southern region will be determined.
•The replicated orchard trial will be a research and educational/outreach tool for field days and grower educational programs to demonstrate techniques used in organic apple production for the Southern Region.
•The replicated orchard trial will provide a basis for developing appropriate technologies used to manage the ground cover and weeds, and appropriate means and options for applying nutrient sources in organic orchards in the southern region.
•The project should have an outcome of supporting organic fruit producers and allow for expanded organic fruit production in the southern region by developing and demonstrating successful production techniques with a scientific basis.

Collaborators: