Organic Farm System: Biodesign Farm

Organic Agriculture September 21, 2016 Print Friendly and PDF

eOrganic authors:

Helen Atthowe, Biodesign Farm

Alex Stone, Oregon State University

Biodesign farmOrganic Farm System: Biodesign Farm

System Overview

About Biodesign Farm

Farmer: Helen Atthowe

Location: Stevensville, in western Montana (Fig. 1: Area Map)

Crops: Mixed vegetables. Main crops are tomatoes, bell peppers, eggplant, broccoli, cabbage, Brussels sprouts, and winter squash.

Markets: Regional farmers markets (75%) and wholesale to organic supermarkets and restaurants (25%)

Years in organic management: Biodesign began in 1993 and was certified organic with the Montana Department of Agriculture Organic Certification Program until 2008, when the farm joined with other small, local organic producers to form the Western Montana Sustainable Grower's Union. The farm was sold in 2010.

Total farm acreage: 30 acres

Cropped acreage: 8 acres

Landscape design: Two fields—one 6 acres and the other 2 acres. Fields were surrounded by native grassland–sagebrush steppe habitat, several pasture-based cattle operations, and some large-scale potato and small grain producers (Fig. 2: Farm Fields Map). "Old field" (2 acres) was cultivated from 1994 through 2005. In 2006, production moved to "New field" (6 acres).

Regional agricultural production: Ravalli County's 2012 gross agricultural production was $34,725,000, with 70% from livestock production and 30% from crops, mostly grains.

Climate and soils: Semiarid (13 to 16 inches of annual precipitation) with a frost-free growing season of 100 to 115 days. Average last frost is 30 May, and average first frost is 10 September. Spring is the wettest period of the year, with about 25% of annual precipitation falling in May and June. Summer temperatures reach the high 90s, and winter lows are regularly below zero. Soils are classified as capability class VI by the USDA Natural Resources Conservation Service and rated as "poor" for agricultural use (Fig. 2: Farm Fields Map).

Awards: Alternative Energy Resource Organization Sustainable Farm Award, 2000

Farm Philosophy

Rather than treating specific crops, problems, or pests, Biodesign focused on supporting natural nutrient and biological control cycles and on managing ecological relationships.

Key Farm Design and Soil and Habitat Building Strategies

  • Small crop fields embedded in native grass/pasture forest habitat
  • Reduced tillage
  • Perennial and annual living mulch to keep soil covered year-round and to provide winter shelter and interspersed season-long bloom for natural enemies
  • Selective mowing of the living mulch to provide
    • Regular addition of organic residues to the soil/soil microbial community
    • Shade and cooling for crops and beneficial enemies during hot, dry spells. During cool, wet periods, the living mulch was mowed short to enhance drying and increase ambient air temperatures. Following planting, it was left unmowed to provide a windbreak for seedlings and transplants.
  • Compost addition in the early years
  • Gravity-flow irrigation management:
    • Drip irrigation to avoid fruit and foliage wetting (for disease management)
    • Sprinkler irrigation to suppress specific pests such as flea beetles

Soil Management System: Build Soil to Support Natural Nutrient Cycles and Grow High-Yielding, High-Quality, Flavorful Crops

Biodesign's goals were to optimize soil organic matter, reduce tillage, support a diverse soil microbial community, and provide year-round soil cover for natural enemies. The soil management system (Soil Table 1) included:

  • Reduced tillage
  • Perennial and annual living mulches to provide year-round soil cover, with above- and below-ground plant diversity
  • Regular addition of mowed clover/weed soil amendments
  • Annual compost addition most years (1993–2002 on Old field and 2006–2007 on New field)
  • Alfalfa meal addition to crop rows in years when no compost was applied (Disease Table 2 and Table 3).
  • In Old field, soil organic matter (SOM) content climbed from 3.5% in 1993 to 5.7% in 2006, while cation exchange capacity (CEC) increased from 10.2 to 16.8 meq/100g (Soil Fig. 1).
  • In New field, SOM increased from 3.3% in 1993 (when New field was in permanent grass pasture) to an average of  5.2% in 2010 (after New field was cultivated for vegetable production, beginning in 2006). CEC increased from 9.8 to 11.7 meq/100g as SOM increased (Soil Fig. 2).
  • Macronutrients increased while the farm was in production. While some reached excessive levels during the 1990s, almost all eventually reached target levels.

The reduced tillage/living mulch system resulted in good yields of high-quality, flavorful crops and high levels of soil organic matter and soil nutrients. Soil health indicators generally showed positive trends (Soil Table 2).

Read more about the Biodesign soil management system here.

Insect Pest Management System: Maximize Ecological Function and Minimize Off-Farm Inputs

Biodesign's goal was to build and manage habitat for biological control organisms (e.g., insect predators and parasites, birds, bats, soil and foliar microorganisms) and to apply insecticides only when a pest was not sufficiently controlled by the system. Pests were sprayed only when absolutely necessary. The insect pest management system included both systemic practices (Insect Table 1) and pest-specific strategies (Insect Table 2):

  • Landscape-level diversity provided by small crop fields bordered on four sides by native grassland/pasture
  • Reduced tillage
  • Perennial and annual living mulch groundcover in row middles to provide in-field interspersed plant diversity; season-long pollen, nectar, and seed food sources; and winter cover
  • Selective mowing of the perennial living mulch to avoid disturbance of natural enemies at key pest pressure times
  • Irrigation management to discourage certain pests
  • Organic soil amendments to maintain balanced crop growth, thus suppressing insect pests
  • Three-year crop rotation by crop family (Solanaceae, Brassicaceae, Fabaceae)
  • Pesticides were applied only when necessary (Insect Table 2)  and applications ceased in 2000; up to 10% pest damage was tolerated in some crops to maintain a food source for natural enemies.

Crop yield and quality losses to insects decreased from 1993 through 2010, according to Helen. This observation is supported by reduced insecticide use (Insect Fig. 1), crop monitoring records (1993–2010), and on-farm research (2006). Farm records document good yields, less than 3% average crop damage across all crops (Insect Fig. 2 and Insect Fig. 5), and high predator/parasite populations (Insect Fig. 3 and Insect Fig. 4). Aphids on peppers and cabbageworms on brassicas were the main insect pests at Biodesign.

Read more about the Biodesign insect pest management system here.

Disease Management System: Create Conditions Unfavorable for Pathogen Growth

Biodesign's goal was to prevent disease incidence by managing for balanced crop growth and healthy soil, while utilizing good cultural practices such as rotation and irrigation management. The disease management system included both systemic practices (Disease Table 1) and disease-specific strategies (Disease Table 4):

  • Organic soil amendments to maintain balanced crop growth
  • Selective mowing of the between-row living mulch to maximize air flow and leaf and fruit drying
  • Drip irrigation and management to avoid foliar and fruit wetting
  • Three-year crop rotation by crop family (Solanaceae, Brassicaceae, Fabaceae).

Diseases, primarily bacterial speck of tomato (Pseudomonas syringae pv. tomato) and cucumber mosaic virus of pepper (Bromoviridae:Cucumovirus) were never highly damaging due in part to the dry climate. However, losses did occur. Over time, losses declined, especially those caused by bacterial speck as documented by crop quality monitoring records (1993–2010), possibly due to Biodesign Farm's design and soil- and habitat-building practices. Cucumber mosaic virus was observed at low levels on peppers in the early 2000s, but did not become more severe over time or affect crop yield.

Read more about the Biodesign disease management system here.

This article is part of the Biodesign Farm Organic Systems Description.

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This is an eOrganic article and was reviewed for compliance with National Organic Program regulations by members of the eOrganic community. Always check with your organic certification agency before adopting new practices or using new materials. For more information, refer to eOrganic's articles on organic certification.

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This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.