1994 Annual Report for SW94-029
Development and Demonstration of Integrated Vegetable Production Systems for the Maritime Pacific Northwest
Summary
Objectives
1. To develop, evaluate and demonstrate integrated vegetable production systems for the maritime Pacific Northwest which improve farm profitability, protect water quality, and enhance long-term soil productivity.
2. To improve methodologies for enhancing farmer and agribusiness participation in the design and implementation of on-farm research and demonstration projects for integrated, sustainable agriculture.
3. To conduct a multi-faceted educational program which accelerates information transfer among producers, extension specialists and agents, agribusiness representatives, governmental agency personnel, and the university research community.
Abstract
This participatory on-farm project has actively involved vegetable growers in the design and implementation of the research. Learning and discovery has occurred at multiple levels through direct observation, farmer-scientist focus sessions, grower-led field days, workshops, and farm tours. This project has focused in three critical components of integrated farming systems: (1) selection and management of winter-annual cover crops to enhance soil and water quality, (2) development and implementation of a strip-tillage production system, and (3) evaluation of beneficial insectary plantings to enhance biological pest control.
This project has focused on developing and evaluating strip-tillage vegetable production systems which integrate winter-annual cover crops for enhancing soil and water quality, suppressing weeds, and providing a habitat for beneficial organisms. In five on-farm trials in 1997 involving sweet corn production in Oregon’s Willamette Valley, an integrated strip-till production system increased economic net return by an average of $47 an acre compared to the conventional tillage system. In one farm, herbicide costs were reduced by $17.53 per acre. In a replicated trial conducted at the OSU Vegetable Research Farm, strip-till systems for broccoli production using legume cover crops produced a yield increase of approximately 2 tons per acre compared to the conventionally-tilled system. In a two-year on-farm trial involving cover crops for nitrogen contribution, the use of legume cover crops reduced fertilizer nitrogen (N) inputs by 60 lbs N/acre and the participating grower reduced his fertilizer applications on approximately 600 acres.
In another on-farm research trial exploring the use of beneficial insectary flowers to increase the abundance of predatory insects, experimental plots using the insectary plant Alyssum maritima showing a significant increase in predacious syrphid flies caught in traps and in number of syrphid eggs laid on broccoli leaves. Parasitism of the cabbage aphid was doubled in the alyssum plots.
The integrated vegetable production system developed in this project offers potential to increase net profit to the growers, improve water quality through reduction of leaching and surface runoff, and enhance soil quality through conservation of soil organic matter and biological diversity. There is also a proven potential to reduce pesticides and fertilizer inputs. This system is being adopted by leading vegetable producers in the Willamette Valley, with more than 500 acres to be planted to integrated strip-till in 1999.
Twilight cover crop twilight tours were hosted by two collaborating growers in 1995, and a mid-summer “Conservation Tillage/Cover Crop Field Day” was held at the OSU Vegetable Research Farm. Two field tours were held in 1996. Presentations of research findings were made at the Oregon Processed Vegetable Growers annual meeting, the Oregon Horticultural Society Meeting, Agronomy Society of America National Meeting, and at two in-service professional education workshops held in conjunction with SARE Program Chapter 3 activities in the Pacific Northwest.
Economic Analysis
An economic evaluation of the costs of cover crop production, based on individual grower records, has shown the variable costs to vary from $35-50/acre, including tillage operations. Efforts to determine N contribution by cover crops has been targeted at recouping the cost of 80-100 pounds of N fertilizer, worth approximately $25-35 per acre. The primary motivating factors for growing cover crops, according to collaborating growers in this project, is to improve soil quality and help reduce nitrate leaching. The economic value of these kinds of qualitative benefits has not yet been estimated
A comparison of the relative economic benefit of the strip-till system compared to the standard tillage systems was conducted using two components: (1) economic value of the crop (yield, grade and price) and (2) calculating costs of tillage for the two systems. Tillage costs were estimated using The Cost of Owning and Operating Farm Machinery in the Pacific Northwest (Willett and Smathers, 1992) and information on specific equipment used by the collaborating growers.
The strip-tillage system produced higher sweet corn yields than the standard tillage practices on 4 of the 5 fields in the trial. Economic analysis showed that for sweet corn production averaged across the three farms and five fields in the 1997 trial, the strip-tillage system produced an economic advantage of $47 per acre greater than the standard tillage systems. This value is based on an average increase in crop value (a combination of yield, grade and price) of $27 per acre and an estimated savings in tillage costs of $20 per acre. The highest increase in economic value associated with strip-tillage was in the Hendricks Farms Shelburn Road field, with a $126 advantage over standard tillage ($98 in product value; $27 in tillage cost savings).
Potential Benefits
Strip-tillage systems for sweet corn production using cover crops were shown to be more profitable than conventional tillage treatments in on-farm trials conducted in 1997. There is the potential to dramatically reduce tillage requirements by 500 to 700 percent. This reduction in tillage will reduce soil erosion and movement of soil and agricultural chemicals into surface water systems through runoff. There is also a dramatic reduction in wind erosion of soil through this conservation tillage system. A major impact associated with adoption of these conservation tillage systems could also be improved conservation of soil organic matter by reducing microbial oxidation following tillage.
Fall-planted winter annual cover crop mixtures of cereals and legumes can significantly reduce soil erosion and leaching of soil nitrate into the groundwater during the rainy Pacific Northwest winters. These cover crops, when managed correctly, can reduce nitrogen fertilizer requirements for the following vegetable crop by 80-100 lbs. N/acre.
Allelopathic cover crops, coupled with reduced tillage systems, form important components of integrated weed management strategies, with dramatic opportunities to reduce herbicide inputs and costs. Beneficial insectary plantings offer promise in increasing the effectiveness of naturally-occurring predacious and parasitic insects in biological insect pest management. We are developing strategies and specific management recommendations to utilize beneficial insectary plants in both annual and perennial cropping systems. These strategies, combined with other integrated pest management tactics, may reduce pesticide inputs into these systems.
Farmer Adoption and Direct Impact
There is an increasing number of vegetable growers in the Willamette Valley who are growing cover crops, largely due to on-farm demonstration tours and other educational events associated with this project. Changes in cover crop practices are also occurring. For example, Stahlbush Island Farms, a 1,400 acre vegetable production operation near Corvallis, switched from growing Austrian field pea cover crops to using fava beans, crimson clover, and common vetch as direct result of being involved with this project. Several of the growers involved with the on-farm strip-till evaluation expanded the acreage on their farms planted using the strip-till system in 1998 and will be planting more than 500 acres in 1999 using the strip-till system. The equipment manufacturer collaborating on this project (Northwest Farm Tillers, Yakima, WA) has committed significant financial resources to completely redesigning their strip-till machine to accommodate the needs of the growers in our project. A consortium of growers are now considering options for developing a new prototype tiller and contracting manufacture
This summary was prepared by the project coordinator for the 1999 reporting cycle.