Project Overview

Reports

Commodities

Target Pests

Practices

Onion growers in the Snake River valley of western Idaho and Malheur County Oregon rely on costly chemical fumigation practices to manage a range of soilborne pests and pathogens, but stakeholders have identified a need for alternative management strategies. Biofumigation using cover crops represents one option that could reduce reliance on chemical fumigation. However, utilization of cover cropping systems in high-value irrigated agriculture requires careful evaluation. Preliminary research has examined short-term outcomes in onion production systems, but there is a strong need for a long-term cost-benefit analysis that weighs the farm-level costs of implementing cover crops against the expected stream of benefits over time.

This project will evaluate the net present value (NPV), benefit-cost ratio (BCR), and internal rate of return (IRR) of cover crops used as biofumigants over a 20-year period under multiple adoption scenarios. The analysis will quantify economic outcomes at both the farm and regional levels. Regional impacts will be estimated by applying projected adoption trajectories across the onion sector, allowing the analysis to capture broader economic implications beyond individual farm-level outcomes. The overall goal is to improve understanding of the long-term financial consequences of adopting alternatives to chemical fumigation. Addressing these economic knowledge gaps will improve decision-support tools for growers, identify priorities for future research, and inform policies that support the development and adoption of practical, economically viable integrated pest management (IPM) solutions.

The overall goal of this project is to conduct long-term cost-benefit analyses of the implementation of cover crops for use as biofumigants in onion production systems.

Objective 1: Quantify the long-term economic benefits of biofumigation practices using yellow mustard and arugula at the farm and industry levels with and without EQIP cost share incentives.

Objective 2: Quantify the long-term economic benefits of the combination strategy of low-rate chemical fumigation and bio fumigation practices using K-pam and oilseed radish at the farm and industry levels with and without EQIP cost share incentives.

For objectives 1 and 2, the net present value (NPV), benefit-cost ratio (BCR), and internal rate of return (IRR) will be computed at the farm level and regionally (at the industry level) for the onion sector over a long-term (20-year) timeframe. Different S- shaped adoption curves will be applied to the individual farm and industry level analyses for the estimation. The resulting financial metrics will be used to evaluate the economic feasibility of implementing cover crops as biofumigants in onion production systems with and without EQIP cost share.

Objective 3: Assess the economic impacts of changes adoption rates and changes in production conditions.

Sensitivity analyses will be conducted to incorporate scenarios with different adoption rates at the farm and industry levels for both practices with and without EQIP cost share. Additional sensitivity analyses will evaluate NPV, BCR and IRR outcomes under changing input prices, including cover crop seed, fumigant, and fertilizer. We will also evaluate the impact of yield increases in subsequent crops considering a range of prices and the impact of no yield increases.