Biosolarization For Disease and Weed Control For Winter High Tunnels

View the project final report

Commodities

• Vegetables: greens (lettuces)

Practices

• Crop Production: high tunnels or hoop houses
• Pest Management: biological control, prevention, sanitation, soil solarization
• Production Systems: organic agriculture

Winter high tunnel salad production has become a viable income stream for many vegetable producers. The winter environment within an unheated tunnel is good for leafy greens, but it is also perfect for cool season weeds and soil borne pathogens. Most producers find these to be limiting factors in the success of their winter crops.

Biosolarization is a new method of disease and weed control. Organic matter is incorporated into the soil, and then the soil is irrigated and covered with clear totally impermeable film (TIF) plastic. TIF is designed for soil fumigation. The sun heats the soil beyond typical field conditions, and the hot, moist soil rapidly decomposes the organic amendments. The byproducts of decomposition are kept in the soil by the gaseous impermeable TIF plastic. These compounds, combined with the heat, negatively impact soil borne pathogens and weed seeds without the use of fungicides or herbicides.

I am seeking to test the efficacy of this technique, using farm generated grass clippings, in high tunnels in the summer to reduce winter disease and weed pressure. I would also like to test used greenhouse plastic as an affordable and sustainable TIF plastic alternative.

Biosolarization is still a relatively new technique. In California, it shows promise as a solution to weed and disease pressure in field grown salad crops. Our objectives are: to test to see if its benefits will carry over from the summer season to winter crops in high tunnels in the Midwest, to compare used greenhouse film as a sustainable and affordable alternative to TIF plastic, and how the quantity of feedstock, farm generated grass clippings tilled into the soil, affects the outcome.