Leveraging Tomato Crop Residues and Pomace for Biosolarization to Deplete Weed Seedbank in Tomato Fields

The biomass from crops left in the field after harvest, or without harvest, could be manipulated to create a hostile environment for soil pests. To assess this potential, a field study was conducted to determine the differential impact of soil organic amendments using plant residue from tomato at two developmental stages (vegetative and fruit-set) and tomato pomace with or without solarization (with and without film) on weed seeds. Under a solarized soil condition, the organic amendments generally enhanced weed seed mortality, suggesting the importance of combining both organic amendment and solarization, i.e., biosolarization, as a viable technique for weed control. The greatest weed seed mortality (47%) was observed with biosolarization that utilized the tomato crop terminated at the fruit-set stage as the organic amendment, on redroot pigweed (Amaranthus retroflexus). Seed mortality caused by biosolarization was mainly attributed to increase soil temperature (6 °C increase), with an additive role of the soil pH and volatile fatty acid accumulation. This study suggested that tomato plant residue can be leveraged to promote weed seedbank depletion, thereby reducing weed pressure in subsequent crops.