Effect of Almond Residue Soil Amendments and Irrigation Regiment on Organic Acid Development and Transport in Soil Shea, Emily Fernández Bayo, Jesús Dionisio Simmons, Christopher crop protection biopesticides waste valorization Preplant soil disinfestation often relies on harmful soil fumigants; however, the efficacy of sustainable alternatives using biomass amendment fermentation is limited to tillage depths (0−15 cm). This soil column study evaluated whether increasing the irrigation frequency could promote anaerobic pest-suppressive conditions in deeper soils by leaching biocidal fermentation products (organic acids) from surface-applied amendments. Columns received either singular (standard) or weekly irrigation. Almond hulls, an agricultural byproduct, were either incorporated 0−15 cm into soil or applied as a surface mulch. Oxygen and organic acids were measured at 4−50 cm over 21 days, and the experiment was conducted in triplicate. Anaerobic conditions (3% O2) were achieved after 5 days, corresponding to acetic acid accumulation below amended layers: maximum concentrations ranged from 42 to 93 mM at 19−50 cm depths. Additional irrigation further increased concentrations in the deepest layer (50 cm) by almost 50%, demonstrating that water management can enable strategies for depth-dependent soil pest control. This may be particularly valuable for soil disinfestation ahead of the establishment of deep-rooted crops. 2024-10-01T08:44:17Z 2024-10-01T08:44:17Z 2024-08-29 journal article Shea, E. et. al. ACS Agric. Sci. Technol. 2024, 4, 899−906. [https://doi.org/10.1021/acsagscitech.4c00133] https://hdl.handle.net/10481/95317 10.1021/acsagscitech.4c00133 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional American Chemical Society