Using Cereal Rye As a Catch Crop to Examine the Residual Effects of Anaerobic Soil Disinfestation and Other Biological Soil Management Practices Following Open-Field Tomato Production.

Anaerobic soil disinfestation (ASD) and other biological soil management practices employing carbon-rich and/or biologically-active ingredients help contribute to overall soil suppressiveness in crop disease management. However, their roles in soil fertility tended to be overshadowed by disease control effects. This study conducted in Citra, FL examined residual fertility effects of ASD and other biological soil management methods following 2016 fall field production of tomato (Solanum lycopersicum), by growing cereal rye (Secale cereale) as an indicator catch crop in spring 2017. Soil treatments for the tomato production season included ASD with composted poultry litter (11 Mg/ha) and molasses (6.9 m³/ha), modified ASD with composted yard trimming waste at 26.9 (YTW1+M) and 13.5 (YTW0.5+M) Mg/ha plus molasses, YTW1 only, Soil Symphony amendments (SSA, 816 kg/ha, a commercial product containing cotton seed meal, chitosan, molasses, and Bacillus spp.),YTW1+SSA, untreated control (UTC), and chemical soil fumigation (Pic-Clor 60 at 224 kg/ha) (CSF). Cereal rye was seeded 29 days after final tomato harvest without additional fertilization. Aboveground biomass was measured at 42 and 70 days after rye seeding (DAS). Dehydrogenase activity was monitored during the tomato season and also at 0, 42, and 70 DAS. Greater dehydrogenase activity was consistently observed in all soil amendment treatments when compared to UTC and CSF at 75 (first harvest) and 95 (final harvest) days after tomato transplanting. The rye aboveground biomass was significantly higher in ASD compared with UTC, CSF, YTW1, and YTW1+SSA but it did not differ significantly from SSA, YTW1+M, and YTW0.5+M at 70 DAS. Dehydrogenase activity was significantly greater in all biological soil treatments when compared to UTC and CSF at 0 and 42 DAS, but no difference was observed at 70 DAS. The residual effects of biological soil management practices indicated their impact on soil fertility and nutrient cycling beyond the cash crop season.