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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Citrus and Other Subtropical Products Research » Research » Publications at this Location » Publication #332997

Research Project: Alternatives to Methyl Bromide Soil Fumigation for Vegetable and Floriculture Production

Location: Citrus and Other Subtropical Products Research

Title: Anaerobic soil disinfestation impact on nutrient dynamics in fresh-market tomato

Author
item DI GIOIA, FRANCESCO - University Of Florida
item OZORES-HAMPTON, MONICA - University Of Florida
item ZHAO, XIN - University Of Florida
item THOMAS, JOHN - University Of Florida
item WILSON, PATRICK - University Of Florida
item LI, ZHOUNA - University Of Florida
item Hong, Jason
item Albano, Joseph
item Rosskopf, Erin

Submitted to: Proceedings of Methyl Bromide Alternatives Conference
Publication Type: Proceedings
Publication Acceptance Date: 9/7/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary: Anaerobic soil disinfestation (ASD) is considered a promising sustainable alternative to chemical soil fumigation (CSF). Suitable for both organic and conventional growing systems. The soil amendment with organic material and its anaerobic decomposition cause a temporary variation of the soil redox potential, pH, and microbial population which in turn may impact the soil fertility, the nutrient dynamics, the plant growth and nutritional status, and the overall crop system environmental impact. A field study was conducted on fresh-market tomato to evaluate the effects of ASD applied using different rates of composted poultry litter (CPL) and molasses as amendments, on soil nutrient content, plant biomass and nutrient accumulation, nitrous oxide (N2O) emissions, and potential nutrient leaching. The standard CSF with Pic-Clor 60 (1,3-dichloropropene + chloropicrin) applied at the rate of 224 kg ha-1 was compared with two ASD treatments applied using a mix of CPL at the rate of 22 Mg ha-1, and molasses at two rates [13.9 (ASD1) and 27.7 m3 ha-1 (ASD2)], respectively. N2O concentrations in the samples were measured by gas chromatography (GC). N2O emissions from intact polyethylene mulched beds were not affected by soil treatment and ranged from 0 to 0.378 µg m-2 h-1. At transplanting (21 DATA), after punching holes in the polyethylene film, N2O emissions were at least one order of magnitude higher, but were not influenced by soil treatment. At the end of the crop cycle, regardless the molasses rate, ASD plots had higher N, P, Zn, and Mo than CSF plots, while no differences were observed for the other nutrients analyzed. These results suggest that the ASD treatment may have a residual fertility effect even after the first crop cycle. Therefore, residual nutrients may be exploited in a double cropping system or should be properly managed for example introducing a catch crop in order to minimize risks of nutrient loss. These should be considered as preliminary results, and further studies are required to assess the potential environmental impact of the ASD technique.

Technical Abstract: Anaerobic soil disinfestation (ASD) is considered a promising sustainable alternative to chemical soil fumigation (CSF). Suitable for both organic and conventional growing systems. The soil amendment with organic material and its anaerobic decomposition cause a temporary variation of the soil redox potential, pH, and microbial population which in turn may impact the soil fertility, the nutrient dynamics, the plant growth and nutritional status, and the overall crop system environmental impact. A field study was conducted on fresh-market tomato to evaluate the effects of ASD applied using different rates of composted poultry litter (CPL) and molasses as amendments, on soil nutrient content, plant biomass and nutrient accumulation, nitrous oxide (N2O) emissions, and potential nutrient leaching. The standard CSF with Pic-Clor 60 (1,3-dichloropropene + chloropicrin) applied at the rate of 224 kg ha-1 was compared with two ASD treatments applied using a mix of CPL at the rate of 22 Mg ha-1, and molasses at two rates [13.9 (ASD1) and 27.7 m3 ha-1 (ASD2)], respectively. Soil nutrient analyses were performed before treatment application, 21 days after treatment application (DATA), and at the end of the crop, 92 days after planting (DAP). Soil solution samples were collected at 7, 14, and 21 DATA, using suction samplers installed to a depth of 30 cm in each experimental plot. N2O gas emissions were monitored from the top of the sealed, mulched beds (BT) 1, 2, and 4 DATA, and at crop planting (21 DATA, while punching holes in the polyethylene bed mulch), using custom made static chambers. N2O concentrations in the samples were measured by gas chromatography (GC). N2O emissions from intact polyethylene mulched beds were not affected by soil treatment and ranged from 0 to 0.378 µg m-2 h-1. At transplanting (21 DATA), after punching holes in the polyethylene film, N2O emissions were at least one order of magnitude higher and ranged from 1.56 to 4.83 µg m-2 h-1, but were not influenced by soil treatment. At the end of the crop cycle, regardless the molasses rate, ASD plots had higher N, P, Zn, and Mo than CSF plots, while no differences were observed for the other nutrients analyzed. These results suggest that the ASD treatment may have a residual fertility effect even after the first crop cycle. Therefore, residual nutrients may be exploited in a double cropping system or should be properly managed for example introducing a catch crop in order to minimize risks of nutrient loss.