|Pezeshki, S Reza|
Submitted to: SETAC Conference
Publication Type: Abstract Only
Publication Acceptance Date: 5/22/2007
Publication Date: 5/22/2007
Citation: Pierce, S.C., Pezeshki, S., Moore, M.T. 2007. Ditch plant productivity under variable flooding: a study of rice cutgrass. Abstracts of the 2007 Annual Meeting of the Mid South Regional Society of Environmental Toxicology and Chemistry, May 22-24, 2007, Nashville, TN. p.8. Interpretive Summary: Abstract only. Interpretive summary not required.
Technical Abstract: Vegetated drainages are an effective method for removal of pollutants associated with agricultural runoff. Leersia oryzoides (Rice Cutgrass), a plant common to agricultural ditches, may be particularly effective in the remediation; however, the responses of L. oryzoides to flooding are undocumented. The objective of this study was to characterize the responses of L. oryzoides to various soil moisture regimes representative of agricultural ditches. Treatments included: a well-watered and well-drained control; a continuously saturated treatment; a pulse-flood treatment that was flooded for 48 hours once a week; and a partially flooded treatment in which the water-level was maintained at 15 cm below the soil surface and was flooded to the soil surface for 48 hours once a week. Responses related to plant productivity and morphology were measured during the 8 week study. Net photosynthesis was reduced near the end of the study when soil became anoxic. However, there was no long-term effect on total productivity. The most severely flooded plants generally had increased stem growth, with little effect of flooding on root growth. Results indicated that management practices altering water levels in agricultural ditches would likely not decrease productivity in L. oryzoides except in circumstances where soil oxygen was depleted for an extended period.