Use of vegetated agricultural drainage ditches to decrease pesticide transport from tomato and alfalfa fields in California, USA.

Irrigation and storm water runoff from agricultural fields has the potential to cause impairment to downstream aquatic receiving systems. Over the last several years, scientists have discovered the benefit of using edge-of-field practices, such as vegetated agricultural drainage ditches, in the mitigation of pesticides and sediment. After demonstrating this practice's feasibility in California, field trials were initiated to document irrigation runoff pesticide mitigation in California alfalfa and tomato fields.

Toxicity evaluation of a conservation effects assessment program watershed, Beasley Lake, in the Mississippi Delta, USA.

Beasley Lake was assessed monthly in 2005 for biological impairment from 17 historic and current-use pesticides in water and leaf litter using Hyalella azteca (Saussure). Sixteen pesticides were detected in both water and leaf litter with peak detections in spring and summer. Detections ranged from 1-125 ng L(-1) in water and 1-539 ng g(-1) OC in leaf litter.

Three-dimensional numerical simulation of water quality and sediment-associated processes with application to a Mississippi Delta lake.

A three-dimensional water quality model was developed for simulating temporal and spatial variations of phytoplankton, nutrients, and dissolved oxygen in freshwater bodies. Effects of suspended and bed sediment on the water quality processes were simulated. A formula was generated from field measurements to calculate the light attenuation coefficient by considering the effects of suspended sediment and chlorophyll.

Diazinon reduction and partitioning between water, sediment and vegetation in stormwater runoff mitigation through rice fields.

Background: Contamination of surface waters by pesticides is a concern in the United States and around the world. Innovative mitigation strategies are needed to remediate this potential environmental contaminant. One potential solution is to divert pesticide-laden drainage or surface water through agricultural rice fields.

Can warmwater streams be rehabilitated using watershed-scale standard erosion control measures alone?

Degradation of warmwater streams in agricultural landscapes is a pervasive problem, and reports of restoration effectiveness based on monitoring data are rare. Described is the outcome of rehabilitation of two deeply incised, unstable sand-and-gravel-bed streams. Channel networks of both watersheds were treated using standard erosion control measures, and aquatic habitats within 1-km-long reaches of each stream were further treated by addition of instream structures and planting woody vegetation on banks ("habitat rehabilitation").

Vegetated agricultural drainage ditches for the mitigation of pyrethroid-associated runoff.

Drainage ditches are indispensable components of the agricultural production landscape. A benefit of these ditches is contaminant mitigation of agricultural storm runoff. This study determined bifenthrin and lambda-cyhalothrin (two pyrethroid insecticides) partitioning and retention in ditch water, sediment, and plant material as well as estimated necessary ditch length required for effective mitigation.

Patterns of avian nest predators and a brood parasite among restored riparian habitats in agricultural watersheds.

In fragmented edge-dominated landscapes, nest predation and brood parasitism may reduce avian reproductive success and, ultimately, populations of some passerine species. In the fragmented agroecosystem of northwest Mississippi, placement of drop-pipe structures has been used as a restoration technique for abating gully erosion along stream banks. These actions have formed small herbaceous and woody habitat extensions into former agricultural lands.

Methyl parathion toxicity in vegetated and nonvegetated wetland mesocosms.

Methyl parathion (MeP) was introduced into constructed wetlands for the purpose of assessing the influence of emergent vegetation on transport and toxicity of the pesticide. Two vegetated (90% cover, mainly Juncus effusus) and two nonvegetated wetland cells (each with a water body of 50 x 5.5 x 0.