Effectiveness of vegetative buffer strips for herbicide retention from agricultural runoff was evaluated in a twoyear natural rainfall study. A source area of 0.41 ha (mainly Canisteo silty clay loam soil), having an average slope of 3%, was fall chisel-plowed, spring disked, and planted to corn. Three herbicides (atrazine, metolachlor, and cyanazine) were applied to the source area in each spring. Six vegetative buffer strips, 1.52 m wide ¥ 20.12 m long, were isolated with metal borders downslope of the source area in a well established bromegrass (Bromus inermis) waterway. These strips provided for three replications of two drainage to buffer area ratio treatments of 15:1 and 30:1. Herbicide retention was dependent on the antecedent moisture conditions of the strips. These retentions ranged from 11 to 100% for atrazine, 16 to 100% for metolachlor, and 8 to 100% for cyanazine. Herbicide retention by the buffer strips for the two treatments were not significantly different for the observed storm events. Herbicide concentrations in solution in outflow from the strips were less than the inflow concentrations for all the three herbicides. Infiltration was the key process for herbicide retention by the buffer strips, although there was some adsorption to in-place soil and/or vegetation. Metolachlor concentrations in sediment increased in outflow for the two treatments; however, the opposite was true for atrazine and cyanazine. Herbicide retention by sediment deposition in the strip represented about 5% of the total herbicide retention by the buffer strips. The buffer strips were found to have high percent sediment retention, ranging from 40 to 100%; thus, the strips would be more effective for retaining strongly adsorbed herbicides.

Several processes take place within vegetated buffer strips that affect their performance. To better understand these processes, a runoff study was conducted to evaluate vegetated buffer strips performance in reducing atrazine, metolachlor, and chlorpyrifos transport as affected by the drainage area to buffer strip area ratio. The simulated runoff water mixed with pesticide-treated soil was distributed onto six vegetated buffer strips, each 1.52 m wide. 20.12 m long, located downslope of the inflow distribution tank in a well established vegetated grassed waterway. These strips provided for three replications of two inflow rates designated as "drainage area/ buffer strip area ratio treatments" of 15:1 and 30:1. Infiltration for the 15:1 treatment averaged 38.8% of the inflow volume, whereas it averaged 30.4% for the 30:1 treatment. Sediment retention efficiencies averaged 90.1% and 86.8% for the 15:1 and 30:1 treatments, respectively. Concentrations of atrazine and metolachlor associated with sediment outflows from the strips were larger than their respective inflow concentrations, while the results were opposite for chlorpyrifos. Concentrations in runoff water for both atrazine and metolachlor in outflow from the strips were smaller than the inflow concentrations; again, the results were opposite for chlorpyrifos. The 15:1 treatment retained an average of 52.5% of the total input of atrazine, 54.4% of metolachlor, and 83.1% of chlorpyrifos. Corresponding numbers for the 30:1 treatment were 46.8% for atrazine, 48.1% for metolachlor, and 76.9% for chlorpyrifos. Analysis of variance using the randomized block design showed that differences of percent retention of pesticide between treatments were not significant for any of the three pesticides at the 10% significance level. A lack of significant difference indicates either a need for more than three replications and/or larger area ratio treatments to be studied. The results of this study indicate that a 30:1 area ratio buffer strip could perform equally as well as a 15:1 area ratio buffer strip. Thus, less land would be required under buffer strips to get the desired results.

Arora, Kapil, Steven K. Mickelson, Matthew J. Helmers, and James L. Baker, 2010. Review of Pesticide Retention Processes Occurring in Buffer Strips Receiving Agricultural Runoff. Journal of the American Water Resources Association (JAWRA) 46(3):618‐647. DOI: 10.1111/j.1752‐1688.2010.00438.x Abstract:  Review of the published results shows that the retention of the two pesticide carrier phases (runoff volume and sediment mass) influences pesticide mass transport through buffer strips. Data averaged across different studies showed that the buffer strips retained 45% of runoff volume (ranging between 0 and 100%) and 76% of sediment mass (ranging between 2 and 100%). Sorption (soil sorption coefficient, Koc) is one key pesticide property affecting its transport with the two carrier phases through buffer strips. Data from different studies for pesticide mass retention for weakly (Koc < 100), moderately (100 < Koc < 1,000), and strongly sorbed pesticides (Koc > 1,000) averaged (with ranges) 61 (0‐100), 63 (0‐100), and 76 (53‐100) %, respectively. Because there are more data for runoff volume and sediment mass retention, the average retentions of both carrier phases were used to calculate that the buffer strips would retain 45% of weakly to moderately sorbed and 70% of strongly sorbed pesticides on an average basis. As pesticide mass retention presented is only an average across several studies with different experimental setups, the application of these results to actual field conditions should be carefully examined.

Objectives:To assess the knowledge, attitude, self-reported practices, and prescription patterns regarding dental floss amongst a select population of dentists in India.Materials and Methods:A pretested 30-item questionnaire was self-administered by authors to the dental faculty and postgraduate students in dental schools in Delhi-National Capital Region (NCR). Nine dental institutes were selected by simple random sampling procedure among 15 institutions and a total of 255 dentists were included in the study.Statistical Analysis:The data obtained were analyzed by SPSS version 18. Descriptive statistics such as frequencies were calculated and Pearson's Chi-square test was used with P value fixed at 0.05.Results:There was lack of adequate knowledge regarding dental floss, among dentists in India. 78% of the dentists responded that the routine use of dental floss was necessary for good periodontal health. Majority of the dentists cited lack of awareness, availability, and cost as the major factors affecting floss usage. Lack of training in the dental education programs may have an impact on the prescription patterns as well. 15.3% of those surveyed do not use floss at all. 63.9% of the dentists prescribed floss routinely to their patients and considered factors like education, occupation, and socioeconomic status of the patient before prescribing dental floss.Conclusion:Health education programs regarding dental floss are necessary to create awareness among the general population and adequate training at undergraduate level is also essential to increase the prescription practices. Dentists should practice recommended oral self-care and act as role models.

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