Desh Duseja

FIELD PERSISTENCE AND MOVEMENT OF TRIFLURALIN IN TWO SOIL TYPES

Trifluralin (α, α, α-trifluoro-2, 4, dinitro-N, N-dipropyl-p-toluidine) was applied in 1973 to Egam loam and Beason clay field plots, which differed in slope and texture of the surface 12 in. of soil. Recommended (1×) and excessive (1.5× and 2×) rates of trifluralin were applied, and the herbicide was incorporated to a depth of 4 in. Movement of trifluralin below the 8-in. depth was essentially nil in both soils, but considerable movement occurred to the 8-in. depth in both. Trifluralin longevity in each soil was essentially the same, although higher rates were applied in the clay soil. On the average, less than 1% of the herbicide remained 5 months after application; an increasing trend of trifluralin residues with 1.5× and 2× rates was discerned, however. No herbicide was found in the soil the following spring (11 months after application). There was some evidence of upward movement of trifluralin in both soils. Trifluralin degradation followed first-order kinetics with half-life values of 35.8 and 25.7 days for Egam and Beason soils, respectively. Five weeks after herbicide application, control of two broad-leaf weeds and one grass weed was poor, being consistent with low herbicide concentrations (0.06 ppm) remaining in the soil at that time. The growth of oats (Avena sativa L.), a species sensitive to trifluralin, was also not significantly affected in the greenhouse at 0.05 ppm of trifluralin concentration.

A SIMPLE QUANTITATIVE CHEMICAL RECOVERY METHOD OF OXYFLUORFEN (2-CHLORO-1-(3-ETHOXY-4-NITROPHENOXY)-4-(TRIFLUOROMETHYL) (GOAL®) FROM LABORATORY FORTIFIED SOIL AND WATER SAMPLES

Oxyfluorfen herbicide chemical extraction and analyses techniques from both soil and water are time consuming or/and require the use of HPLC. Our paper reports the results of a simple method for the extraction and gas chromatographic (GC) analyses in laboratory oxyfluorfen fortified soil and water samples. A representative field sample from a Byler silt loam (Typic fragiudalf, mixed, thermic) soil site was collected from the 0–10 cm depth, and appropriately air-dried and sieved (2-mm size). Soil had an organic matter (O.M.) content (Walkley Black) of 2% w/w, and pH of 6.5. The soil sample was fortified with 0.05 to 2.0 μg/g levels of oxyfluorfen herbicide, extracted (1:5 soil: acetonitrile), and directly injected into the HP 6890 gas chromatograph (μ-ECD detector). Deionized (DI) laboratory water samples were spiked at the 0.010 and 0.100 μg/mL levels. They were intermittently shaken by hand with n-hexane for 3 min., and the supernatant directly analyzed by GC. Quantitative recoveries of the herbicide in duplicate samples were obtained in both soil and water. Recovery percentage as well as GC response suggest that soil MDLs of at least 0.005 μg/g in soil are achievable. Organic solvent/water ratio does not appear to affect the recovery of oxyfluorfen from fortified water samples. However, the solvent exchange step in soil extraction can affect the oxyfluorfen recovery. These extraction techniques represent considerable savings in time and labor compared with traditional methods. *Oxyfluorfen; 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene, trade name Goal®, was obtained from the Rohm and Hass Company, Independence Mall West, Philadelphia, PA. 19105. Trade names and company names are mentioned with the understanding that no discrimination is intended nor endorsement implied.

Sewage sludge effects on soil: heavy metal accumulation and movement

Abstract Treated municipal sewage sludge at 0, 11.2, 33.6, and 67.2 metric tons/ha was applied each year for two consecutive years and incorporated into a Byler loam soil (Typic Fragiudalf) having an initial pH of 5.6. Sorghum (Sorghum vulgare L.) was grown in replicated plots (6.1m × 4.6m). Soil samples were taken at 0 to 20 cm and 20 to 40 cm depth at the end of each year and analyzed for DTPA‐extractable Cu, Zn, Cd, and Ni. Surface soil exhibited significant increases in heavy metal concentrations in the first year at the 67.2 metric tons/ha rates. Heavy metal concentrations increased with continued sludge application. However, this increase was not in proportion to the amount of sludge applied suggesting some immobilization of metals with time. After two years, downward movement and significant increases in Cu, Zn, and Ni levels were noted at the 20 to 40 cm depth at the higher rates. Heavy metal levels in the surface soil did not appear to be phytotoxic as judged from sorghum grain and dry matter yie...

Available phosphorus status of an acid soil treated with sewage sludge and farm manure

Abstract Anaerobically digested sewage sludge at 11.2, 33.6, and 67.2 metric tons/ha and farm manure at 6.7, 20.2, and 40.4 metric tons/ ha rates were applied annually for two consecutive years to an acid Byler loam soil (Typic Fragiudalf) cropped to corn (Zea mays L.) and sorghum (Sorghum vulgare L.). A recommended NPK check was included. Available P (1% (NH4)2SO4 in 0.05N H2SO4 ‐ extractable) levels in the soil were determined after crop harvest in the ensuing spring, each of the two years. Levels of available P in the organic amended plots did not increase significantly in the surface soil (0 to 20cm) layer the first year. Some movement of P into the subsurface soil (20 to 40cm) layer was observed, however. Significant buildup of available P due to the organic amendments was observed in the surface soil layer with little movement below 20cm during the second year.

Trifluralin soil behavior: Persistence, movement and weed control

Abstract Trifluralin (α,α,α‐trifluoro‐2, 4‐dinitro‐N, N‐dipropyl‐p‐toluidine) was applied in 1976 to Egam loam and Beason clay soils on the same field plots that were utilized in a 1973 study. The rates and methods of herbicide application, herbicide formulation and soil incorporation and plot size were also the same. Soybean (Glycine max L.) was seeded in both years with the same crop row‐width. Average herbicide residues, expressed as per cent of 0 day residues in 1976, were initially up to 7% higher in 1976 than in 1973, in both soils. The residues dissipated to about the same level, however, in both years starting 70 days after herbicide application, could be largely explained on the basis of rainfall distribution patterns in the two years. Less than 4% herbicide remained in 1976, 126 days after its application. The herbicide persistence was generally higher at higher herbicide rates in each soil, and could be described by first‐order kinetics. The herbicide moved downward below the depth of herbicide...

Soil dissipation of three herbicides

Abstract Three herbicides, trifluralin, (α,α, α‐ trifluoro‐2, 6‐dinitro‐N,N‐dipropyl‐p‐toluidine), profluralin (N‐dyclopropylmeehyl)‐α,α,α,‐trifluoro‐2, 6‐dinitro‐N‐propyl‐p‐toluidine), and dinitramine (N4, N4‐diethyl‐α, α,α‐trifluoro‐3, 5‐dinitrotoluene‐2, 4‐diamine) were incubated in an Etowah silt loam soil under laboratory conditions. The herbicides were incubated at 0.5 ppmw herbicide concentrations at 73 and 95°F, and for a time period ranging from 7 to 17 days. Three pH levels (5.3, 6.4, and 7.5) and three moisture contents (0, 50, and 100% FC) were generally used. Maximum disappearance of each herbicide occurred at the intermediate pH of 6.4. The herbicide losses were enhanced by increasing moisture contents and increasing temperature, and time. At 7 days incubation, at 507%FC moisture and soil pH of 6.4, herbicide dissipation at 73°F was in the order: Profluralin(=30%)> Trifluralin=Dinitramine (=20%).

The effect of sewage sludge and manure on soil available calcium, magnesium, and potassium

Abstract Beef cattle feedlot manure at 0, 6.7, 20.2, and 40.4 mt/ha and anaerobically digested municipal sewage sludge at 0, 11.2, 33.6, and 67.2 mt/ha were applied and incorporated into an acid (pH 5.6) Byler loam soil (Typic Fragiudalf) for two consecutive years. Corn (Zea mays L.) and sorghum (Sorghum vulgare L.) were grown in replicated plots (6.1m × 4.6m). At the end of each year, soil samples were taken at 0 to 20 cm and 20 to 40 cm depths. They were analyzed for available calcium, magnesium, and potassium (IN NH4‐acetate extractable, pH 7). Sewage sludge treatments had no effect on soil available calcium, magnesium, and potassium levels in the surface and subsurface soil in corn and sorghum plots. Immobilization of sludge nutrients with time and rates was indicated. In each year, manurial treatments did not change soil available calcium levels for both crops as calcium immobilization in the soil was suggested. However, at the 40.4 mt/ha rate, manurial treatments did significantly increase surface s...