ISSN:
1435-0661
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
N -ethyl-N′-(1-methyl-ethyl)-1,3,5-triazine-2,4-diamine] on the environment. A two-part study was conducted to evaluate: (i) atrazine release rate as a function of starch granule size, temperature, and water potential; and (ii) to compare the leaching of SE atrazine with the leaching of a commercial formulation in a calcareous soil. Atrazine release-rates from the starch granules were determined as a function of three granule sizes (1.40-0.85, 0.85-0.43, and 〈0.43 mm) at five temperatures (4, 10, 20, 25, and 35°C), and five matric potentials (0, -0.1, -0.5, -1.0, and -1.5 Mpa). Atrazine release-rates from the starch granules increased with decreasing granule size, increasing temperature, and increasing water potential. To evaluate leaching as function of atrazine formulation, each starch-encapsulated granule size, commercial formulation, and control treatment was replicated six times in irrigated soil columns (0.188 m2× 0.25 m). A pulse of bromide (10.7 kg Br- ha-1) and atrazine (1.7 kg ha-1) were coapplied to the soil columns and effluent concentrations monitored. Irrigation evens of 55 mm in 5 h were applied through drip emitters at 10-d intervals for 120 d for a total application of 11.5 pore volumes. Averaged bromide breakthrough curves for each soil column treatment were similar, which indicated that differences in the averaged atrazine mobilities were a result of formulation and not of heterogeneity in the soil matrix. Starch-encapsulated atrazine leaching decreased with increasing granule size; however, all SE formulations were less mobile than the commercial formulation. After 11.5 pore volumes and 120d, 〉:52% of the commercial atrazine had leached through the soil columns, compared with 〈38% for the smallest starch granule size and 11% for the largest granule. Starch-encapsulated formulations may be an effective tool for reducing pesticide leaching in calcareous soils.
Type of Medium:
Electronic Resource
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