Nitrification Inhibition by Nitrapyrin and Etridiazol in Soils Amended with Sewage Sludge Compost1
- G. McClung,
- D. C. Wolf and
- J. E. Foss2
Nitrification inhibitors, which have been used to reduce fertilizer N losses from soils, may have potential for use with organic soil amendments such as sewage sludge compost. Effects of two nitrification inhibitors, nitrapyrin [2-chloro-6-(trichloromethyl)pyridine] and etridiazol [5-ethoxy-3-(trichloromethyl)-1,2,4-thiadiazole] on nitrification were investigated in laboratory studies with Beltsville silt loam (Typic Fragiudult), Hagerstown silty clay loam (Typic Hapludalf), and Pocomoke loamy sand (Typic Umbraquult). The soils were amended with sewage sludge compost at rates of 0.0, 44.6, and 89.2 g/kg and incubated at 25°C, and at compost rates of 0.0 and 89.2 g/kg and incubated at 15°C. In all soil-compost combinations at either temperature, there were no significant differences between nitrapyrin and etridiazol as measured by NH4-N or NO3-N concentrations in the soils. At least 83% inhibition of nitrification was observed in all soil-compost combinations following 18 weeks of incuhation at 25°C with the highest inhibitor rate of 50 µg/g. After 9 weeks of incubation at 15°C, > 76% inhibition of nitrification was observed in all soil-compost combinations with the highest inhibitor rate of 10 µg/g. Generally NO3-N production decreased with increased inhibitor concentration and with decreased compost rate.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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