ISSN:
1573-0867
Keywords:
1-amidino-2-thiourea
;
3,5-diamino-1,2,4-thiadiazole
;
dicyandiamide
;
thiourea
;
nitrification inhibitor
;
urea
;
ammonium sulfate
;
Nitrosomonas europaea
;
N-fertilizer
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The degradation of guanylthiourea (GTU) via 3,5-diamino-1,2,4-thiadiazole (TDZ) to dicyandiamide (DCD) was studied in selected soils. All three compounds could be determined by HPLC. GTU decomposed rapidly (within hours-days), the reaction from TDZ to DCD continued more slowly (within days-weeks). Soil type and temperature had an essential effect on the rate of degradation; conspicuous was a more rapid breakdown of GTU in presence of ammonium sulfate (AS) than in combination with urea. Each compound is a nitrification inhibitor; inNitrosomonas cell suspensions, 0.5 ppm GTU and 10 ppm TDZ achieved an effect comparable to 200 ppm DCD. The combination of these two effects—degradation in soil and inhibition of nitrification—were studied in soil incubation experiments. The three substances had inhibitory effects also in soil, however at significantly different application rates (20 ppm GTU or TDZ and 30 ppm DCD). Using these concentrations, AS/DCD and urea/GTU showed similar effects. Urea/GTU retarded nitrification by the factor 1.7 as compared to urea/DCD. AS/GTU had no advantage over AS/DCD which can be explained by the more rapid degradation of GTU in presence of AS. Urea/GTU apparently presents a promising possibility to utilize N-fertilizers more efficiently.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01080681
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