US EPA

1556507 

Journal Article 

Dicyandiamide increases the fertilizer N loss from an alkaline calcareous soil treated with N-15-labelled urea under warm climate and under different crops 

Mahmood, T; Ali, R; Latif, Z; Ishaque, W 

2011 

Yes 

Biology and Fertility of Soils
ISSN: 0178-2762
EISSN: 1432-0789 

47 

6 

619-631 

10.1007/s00374-011-0559-z 

WOS:000292971700002 

Using an alkaline calcareous soil, experiments were
conducted to elucidate the effects of nitrification inhibitor dicyandiamide (DCD) on the fate of
N-15-labelled urea applied to cotton, maize, and wheat under greenhouse conditions. Combined
effects of DCD and two levels of wheat straw (applied to cotton) and of fertilizer application
method (conventional broadcast vs. point injection in maize and wheat) on the recovery of the
fertilizer N were also studied. High soil temperatures prevailed under cotton and maize, whereas
the soil temperature was relatively moderate during the wheat growing season. The fertilizer N
loss under cotton was lowest (44% of the applied) when urea was applied alone; the loss increased
due to DCD (54%) or wheat straw (50-54%) and was highest (63-64%) when DCD and wheat straw were
applied together. Under maize also, DCD increased the loss of the fertilizer N applied by the
conventional method (51% without DCD vs. 66% with DCD) or by point injection (26% without DCD vs.
42% with DCD). With the conventional method under wheat, DCD had no effect on the fertilizer N
loss (34-37% of the applied). The fertilizer N loss under wheat was least (16%) when urea
solution was point-injected but increased (24-26%) due to DCD or/and when pH of the urea solution
was reduced to 2. Besides, DCD significantly reduced the fertilizer N uptake and increased the
fertilizer N immobilization in soil under cotton and maize. However, DCD applied in combination
with a higher level of wheat straw significantly increased the cotton dry matter and N yields due
to increased N availability from sources other than the fertilizer. The results suggested that
the use of DCD may not be beneficial in alkaline calcareous soils and that point injection of
urea solution without any amendment is more effective in conserving the fertilizer N as compared
to the conventional broadcast method. 

Cotton; Dicyandiamide; Maize; N-15 balance; Point injection; Wheat