Article info.

ABSTRACT

Received 15 Aug 2016
Revised 17 Mar 2017

Accepted 29 Jul 2017

Improvements on nitrogen (N) efficiency in rice cultivation have been increasingly concerned with using new types of N fertilizer. The aims of the study were to investigate the effect of N fertilizer types and alternate wetting and drying irrigation on rice yield and N₂O emission in rice cultivation in the Mekong Delta of Vietnam. The design of experiment was split plot with two water management regimes in main plots including (1) alternate wetting and drying (AWD) and (2) farmer practice (FP); and four N fertilizer types in sub-plots as (1) urea, (2) N-(n-butyl) thiophosphoric triamide (nBTPT) urease inhibitor, (3) NPK briquette deep placement technique, and (4) isobutylidene diurea (IBDU) slow N-release. N₂O emission was investigated every three days from 10 to 60 days after sowing. The results showed that AWD treatment had higher rice yields (5.14 t.ha^-1) than FP treatment (4.68 t.ha^-1), but rice yields of the new fertilizer type treatments were not significantly different compared with those of urea treatment. Concentrations of N₂O increased after broadcasting fertilizer in treatments of urea and urea-nBTPT and decreased thereafter in both FP and AWD irrigations. In treatments of NPK briquette and NPK IBDU, N₂O fluxes remained low throughout crop although the fluxes increased in times of soil drainage under AWD regime. Cumulative N₂O emissions of urea-nBTPT, NPK briquette and NPK IBDU treatments (1.67, 1.47 and 1.29 kgN₂O.ha^-1, respectively) were significantly lower than those of urea treatment (2.47 kgN₂O.ha^-1). The results suggested that application of urea-nBTPT, NPK briquette and NPK IBDU was effective in mitigating N₂O emission in rice fields which contributes to attenuating the greenhouse effect.

Keywords

Alternate wetting and drying irrigation, fertilizer deep placement, isobutylidene diurea, nitrous oxide emission, NPK briquette, rice yield, urease inhibitor

Cited as: Phong, V.T., Dao, N.T.A., Hoa, N.M., 2017. Effects of nitrogen fertilizer types and alternate wetting and drying irrigation on rice yield and nitrous oxide emission in rice cultivation. Can Tho University Journal of Science. Vol 6: 38-46.