Uptake efficiency of N-15-urea in flooded and aerobic rice fields under semi-arid conditions

作者：Kadiyala M D M^*; Mylavarapu R S; Li Y C; Reddy G B; Reddy K R; Reddy M D

来源：Paddy and Water Environment, 2015, 13(4): 545-556.

DOI：10.1007/s10333-014-0473-8

• Aerobic rice
• N-15-labeled nitrogen
• Nitrogen use efficiency
• Residual N

The sustainability of traditional rice (Oryza sativa L.) cultivation in many Asian countries is being questioned due to severe water shortage conditions, envisaging the need for development of water-saving rice production technologies. A 2-year-field study on a typic Haplustalf soil was conducted to compare traditional transplanted rice-maize system with water-saving aerobic rice-maize system, with an overall objective of investigating the fate of fertilizer nitrogen (N) using N-15-labeled urea. Results from the field experiments showed that the rice plants positively responded to N fertilizer application. The average fertilizer N recovery by rice crop over the 2 years in aerobic rice was 26 kg per 100 kg of applied fertilizer N in the main field and 21 kg per 100 kg of applied N in the microplot, while the recoveries were 41 and 32 kg ha(-1) per 100 kg of applied N in traditionally cultivated rice under flooded conditions. The fraction of N-15 that was found in soil after the harvest of rice crop ranged from 11.4 to 47.1 kg ha(-1) in aerobic rice and 14.2-51.4 kg ha(-1) in flooded rice. Average recovery of N-15 fertilizer in maize after the first growing season was 3.3 %, and the corresponding recovery in soil was 19 %. An additional 1.3 % of the fertilizer was recovered by crops during the two subsequent seasons. This study indicates the need to develop management practices that improve N use efficiency in aerobic rice by reducing losses to improve yields and reduce N export to the environment.

• 出版日期2015-10