Effect of rates and sources of nitrogen on rice yield, nitrogen efficiency, and methane emission from irrigated rice cultivation

• Published in: Archiv für Acker- und Pflanzenbau und Bodenkunde Vol. 63; no. 7; pp. 1009 - 1022
• Main Authors: Ku, Hyun-Hwoi, Hayashi, Keiichi, Agbisit, Ruth, Villegas-Pangga, Gina
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 07.06.2017; Taylor & Francis Ltd
• Subjects: Cattle manure; Climate change; Crop production; Crop yield; Cultivation; Emission measurements; Environmental impact; Global warming; Global warming potential (GWP); Grain cultivation; greenhouse gases; irrigated rice; Methane; N efficiency; Nitrogen; organic fertilization; Rice; Urea
• ISSN: 0365-0340; 1476-3567
• DOI: 10.1080/03650340.2016.1255327

The agronomic benefits of manure application to increase rice production have been recognized, but the impact on global change has always been a controversial topic. This study was designed to determine the separate and combined effects of cattle manure (CM) and nitrogen (N) fertilizer on rice yield, N efficiency, and methane (CH 4 ) emissions from rice cultivation. A pot-scale experiment was conducted with four levels (0, 60, 120, and 180 kg ha −1 ) of N from urea and two levels (120 and 180 kg ha −1 ) of N from combination of urea and CM (Urea:CM = 60:60 and 60:120). Rice yield and physiological N efficiency were obtained using agronomic measurements. To determine the global warming potential (GWP) of each treatment, CH 4 emissions were measured throughout the rice-growing period. Grain yield (GY) was not significantly different between the treatments of 120 and 180 kg ha −1 regardless of N source. However, both rates of CM treatments enhanced CH 4 emission and differences in GWP were significant. In conclusion, urea applied at 120 kg N ha −1 was optimal for rice productivity and environmental impact (EI) despite CM played a crucial role in improving the N efficiency and total N in the soil after harvest.