Nitrogen (N) applications can have a significant effect on soil N availability. The effect of 3 years of N fertilization on soil net N mineralization during the growing season (May–September) was studied in 2005 and 2006 in grassland of northern China. The experimental design was a randomized complete block with
four replications of five rates of N addition as urea (0, 2, 4, 8 and 16 g N m⁻² year⁻¹). Results indicated that net N mineralization rate varied seasonally and between years, ranging from )0.04 to 0.52 µg u⁻¹ d⁻¹ in 2005 and from -0.09 to 0.39 µg u⁻¹ d⁻¹ in 2006. Mean N mineralization and nitrification rates were highest in July, in 2005 and 2006, whereas highest ammonification rates occurred in September. Rainfall was significantly correlated with net nitrification. In comparison with the untreated control, N mineralization increased sharply when N fertilization increased from 2 to 8 g N m⁻² year⁻¹. Mobile soli NO₃⁻ accumulated late
in the growing season for the 16 g N m⁻² year⁻¹. treatment, suggesting the potential for NO₃ and associated cation leaching. These results suggest that N fertilization of 8 g N m⁻² year⁻¹ (80 kg N ha⁻¹) is suitable for the management of grassland ecosystems of Inner Mongolia.
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Title
Effect of nitrogen fertilization on net nitrogen mineralization in a grassland soil, northern China
Publication Details
Grass and Forage Science, Vol.67, pp.219-230
Resource Type
Journal article
Publisher
Wiley-Blackwell Publishing Ltd.; United Kingdom
Series
67
Copyright
2012 Blackwell Publishing Ltd.
Identifiers
WOS:000303435700006; 99380090762906600
Academic Unit
Biology; Hal Marcus College of Science and Engineering