Rhizosphere soil nitrification ability controls nitrogen ‐use efficiency in rice growth period

The impacts of the rhizosphere soil nitrification rate on NUE and denitrification losses at different rice growth stages in two paddy soils were investigated. Rhizosphere nitrification played a dominant role in increasing denitrification and decreasing NUE. Rhizosphere nitrification rate was affected by soil pH and nitrifying microbial community composition. AbstractNitrification in the rhizosphere is a crucial process in controlling nitrogen-use efficiency (NUE) in flooded paddy soils. To understand the relationship between the nitrification ability of the rhizosphere and NUE, pot experiments using15N tracer technique were conducted to investigate the impacts of the rhizosphere soil net nitrification rate on NUE and denitrification losses at different rice growth stages in two paddy soils, which were sampled from Jurong (JR) and Yancheng (YC) in Jiangsu Province in China. The results showed that the nitrification rate in JR rhizosphere soil was lower than in YC rhizosphere soil at all rice growth stages. The abundance of ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA), and pH in YC rhizosphere soils were always higher than in JR rhizosphere soils. Rice yield, biomass, NUE, leaf glutamine synthetase (GS) activity, and nitrate reductase (NR) activity were higher in JR soils with low nitrification rates than in YC soils with high nitrification rates (p <  0.05). In contrast, denitrification loss from JR soil (12.69%–23.41%) was lower than that from YC...
Source: Food and Energy Security - Category: Food Science Authors: Tags: ORIGINAL ARTICLE Source Type: research