Title

Split N and P addition decreases straw mineralization and the priming effect of a paddy soil: a 100-day incubation experiment.

Authors

Wang, Dongdong; Zhu, Zhenke; Shahbaz, Muhammad; Chen, Liang; Liu, Shoulong; Inubushi, Kazuyuki; Wu, Jinshui; Ge, Tida

Abstract

The effect of mineral fertilization and its application pattern on microbial activity and the subsequent CO2 and CH4 emissions arising from soil organic matter (SOM) or added substrate remains unclear. We quantified the decomposition of 13C-labeled straw and the priming effect (PE) governed by the N and P fertilizer application pattern during a 100-day experiment in a flooded soil. Straw addition increased the total CO2 and CH4 emissions. Straw mineralization increased by 30% and decreased by 19% after full and split NP application, respectively, compared with only straw addition. However, application of NP fertilization (full or split) inhibited straw-derived CH4 emissions compared with only straw addition. SOM decomposition was increased by straw addition, yielding a positive PE for CO2 emission. The application of split NP fertilization along with straw addition improved microbial activity, yielding the highest positive PE for CO2 emission. In contrast, compared with the control (no addition), split NP application decreased the positive PE for CH4 emission. Therefore, the straw-C-derived total CO2 equivalent emission was decreased by split NP application. These results were mainly attributable to the increased Olsen P, microbial biomass, enzyme activity, and straw-derived C microbial use efficiency of split NP application, which negatively affected the PE for CH4 emission; this was supported by the results of standardized total effects determined from structural equation models. Overall, compared with full application, split NP fertilizer application significantly decreased the straw-C mineralization rate and PE for CH4 emission, thereby mitigating greenhouse gas emission and SOM storage in paddy soil.

Subjects

HUMUS; STRAW; STRUCTURAL equation modeling; MINERALIZATION; FERTILIZER application; SOILS; NITROGEN fertilizers

Publication

Biology & Fertility of Soils, 2019, Vol 55, Issue 7, p701

ISSN

0178-2762

Publication type

Academic Journal

DOI

10.1007/s00374-019-01383-6