TY  - JOUR
AU  - Wu, Lei
AU  - Zhang, Wenju
AU  - Wei, Wenjuan
AU  - He, Zhilong
AU  - Kuzyakov, Yakov
AU  - Bol, Roland
AU  - Hu, Ronggui
TI  - Soil organic matter priming and carbon balance after straw addition is regulated by long-term fertilization
JO  - Soil biology & biochemistry
VL  - 135
SN  - 0038-0717
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2019-04138
SP  - 383 - 391
PY  - 2019
AB  - Straw incorporation is crucial to soil organic carbon (SOC) sequestration, thus improving soil fertility and mitigating climate change. The fate of straw C and the associated net SOC balance remain largely unexplored, particularly in soils subjected to long-term mineral and organic fertilization. To address this, soil (δ13C: –19‰) that had been continuously cropped with maize for 31 years and subjected to five long-term fertilization regimes, including (i) control (Unfertilized), (ii) mineral fertilizer (NPK) application, (iii) 200% NPK (2 × NPK) application, (iv) manure (M) application, and (v) NPK plus manure (NPKM) application, was incubated with or without addition of rice straw (δ13C: –29‰) for 70 days. Straw addition largely primed SOC mineralization. The priming effect (PE) was considerably higher in 2 × NPK (+122% of CO2 from soil without straw addition) but lower in M (+43%) relative to the unfertilized soil (+82%), highlighting the importance of fertilization in controlling PE intensity. Fertilization increased the straw-derived microbial biomass C by 90–577% and straw-derived SOC by 34–68% compared to the unfertilized soil, primarily due to the increased abundance of Gram-negative bacteria and cellobiohydrolase activity. Straw-derived SOC was strongly positively correlated with straw-derived microbial biomass C, suggesting that dead microbial biomass (necromass) was a dominant precursor of SOC formation. Consequently, fertilization facilitated microbial utilization of straw C and its retention in soil, particularly in the M and NPKM fertilized soils. The amounts of straw-derived SOC overcompensated for the SOC losses by mineralization, resulting in net C sequestration which was highest in the NPK fertilized soil. Our study emphasizes that NPK fertilization decreases the intensity of the PE induced by straw addition and increases straw C incorporation into SOC, thus facilitating C sequestration in agricultural soils.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000477689700044
DO  - DOI:10.1016/j.soilbio.2019.06.003
UR  - https://juser.fz-juelich.de/record/864342
ER  -