Effects of long-term fertilizer treatments on CH4 fluxes and key functional microorganisms in a double-cropping paddy field

Abstract Soil organic matter (SOM) and its fractions play an important role in maintaining or improving soil quality and soil fertility. Therefore, the effects of a 34-year long-term fertilizer regime on six functional SOM fractions under a double-cropping rice paddy field of southern China were studied in the current paper. The field experiment included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM) and without fertilizer input as control (CK). The results showed that coarse unprotected particulate organic matter (cPOM), biochemically, physically–biochemically and chemically protected silt-sized fractions (NH-dSilt, NH-μSilt and H-dSilt) were the main carbon (C) storage fractions under long-term fertilization conditions, accounting for 16.7–26.5, 31.1–35.6, 16.2–17.3 and 7.5–8.2% of the total soil organic carbon (SOC) content in paddy soil, respectively. Compared with control, OM treatment increased the SOC content in the cPOM, fine unprotected POM fraction, pure physically protected fraction and physico-chemically protected fractions by 58.9, 106.7, 117.6 and 28.3%, respectively. The largest proportion of SOC to total SOC in the different fractions was biochemically protected, followed by chemically and unprotected, and physically protected were the smallest. These results suggested that a physical protection mechanism plays an important role in stabilizing C of paddy soil. In summary, the results showed that higher functional SOM fractions and physical protection mechanism play an important role in SOM cycling in terms of C sequestration under the double-cropping rice paddy field.

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Effect of different long-term fertilizer managements on soil nitrogen fixing bacteria community in a double-cropping rice paddy field of southern China

PLoS ONE ◽

10.1371/journal.pone.0256754 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0256754

Author(s):

Haiming Tang ◽

Chao Li ◽

Lihong Shi ◽

Xiaoping Xiao ◽

Kaikai Cheng ◽

...

Keyword(s):

Paddy Field ◽

Rice Paddy ◽

Soil Microorganism ◽

Organic Manure ◽

Chemical Fertilizer ◽

N Fixation ◽

Soil N ◽

Rice Paddy Field ◽

Double Cropping

Soil microorganism plays an important role in nitrogen (N) fixation process of paddy field, but the related information about how soil microorganism that drive N fixation process response to change of soil phy-chemical characteristics under the double-cropping rice (Oryza sativa L.) paddy field in southern of China is need to further study. Therefore, the impacts of 34-years different long-term fertilization system on soil N-fixing bacteria community under the double-cropping rice paddy field in southern of China were investigated by taken chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method in this paper. The field experiment were set up four different fertilizer treatments: chemical fertilizer alone (MF), rice straw and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM), and unfertilized as a control (CK). This results showed that compared with CK treatment, the diversity index of cbbLR and nifH genes with OM and RF treatments were significantly increased (p<0.05), respectively. Meanwhile, the abundance of cbbLR gene with OM, RF and MF treatments were increased by 23.94, 12.19 and 6.70×107 copies g-1 compared to CK treatment, respectively. Compared with CK treatment, the abundance of nifH gene with OM, RF and MF treatments were increased by 23.90, 8.82 and 5.40×109 copies g-1, respectively. This results indicated that compared with CK treatment, the soil autotrophic azotobacter and nitrogenase activities with OM and RF treatments were also significantly increased (p<0.05), respectively. There were an obvious difference in features of soil N-fixing bacteria community between application of inorganic fertilizer and organic manure treatments. Therefore, this results demonstrated that abundance of soil N-fixing bacteria community in the double-cropping rice paddy field were increased by long-term applied with organic manure and crop residue managements.

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Effects of long‐term fertilizer management on soil bacterial diversity in double‐cropping paddy field of southern China

Agronomy Journal ◽

10.1002/agj2.20302 ◽

2020 ◽

Vol 112 (5) ◽

pp. 3644-3652

Author(s):

Haiming Tang ◽

Yilan Xu ◽

Chao Li ◽

Xiaoping Xiao ◽

Kaikai Cheng ◽

...

Keyword(s):

Bacterial Diversity ◽

Paddy Field ◽

Southern China ◽

Fertilizer Management ◽

Soil Bacterial Diversity ◽

Double Cropping ◽

Soil Bacterial

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Effects of long-term fertilizer practice on fungal and actinobacterial cellulolytic communities with different humified particle-size fractions in a double-cropping paddy field

10.21203/rs.3.rs-227248/v1 ◽

2021 ◽

Author(s):

Haiming Tang ◽

Chao Li ◽

Yilan Xu ◽

Kaikai Cheng ◽

Lihong Shi ◽

...

Keyword(s):

Particle Size ◽

Paddy Field ◽

Crop Residue ◽

Organic Manure ◽

Chemical Fertilizer ◽

Magic Angle ◽

Size Fractions ◽

Particle Size Fractions ◽

Double Cropping

Abstract Cellulose plays an important role in maintaining or improving soil carbon (C) cycling and soil fertility. And there has closely relationship between functional cellulose genes (cbhI and GH48) with characterize of soil organic matter chemical components (fulvic acid and humic acid) and soil physical fractions. However, there is still limited information on how functional cellulose degradation responded to long-term fertilizer management and their relative importance for C sequestration under double-cropping rice paddy field in southern China. Therefore, the effects of 34-year long-term fertilizer regime on community abundance of cbhI and GH48 in five soil particle-size fractions were investigated by using polarization magic angle spinning 13C nuclear magnetic resonance spectroscopy. The field experiment consisted of four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM), and without fertilizer input as control (CK). The results showed that distribution of soil humus and cellulolytic microbial community abundance were significantly increased under long-term application of crop residue and organic manure condition. And the FA, HA and HM C contents in >2000 μm and 2000-50 μm fractions with MF, RF and OM treatments were significantly higher than that of CK treatment. Meanwhile, the alkyl C and Oalkyl C groups of FA in >2000 μm and 2000-50 μm fractions were higher than that of the other fractions, the order of relative abundance of different C groups of HA in different particle-size fractions were following alkyl C>o-alkyl C>aromatic C>carboxylic C with MF, RF, OM and CK treatments. The results indicated that abundance of cbhI and GH48 genes in different particle-size fractions were significantly increased with RF and OM treatments, compared with CK treatment. There were significantly positive correlation between chemical composition of FA and HA with cbhI and GH48 abundances. As a result, the cellulolytic gene abundance were significantly increased under combined application of crop residue and organic manure with chemical fertilizer condition.

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Effects of fertilizer practice on fungal and actinobacterial cellulolytic community with different humified particle-size fractions in double-cropping field

Scientific Reports ◽

10.1038/s41598-021-97975-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Haiming Tang ◽

Chao Li ◽

Yilan Xu ◽

Kaikai Cheng ◽

Lihong Shi ◽

...

Keyword(s):

Particle Size ◽

Paddy Field ◽

Crop Residue ◽

Organic Manure ◽

Chemical Fertilizer ◽

Soil Humus ◽

Size Fractions ◽

Particle Size Fractions ◽

Double Cropping

AbstractCellulose plays an important role in maintaining or improving soil carbon (C) cycling and soil fertility of paddy field. There had close relationship between functional cellulose genes (cbhI and GH48) with characterize of soil organic matter chemical components (fulvic acid and humic acid) and soil physical fractions. However, there is still limited information about how functional cellulose degradation response to long-term fertilizer management and their relative importance for C sequestration under the double-cropping rice paddy field in southern of China. Therefore, the objective of this study were investigated the effects of 34-years long-term fertilizer regime on community abundance of cbhI and GH48 genes in five soil particle-size fractions (> 2000 μm, 2000–200 μm, 200–50 μm, 50–2 μm and 2–0.1 μm) by using polarization magic angle spinning 13C nuclear magnetic resonance spectroscopy. The field experiment was included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM), and without fertilizer input as a control (CK). The results showed that distribution of soil humus and cellulolytic microbial community abundance was significant increased under long-term application of crop residue and organic manure condition. And the FA, HA and HM C contents in > 2000 μm and 2000–50 μm fractions with MF, RF and OM treatments were significant higher than that of CK treatment. Meanwhile, the alkyl C and Oalkyl C groups of FA and HA in > 2000 μm fraction with MF, RF, OM and CK treatments were higher than that of the other fractions. There had higher AL% and lower ARO% of FA and HA in different particle-size fractions with MF, RF, OM and CK treatments. The results indicated that abundance of cbhI and GH48 genes in different particle-size fractions with RF and OM treatments were significant increased, compared with CK treatment. There had significant positive correlation between soil humus C components (FA and HA) with abundance of cbhI and GH48 genes, and the o-alkyl C and AL% of FA were positively correlated with abundance of cbhI and GH48 genes. As a result, the community abundance of cbhI and GH48 genes were significant increased under combined application of crop residue and organic manure with chemical fertilizer condition.

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