Changes in the soil C and N contents, C decomposition and N mineralization potentials in a rice paddy after long-term application of inorganic fertilizers and organic matter

Abstract. Soil organic matter (SOM) inputs, increased precipitation and clipping (reducing belowground photosynthates allocation) are predicted to affect soil C and N cycling in temperate grassland ecosystems. However, the interactive effects between SOM inputs (or increased precipitation) and clipping on soil C and N mineralization in temperate steppes are still poorly understood. A field manipulation experiment was conducted to quantify the effects of SOM inputs, increased precipitation, clipping and their interactions on soil C and N mineralization in a temperate steppe of northeastern China from 2010 to 2011. The results showed that SOM inputs significantly increased soil C mineralization rate (CMR) and net N mineralization rate (NMR). Increased precipitation-induced enhancement of soil CMR essentially ceased after the first year, stimulation of soil NMR and NNR continued into the second year. However, clipping only marginally decreased soil CMR and NMR during the two years. There were significant synergistic interactions between SOM inputs (or increased precipitation) and clipping on soil CMR and NMR, as SOM inputs (or increased precipitation) showed greater effects on soil CMR and NMR under clipped plots than under unclipped plots, which could be explained by the relative shifts in soil microbial community structure because of bacterial biomass increases, and by the relative decreases in arbuscular mycorrhizal fungi biomass due to the reduction of belowground photosynthates allocation. These results highlight the importance of plants in mediating the responses of soil C and N mineralization to potentially increased SOM and precipitation by controlling belowground photosynthates allocation in the temperate steppe. Thus, the findings have important implications for improving prediction of C and N sequestration potential and its feedbacks to climate change in temperate steppe ecosystems.

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Simulation of protozoa-induced mineralization of bacterial carbon and nitrogen

Canadian Journal of Soil Science ◽

10.4141/cjss92-020 ◽

1992 ◽

Vol 72 (3) ◽

pp. 201-216 ◽

Cited By ~ 17

Author(s):

P. M. Rutherford ◽

N. G. Juma

Keyword(s):

N Mineralization ◽

Ecological Research ◽

Clay Loam ◽

Glucose Addition ◽

Soil C ◽

Carbon And Nitrogen ◽

Soil C And N ◽

C And N ◽

Typic Cryoboroll ◽

Bacterial C

Modelling in soil ecological research is a means of linking the dynamics of microbial and faunal populations to soil processes. The objectives of this study were (i) to simulate bacterial-protozoan interactions and flows of C and N in clay loam Orthic Black Chernozemic soil under laboratory condtions; and (ii) to quantify the flux of C and N (inputs and outputs) through various pools using the simulation model. The unique features of this model are: (i) it combines the food chain with specific soil C and N pools, and (ii) it simultaneously traces the flows of C, 14C, N and 15N. It was possible to produce a model that fitted the data observed for the soil. The simulated CO2-C evolved during the first 12 d was due mainly to glucose addition (171 μg C g−1 soil) and cycling of C in the soil (160 μg C g−1 soil). During this interval, bacterial C uptake was 5.5-fold greater than the initial bacterial C pool size. In the first 12 d protozoa directly increased total CO2-C evolution by 11% and increased NH4-N mineralization 3-fold, compared to soil containing only bacteria. Mineralization of C and N was rapid when bacterial numbers were increased as a result of glucose addition. Key words: Acanthamoeba sp., modelling, N mineralization-immobilization, organic matter, Pseudomonas sp., Typic Cryoboroll

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Linking Cover Crop Residue Quality and Tillage System to CO2-C Emission, Soil C and N Stocks and Crop Yield Based on a Long-Term Experiment

Agronomy ◽

10.3390/agronomy10121848 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1848

Author(s):

Otávio A. Leal ◽

Telmo J. C. Amado ◽

Jackson E. Fiorin ◽

Cristiano Keller ◽

Geovane B. Reimche ◽

...

Keyword(s):

Crop Yield ◽

Cover Crops ◽

No Tillage ◽

Yield Data ◽

Soil C ◽

Term Experiment ◽

Long Term Experiment ◽

Soil C And N ◽

C And N

Cover crops (CC), particularly legumes, are key to promote soil carbon (C) sequestration in no-tillage. Nevertheless, the mechanisms regulating this process need further elucidation within a broad comprehensive framework. Therefore, we investigated effects of CC quality: black oat (Avena strigosa Schreb) (oat), common vetch (Vicia sativa L.) (vetch), and oat + vetch on carbon dioxide-C (CO2-C) emission (124 days) under conventional- (CT), minimum- (MT) and no-tillage (NT) plots from a long-term experiment in Southern Brazil. Half-life time (t1/2) of CC residues and the apparent C balance (ACB) were obtained for CT and NT. We linked our data to long-term (22 years) soil C and nitrogen (N) stocks and crop yield data of our experimental field. Compared to CT, NT increased t1/2 of oat, oat + vetch and vetch by 3.9-, 3.1- and 3-fold, respectively; reduced CO2-C emissions in oat, oat + vetch and vetch by 500, 600 and 642 kg ha−1, respectively; and increased the ACB (influx) in oat + vetch (195%) and vetch (207%). For vetch, CO2-C emission in MT was 77% greater than NT. Legume CC should be preferentially combined with NT to reduce CO2-C emissions and avoid a flush of N into the soil. The legume based-NT system showed the greatest soil C and N sequestration rates, which were significantly and positively related to soybean (Glycine max (L.) Merrill) and maize (Zea mays L.) yield. Soil C (0–90 cm depth) and N (0–100 cm depth) sequestration increments of 1 kg ha−1 corresponded to soybean yield increments of 1.2 and 7.4 kg ha−1, respectively.

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Management effects on the dynamics and storage rates of organic matter in long-term crop rotations

Canadian Journal of Soil Science ◽

10.4141/s03-022 ◽

2004 ◽

Vol 84 (1) ◽

pp. 49-61 ◽

Cited By ~ 16

Author(s):

E. A. Paul ◽

H. P. Collins ◽

K. Paustian ◽

E. T. Elliott ◽

S. Frey ◽

...

Keyword(s):

Organic Matter ◽

C Sequestration ◽

Organic C ◽

Soil C ◽

Site Analysis ◽

Laboratory Incubation ◽

C And N ◽

A Site ◽

Management Effects

Factors controlling soil organic matter (SOM) dynamics in soil C sequestration and N fertility were determined from multi-site analysis of long-term, crop rotation experiments in Western Canada. Analyses included bulk density, organic and inorganic C and N, particulate organic C (POM-C) and N (POM -N), and CO2-C evolved during laboratory incubation. The POM-C and POM-N contents varied with soil type. Differences in POM-C contents between treatments at a site (δPOM-C) were related (r2= 0.68) to treatment differences in soil C (δSOC). The CO2-C, evolved during laboratory incubation, was the most sensitive indicator of management effects. The Gray Luvisol (Breton, AB) cultivated plots had a fivefold difference in CO2-C release relative to a twofold difference in soil organic carbon (SOC). Soils from cropped, Black Chernozems (Melfort and Indian Head, SK) and Dark Brown Chernozems (Lethbridge, AB) released 50 to 60% as much CO2-C as grassland soils. Differences in CO2 evolution from the treatment with the lowest SOM on a site and that of other treatments (δCO2-C) in the early stages of the incubation were correlated to δPOM-C and this pool reflects short-term SOC storage. Management for soil fertility, such as N release, may differ from management for C sequestration. Key words: Multi-site analysis, soil management, soil C and N, POM-C and N, CO2 evolution

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Trade-offs between the short- and long-term effects of residue quality on soil C and N dynamics

Plant and Soil ◽

10.1007/s11104-010-0360-z ◽

2010 ◽

Vol 338 (1-2) ◽

pp. 159-169 ◽

Cited By ~ 36

Author(s):

Roberta Gentile ◽

Bernard Vanlauwe ◽

Pauline Chivenge ◽

Johan Six

Keyword(s):

Residue Quality ◽

Long Term Effects ◽

N Dynamics ◽

Soil C ◽

Trade Offs ◽

Short And Long Term ◽

Soil C And N ◽

C And N ◽

C And N Dynamics

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Effet à long terme d'apports d'engrais minéraux et de fumier sur les teneurs en C et en N des fractions densimétriques et des agrégats du loam limoneux Le Bras

Canadian Journal of Soil Science ◽

10.4141/s96-020 ◽

1997 ◽

Vol 77 (3) ◽

pp. 351-358 ◽

Cited By ~ 12

Author(s):

A. N'Dayegamiye ◽

M. Goulet ◽

M. R. Laverdière

Keyword(s):

N Mineralization ◽

Size Fraction ◽

Aggregate Size ◽

Mineral Fertilizer ◽

Microbial Biomass N ◽

Organic Residues ◽

Soil C ◽

Size Fractions ◽

C And N

Long-term mineral fertilizer applications could reduce organic matter (OM) levels in soil if coupled with crop rotations with low organic residues inputs. The main objective of this study was to evaluate the C and N contents in whole soil, in densimetric OM fractions and in different aggregate size fractions of a Le Bras silt loam (Humic Gleysol). The treatments were arranged in a split-plot design, with dairy cattle manure applied at 0 and 20 Mgha−1 as the main factor. The subplots consisted of six fertilizer treatments (NK, PK, NP, NPK, NPKMg and the unfertilized check). The four year rotation included silage corn, (Zea mays L.) silage corn, wheat (Triticum Aestivum L.) and barley (Hordeum vulgaris L.). Contrary to mineral fertilizer, long-term manure applications significantly increased the C content in whole soil and also in the light and heavy fractions of OM (Fl and Fd). Mineral fertilizer significantly increased the C and N contents only in Fl. Moreover, manure application also increased the weight of the 5–8 mm aggregate size fraction and the C and N content in the 5–8 mm, 2–5 mm, 1–2 mm and 0,25–1 mm aggregate size fractions, compared to mineral fertilizer alone. In manured plots, soil C biomass, microbial respiration (CO2) and N mineralization (NO3) levels increased by 30% compared with mineral fertilizer treatments. Results of this study demonstrate the important effect of manure applications on C and N enrichment in soil and also on soil macroaggregation and biological activity. To maintain optimal C and N levels in soil and to favour soil macroaggregation, long-term mineral fertilizer application should be combined with crops in rotations which ensure high organic residues returns to soils. Key words: Macroaggregation, microbial biomass, N mineralization, long-term, light fraction, heavy fraction

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Long-term dynamics of soil C and N in intensive rice-based cropping systems of the Indo-Gangetic Plains (IGP): A modelling approach

Ecological Modelling ◽

10.1016/j.ecolmodel.2012.02.020 ◽

2012 ◽

Vol 232 ◽

pp. 40-63 ◽

Cited By ~ 2

Author(s):

M.E. Shibu ◽

H. Van Keulen ◽

P.A. Leffelaar

Keyword(s):

Cropping Systems ◽

Gangetic Plains ◽

Soil C ◽

Soil C And N ◽

C And N ◽

Modelling Approach

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Mineralisation of organic matter in intact versus sieved/refilled soil cores

Soil Research ◽

10.1071/sr01003 ◽

2002 ◽

Vol 40 (1) ◽

pp. 149 ◽

Cited By ~ 15

Author(s):

R. Stenger ◽

G. F. Barkle ◽

C. P. Burgess

Keyword(s):

Organic Matter ◽

N Mineralisation ◽

Soil Cores ◽

Nitrogen Mineralisation ◽

Soil C ◽

Soil Microbial ◽

Conditioning Period ◽

Incubation Study ◽

Soil C And N ◽

C And N

In a 6-month laboratory incubation study, we compared the net C and N mineralisation of the soil organic matter (SOM) of 3 pasture soils and the mineralisation of glucose-C in intact versus sieved/refilled soil cores. The main questions were whether the net C and N mineralisation differed between intact and sieved/refilled soil cores after a conditioning period of 4 weeks, and how much the C and N mineralisation of SOM differed among the similarly managed pasture soils. Apart from the net nitrogen mineralisation in one soil, there were no significant differences in cumulated mineralisation of C or N from SOM between the core types. In a fine-textured soil, net mineralisation of glucose-C differed significantly between core types, which was attributed to the different distribution of the amended glucose in intact and sieved/refilled cores. Net C and N mineralisation of SOM were closely correlated in the sieved/refilled cores, whereas no significant correlation was found in the intact cores. Expressing net C and N mineralisation as percentages of total soil C and N showed a more than 2-fold maximum difference between the soils in spite of similar long-term organic matter input. Subsequent studies should be done using more replicates and wider diameter, better controllable cores on ceramic plates. CO2, net nitrogen mineralisation (NNM), soil microbial biomass.

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