Effect of leaching and clay content on carbon and nitrogen mineralisation in maize and pasture soils

We conducted a 7-week laboratory incubation experiment to evaluate the effect of leaching on net C and N mineralisation in soils. The soils were collected from adjacent fields of long-term pasture and maize, where each field contained an Inceptisol and an Andisol. The concentration of clay mineral was 200 g/kg halloysite in the Inceptisol and 120 g/kg allophane in the Andisol. Half the samples were leached weekly with 0.002 M CaCl2 at a suction of 20 kPa to remove soluble products, and half were not leached. Carbon mineralisation was determined from CO2-C evolved each week. Net N mineralisation was measured for the leached samples from the NH4-N and NO3-N in the CaCl2 extracts, and for the batch of non-leached samples by extraction in 0.5 M K2SO4. Carbon and net N mineralisation were greater in the soils under pasture than in soils under maize. The proportion of total C mineralised as CO2-C, and of total N mineralised as NH4-N and NO3-N, followed the order Inceptisol-pasture > Inceptisol-maize > Andisol-pasture > Andisol-maize, suggesting that allophane and Al ions reduced net mineralisation. Dissolved organic carbon (DOC) produced during incubation, as a proportion of total C, was greatest for the Inceptisol-maize sample and least for the Andisol-pasture sample. Non-leaching resulted in the accumulation of acids and solutes, and decreased C mineralisation for the Inceptisol samples.

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Distribution and altitudinal patterns of carbon and nitrogen storage in various forest ecosystems in the central Yunnan Plateau, China

Scientific Reports ◽

10.1038/s41598-021-85710-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jianqiang Li ◽

Qibo Chen ◽

Zhuang Li ◽

Bangxiao Peng ◽

Jianlong Zhang ◽

...

Keyword(s):

Forest Ecosystems ◽

Sustainable Forest Management ◽

Carbon And Nitrogen ◽

Pinus Yunnanensis ◽

Yunnan Plateau ◽

Baseline Information ◽

C And N ◽

Quercus Semecarpifolia ◽

Management Policies

AbstractThe carbon (C) pool in forest ecosystems plays a long-term and sustained role in mitigating the impacts of global warming, and the sequestration of C is closely linked to the nitrogen (N) cycle. Accurate estimates C and N storage (SC, SN) of forest can improve our understanding of C and N cycles and help develop sustainable forest management policies in the content of climate change. In this study, the SC and SN of various forest ecosystems dominated respectively by Castanopsis carlesii and Lithocarpus mairei (EB), Pinus yunnanensis (PY), Pinus armandii (PA), Keteleeria evelyniana (KE), and Quercus semecarpifolia (QS) in the central Yunnan Plateau of China, were estimated on the basis of a field inventory to determine the distribution and altitudinal patterns of SC and SN among various forest ecosystems. The results showed that (1) the forest SC ranged from 179.58 ± 20.57 t hm−1 in QS to 365.89 ± 35.03 t hm−1 in EB. Soil, living biomass and litter contributed an average of 64.73%, 31.72% and 2.86% to forest SC, respectively; (2) the forest SN ranged from 4.47 ± 0.94 t ha−1 in PY to 8.91 ± 1.83 t ha−1 in PA. Soil, plants and litter contributed an average of 86.88%, 10.27% and 2.85% to forest SN, respectively; (3) the forest SC and SN decreased apparently with increasing altitude. The result demonstrates that changes in forest types can strongly affect the forest SC and SN. This study provides baseline information for forestland managers regarding forest resource utilization and C management.

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Long-term Carbon and Nitrogen Dynamics at SPRUCE Revealed through Stable Isotopes in Peat Profiles

10.5194/bg-2016-261 ◽

2016 ◽

Author(s):

Erik A. Hobbie ◽

Janet Chen ◽

Paul J. Hanson ◽

Colleen M. Iversen ◽

Karis J. Mcfarlane ◽

...

Keyword(s):

Industrial Revolution ◽

Continuous Variables ◽

Carbon And Nitrogen ◽

Carbon And Nitrogen Dynamics ◽

Aerobic Decomposition ◽

C And N ◽

C And N Cycling ◽

Δ15n And Δ13c ◽

Forested Bog

Abstract. We used δ15N and δ13C patterns from 16 peat depth profiles to interpret changes in C and N cycling in the Marcell S1 forested bog in northern Minnesota over the past ~ 10 000 years. In multiple regression analyses, δ15N and δ13C correlated strongly with depth, plot location, C / N, %N, and each other. Continuous variables in the regression model mainly reflected 13C and 15N fractionation accompanying N and C losses, with an estimated 40 % of fractionations involving C-N bonds. In contrast, nominal variables such as plot, depth, and vegetation cover reflected peatland successional history and climate. Higher δ15N and lower δ13C in plots closer to uplands may reflect distinct hydrology and accompanying shifts in C and N dynamics in the lagg drainage area surrounding the bog. The Suess effect (declining δ13CO2 since the Industrial Revolution) and aerobic decomposition lowered δ13C in recent surficial samples. A decrease of 1 ‰ in the depth coefficient for δ15N from −35 cm to −25 cm probably indicated the depth of ectomycorrhizal activity after tree colonization of the peatland. Low δ13C at −213 cm and −225 cm (~ 8500 years BP) corresponded to a warm period during a sedge-dominated rich fen stage, whereas higher δ13C thereafter reflected subsequent cooling. Because of multiple potential mechanisms influencing δ13C, there was no clear evidence for the influence of methanogenesis or methane oxidation on bulk δ13C.

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Management of sugarcane harvest residues: consequences for soil carbon and nitrogen

Soil Research ◽

10.1071/sr06080 ◽

2007 ◽

Vol 45 (1) ◽

pp. 13 ◽

Cited By ~ 83

Author(s):

Fiona A. Robertson ◽

Peter J. Thorburn

Keyword(s):

Microbial Biomass ◽

Soil Fertility ◽

Microbial Activity ◽

Soil N ◽

Soil Organic C ◽

Total N ◽

Organic C ◽

Soil Microbial ◽

C And N

The Australian sugar industry is moving away from the practice of burning the crop before harvest to a system of green cane trash blanketing (GCTB). Since the residues that would have been lost in the fire are returned to the soil, nutrients and organic matter may be accumulating under trash blanketing. There is a need to know if this is the case, to better manage fertiliser inputs and maintain soil fertility. The objective of this work was to determine whether conversion from a burning to a GCTB trash management system is likely to affect soil fertility in terms of C and N. Indicators of short- and long-term soil C and N cycling were measured in 5 field experiments in contrasting climatic conditions. The effects of GCTB varied among experiments. Experiments that had been running for 1–2 years (Harwood) showed no significant trash management effects. In experiments that had been running for 3–6 years (Mackay and Tully), soil organic C and total N were up to 21% greater under trash blanketing than under burning, to 0.10 or 0.25 m depth (most of this effect being in the top 50 mm). Soil microbial activity (CO2 production) and soil microbial biomass also increased under GCTB, presumably as a consequence of the improved C availability. Most of the trash C was respired by the microbial biomass and lost from the system as CO2. The stimulation of microbial activity in these relatively short-term GCTB systems was not accompanied by increased net mineralisation of soil N, probably because of the greatly increased net immobilisation of N. It was calculated that, with standard fertiliser applications, the entire trash blanket could be decomposed without compromising the supply of N to the crop. Calculations of possible long-term effects of converting from a burnt to a GCTB production system suggested that, at the sites studied, soil organic C could increase by 8–15%, total soil N could increase by 9–24%, and inorganic soil N could increase by 37 kg/ha.year, and that it would take 20–30 years for the soils to approach this new equilibrium. The results suggest that fertiliser N application should not be reduced in the first 6 years after adoption of GCTB, but small reductions may be possible in the longer term (>15 years).

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Soil aggregation according to the dynamics of carbon and nitrogen in soil under different cropping systems

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2016000900065 ◽

2016 ◽

Vol 51 (9) ◽

pp. 1652-1659 ◽

Cited By ~ 2

Author(s):

Getulio de Freitas Seben Junior ◽

José Eduardo Corá ◽

Rattan Lal

Keyword(s):

Cropping Systems ◽

C Sequestration ◽

Pigeon Pea ◽

Soil Aggregation ◽

Total N ◽

Soil C ◽

Carbon And Nitrogen ◽

Physical Fractionation ◽

C Stock ◽

C And N

Abstract The objective of this work was to evaluate total soil carbon and nitrogen, as well as their contents in particulate and mineral-associated C fractions; to determine C stock and sequestration rates in the soil; and to verify the effect of C and N contents on soil aggregation, using different crop rotations and crop sequences under no-tillage. The study was carried out for nine years in a clayey Oxisol. The treatments consisted of different cropping systems formed by the combination of three summer crops (cropped until March) - corn (Zea mays) monocropping, soybean (Glycine max) monocropping, and soybean/corn rotation - and seven second crops (crop successions). Soil samples were taken at the 0.00-0.10-m layer for physical fractionation of C and N, and to determine soil aggregation by the wet method. Soybean monocropping increased C and N in particulate C fraction, while the crop systems with corn monocropping x pigeon pea (Cajanus cajan), corn monocropping x sun hemp (Crotalaria juncea), and soybean monocropping x corn as a crop succession increased total C in the soil. Greater rates of soil C sequestration were observed with soybean/corn rotation and with soybean monocropping, as well as with sun hemp as a second crop. The increase in total N increases soil C stock. Soil aggregation was most affected at particulate C fraction. Increases in soil N promote C addition to particulate fraction and enhance soil aggregation.

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The changes of soil nitrogen and carbon contents in a long-term field experiment under different systems of nitrogen fertilization

Plant Soil and Environment ◽

10.17221/435-pse ◽

2008 ◽

Vol 54 (No. 11) ◽

pp. 463-470 ◽

Cited By ~ 7

Author(s):

V. Nedvěd ◽

J. Balík ◽

J. Černý ◽

M. Kulhánek ◽

M. Balíková

Keyword(s):

Field Experiment ◽

N Fertilization ◽

Hot Water ◽

Control Treatment ◽

Organic N ◽

Total N ◽

C And N ◽

N Compounds ◽

Term Field

Content of N and C in soil were investigated in a long-term field experiment under different systems of N fertilization. Chernozem and Cambisol were extracted using hot water (Nhws, Chws) and 0.01M CaCl2 (NCaCl2, CDOC). The Ct/Nt ratio in Chernozem was 9.6:1 and in Cambisol 6.1:1. The lowest Ct/Nt ratio in both experiments was found in the control treatment. Results showed that C and N compounds are less stable in Cambisol, which leads to a higher rate of mineralization. In the Chernozem, Nhws formed 3.66% from the total N content in the soil whereas NCaCl2 formed only 0.82%. Chws formed 2.98% and CDOC 0.34% from total C content. Cambisol contains 4.81% of Nhws and 0.84% of NCaCl2 from the total N amount and 5.76% of Chws and 0.70% of CDOC from the total C content, respectively. Nitrogen extracted by 0.01M CaCl2 formed only 22.4% of N extractable by hot water in Chernozem and 17.5% in Cambisol. The lowest C/N ratios were obtained after the CaCl2 extraction (3.0–6.2:1). The application of manure increased the content of soil organic N and C compared to the sewage sludge treatments.

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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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Effect of cotton - cowpea intercropping on C and N mineralisation patterns of residue mixtures and soil

Soil Research ◽

10.1071/sr07115 ◽

2009 ◽

Vol 47 (2) ◽

pp. 190 ◽

Cited By ~ 6

Author(s):

L. Rusinamhodzi ◽

H. K. Murwira ◽

J. Nyamangara

Keyword(s):

Rate Constant ◽

Crop Residues ◽

Nutrient Use Efficiency ◽

Field Capacity ◽

C Sequestration ◽

N Mineralisation ◽

N Losses ◽

Mineral N ◽

C Mineralisation ◽

C And N

Carbon and nitrogen mineralisation potential of mixed cotton (Gossypium hirsutum L.) and cowpea (Vigna unguiculata (L.) Walp) crop residues produced under intercropping, as well as a reddish-brown soil classified by FAO as Ferralic Cambisol previously under intercrops, were studied over a 10-week incubation period under controlled conditions (25°C and moisture content of 70% field capacity, 125 mm) in the laboratory. Treatments consisted of cotton residues (100 : 0), cowpea residues (0 : 100), and cotton–cowpea residues (50 : 50, 70 : 30, and 30 : 70). These ratios were based on yields obtained in different cotton–cowpea intercrop treatments from a field study. Cowpea residues (0 : 100) released the highest amount of mineral N of 36.4 mg/kg soil, and cotton residues (100 : 0) least, 19.2 mg/kg soil, while the other mixtures were in between. All treatments except for cowpea residues (0 : 100) and the 30 : 70 mixture showed immobilisation of soil N during the first 2 weeks of incubation. The trend for C mineralisation was similar to that of N, and cowpea residues (0 : 100) released the highest amount, 492 mg C/kg soil, while cotton residues (100 : 0) recorded the least, 315 mg C/kg soil. The C mineralisation patterns of cowpea residues (0 : 100) and 30 : 70 treatments were exponential and were well described by the equation: where CE is exponentially mineralisable C fraction, k is the rate constant, and t is time in days. The mineralisation patterns for other treatments were sigmoidal and were well described by the equation: where CS is sigmoidally mineralisable C fraction; t 0 is time in days required for complete mineralisation of CS , while k is rate constant. The amount of N released from soil previously under cotton–cowpea intercrops and sole crops was approximately one-third of the amount released when the residues were incorporated. The highest amount of N released (12.2 mg/kg soil) was from soil previously under sole cowpea, while soil from the 1 : 1 cotton–cowpea intercrop released 9.9 mg/kg soil and soil from sole cotton released 5.9 mg/kg soil. There was no significant effect (P > 0.05) of previous crop on C mineralisation patterns of the soil. Mixtures slow down N losses and increase nutrient use efficiency of legume residues, especially in the short-term. When cotton is grown as a sole crop, starter N to offset negative effects of initial N-immobilisation at the start of season is required. A better understanding of controlling parameters of decomposition can make it possible to predict C and N mineralisation patterns in mixtures. Reduced C mineralisation in cotton–cowpea mixtures may result in more C sequestration and, hence, SOM build-up and improved sustainability in the long term in intercropping systems.

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Carbon and nitrogen reserves in marandu palisade grass subjected to intensities of continuous stocking management

The Journal of Agricultural Science ◽

10.1017/s0021859614001130 ◽

2014 ◽

Vol 153 (8) ◽

pp. 1449-1463 ◽

Cited By ~ 13

Author(s):

S. C. DA SILVA ◽

L. E. T. PEREIRA ◽

A. F. SBRISSIA ◽

A. HERNANDEZ-GARAY

Keyword(s):

Plant Growth ◽

Leaf Area ◽

Grazing Intensity ◽

Late Spring ◽

Area Index ◽

Total N ◽

Carbon And Nitrogen ◽

Grazing Intensities ◽

C And N ◽

Four Levels

SUMMARYPlant organic reserves and sward leaf area index (LAI) influence plant growth, persistency and herbage accumulation in grazed swards. The present study was conducted to describe patterns of variation in herbage accumulation and carbohydrate and nitrogen (N) reserves in shoot and root of marandu palisade grass subjected to intensities of continuous stocking management throughout the year. Treatments corresponded to four levels of grazing intensity – severe (S), severe/moderate (S/M), moderate (M) and lenient (L) – and were implemented in the field using bands of sward surface height (SSH – 10, 20, 30 and 40 cm ± 10%, respectively) maintained through continuous stocking and variable stocking rate. Total N concentration was higher in the shoot relative to the root compartment during autumn, early and late spring. On the other hand, the concentration of non-structural carbohydrates (NSC) and soluble N was higher in the root compartment, regardless of grazing intensity and season of the year. When taking into account the pool of C and N reserves, the shoot compartment represented the main storage organ, since it corresponded to the largest pool of NSC (averages of 0·102 ± 0·0038 and 0·201 ± 0·0088 kg/m2 for root and shoot, respectively) and soluble N (averages of 2·7 ± 0·26 and 5·3 ± 0·59 kg/m2 for root and shoot, respectively). During late spring, the time of active plant growth, there was a clear contrast in herbage accumulation and sward LAI among grazing intensities, particularly between the severe and lenient grazing treatments. The results show that even with larger pools of soluble N and NSC in the shoot compartment, herbage accumulation was limited by the reduced leaf area of swards subjected to the severe grazing treatment, indicating that under continuous stocking growth seems to be sustained by current assimilates instead of organic reserves. Therefore, targets of grazing management for maximizing herbage accumulation throughout the year should provide adequate combinations between quantity and quality of sward leaf area. This condition was obtained in the severe/moderate and moderate grazing intensities, and corresponded to sward heights between 20 and 30 cm for marandu palisade grass.

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Distribution of Carbon and Nitrogen and Ecological Stoichiometry of the Plant-Litter-Soil Continuum in an Evergreen Broad-Leaved Forest

10.20944/preprints201810.0568.v1 ◽

2018 ◽

Author(s):

Hui Wang ◽

Bing Wang ◽

Xiang Niu ◽

Qingfeng Song ◽

Haonan Bai ◽

...

Keyword(s):

Fine Roots ◽

Ecological Stoichiometry ◽

Soil Depth ◽

Plant Litter ◽

N Content ◽

Total N ◽

Carbon And Nitrogen ◽

Broad Leaved Forest ◽

C And N ◽

Leaved Forest

We analyzed the plant-litter-soil continuum to investigate the carbon and nitrogen distribution and ecological stoichiometry of an evergreen broad-leaved forest at Dagangshan Mountain, Jiangxi. The results showed that the average C and N contents and C:N ratios in the leaves and fine roots among 6 different tree species were 401.87g/kg, 21.41g/kg, 19.27 and 348.64g/kg, 15.73g/kg, 23.97, respectively; the average C and N contents and C:N ratios were 323.06 g/kg, 12.76 g/kg, 25.58 respectively in leaf litter, and 16.40 g/kg, 1.09 g/kg, 16.27 respectively for soil. In contrast with the C content, the total N content of the fine roots and litter had a high coefficient of variation and a high spatial heterogeneity. We ranked the six different representative tree species according to total C and N content in leaves and fine roots. The results for each species were generally consistent with each other, showing a positive correlation relationship between total C and N content in the leaves and roots. Among them, S. discolor (Champ. ex Benth.) Muell. plants displayed high carbon and nitrogen storage capacities, and on the other hand, C. fargesii Franch., C. myrsinifolia (Blume) Oersted, A. fortunei (Hemsl.) Makino, and V. fordii (Hemsl.) Airy Shaw showed a high nitrogen transfer rate. Total soil N and C decreased with depth. Soil organic carbon (SOC), soil resistant organic carbon (ROC), total N, alkali nitrogen, NH4+-N and NO3--N contents were all also negative correlated with soil depth, but the contents of the NH4+-N and NO3--N did not change significantly; The spatial distribution of soil NO3--N was significantly heterogeneous. At 0-10 cm soil depth, SOC was positively correlated with alkaline nitrogen, and at 10-20 cm soil depth, SOC was significantly positively correlated with total N. In general, when soil carbon was abundant, nitrogen supply capacity was also high.

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Long-term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. IX. Simulation of soil carbon and nitrogen pools using CENTURY model

Soil Research ◽

10.1071/sr06105 ◽

2007 ◽

Vol 45 (3) ◽

pp. 206 ◽

Cited By ~ 13

Author(s):

C. R. Chilcott ◽

R. C. Dalal ◽

W. J. Parton ◽

J. O. Carter ◽

A. J. King

Keyword(s):

Organic Matter ◽

Soil Carbon ◽

Continuous Cultivation ◽

Carbon Pools ◽

Century Model ◽

Nitrogen Mineralisation ◽

Carbon And Nitrogen ◽

Soil Carbon And Nitrogen ◽

The Impact

Cultivation and cropping of soils results in a decline in soil organic carbon and soil nitrogen, and can lead to reduced crop yields. The CENTURY model was used to simulate the effects of continuous cultivation and cereal cropping on total soil organic matter (C and N), carbon pools, nitrogen mineralisation, and crop yield from 6 locations in southern Queensland. The model was calibrated for each replicate from the original datasets, allowing comparisons for each replicate rather than site averages. The CENTURY model was able to satisfactorily predict the impact of long-term cultivation and cereal cropping on total organic carbon, but was less successful in simulating the different fractions and nitrogen mineralisation. The model firstly over-predicted the initial (pre-cropping) soil carbon and nitrogen concentration of the sites. To account for the unique shrinking and swelling characteristics of the Vertosol soils, the default annual decomposition rates of the slow and passive carbon pools were doubled, and then the model accurately predicted initial conditions. The ability of the model to predict carbon pool fractions varied, demonstrating the difficulty inherent in predicting the size of these conceptual pools. The strength of the model lies in the ability to closely predict the starting soil organic matter conditions, and the ability to predict the impact of clearing, cultivation, fertiliser application, and continuous cropping on total soil carbon and nitrogen.

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