Effects of temperature and processing conditions on biochar chemical properties and their influence on soil C and N transformations

Abstract. Rice production is increasingly challenged by irrigation water scarcity, however covering paddy rice soils with films (ground cover rice production system: GCRPS) can significantly reduce water demand as well as overcome temperature limitations at the beginning of the vegetation period resulting in increased grain yields in colder regions of rice production with seasonal water shortages. It has been speculated that the increased soil aeration and temperature under GCRPS may result in losses of soil organic carbon and nitrogen stocks. Here we report on a regional scale experiment, conducted by sampling paired adjacent Paddy and GCRPS fields at 49 representative sites in the Shiyan region, which is typical for many mountainous areas across China. Parameters evaluated included soil C and N stocks, soil physical and chemical properties, potential carbon mineralization rates, fractions of soil organic carbon and stable carbon isotopic composition of plant leaves. Furthermore, root biomass was quantified at maximum tillering stage at one of our paired sites. Against expectations the study showed that: (1) GCRPS significantly increased soil organic C and N stocks 5–20 years following conversion of production systems, (2) there were no differences between GCRPS and Paddy in soil physical and chemical properties for the various soil depths with the exception of soil bulk density, (3) GCRPS had lower mineralization potential for soil organic C compared with Paddy over the incubation period, (4) GCRPS showed lower δ15N in the soils and plant leafs indicating less NH3 volatilization in GCRPS than in Paddy; and (5) GCRPS increased yields and root biomass in all soil layers down to 40 cm depth. Our results suggest that GCRPS is an innovative rice production technique that not only increases yields using less irrigation water, but that it also is environmentally beneficial due to increased soil C and N stocks at regional scale.

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Response of soil C and N transformations to tannin fractions originating from Scots pine and Norway spruce needles

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2005.10.013 ◽

2006 ◽

Vol 38 (6) ◽

pp. 1364-1374 ◽

Cited By ~ 51

Author(s):

Sanna Kanerva ◽

Veikko Kitunen ◽

Oili Kiikkilä ◽

Jyrki Loponen ◽

Aino Smolander

Keyword(s):

Norway Spruce ◽

Scots Pine ◽

N Transformations ◽

Soil C ◽

Soil C And N ◽

C And N ◽

Spruce Needles

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SOIL C AND N AS INDICATORS OF VINEYARD SOIL QUALITY IN THE RAVNI KOTARI REGION OF CROATIA

10.1130/abs/2020se-345231 ◽

2020 ◽

Author(s):

Sonia C. Clemens ◽

◽

Mia Brkljaca ◽

Delaina Pearson ◽

C. Brannon Andersen

Keyword(s):

Soil Quality ◽

Soil C ◽

Vineyard Soil ◽

Soil C And N ◽

C And N

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Spatially Related Sampling Uncertainty in the Assessment of Labile Soil Carbon and Nitrogen in an Irish Forest Plantation

Applied Sciences ◽

10.3390/app11052139 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2139

Author(s):

Junliang Zou ◽

Bruce Osborne

Keyword(s):

Spatial Variability ◽

Soil Carbon ◽

Sampling Effort ◽

Limited Information ◽

Sampling Area ◽

Soil C ◽

Distribution Maps ◽

Soil C And N ◽

C And N ◽

Highly Correlated

The importance of labile soil carbon (C) and nitrogen (N) in soil biogeochemical processes is now well recognized. However, the quantification of labile soil C and N in soils and the assessment of their contribution to ecosystem C and N budgets is often constrained by limited information on spatial variability. To address this, we examined spatial variability in dissolved organic carbon (DOC) and dissolved total nitrogen (DTN) in a Sitka spruce forest in central Ireland. The results showed moderate variations in the concentrations of DOC and DTN based on the mean, minimum, and maximum, as well as the coefficients of variation. Residual values of DOC and DTN were shown to have moderate spatial autocorrelations, and the nugget sill ratios were 0.09% and 0.10%, respectively. Distribution maps revealed that both DOC and DTN concentrations in the study area decreased from the southeast. The variability of both DOC and DTN increased as the sampling area expanded and could be well parameterized as a power function of the sampling area. The cokriging technique performed better than the ordinary kriging for predictions of DOC and DTN, which are highly correlated. This study provides a statistically based assessment of spatial variations in DOC and DTN and identifies the sampling effort required for their accurate quantification, leading to improved assessments of forest ecosystem C and N budgets.

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Impacts of irrigation on soil C and N stocks in grazed grasslands depends on aridity and irrigation duration

Geoderma ◽

10.1016/j.geoderma.2021.115109 ◽

2021 ◽

Vol 399 ◽

pp. 115109

Author(s):

Paul L. Mudge ◽

Jamie Millar ◽

Jack Pronger ◽

Alesha Roulston ◽

Veronica Penny ◽

...

Keyword(s):

Soil C ◽

Soil C And N ◽

C And N

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C and N urban soil budget and its spatial differentiation in comparison with natural areas in the Wroclaw region of Poland

E3S Web of Conferences ◽

10.1051/e3sconf/20184500085 ◽

2018 ◽

Vol 45 ◽

pp. 00085

Author(s):

Izabela Sówka ◽

Yaroslav Bezyk ◽

Maxim Dorodnikov

Keyword(s):

Urban Soil ◽

Spatial Differentiation ◽

Clay Content ◽

Dry Mass ◽

Microbial Biomass C ◽

Natural Areas ◽

Soil C ◽

Soil C And N ◽

C And N ◽

Natural Grassland

An assessment of C and N balance in urban soil compared to the natural environment was carried out to evaluate the influence of biological processes along with human-induced forcing. Soil C and N stocks were quantified on the samples (n=18) collected at 5 - 10 cm depth from dominated green areas and arable lands in the city of Wroclaw (Poland) and the relatively natural grassland located ca. 36 km south-west. Higher soil carbon and nitrogen levels (C/N ratio = 11.8) and greater microbial biomass C and N values (MBC = 95.3, MBN = 14.4 mg N kg-1) were measured in natural grassland compared with the citywide lawn sites (C/N ratio = 15.17, MBC = 84.3 mg C kg-1, MBN = 11.9 mg N kg-1), respectively. In contrast to the natural areas, the higher C and N concentration was measured in urban grass dominated soils (C = 2.7 % and N = 0.18 % of dry mass), which can be explained mainly due to the high soil bulk density and water holding capacity (13.8 % clay content). The limited availability of soil C and N content was seen under the arable soil (C = 1.23 %, N = 0.13 %) than in the studied grasslands. In fact, the significantly increased C/N ratios in urban grasslands are largely associated with land conversion and demonstrate that urban soils have the potential to be an important reservoir of C.

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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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