Effects of apple branch biochar on soil C mineralization and nutrient cycling under two levels of N

In Taiwan, farmers often apply excess compost to ensure adequate crop yield in highly frequent tillage, highly weathered, and lower fertility soils. The potential of biochar (BC) for diminishing soil C mineralization, and improving soil nutrient availability in compost over-fertilized soil is promising, but the study is still under-examined. To test the hypothesis, 434 days in vitro C mineralization kinetics of incubation experiment were conducted. Woody BC 0%, 0.5%, 1.0% and 2.0% (w/w) made of lead tree (Leucaena leucocephala (Lam.) de. Wit) were added to an Oxisols, and two Inceptisols of Taiwan. In each treatment, 5% swine manure compost (2 times recommended amount) was added and served as the over-fertilized soil. The results indicated that soil type strongly influenced the impact of BC addition on soil carbon mineralization potential. Respiration per unit of total organic carbon (total mineralization coefficient, TMC) of three studied soils significantly decreased with BC addition increased. Principal component analysis (PCA) suggested that for retaining more plant nutrients in addition to the effects of carbon sequestration, it is recommended that farmer could use locally produced biochars and composts in highly weathered and highly frequent tillage soil. Adding 0.5%-1% woody BC in soil should be reasonable and appropriate.

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How does simulated climate change affect the susceptibility of SOM to priming by LMWOS in the Subarctic?

10.5194/egusphere-egu21-10220 ◽

2021 ◽

Author(s):

Meng Na ◽

Mingyue Yuan ◽

Lettice Hicks ◽

Johannes Rousk

Keyword(s):

Climate Change ◽

Plant Communities ◽

N Mineralization ◽

Fungal Growth ◽

N Fertilization ◽

C Mineralization ◽

Soil C ◽

Gross N Mineralization ◽

Simulated Climate ◽

Simulated Climate Change

Soil organic matter (SOM) stabilization plays an important role in the long-term storage of carbon (C). However, many ecosystems are undergoing climate change, which will change the soil C balance via altered plant communities and productivity that change C inputs, and altered C losses via changes in SOM decomposition. The ongoing change of aboveground plant communities in the Subarctic (&#8220;greening&#8221;) will increase rhizosphere inputs containing low molecular weight organic substances (LMWOS), which will likely affect C-starved microbial decomposers and their subsequent contribution to SOM mineralization (priming effect).In the present study, we simulated the effects of climate change with N fertilization (simulating warming enhanced nutrient cycling) and litter additions (simulating arctic greening) in Abisko, Sweden. The 6 sampled field-treatments included a full factorial combination of 3-years of chronic N addition and litter additions, as well as, a single year of extreme climate change (3x N fertilizer or litter additions in one growth season). We found that N treatments changed plant community composition and productivityand that the associated shift in belowground LMWOS induced shifts in the soil microbial community. In the chronic N fertilization treatments, plant productivity, and therefore belowground LMWOS input, increased. This coincided with a tendency for more bacterial dominated decomposition (lower fungi/bacterial growth ratio). However, N treatments had no effect on soil C mineralization, but increased gross N mineralization.These responses in belowground communities and processes driven by rhizosphere input prompted the next question: how does simulated climate change affect the susceptibility of SOM to priming by LMWOS? To assess this question and determine the microbial mechanisms underpinning priming of SOM mineralization, we added a factorial set of additions including 13C-glucose with and without mineral N, and 13C-alanine semi-continuously (every 48 hours) to simulate the effect of rhizosphere LMWOS on SOM mineralization and microbial activity. We incubated these samples for 2 weeks and assessed the priming of soil C and gross N mineralization, bacterial and fungal growth rates, PLFAs, enzyme activities, and microbial C use efficiency (CUE). We found that alanine addition primed soil C mineralization by 34%, which was higher than soil C priming induced by glucose and glucose with N. Furthermore, glucose primed fungal growth, whereas the alanine primed bacterial growth, but microbial PLFAs did not respond to either treatment. The C enzyme acquisition activity was higher than N enzyme acquisition activity in all the treatments, while P enzyme acquisition activity was higher than C for all the treatments. Surprisingly, this suggested a chronic microbial limitation by P, which was unaffected by field and lab treatments. LMWOS additions generally reduced microbial CUE. Responses of microbial mineralization of N from SOM to LMWOS suggested a directed microbial effort towards targeting resources that limited bacterial or fungal growth, suggesting that microbial SOM-use shifted to N-rich components (selective microbial &#8220;N-mining&#8221;), in contrast with enzyme results. Surprisingly, alanine primed the highest N mineralization compared other additions indicating that there was strong N-mining even if N was sufficient.

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The C:N:P Stoichiometry of Planted and Natural Larix principis-rupprechtii Stands along Altitudinal Gradients on the Loess Plateau, China

Forests ◽

10.3390/f11040363 ◽

2020 ◽

Vol 11 (4) ◽

pp. 363

Author(s):

Fujing Bo ◽

Yunxiang Zhang ◽

Han Y. H. Chen ◽

Pingan Wang ◽

Xuming Ren ◽

...

Keyword(s):

Nutrient Cycling ◽

Natural Forests ◽

Resorption Efficiency ◽

The Loess Plateau ◽

Planted Forests ◽

C:N:P Stoichiometry ◽

Soil C ◽

Nitrogen Resorption ◽

N:P Ratios ◽

Nitrogen Resorption Efficiency

Carbon:nitrogen:phosphorus (C:N:P) stoichiometry plays a critical role in nutrient cycling, biodiversity, and ecosystem functionality. However, our understanding of the responses of C:N:P stoichiometry to elevation and forest management remains elusive. Here we sampled 18 Larix principis-rupprechtii sites along altitudinal gradients (1700-2300 m) on Guandishan Mountain in the Loess Plateau, China. We determined the leaf, litter, and soil C N P contents and C:N:P stoichiometric ratios, as well as nutrient resorption efficiency (NuRE), and diameter at breast height (DBH) increments in both planted and natural stands, and then tested the impacts of elevation and stand origin on these parameters’ management. We found different C:N:P stoichiometry between natural and planted forests. The results revealed that: soil C, N, and N:P ratios, litter C:P and N:P ratios, leaf C:N and N:P ratios increased significantly; however, soil C:N ratios, litter P, leaf N and P, nitrogen resorption efficiency (NRE), and DBH increments decreased significantly with elevation in the planted forests. Soil C,N and N:P ratios, litter C, as well as C:N and C:P ratios increased significantly with elevation in natural forests. The soil N, P and N:P ratios, litter C:P and N:P ratios, leaf C, C:P and N:P ratios, nitrogen resorption efficiency (NRE), phosphorus resorption efficiency (PRE), and DBH increments were, on average, higher in the planted, rather than natural forests. Our results indicated that there was an enhancing P-limitation in both the planted and natural forests, and the plantations were more restricted by P. Moreover, compared to natural forests, plantations converged toward a higher conservative N- and P-use strategy by enhancing resorption efficiencies of internal nutrient cycling and a higher annual growth rate.

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Potential Indicators of Soil Health Degradation in Different Land Use-Based Ecosystems in the Shiwaliks of Northwestern India

Sustainability ◽

10.3390/su11143908 ◽

2019 ◽

Vol 11 (14) ◽

pp. 3908 ◽

Cited By ~ 5

Author(s):

Arnab Bhowmik ◽

Surinder Singh Kukal ◽

Debasish Saha ◽

Harmandeep Sharma ◽

Anu Kalia ◽

...

Keyword(s):

Land Use ◽

Nutrient Cycling ◽

Land Degradation ◽

Soil Health ◽

Health Indicators ◽

Soil Microflora ◽

Enzymatic Activities ◽

Soil Biology ◽

Soil C ◽

Land Use Systems

Identifying the importance of soil biology in different land use systems is critical to assess the present conditions of declining soil (C) and global land degradation while regulating soil health and biogeochemical nutrient cycling. A study was undertaken in a mixed watershed comprising of different land use systems (agricultural, grassland, agroforestry, and eroded); situated in the Shiwalik region in the foot hills of the lower Himalayas in India, a fragile ecosystem susceptible to land degradation. Soil samples from 0–15 and 15–30 cm depths were collected from these land use systems and analyzed for a suite of different soil health indicators, including physio-chemical soil properties, aggregate stability, soil microflora, and the enzymatic activities that are critical for nutrient cycling. Principal component analysis was used to group different land uses and understand their association with soil microflora, enzyme activities, and soil physio-chemical properties. We found that a greater number of soil microflora and enzymatic activities were associated with grassland and agroforestry land use systems. Aggregate-associated soil C correlated well with the soil microflora under different land use systems studied. The biplots revealed that the fungal:bacterial ratio (2 × 103–0.1 × 103) was a robust indicator of C accumulation and soil health, and was in greater association with the agroforestry land use system. Random forest, a non-parametric statistical test, on average explained that 68% to 92% of the variability in soil microbial population was due to land use and other soil health properties. Overall, the biological soil health indicators used in this study demonstrated the fact that land use management systems that employ constant crop cover with minimal disturbance have the potential to improve soil sustainability and ecological functioning.

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Effect of enclosure on soil C mineralization and priming effect inStipa grandisgrassland of Inner Mongolia

Acta Ecologica Sinica ◽

10.5846/stxb201210061373 ◽

2013 ◽

Vol 33 (12) ◽

pp. 3622-3629

Author(s):

王若梦 WANG Ruomeng ◽

董宽虎 DONG Kuanhu ◽

何念鹏 HE Nianpeng ◽

朱剑兴 ZHU Jianxing ◽

代景忠 DAI Jingzhong ◽

...

Keyword(s):

Inner Mongolia ◽

Priming Effect ◽

C Mineralization ◽

Soil C

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Decomposition of carbon adsorbed on iron (III)-treated clays and their effect on the stability of soil organic carbon and external carbon inputs

Biogeochemistry ◽

10.1007/s10533-021-00873-w ◽

2021 ◽

Author(s):

Mengyang You ◽

Xia Zhu-Barker ◽

Timothy A. Doane ◽

William R. Horwath

Keyword(s):

Organic Carbon ◽

Layer Structure ◽

Mineral Soil ◽

Clay Mineralogy ◽

Plant Residue ◽

C Mineralization ◽

Organic C ◽

Soil C ◽

Native Soil ◽

The Stability

AbstractThe interaction of organic carbon (OC) with clay and metals stabilizes soil carbon (C), but the influence of specific clay-metal-OC assemblages (flocs) needs further evaluation. This study aimed to investigate the stability of flocs in soil as affected by external C inputs. Flocs representing OC-mineral soil fractions were synthesized using dissolved organic C (DOC) combined with kaolinite (1:1 layer structure) or montmorillonite (2:1 layer structure) clays in the absence or presence of two levels of Fe (III) (named low or high Fe). Flocs were mixed with soil (classified as Luvisol) and incubated with or without 13C labelled plant residue (i.e., ryegrass) for 30 days. The CO2 emissions and DOC concentrations as well as their 13C signatures from all treatments were examined. Total C mineralization from flocs was approximately 70% lower than non-flocced DOC. The flocs made with montmorillonite had 16–43% lower C mineralization rate than those made with kaolinite with no Fe or low Fe. However, when flocs were made with high Fe, clay mineralogy did not significantly affect total C mineralization. A positive priming effect (PE) of flocs on native soil OC was observed in all treatments, with a stronger PE found in lower Fe treatments. The high-Fe clay flocs inhibited ryegrass decomposition, while the flocs made without clay had no impact on it. Interestingly, flocs significantly decreased the PE of ryegrass on native soil OC decomposition. These results indicate that the adsorption of DOC onto clay minerals in the presence of Fe (III) stabilizes it against decomposition processes and its stability increases as Fe in flocs increases. Flocs also protect soil OC from the PE of external degradable plant C input. This study showed that Fe level and clay mineralogy play an important role in controlling soil C stability.

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Intracellular Storage Reduces Stoichiometric Imbalances in Soil Microbial Biomass – A Theoretical Exploration

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.714134 ◽

2021 ◽

Vol 9 ◽

Author(s):

Stefano Manzoni ◽

Yang Ding ◽

Charles Warren ◽

Callum C. Banfield ◽

Michaela A. Dippold ◽

...

Keyword(s):

Microbial Biomass ◽

Nutrient Cycling ◽

Theoretical Perspective ◽

Nutrient Retention ◽

Model Parameters ◽

Soil C ◽

Soil Microbial ◽

Pulse Experiment ◽

Intracellular Storage

Microbial intracellular storage is key to defining microbial resource use strategies and could contribute to carbon (C) and nutrient cycling. However, little attention has been devoted to the role of intracellular storage in soil processes, in particular from a theoretical perspective. Here we fill this gap by integrating intracellular storage dynamics into a microbially explicit soil C and nutrient cycling model. Two ecologically relevant modes of storage are considered: reserve storage, in which elements are routed to a storage compartment in proportion to their uptake rate, and surplus storage, in which elements in excess of microbial stoichiometric requirements are stored and limiting elements are remobilized from storage to fuel growth and microbial maintenance. Our aim is to explore with this model how these different storage modes affect the retention of C and nutrients in active microbial biomass under idealized conditions mimicking a substrate pulse experiment. As a case study, we describe C and phosphorus (P) dynamics using literature data to estimate model parameters. Both storage modes enhance the retention of elements in microbial biomass, but the surplus storage mode is more effective to selectively store or remobilize C and nutrients according to microbial needs. Enhancement of microbial growth by both storage modes is largest when the substrate C:nutrient ratio is high (causing nutrient limitation after substrate addition) and the amount of added substrate is large. Moreover, storage increases biomass nutrient retention and growth more effectively when resources are supplied in a few large pulses compared to several smaller pulses (mimicking a nearly constant supply), which suggests storage to be particularly relevant in highly dynamic soil microhabitats. Overall, our results indicate that storage dynamics are most important under conditions of strong stoichiometric imbalance and may be of high ecological relevance in soil environments experiencing large variations in C and nutrient supply.

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The effect of moisture and temperature on soil C mineralization in wetland and steppe of the Zoige region, China

Acta Ecologica Sinica ◽

10.5846/stxb201302030230 ◽

2013 ◽

Vol 33 (20) ◽

pp. 6436-6443 ◽

Cited By ~ 2

Author(s):

王丹 WANG Dan ◽

吕瑜良 LV Yuliang ◽

徐丽 XU Li ◽

张洪轩 ZHANG Hongxuan ◽

王若梦 WANG Ruomeng ◽

...

Keyword(s):

C Mineralization ◽

Soil C ◽

Effect Of Moisture

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Long-term C-CO2 emissions and carbon crop residue mineralization in an oxisol under different tillage and crop rotation systems

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832011000300017 ◽

2011 ◽

Vol 35 (3) ◽

pp. 819-832 ◽

Cited By ~ 10

Author(s):

Ben-Hur Costa de Campos ◽

Telmo Jorge Carneiro Amado ◽

Carlos Gustavo Tornquist ◽

Rodrigo da Silveira Nicoloso ◽

Jackson Ernani Fiorin

Keyword(s):

Co2 Emissions ◽

Crop Rotation ◽

Crop Residue ◽

Crop Residues ◽

Cropping Systems ◽

Co2 Efflux ◽

C Mineralization ◽

Tillage Systems ◽

Soil C

Soil C-CO2 emissions are sensitive indicators of management system impacts on soil organic matter (SOM). The main soil C-CO2 sources at the soil-plant interface are the decomposition of crop residues, SOM turnover, and respiration of roots and soil biota. The objectives of this study were to evaluate the impacts of tillage and cropping systems on long-term soil C-CO2 emissions and their relationship with carbon (C) mineralization of crop residues. A long-term experiment was conducted in a Red Oxisol in Cruz Alta, RS, Brazil, with subtropical climate Cfa (Köppen classification), mean annual precipitation of 1,774 mm and mean annual temperature of 19.2 ºC. Treatments consisted of two tillage systems: (a) conventional tillage (CT) and (b) no tillage (NT) in combination with three cropping systems: (a) R0- monoculture system (soybean/wheat), (b) R1- winter crop rotation (soybean/wheat/soybean/black oat), and (c) R2- intensive crop rotation (soybean/ black oat/soybean/black oat + common vetch/maize/oilseed radish/wheat). The soil C-CO2 efflux was measured every 14 days for two years (48 measurements), by trapping the CO2 in an alkaline solution. The soil gravimetric moisture in the 0-0.05 m layer was determined concomitantly with the C-CO2 efflux measurements. The crop residue C mineralization was evaluated with the mesh-bag method, with sampling 14, 28, 56, 84, 112, and 140 days after the beginning of the evaluation period for C measurements. Four C conservation indexes were used to assess the relation between C-CO2 efflux and soil C stock and its compartments. The crop residue C mineralization fit an exponential model in time. For black oat, wheat and maize residues, C mineralization was higher in CT than NT, while for soybean it was similar. Soil moisture was higher in NT than CT, mainly in the second year of evaluation. There was no difference in tillage systems for annual average C-CO2 emissions, but in some individual evaluations, differences between tillage systems were noticed for C-CO2 evolution. Soil C-CO2 effluxes followed a bi-modal pattern, with peaks in October/November and February/March. The highest emission was recorded in the summer and the lowest in the winter. The C-CO2 effluxes were weakly correlated to air temperature and not correlated to soil moisture. Based on the soil C conservation indexes investigated, NT associated to intensive crop rotation was more C conserving than CT with monoculture.

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