scholarly journals Biomass and carbon stocks in Schima superba dominated subtropical forests of eastern China

2014 ◽  
Vol 60 (No. 5) ◽  
pp. 198-207 ◽  
Author(s):  
A. Ali ◽  
W.J. Ma ◽  
X.D. Yang ◽  
B.W. Sun ◽  
Q.R. Shi ◽  
...  
Keyword(s):  
Multiple Regression ◽  
Wood Density ◽  
Significant Variation ◽  
Eastern China ◽  
National Forest ◽  
Growth Stages ◽  
Soil C ◽  
Forest Park ◽  
C Stocks ◽  
One Way Anova

Quantitative relationships between stand indices and carbon dioxide (CO<sub>2</sub>) stocking are missing in the evergreen broadleaved forests (EBLFs) in eastern China and this hinders to estimate carbon (C) budget in the subtropical region. We determined the vegetation-soil C pool and CO<sub>2</sub> stocking using stand indices [diameter at breast height (DBH), total height (H) and wood density] in Schima superba dominated EBLFs in the Tiantong National Forest Park in eastern China. Vegetation biomass was determined by a non-destructive method using the tree volume and wood density approach while soil C concentration was determined using the oil bath-K<sub>2</sub>CrO<sub>7</sub> titration method. Finally, multiple regression and one-way ANOVA with LSD test were used for data analysis. Results showed that total C stocks in the vegetation and the 0&ndash;20 cm surface soil were 90.53 t&middot;ha<sup>&ndash;1</sup> and 116.24 t&middot;ha<sup>&ndash;1</sup>, respectively. The study revealed that the total amount of CO<sub>2</sub> stocks in the studied forest is 331.87 t&middot;ha<sup>&ndash;1</sup>. One-way ANOVA with LSD test showed that CO<sub>2</sub> stocks varied significantly (P &lt; 0.05) between the tree growth stages. There was a significant variation in CO<sub>2</sub> stocking capacity within sapling and pole growth stages but no significant variation within standard stage. The stepwise multiple regression analysis showed that DBH, BA and H were related to the C stocking while wood density had no significant effect. The significant amount of C stocking in EBLFs in the Tiantong National Forest Park of eastern China showed the potential and significant C stocks by trees. As the C pool structure changes due to a change in the forest type and location, therefore this study is important to estimate C stocks and predict CO<sub>2</sub> stocks from stand indices in EBLFs which serve as a scientific basis for sustainable forestry operations, rational utilization of forest resources and global warming reduction in EBLFs in subtropical regions of China. &nbsp; &nbsp;

scholarly journals Effects of Organic Fertilizers on the Soil Microorganisms Responsible for N2O Emissions: A Review

2021 ◽  
Vol 9 (5) ◽  
pp. 983
Author(s):  
Cristina Lazcano ◽  
Xia Zhu-Barker ◽  
Charlotte Decock
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Best Management Practices ◽  
Management Practices ◽  
Organic Fertilizers ◽  
N2o Emissions ◽  
Soil C ◽  
Best Management ◽  
C Stocks ◽  
Denitrifying Microorganisms

The use of organic fertilizers constitutes a sustainable strategy to recycle nutrients, increase soil carbon (C) stocks and mitigate climate change. Yet, this depends largely on balance between soil C sequestration and the emissions of the potent greenhouse gas nitrous oxide (N2O). Organic fertilizers strongly influence the microbial processes leading to the release of N2O. The magnitude and pattern of N2O emissions are different from the emissions observed from inorganic fertilizers and difficult to predict, which hinders developing best management practices specific to organic fertilizers. Currently, we lack a comprehensive evaluation of the effects of OFs on the function and structure of the N cycling microbial communities. Focusing on animal manures, here we provide an overview of the effects of these organic fertilizers on the community structure and function of nitrifying and denitrifying microorganisms in upland soils. Unprocessed manure with high moisture, high available nitrogen (N) and C content can shift the structure of the microbial community, increasing the abundance and activity of nitrifying and denitrifying microorganisms. Processed manure, such as digestate, compost, vermicompost and biochar, can also stimulate nitrifying and denitrifying microorganisms, although the effects on the soil microbial community structure are different, and N2O emissions are comparatively lower than raw manure. We propose a framework of best management practices to minimize the negative environmental impacts of organic fertilizers and maximize their benefits in improving soil health and sustaining food production systems. Long-term application of composted manure and the buildup of soil C stocks may contribute to N retention as microbial or stabilized organic N in the soil while increasing the abundance of denitrifying microorganisms and thus reduce the emissions of N2O by favoring the completion of denitrification to produce dinitrogen gas. Future research using multi-omics approaches can be used to establish key biochemical pathways and microbial taxa responsible for N2O production under organic fertilization.

Carbon stocks in Tasmanian soils

Soil Research ◽  
2012 ◽  
Vol 50 (2) ◽  
pp. 83 ◽  
Author(s):  
W. E. Cotching
Keyword(s):  
Management Practices ◽  
Agricultural Soils ◽  
C Sequestration ◽  
Mean Annual Temperature ◽  
Soil C ◽  
C Stocks ◽  
Initial Soil ◽  
If Current ◽  
Intensive Cropping ◽  
The Difference

Soil carbon (C) stocks were calculated for Tasmanian soil orders to 0.3 and 1.0 m depth from existing datasets. Tasmanian soils have C stocks of 49–117 Mg C/ha in the upper 0.3 m, with Ferrosols having the largest soil C stocks. Mean soil C stocks in agricultural soils were significantly lower under intensive cropping than under irrigated pasture. The range in soil C within soil orders indicates that it is critical to determine initial soil C stocks at individual sites and farms for C accounting and trading purposes, because the initial soil C content will determine if current or changed management practices are likely to result in soil C sequestration or emission. The distribution of C within the profile was significantly different between agricultural and forested land, with agricultural soils having two-thirds of their soil C in the upper 0.3 m, compared with half for forested soils. The difference in this proportion between agricultural and forested land was largest in Dermosols (0.72 v. 0.47). The total amount of soil C in a soil to 1.0 m depth may not change with a change in land use, but the distribution can and any change in soil C deeper in the profile might affect how soil C can be managed for sequestration. Tasmanian soil C stocks are significantly greater than those in mainland states of Australia, reflecting the lower mean annual temperature and higher precipitation in Tasmania, which result in less oxidation of soil organic matter.

scholarly journals Systematic Review of Dairy Processing Sludge and Secondary STRUBIAS Products Used in Agriculture

2021 ◽  
Vol 5 ◽  
Author(s):  
Yihuai Hu ◽  
Olha Khomenko ◽  
Wenxuan Shi ◽  
Ángel Velasco-Sánchez ◽  
S. M. Ashekuzzaman ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Systematic Review ◽  
Hydrothermal Carbonization ◽  
Processing Plant ◽  
The European Union ◽  
Soil C ◽  
Concept System ◽  
Dairy Processing ◽  
C Stocks ◽  
Dairy Processing Sludge

Worldwide dairy processing plants produce high volumes of dairy processing sludge (DPS), which can be converted into secondary derivatives such as struvite, biochar and ash (collectively termed STRUBIAS). All of these products have high fertilizer equivalent values (FEV), but future certification as phosphorus (P)-fertilizers in the European Union will mean they need to adhere to new technical regulations for fertilizing materials i.e., content limits pertaining to heavy metals (Cd, Cu, Hg, Ni, Pb, and Zn), synthetic organic compounds and pathogens. This systematic review presents the current state of knowledge about these bio-based fertilizers and identifies knowledge gaps. In addition, a review and calculation of greenhouse gas emissions from a range of concept dairy sludge management and production systems for STRUBIAS products [i.e., biochar from pyrolysis and hydrochar from hydrothermal carbonization (HTC)] is presented. Results from the initial review showed that DPS composition depends on product type and treatment processes at a given processing plant, which leads to varied nutrient, heavy metal and carbon contents. These products are all typically high in nutrients and carbon, but low in heavy metals. Further work needs to concentrate on examining their pathogenic microorganism and emerging contaminant contents, in addition to conducting an economic assessment of production and end-user costs related to chemical fertilizer equivalents. With respect to STRUBIAS products, contaminants not present in the raw DPS may need further treatment before being land applied in agriculture e.g., heated producing ashes, hydrochar, or biochar. An examination of these products from an environmental perspective shows that their water quality footprint could be minimized using application rates based on P incorporation of these products into nutrient management planning and application by incorporation into the soil. Results from the concept system showed that elimination of methane emissions was possible, along with a reduction in nitrous oxide. Less carbon (C) is transferred to agricultural fields where DPS is processed into biochar and hydrochar, but due to high recalcitrance, the C in this form is retained much longer in the soil, and therefore STRUBIAS products represent a more stable and long-term option to increase soil C stocks and sequestration.

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