The influence of grazing exclosure on soil C stocks and dynamics, and ecological indicators in upland arid and semi-arid rangelands

2014 ◽  
Vol 41 ◽  
pp. 145-154 ◽  
Author(s):  
Fayez Raiesi ◽  
Maryam Riahi
Keyword(s):  
Ecological Indicators ◽  
Soil C ◽  
C Stocks ◽  
Arid Rangelands ◽  
Semi Arid

Sensitivity of soil organic carbon to grazing management in the semi-arid rangelands of south-eastern Australia

2017 ◽  
Vol 39 (2) ◽  
pp. 153 ◽  
Author(s):  
S. E. Orgill ◽  
C. M. Waters ◽  
G. Melville ◽  
I. Toole ◽  
Y. Alemseged ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Ground Cover ◽  
Grazing Management ◽  
Woody Vegetation ◽  
Soil C ◽  
C Stocks ◽  
Close Proximity ◽  
Arid Rangelands ◽  
Semi Arid

This study compared the effects of grazing management on soil organic carbon (OC) stocks in the semi-arid rangelands of New South Wales, Australia. A field survey was conducted at three locations (Brewarrina, Cobar–North and Cobar–South), with paired sites of long-term (>8 years) rotational grazing management and continuously grazed pastures (either set stocked or no stocking). At each location, soil OC, carbon (C) fractions, soil nitrogen (N) and microsite and site factors (including ground cover and woody vegetation) were measured. The control of total grazing pressure (TGP) through rotational grazing and exclusion fencing did not increase soil C stocks compared with continuous grazing for the majority of comparisons. However, in some parts of the landscape, higher soil C stock was found with TGP control, for example on the ridges (21.6 vs 13.3 t C ha–1 to 0.3 m). C stocks increased with litter and perennial ground cover and with close proximity to trees. At Brewarrina, C stocks were positively affected by perennial plant cover (P < 0.001) and litter (P < 0.05), whereas at Cobar–North and Cobar–South C stocks were positively affected by the presence of trees (P < 0.001), with higher C stocks in close proximity to trees, and with increasing litter cover (P < 0.01). The present study demonstrates that natural resource benefits, such as increased perennial cover, can be achieved through controlling TGP in the rangelands but increases in soil C may be limited in certain parts of the landscape. These findings also highlight that interactions between managed and unmanaged TGP and microsite factors, such as ground cover and proximity to woody vegetation, need to be considered when evaluating the role of changed grazing management on soil C.

scholarly journals Soil Organic Carbon Stocks and Its Driving Factors Under Different Land-Use Patterns in Semiarid Grasslands of the Loess Plateau, China

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Hao Zhang ◽  
Jianping Li ◽  
Yi Zhang ◽  
Yutao Wang ◽  
Juan Zhang ◽  
...  
Keyword(s):  
Land Use ◽  
Arid Areas ◽  
The Loess Plateau ◽  
Soil C ◽  
C Stocks ◽  
C Stock ◽  
Semi Arid ◽  
Grazed Grassland ◽  
Soil C Stock ◽  
Topsoil Layer

Fencing for grazing exclusion and grazing are common land-use methods in the semi-arid areas of the Loess Plateau in China, which have been widely found to change grassland soil organic carbon (SOC); however empirical studies that evaluated driving factors of soil carbon (C) stocks under the different land use are still weak. In this study, we investigated soil physicochemical and soil respiration (Rs) in the fenced and grazed grassland, to study the soil C stock variations and the main driving mechanism of soil C accumulation. The results showed that bulk density (BD), soil moisture content (SMC), and soil porosity (SP) had no significant difference between fenced and grazed grassland. Fencing increased the SOC, total nitrogen (TN), and C/N ratio, and significantly increased the aboveground biomass (AGB), belowground biomass (BGB), and the amount of soil large macro-aggregates in the topsoil layer (0-10 cm), and the soil stability was improved. Meanwhile, grazing increased soil temperature (ST) and Rs. The soil C stock in the topsoil layer (0-10 cm) of fenced grassland was significantly higher than that of grazed grassland. The soil C/N ratio, BD, and MWD explained large proportions of the variations in soil C stocks. Our results indicate that fencing can improve the stability of soil structure, and reduce Rs, then increase soil C stocks, which is an effective way to improve soil C stocks of grassland ecological in semi-arid areas of northwest China.

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.

Chemical composition and in vitro ruminal fermentation of common tree forages in the semi-arid rangelands of Swaziland

2008 ◽  
Vol 142 (1-2) ◽  
pp. 99-110 ◽  
Author(s):  
Solomon Tefera ◽  
V. Mlambo ◽  
B.J. Dlamini ◽  
A.M. Dlamini ◽  
K.D.N. Koralagama ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Ruminal Fermentation ◽  
Arid Rangelands ◽  
Common Tree ◽  
Semi Arid

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.

Adaptive management of stocking rates to reduce effects of drought on cow-calf production systems in semi-arid rangelands

2009 ◽  
Vol 100 (1-3) ◽  
pp. 43-50 ◽  
Author(s):  
H. Díaz-Solís ◽  
W.E. Grant ◽  
M.M. Kothmann ◽  
W.R. Teague ◽  
J.A. Díaz-García
Keyword(s):  
Adaptive Management ◽  
Production Systems ◽  
Arid Rangelands ◽  
Cow Calf ◽  
Effects Of Drought ◽  
Stocking Rates ◽  
Semi Arid

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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