scholarly journals Soil organic carbon and land use: Processes and potential in Ontario’s long-term agro-ecosystem research sites

2014 ◽  
Vol 94 (3) ◽  
pp. 317-336 ◽  
Author(s):  
Katelyn A. Congreves ◽  
Jillian M. Smith ◽  
Deanna D. Németh ◽  
David C. Hooker ◽  
Laura L. Van Eerd

Congreves, K. A., Smith, J. M., Németh, D. D., Hooker, D. C. and Van Eerd, L. L. 2014. Soil organic carbon and land use: Processes and potential in Ontario’s long-term agro-ecosystem research sites. Can. J. Soil Sci. 94: 317–336. Soil organic carbon (SOC) is crucial for maintaining a productive agro-ecosystem. Long-term research must be synthesized to understand the effects of land management on SOC storage and to develop best practices to prevent soil degradation. Therefore, this review compiled an inventory of long-term Ontario studies and assessed SOC storage under common Ontario land management regimes via a meta-analysis and literature review. In general, greater SOC storage occurred in no-till (NT) vs. tillage systems, in crop rotation vs. continuous corn, and in N fertilizer vs. no N fertilizer systems; however, soil texture and perhaps drainage class may determine the effects of tillage. The effect on SOC storage was variable when deeper soil depth ranges (0–45 cm) were considered for NT and rotational cropping, which suggests an unpredictable effect of land management on SOC at depths below the plough layer. Therefore, researchers are encouraged to use the presented inventory of nine long-term research sites and 18 active experiments in Ontario to pursue coordinated studies of long-term land management on SOC at depths extending below the plough layer.

2014 ◽  
pp. 140519062003007
Author(s):  
Katelyn A. Congreves ◽  
Jilian M Smith ◽  
Deanna D Németh ◽  
David Hooker ◽  
Laura L. Van Eerd

2014 ◽  
Vol 10 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Abebe Shiferaw ◽  
Christian Hergarten ◽  
Tibebu Kassawmar ◽  
Gete Zeleke

Agriculture ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 181 ◽  
Author(s):  
Deb Aryal ◽  
Danilo Morales Ruiz ◽  
César Tondopó Marroquín ◽  
René Pinto Ruiz ◽  
Francisco Guevara Hernández ◽  
...  

Land use change from forests to grazing lands is one of the important sources of greenhouse gas emissions in many parts of the tropics. The objective of this study was to analyze the extent of soil organic carbon (SOC) loss from the conversion of native forests to pasturelands in Mexico. We analyzed 66 sets of published research data with simultaneous measurements of soil organic carbon stocks between native forests and pasturelands in Mexico. We used a generalized linear mixed effect model to evaluate the effect of land use change (forest versus pasture), soil depth, and original native forest types. The model showed that there was a significant reduction in SOC stocks due to the conversion of native forests to pasturelands. The median loss of SOC ranged from 31.6% to 52.0% depending upon the soil depth. The highest loss was observed in tropical mangrove forests followed by highland tropical forests and humid tropical forests. Higher loss was detected in upper soil horizon (0–30 cm) compared to deeper horizons. The emissions of CO2 from SOC loss ranged from 46.7 to 165.5 Mg CO2 eq. ha−1 depending upon the type of original native forests. In this paper, we also discuss the effect that agroforestry practices such as silvopastoral arrangements and other management practices like rotational grazing, soil erosion control, and soil nutrient management can have in enhancing SOC stocks in tropical grasslands. The results on the degree of carbon loss can have strong implications in adopting appropriate management decisions that recover or retain carbon stocks in biomass and soils of tropical livestock production systems.


2014 ◽  
Vol 14 (2) ◽  
pp. 103-108 ◽  
Author(s):  
S Bhandari ◽  
S Bam

The study was carried out in Chovar village of Kritipur Municipality, Kathmandu to compare the soil organic carbon (SOC) of three main land use types namely forest, agricultural and barren land and to show how land use and management are among the most important determinants of SOC stock. Stratified random sampling method was used for collecting soil samples. Walkley and Black method was applied for measuring SOC. Land use and soil depth both affected SOC stock significantly. Forest soil had higher SOC stock (98 t ha-1) as compared to agricultural land with 36.6 t ha-1 and barren land with 83.6 t ha-1. Similarly, the SOC in terms of CO22-1, 79.27 to 22.02 CO2-e ha-1 and 121.11 to 80.74 CO2-1 for 0- 20 cm to 40-60 cm soil depth, respectively. Bulk density (BD) was found less in forest soil compared to other lands at all depths, which showed negative correlation with SOC. The study showed a dire need to increase current soil C stocks which can be achieved through improvements in land use and management practices, particularly through conservation and restoration of degraded forests and soils.   DOI: http://dx.doi.org/10.3126/njst.v14i2.10422   Nepal Journal of Science and Technology Vol. 14, No. 2 (2013) 103-108


2020 ◽  
Author(s):  
Dedy Antony ◽  
Jo Clark ◽  
Chris Collins ◽  
Tom Sizmur

<p>Soils are the largest terrestrial pool of organic carbon and it is now known that as much as 50% of soil organic carbon (SOC) can be stored below 30 cm. Therefore, knowledge of the mechanisms by which soil organic carbon is stabilised at depth and how land use affects this is important.</p><p>This study aimed to characterise topsoil and subsoil SOC and other soil properties under different land uses to determine the SOC stabilisation mechanisms and the degree to which SOC is vulnerable to decomposition. Samples were collected under three different land uses: arable, grassland and deciduous woodland on a silty-clay loam soil and analysed for TOC, pH, C/N ratio and texture down the first one metre of the soil profile. Soil organic matter (SOM) physical fractionation and the extent of fresh mineral surfaces were also analysed to elucidate SOM stabilisation processes.</p><p>Results showed that soil texture was similar among land uses and tended to become more fine down the soil profile, but pH did not significantly change with soil depth. Total C, total N and C/N ratio decreased down the soil profile and were affected by land use in the order woodland > grassland > arable. SOM fractionation revealed that the free particulate organic matter (fPOM) fraction was significantly greater in both the topsoil and subsoil under woodland than under grassland or arable. The mineral associated OC (MinOC) fraction was proportionally greater in the subsoil compared to topsoil under all land uses: arable > grassland > woodland. Clay, Fe and Mn availability play a significant role (R<sup>2</sup>=0.87) in organic carbon storage in the top 1 m of the soil profile.</p><p>It is evidently clear from the findings that land use change has a significant effect on the dynamics of the SOC pool at depth, related to litter inputs to the system.</p>


Soil Research ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 41 ◽  
Author(s):  
Guo-Ce Xu ◽  
Zhan-Bin Li ◽  
Peng Li ◽  
Ke-Xin Lu ◽  
Yun Wang

Soil organic carbon (SOC) plays an important role in maintaining and improving soil fertility and quality, in addition to mitigating climate change. Understanding SOC spatial variability is fundamental for describing soil resources and predicting SOC. In this study, SOC content and SOC mass were estimated based on a soil survey of a small watershed in the Dan River, China. The spatial heterogeneity of SOC distribution and the impacts of land-use types, elevation, slope, and aspect on SOC were also assessed. Field sampling was carried out based on a 100 m by 100 m grid system overlaid on the topographic map of the study area, and samples were collected in three soil layers to a depth of 40 cm. In total, 222 sites were sampled and 629 soil samples were collected. The results showed that classical kriging could successfully interpolate SOC content in the watershed. Contents of SOC showed strong spatial heterogeneity based on the values of the coefficient of variation and the nugget ratio, and this was attributed largely to the type of land use. The range of the semi-variograms increased with increasing soil depth. The SOC content in the soil profile decreased as soil depth increased, and there were significant (P < 0.01) differences among the three soil layers. Land use had a great impact on the SOC content. ANOVA indicated that the spatial variation of SOC contents under different land use types was significant (P < 0.05). The SOC mass of different land-use types followed the order grassland > forestland > cropland. Mean SOC masses of grassland, forestland, and cropland at a depth of 0–40 cm were 5.87, 5.61, and 5.07 kg m–2, respectively. The spatial variation of SOC masses under different land-use types was significant (P < 0.05). ANOVA also showed significant (P < 0.05) impact of aspect on SOC mass in soil at 0–40 cm. Soil bulk density played an important role in the assessment of SOC mass. In conclusion, carbon in soils in the source area of the middle Dan River would increase with conversion from agricultural land to forest or grassland.


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