Global gross nitrification rates are dominantly driven by soil carbon‐to‐nitrogen stoichiometry and total nitrogen

2021 ◽  
Author(s):  
Ahmed S. Elrys ◽  
Jing Wang ◽  
Mohamed A. S. Metwally ◽  
Yi Cheng ◽  
Jin‐Bo Zhang ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Total Nitrogen ◽  
Gross Nitrification

Changes in soil chemical and physical properties following legumes and opportunity cropping on a cracking clay soil

1999 ◽  
Vol 39 (4) ◽  
pp. 445 ◽  
Author(s):  
R. D. Armstrong ◽  
B. J. Kuskopf ◽  
G. Millar ◽  
A. M. Whitbread ◽  
J. Standley
Keyword(s):  
Hydraulic Conductivity ◽  
Organic Carbon ◽  
Physical Properties ◽  
Soil Carbon ◽  
Total Nitrogen ◽  
The Other ◽  
Labile Carbon ◽  
Soil Hydraulic Conductivity ◽  
Penetrometer Resistance ◽  
Pasture Legumes

Incorporating legumes into the cropping system has been shown to significantly improve the nitrogen nutrition of cereal crops in Central Queensland. However, little is known about the effect of these legumes on the chemical and physical properties of soil. We examined changes in soil chemical (total nitrogen, organic carbon and pH) and physical (bulk density, cone penetrometer resistance and saturated hydraulic conductivity) properties following either continuous cropping (sorghum or mungbean) or pasture legumes (siratro, lucerne, lablab and desmanthus) over 4 years. Soil carbon was also fractionated using a KMnO4 oxidation procedure which classifies the soil carbon into either labile or non-labile pools. All pasture legumes except desmanthus increased soil total nitrogen in the topsoil (0–10 cm) after only 2 years compared with sorghum. Total nitrogen in the soil did not significantly change under mungbean. Soil organic carbon progressively increased under siratro, desmanthus and sorghum but remained unchanged under the other legumes. Before the experiment, the percentage of total soil carbon classified as labile (oxidised by 333 mmol KMnO4/L) ranged from 14 to 17%. The amount of labile carbon increased by 17% after 3 years of siratro, remained unchanged under desmanthus and sorghum, and decreased under the annual legumes and lucerne. Non-labile carbon remained either unchanged or increased under all legumes, whereas it tended to decrease after 3 consecutive sorghum crops. Soil pH was generally highest under sorghum and lowest under lablab. Soil after sorghum had higher bulk density and penetrometer resistance compared with the effect of legumes but these differences were comparatively small. Saturated hydraulic conductivity of the soil was much higher on the soil surface than at 10 cm. On the surface, soil hydraulic conductivity (saturated) values were generally lower following siratro and higher after sorghum than the other species. At 10 cm depth, soil hydraulic conductivity (saturated) was generally lower in sorghum and, to a lesser extent, in mungbean plots reflecting the significantly lower density of macropores under these crops. It was concluded that although all legumes generally enhanced the chemical and physical properties of the cracking clay, perennial legumes such as siratro would have a greater beneficial effect in the longer term than annual legumes.

Predicting contents of carbon and its component fractions in Australian soils from diffuse reflectance mid-infrared spectra

Soil Research ◽  
2013 ◽  
Vol 51 (8) ◽  
pp. 577 ◽  
Author(s):  
J. A. Baldock ◽  
B. Hawke ◽  
J. Sanderman ◽  
L. M. Macdonald
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Total Nitrogen ◽  
Diffuse Reflectance ◽  
Inorganic Carbon ◽  
Soil Samples ◽  
Mid Infrared ◽  
Organic And Inorganic Carbon ◽  
Mir Spectra

Quantifying the content and composition of soil carbon in the laboratory is time-consuming, requires specialised equipment and is therefore expensive. Rapid, simple and low-cost accurate methods of analysis are required to support current interests in carbon accounting. This study was completed to develop national and state-based models capable of predicting soil carbon content and composition by coupling diffuse reflectance mid-infrared (MIR) spectra with partial least-squares regression (PLSR) analyses. Total, organic and inorganic carbon contents were determined and MIR spectra acquired for 20 495 soil samples collected from 4526 locations from soil depths to 1 m within Australia’s agricultural regions. However, all subsequent MIR/PLSR models were developed using soils only collected from the 0–10, 10–20 and 20–30 cm depth layers. The extent of grinding applied to air-dried soil samples was found to be an important determinant of the variability in acquired MIR spectra. After standardisation of the grinding time, national MIR/PLSR models were developed using an independent test-set validation approach to predict the square-root transformed contents of total, organic and inorganic carbon and total nitrogen. Laboratory fractionation of soil organic carbon into particulate, humus and resistant forms was completed on 312 soil samples. Reliable national MIR/PLSR models were developed using cross-validation to predict the contents of these soil organic carbon fractions; however, further work is required to enhance the representation of soils with significant contents of inorganic carbon. Regional MIR/PLSR models developed for total, organic and inorganic carbon and total nitrogen contents were found to produce more reliable and accurate predictions than the national models. The MIR/PLSR approach offers a more rapid and more cost effective method, relative to traditional laboratory methods, to derive estimates of the content and composition of soil carbon and total nitrogen content provided that the soils are well represented by the calibration samples used to build the predictive models.

scholarly journals Spatial Variability of Soil Organic Carbon and Total Nitrogen in Desert Steppes of China’s Hexi Corridor

2021 ◽  
Vol 9 ◽  
Author(s):  
Xuyang Wang ◽  
Yuqiang Li ◽  
Yulong Duan ◽  
Lilong Wang ◽  
Yayi Niu ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Total Nitrogen ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Elevation Gradient ◽  
Dominant Factor ◽  
Desert Steppe ◽  
Carbon And Nitrogen

Stock estimates are critical to quantifying carbon and nitrogen sequestration, quantifying greenhouse gas emissions, and understanding key biogeochemical processes (i.e., soil carbon and nutrient cycling). Many studies have assessed soil organic matter and nutrients in different ecosystems. However, the spatial distribution of carbon and nitrogen and the key influencing factors in arid desert steppe remain unclear. Here, we investigated the soil organic carbon (SOC) and soil total nitrogen (STN) to a depth of 100 cm at 126 sites in a desert steppe in northwestern China. SOC and STN contents decreased with increasing depth; the highest average SOC and STN contents were 12.70 and 0.65 g kg−1 in the surface 5 cm, and the lowest were from 80 to 100 cm (4.49 and 0.16 g kg−1, respectively). SOC density (SOCD) and STN density (STND) to a depth of 100 cm averaged 8.94 and 0.45 kg m−2, respectively. The top 1 m of the soils stored approximately 1,041 Tg SOC and 52 Tg STN in the study area. Geostatistical analysis showed strong and moderate spatial autocorrelation for SOCD in different soil layers, but the autocorrelation for STND gradually weakened with increasing depth. SOCD and STND decreased from southwest to northeast in the study area, along an elevation gradient. Both were significantly positively correlated with topographic variables, precipitation, and the normalized-difference vegetation index, but negatively correlated with temperature and aridity. More than 40% of the SOCD and STND spatial variation was explained by elevation, which was the dominant factor. The data and high-resolution maps from this study will support future soil carbon and nitrogen analyses.

scholarly journals Soil Carbon and Nitrogen Stock as Affected by Agricultural Wastes in a Typic Haplusult of Owerri, Southeastern Nigeria

2016 ◽  
Vol 4 (7) ◽  
pp. 592
Author(s):  
Stanley Uchenna Onwudike ◽  
Bethel Ugochukwu Uzoho ◽  
Bernadine Ngozi Ndukwu ◽  
Innocent Uzoma Opara ◽  
Ojinere Clitton Anyamele
Keyword(s):  
Organic Carbon ◽  
Soil Carbon ◽  
Total Nitrogen ◽  
Chemical Properties ◽  
Southeastern Nigeria ◽  
Carbon And Nitrogen ◽  
Saw Dust ◽  
Soil Carbon And Nitrogen ◽  
Nitrogen Stock ◽  
Poultry Droppings

We evaluated the effect of saw dust ash (SDA) and poultry droppings (PD) on soil physico-chemical properties, soil carbon and nitrogen stock and their effects on the growth and yield of okra (Abelmoshus esculentus) on a typic haplusult in Owerri, Imo State Southeastern Nigeria. The experiment was a factorial experiment consisted of saw dust ash applied at the rates of 0, 5 and 10 t/ha and poultry droppings applied at the rates of 0, 5 and 10 t/ha. The treatments were laid out in a randomized complete block design and replicated four times. Results showed that plots amended with 10 t/ha PD + 10 t/ha SDA significantly reduced soil bulk density from 1.37 – 1.07 g/cm3, increased soil total porosity from 48.4 – 59.7% and the percentage of soil weight that is water (soil gravimetric moisture content) was increased by 68.4%. There were significant improvements on soil chemical properties with plots amended with 10 t/ha PD + 10 t/ha SDA recording the highest values on soil organic carbon, soil total nitrogen and exchangeable bases. Plots amended with 10 t/ha PD + 10 t/ha SDA significantly increased soil carbon stock by 24% and soil nitrogen stock by 49.5% more than other treatments. There was significant increase in the growth of okra when compared to the un-amended soil with application of 10 t/ha PD + 10 t/ha SDA increasing the fresh okra pod yield by 78.5%. Significant positive correlation existed between SCS and organic carbon (r = 0.6128), exchangeable Mg (r= 0.5035), total nitrogen (r = 0.6167) and soil pH (r = 0.5221). SNS correlated positively with organic carbon (r = 0.5834), total nitrogen (r= 0.6101) and soil pH (r = 5150). Therefore applications of these agro-wastes are effective in improving soil properties, increasing soil carbon and nitrogen stock. From the results of the work, application of 10 t/ha PD + 10 t/ha SDA which was the treatment combination that improved soil properties and growth performances of okra than other treatments studied is hereby recommended for soil carbon and nitrogen stock improvement and okra production in the region.

Which Method Should Be Used to Assess Protein Intake in Peritoneal Dialysis Patients? Assessment of Agreement Between Protein Equivalent of Total Nitrogen Appearance and 24-Hour Dietary Recall

2020 ◽  
Author(s):  
Maryanne Zilli Canedo Silva ◽  
Barbara Perez Vogt ◽  
Nayrana Soares Carmo Reis ◽  
Rogerio Carvalho Oliveira ◽  
Jacqueline Costa Teixeira Caramori
Keyword(s):  
Peritoneal Dialysis ◽  
Total Nitrogen ◽  
Protein Intake ◽  
Dialysis Patients ◽  
Dietary Recall

SAFARI 2000 ORGANIC SOIL CARBON AND NITROGEN DATA (ZINKE ET AL.)

2002 ◽  
Author(s):  
W. R. EMANUEL ◽  
J. S. OLSON ◽  
W. M. POST ◽  
A. G. STANGENBERGER ◽  
P. J. ZINKE
Keyword(s):  
Soil Carbon ◽  
Organic Soil ◽  
Carbon And Nitrogen ◽  
Soil Carbon And Nitrogen

LBA REGIONAL ORGANIC SOIL CARBON AND NITROGEN DATA (ZINKE ET AL.)

2003 ◽  
Author(s):  
W. R. EMANUEL ◽  
J. S. OLSON ◽  
W. M. POST ◽  
A. G. STANGENBERGER ◽  
P. J. ZINKE
Keyword(s):  
Soil Carbon ◽  
Organic Soil ◽  
Carbon And Nitrogen ◽  
Soil Carbon And Nitrogen
Sign in / Sign up

Export Citation Format

Share Document