Increases in organic carbon concentration and stock after clay addition to sands: validation of sampling methodology and effects of modification method

Soil Research ◽  
2017 ◽  
Vol 55 (2) ◽  
pp. 124 ◽  
Author(s):  
Amanda Schapel ◽  
David Davenport ◽  
Petra Marschner
Keyword(s):  
Organic Carbon ◽  
Plant Growth ◽  
Bulk Density ◽  
Density Measurement ◽  
South Australia ◽  
Low Fertility ◽  
Clay Modification ◽  
Organic Carbon Concentration ◽  
Modification Method ◽  
Water Repellence

Plant growth on sands is often constrained by water repellence, low fertility and low water-holding capacity (WHC). These soils also have low organic carbon (OC) concentration, particularly in a bleached A2 horizon. Addition of subsoil clay to sands (clay modification) can overcome these constraints and increase WHC; however, little is known about the effect on OC concentration. Clay addition is predicted to increase OC storage via increased OC input from improved plant growth and increased stabilisation of OC by binding to clays. The objectives of this study were (i) to validate the number of soil samples required within a 25-m grid for accurate OC and bulk density measurement in clay-modified soils and (ii) to determine OC concentration, bulk density and OC stocks in clay-modified compared with unmodified soil. The study was carried out on two agricultural properties in South Australia, where unmodified controls (sands with 1–3% clay) were compared with three methods of modification using clay (clay spread, delved and spaded). Soil cores to 50cm depth were collected after harvest within a 25-m grid. The study showed that clay modification could increase OC stocks (0–30cm) by up to 14tha–1 in the South East and 22tha–1 in the Eyre Peninsula. However, the magnitude of the OC stock increase was influenced by the modification method and depended on concentration and depth of incorporation of the added clay and organic matter.

Soil nitrogen availability in the cereal zone of South Australia .1. Soil organic carbon, total nitrogen, and nitrogen mineralisation rates

Soil Research ◽  
1996 ◽  
Vol 34 (6) ◽  
pp. 937 ◽  
Author(s):  
ZH Xu ◽  
JN Ladd ◽  
DE Elliott
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Bulk Density ◽  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
South Australia ◽  
N Availability ◽  
N Mineralisation ◽  
Soil Nitrogen Availability ◽  
Total N

Assessments of soil nitrogen (N) availability were undertaken using soils sampled at 0-10 and 10-20 cm depths from 123 experimental sites where the responses of cereal crops to N fertilisers were tested, throughout the cereal zone of South Australia. Rates of N mineralisation and percentage N mineralisation, as determined by a laboratory aerobic incubation method, were related to soil properties. Mineralisable N (N mineralised during a Li-week incubation) of 0-10 cm soil varied from 14 to 121 kg N/ha with a median of 50 kg N/ha, and that of 10-20 cm soil, from 5 to 42 kg N/ha (median 19 kg N/ha). Mineralisable N in 0-10 cm soil accounted for 90% of total mineralisable N in 0-20 cm soil. The percentages of N mineralised were generally higher in 0-10 cm soil (0.8-12.5%, median 3.4%) than in 10-20 cm soil (0.4-8.3%, median 2.3%). Soil organic carbon (OC) and total N could be well estimated from each other, and fron! soil pH, bulk density, and held capacity, with coefficients of determination (R2) ranging from 0.64 to 0.78. Overall, either mineralisable N or percentage N mineralisation rate in the surface soils could be well estimated from soil OC, total N, C to N ratio, bulk density, field capacity, and pH (R2, 0.78-0.86 for mineralisable N, and 0.67-0.91 for percentage N mineralisation rate).

Variation in organic-carbon concentration and bulk density in Flemish grassland soils

2006 ◽  
Vol 169 (5) ◽  
pp. 616-622 ◽  
Author(s):  
Inge Mestdagh ◽  
Peter Lootens ◽  
Oswald Van Cleemput ◽  
Lucien Carlier
Keyword(s):  
Organic Carbon ◽  
Bulk Density ◽  
Carbon Concentration ◽  
Grassland Soils ◽  
Organic Carbon Concentration

scholarly journals The Effect of Fulvic Acids Derived from Different Materials on Changing Properties of Albic Black Soil in the Northeast Plain of China

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1535 ◽  
Author(s):  
Mahendar Kumar Sootahar ◽  
Xibai Zeng ◽  
Shiming Su ◽  
Yanan Wang ◽  
Lingyu Bai ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Plant Growth ◽  
Fulvic Acid ◽  
Crop Production ◽  
Fulvic Acids ◽  
Black Soil ◽  
Low Fertility ◽  
Liquid Form ◽  
Available N ◽  
Positive Effects

Despite low fertility and content of organic carbon in albic black soil, grains are grown in this type of soil in the northeast plain of China in order to find ways to improve the soil’s fertility and crop production. We carried out pot experiments of maize applied with one of three different treatments of fulvic acids (FA) derived from different parent materials: Plant-derived solid (PDSF), mineral-derived liquid (MDLF), and plant-derived liquid (PDLF) applied at respective rates of 2.5, 5, and 5 g kg−1 as well as a control applied at 0 g kg−1. The results showed that soil organic carbon and light fraction C was greater by 29% to 21% and 38% to 21%, respectively, among the treatments compared to that of the control. Similarly, available N content was significantly greater in the PDLF treatment, and P content was also significantly greater in the PDSF treatment. In contrast, available K and extractable Mg contents were lower, as well as organic–inorganic degree complexes and organic–inorganic composites in the PDSF, MDLF, and PDLF treatments compared with those of the control. Further results showed that MDLF and PDLF Fulvic acids (FA) accelerated plant growth, while PDSF limited plant growth. Our study provides empirical evidence that addition of fulvic acid from MDLF and PDLF had more positive effects on soil properties and plant growth than fulvic acid from PDSF. This investigation suggests that application of fulvic acid in liquid form can improve nutrient availability and affect other important chemical, biological, and physical properties of soils.

The Carbon:²³⁴Thorium ratios of sinking particles in the California Current Ecosystem 2: Examination of a thorium sorption, desorption, and particle transport model

2019 ◽  
Author(s):  
Michael Stukel ◽  
Thomas Kelly
Keyword(s):  
Organic Carbon ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Transport Model ◽  
California Current ◽  
In Situ Measurements ◽  
Power Law Distribution ◽  
Sinking Particles ◽  
Organic Carbon Concentration

Thorium-234 (234Th) is a powerful tracer of particle dynamics and the biological pump in the surface ocean; however, variability in carbon:thorium ratios of sinking particles adds substantial uncertainty to estimates of organic carbon export. We coupled a mechanistic thorium sorption and desorption model to a one-dimensional particle sinking model that uses realistic particle settling velocity spectra. The model generates estimates of 238U-234Th disequilibrium, particulate organic carbon concentration, and the C:234Th ratio of sinking particles, which are then compared to in situ measurements from quasi-Lagrangian studies conducted on six cruises in the California Current Ecosystem. Broad patterns observed in in situ measurements, including decreasing C:234Th ratios with depth and a strong correlation between sinking C:234Th and the ratio of vertically-integrated particulate organic carbon (POC) to vertically-integrated total water column 234Th, were accurately recovered by models assuming either a power law distribution of sinking speeds or a double log normal distribution of sinking speeds. Simulations suggested that the observed decrease in C:234Th with depth may be driven by preferential remineralization of carbon by particle-attached microbes. However, an alternate model structure featuring complete consumption and/or disaggregation of particles by mesozooplankton (e.g. no preferential remineralization of carbon) was also able to simulate decreasing C:234Th with depth (although the decrease was weaker), driven by 234Th adsorption onto slowly sinking particles. Model results also suggest that during bloom decays C:234Th ratios of sinking particles should be higher than expected (based on contemporaneous water column POC), because high settling velocities minimize carbon remineralization during sinking.

Growth of Container-grown Plants With and Without Azomite Soil Amendment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 492c-492
Author(s):  
Chris Ely ◽  
Mark A. Hubbard
Keyword(s):  
Plant Growth ◽  
Physical Properties ◽  
Bulk Density ◽  
Soil Amendment ◽  
Extended Period ◽  
Mineral Elements ◽  
Field Soil ◽  
Rooted Cuttings ◽  
Sodium Calcium ◽  
Water Holding

Azomite is a mined, commercially available, hydrated sodium calcium aluminosiliclate soil amendment reported to act as a source of mineral elements. To determine its effect on plant growth, Dendranthema `Connie' rooted cuttings, Malus seedlings, and Citrus seedlings were grown in containers in one of two growing media: ProMix BX or ProMix BX with Azomite (1:1, v:v). Plant height was monitored weekly and after 6 weeks of growth, fresh and dry plant weights of roots and shoots were determined. There was no difference in any of the parameters measured as a result of the addition of Azomite. Any nutritional influence of the Azomite may only be evident in different conditions, e.g., field soil, or over an extended period of time. The Azomite altered the medium's physical properties and therefore bulk density and water-holding capacity of the Azomite were determined for consideration.

scholarly journals Sewage sludge application enhances soil properties and rice growth in a salt-affected mudflat soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuhua Shan ◽  
Min Lv ◽  
Wengang Zuo ◽  
Zehui Tang ◽  
Cheng Ding ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Organic Carbon ◽  
Plant Growth ◽  
Root Growth ◽  
Soil Fertility ◽  
Soil Properties ◽  
Soluble Sugar ◽  
Soil Reclamation ◽  
Rice Growth ◽  
Promote Plant Growth

AbstractThe most important measures for salt-affected mudflat soil reclamation are to reduce salinity and to increase soil organic carbon (OC) content and thus soil fertility. Salinity reduction is often accomplished through costly freshwater irrigation by special engineering measures. Whether fertility enhancement only through one-off application of a great amount of OC can improve soil properties and promote plant growth in salt-affected mudflat soil remains unclear. Therefore, the objective of our indoor pot experiment was to study the effects of OC amendment at 0, 0.5%, 1.0%, 1.5%, and 2.5%, calculated from carbon content, by one-off application of sewage sludge on soil properties, rice yield, and root growth in salt-affected mudflat soil under waterlogged conditions. The results showed that the application of sewage sludge promoted soil fertility by reducing soil pH and increasing content of OC, nitrogen and phosphorus in salt-affected mudflat soil, while soil electric conductivity (EC) increased with increasing sewage sludge (SS) application rates under waterlogged conditions. In this study, the rice growth was not inhibited by the highest EC of 4.43 dS m−1 even at high doses of SS application. The SS application increased yield of rice, promoted root growth, enhanced root activity and root flux activity, and increased the soluble sugar and amino acid content in the bleeding sap of rice plants at the tillering, jointing, and maturity stages. In conclusion, fertility enhancement through organic carbon amendment can “offset” the adverse effects of increased salinity and promote plant growth in salt-affected mudflat soil under waterlogged conditions.

Sign in / Sign up

Export Citation Format

Share Document