Stability and organic matter content of surface soil aggregates under different methods of cultivation and in grassland

1982 ◽  
Vol 2 (2) ◽  
pp. 155-175 ◽  
Author(s):  
J.T. Douglas ◽  
M.J. Goss
Keyword(s):  
Organic Matter ◽  
Surface Soil ◽  
Soil Aggregates ◽  
Organic Matter Content ◽  
Matter Content

Growth of Eucalyptus species in a Brown Kandosol, and changes in soil phosphorus fractionation following fertilisation

Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 190 ◽  
Author(s):  
Terrence A. Short ◽  
Peter M. Kopittke ◽  
David R. Mulligan ◽  
Neal W. Menzies
Keyword(s):  
Organic Matter ◽  
Surface Soil ◽  
Soil Phosphorus ◽  
Organic Matter Content ◽  
Maximum Growth ◽  
Phosphorus Fractionation ◽  
Matter Content ◽  
Eucalyptus Species ◽  
P Application ◽  
Fertiliser Application

As observed with many soils, much of the P in the Brown Kandosol soils of Weipa (Australia) is associated with organic matter. However, following bauxite mining, much of this organic matter is either lost due to mineralisation, or is ‘diluted’ by the mixing of the soil profile. Using a sequential P extraction, the partitioning of P following fertiliser application was examined in an ‘undisturbed’ (Surface) soil and a Mixed soil. In addition, the effect of split-P applications on the growth of 2 native Eucalyptus species was examined. Following its addition to the soil, much of the P was converted comparatively rapidly to forms with reduced availability; by the time of the first measurement (4 weeks) only approximately 10% of the added P remained as the readily available AER-P. For the Surface soil, much of this added P was initially converted to organic P (Po) (measured as hydroxide-Po), before progressively moving into the hydroxide-Pi fraction. In comparison, in the mixed soil, competition for P from microbial biomass was lower (due to a lower organic matter content) and the P was rapidly converted to the hydroxide-Pi fraction before moving to unavailable forms (residual P). Although the use of split-P applications was expected to increase plant growth, maximum growth of Eucalyptus tetrodonta and Eucalyptus leptophleba was generally achieved when all P fertiliser was applied in the first few weeks of growth. Indeed, splitting the P application beyond 16 weeks caused a significant reduction in growth.

Comparison of aggregate stability within six soil profiles under conventional tillage using various laboratory tests

Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Radka Kodešová ◽  
Marcela Rohošková ◽  
Anna Žigová
Keyword(s):  
Organic Matter ◽  
Soil Aggregates ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Clay Content ◽  
Soil Aggregate ◽  
Matter Content ◽  
The Other ◽  
Structure Stability ◽  
Soil Aggregate Stability

AbstractSoil structure stability was studied in every diagnostic horizons of six soil types (Haplic Chernozem, Greyic Phaeozem, two Haplic Luvisols, Haplic Cambisol, Dystric Cambisol) using different techniques investigating various destruction mechanisms of soil aggregates. Soil aggregate stability, assessed by the index of water stable aggregates (WSA), varied depending on the organic matter content, clay content and pHKCl. The presence of clay and organic matter coatings and fillings, and presence of iron oxides in some soils increased stability of soil aggregates. On the other hand periodical tillage apparently decreased aggregate stability in the Ap horizons. Coefficients of aggregate vulnerability resulting from fast wetting (KV 1) and slow wetting (KV 2) tests showed similar trends of the soil aggregate stability as the WSA index, when studied for soils developed on the similar parent material. There was found close correlation between the WSA index and the KV 1 value, which depended also on the organic matter content, clay content and pHKCl. Less significant correlation was obtained between the WSA index and the KV 2 value, which depended on the organic matter content and clay content. Coefficients of vulnerability resulting from the shaking after pre-wetting test (KV 3) showed considerably different trends in comparison to the other tests due to the different factors affecting aggregate stability against the mechanical destruction. The KV 3 value depended mostly on cation exchange capacity, pHKCl and organic matter content.

scholarly journals Evaluation of the Effects of Organic Matter and Other Soil Characteristics Upon the Aggregate Stability of Some Tropical Soils

1969 ◽  
Vol 43 (4) ◽  
pp. 268-272 ◽  
Author(s):  
M. A. Lugo-López ◽  
J. Juárez, Jr.
Keyword(s):  
Organic Matter ◽  
Soil Aggregates ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Tropical Soils ◽  
Development Project ◽  
Matter Content ◽  
Degree Of Stability ◽  
Statistical Studies ◽  
Level Of Significance

This paper reports on statistical studies conducted to evaluate the degree of stability of soil aggregates in terms of the respective organic-matter, clay, and silt contents of selected soils from the Lajas Valley irrigation development project. Simple regression analyses revealed that there was no correlation between aggregate stability and clay or silt content. However, a highly significant correlation was obtained when organic-matter content was considered as the independent variable. In spite of the level of significance only 16 percent of the variability in aggregate stability can be explained on a basis of the soil organic-matter content, thus limiting the possible usefulness of estimates made by using the equation developed.

The Formation Mechanism Of Mudflat Soil Aggregates Driven By Exogenous Organic Matters

2020 ◽  
Author(s):  
Yanchao Bai ◽  
Chuanhui Gu ◽  
Yuhua Shan
Keyword(s):  
Organic Matter ◽  
Microbial Diversity ◽  
Crop Production ◽  
Soil Structure ◽  
Soil Aggregates ◽  
Organic Matter Content ◽  
Matter Content ◽  
Arable Soil ◽  
Nutrient Level ◽  
Salt Reduction

<p>Mudflats are valuable land resources located in the interaction zone between land and sea and are found in many parts of the world. The newly reclaimed mudflats are high in salinity and low in fertility as indicated by poor soil structure, extremely low organic matter content, low nutrient level and lack of microbial diversity, which is not suitable for cultivation. The keys to mudflat reclamation to arable lands are (1) to reduce salinity and (2) to increase the soil organic matter content and thus soil fertility. The former determines whether the reclaimed mudflat can be used for crop production and the latter determines whether the crop production is sustainable. On the basis of salt reduction measures, adding exogenous organic matter to drive the formation of soil aggregates in mudflat saline-alkali soil is a prerequisite for inhibiting the return of salt, improving fertility and promoting the transformation of mudflat reclaimed soil into arable soil. Research on the formation of clustered soil aggregates during the evolution of mudflat soil into arable soil should focus on the regulatory, formation, and stability mechanism of different exogenous organic matter. In addition, exploration of the effects of the special properties of mudflat soil, e.g., high salinity, high pH, and low microbial diversity, on the formation and stability of soil aggregates is necessary. The regularity and regulation of soil structure and fertility evolution of the mudflat driven by exogenous organic matter were clarified. Research on soil aggregate formation not only enrich the basic theory of soil quality evolution of mudflat, but also have practical guiding significance for the maturation of mudflat soil.</p>

Macro-nutrient availability in surface soil of urban tree pits influenced by land use, soil age, and soil organic matter content

2015 ◽  
Vol 18 (3) ◽  
pp. 921-936 ◽  
Author(s):  
Maryam Kargar ◽  
Pierre Jutras ◽  
O. Grant Clark ◽  
William H. Hendershot ◽  
Shiv O. Prasher
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Nutrient Availability ◽  
Surface Soil ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Organic Matter Content ◽  
Urban Tree ◽  
Soil Age

Sorption of Simazine andS-Metolachlor to Soils from a Chronosequence of Turfgrass Systems

Weed Science ◽  
2013 ◽  
Vol 61 (3) ◽  
pp. 508-514 ◽  
Author(s):  
Travis W. Gannon ◽  
Adam C. Hixson ◽  
Jerome B. Weber ◽  
Wei Shi ◽  
Fred H. Yelverton ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Soil ◽  
Organic Matter Content ◽  
Sorption Isotherms ◽  
Matter Content ◽  
Soil Sorption ◽  
Sorption Coefficient ◽  
Soil System ◽  
Subsurface Soil ◽  
Pesticide Sorption

Pesticide sorption by soil is among the most sensitive input parameters in many pesticide-leaching models. For many pesticides, organic matter is the most important soil constituent influencing pesticide sorption. Increased fertility, irrigation, and mowing associated with highly maintained turfgrass areas result in constant deposition of organic material, creating a soil system that can change drastically with time. Changes in soil characteristics could affect the environmental fate of pesticides applied to turfgrass systems of varying ages. Sorption characteristics of simazine andS-metolachlor were determined on five soils from bermudagrass systems of increasing ages (1, 4, 10, 21, and 99 yr) and compared to adjacent native pine and bare-ground areas. Surface soil (0 to 5 cm) and subsurface soil (5 to 15 cm) from all sites were air-dried and passed through a 4-mm sieve for separation from plant material. Using a batch-equilibrium method, sorption isotherms were determined for each soil. Data were fit to the Freundlich equation, andKd(soil sorption coefficient) andKoc(organic carbon sorption coefficient) values were determined. Sorption and soil system age were directly related to organic matter content in the soil. Sorption of both herbicides increased with age of the soil system and was greatest on the surface soil from the oldest bermudagrass soil system. Herbicide sorption decreased at greater soil depths with lower organic matter. Greater amount of14C–simazine sorbed to subsurface soil of the oldest turfgrass system compared to14C–S-metolachlor. Results indicate that as bermudagrass systems age and accumulate higher organic matter levels increased herbicide sorption may decrease the leaching potential and bioavailability of simazine andS-metolachlor.

Extraction Methods Study and Structure Analysis of Humic Acid in Surface Soil along Main Transportation Road

2012 ◽  
Vol 518-523 ◽  
pp. 201-204
Author(s):  
Yue Jin Zhang ◽  
Juan Wang
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Surface Soil ◽  
Ph Value ◽  
Organic Matter Content ◽  
Extraction Methods ◽  
Matter Content ◽  
Soil Samples ◽  
Sorption Ability ◽  
Scanning Electron

The five surface soil samples were collected in along zhonghuan road of Jiaxing city. According to different solubility in acid and alkali solution, the soil organic matters were divided into different kinds of components such as fulvic acid, humic acid and Humin. Both humic acid and minerals were extracted by sequence and the images were displayed in assistance of scanning electron microscope. Different extraction time and extraction conditions were optimized and the methods were established in the last. Correlations between organic matter content, pH value and contents of HA were fitted and a linear relationship was found between OM and HA. On the help of SEM, different structure of HA and minerals were found that images of HA were columnar and that of mineral were Massive. It is just the reason that why the OM has great sorption ability than the minerals.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

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