The role of Ca-organic interactions in soil aggregate stability .I. Laboratory studies with glucose 14C, CaCO3 and CaSO4.2.H2O

Soil Research ◽  
1989 ◽  
Vol 27 (2) ◽  
pp. 389 ◽  
Author(s):  
M Muneer ◽  
JM Oades
Keyword(s):  
Sandy Loam ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
Control Soil ◽  
Laboratory Studies ◽  
Soil Aggregate Stability ◽  
Fine Sandy Loam ◽  
Water Stable Aggregates ◽  
Dispersible Clay

14C-glucose with or without CaCO3 or CaS04.2H2O was incubated in a leached fine sandy loam under controlled temperature and humidity for 120 days. The addition of CaSO4.2H2O decreased the release of 14CO2, compared with soil with 14C-glucose and CaCO3 and 14C-glucose only. Addition of CaCO3 initially stimulated release of 14CO2 but subsequently the release of 14CO2 was inhibited compared with treatments with no calcium additions. Addition of both CaSO4.2H20 and CaCO3 resulted in more residual 14C in the soil at the end of the incubation period than in the control soil to which no calcium was added. The addition of CaSO4.2H2O and CaCO3 led to increases in water-stable aggregates 50-250 �m diameter, and decreased the amount of dispersible clay. In the presence of calcium and glucose, the stabilization of aggregates >1000�m occurred and they persisted for a longer time than when no additions of calcium were made.

The role of Ca-organic interactions in soil aggregate stability .II. Field studies with 14C-labeled straw, CaCO3 and CaSO4.2.H2O

Soil Research ◽  
1989 ◽  
Vol 27 (2) ◽  
pp. 401 ◽  
Author(s):  
M Muneer ◽  
JM Oades
Keyword(s):  
Wheat Straw ◽  
Sandy Loam ◽  
Aggregate Stability ◽  
Field Studies ◽  
Soil Aggregate ◽  
Soil Aggregate Stability ◽  
Fine Sandy Loam ◽  
The Stability ◽  
Dispersible Clay

Uniformly 14C-labelled straw with or without CaCO3 or CaSO4.2H2O was incubated in a leached, fine sandy loam in the field. The addition of both Ca salts increased the residual 14C in the soil after several months decomposition, CaSO4.2H2O being more effective than CaCO3 in this respect. Addition of the Ca salts decreased the amount of dispersible clay and increased the proportion of particles 50-250 �m diameter. The addition of 14C-labelled wheat straw (with or without CaSO4.2H2O or CaCO3) increased the stability of aggregates >2000 pm diameter. Addition of Ca during decomposition of straw resulted in a synergistic stabilization of aggregates >1 mm. Moreover, the stabilization was prolonged in the presence of Ca.

Role of cationic polarization in humus-increased soil aggregate stability

2016 ◽  
Vol 67 (3) ◽  
pp. 341-350 ◽  
Author(s):  
X. R. Huang ◽  
H. Li ◽  
S. Li ◽  
H. L. Xiong ◽  
X. J. Jiang
Keyword(s):  
Aggregate Stability ◽  
Soil Aggregate ◽  
Soil Aggregate Stability

scholarly journals Effects of vegetation restoration on the aggregate stability and distribution of aggregate-associated organic carbon in a typical karst gorge region

2015 ◽  
Vol 7 (3) ◽  
pp. 2213-2242 ◽  
Author(s):  
F. K. Tang ◽  
M. Cui ◽  
Q. Lu ◽  
Y. G. Liu ◽  
H. Y. Guo ◽  
...  
Keyword(s):  
Particle Size ◽  
Organic Carbon ◽  
Soil Depth ◽  
Aggregate Stability ◽  
Fractal Dimensions ◽  
Soil Aggregate ◽  
Vegetation Restoration ◽  
Soil Aggregate Stability ◽  
Water Stable Aggregates ◽  
Bare Land

Abstract. Changes in soil utilization significantly affect aggregate stability and aggregate-associated soil organic carbon (SOC). A field investigation and indoor analysis were conducted in order to study the soil aggregate stability and organic carbon distribution in the water-stable aggregates (WSA) of the bare land (BL), grassland (GL), shrubland (SL), and woodland (WL) in a typical karst gorge region. The results indicated that the BL, GL, SL, and WL were dominated by particles with sizes > 5 mm under dry sieving treatment, and that the soil aggregate contents of various sizes decreased as the particle size decreased. In addition, the BL, GL, SL, and WL were predominantly comprised of WSA < 0.25 mm under wet sieving treatment, and that the WSA contents initially increased, then decreased, and then increased again as the particle size decreased. Furthermore, at a soil depth of 0–60 cm, the mean weight diameter (MWD), geometrical mean diameter (GMD), and fractal dimensions (D) of the dry aggregates and water-stable aggregates in the different types of land were ranked, in descending order, as WL > GL > SL > BL. The contents of WSA > 0.25 mm, MWD and GMD increased significantly, in that order, and the percentage of aggregate destruction (PAD) and fractal dimensions decreased significantly as the soil aggregate stability improved. The results of this study indicated that, as the SOC contents increased after vegetation restoration, the average SOC content of WL was 2.35, 1.37, and 1.26 times greater than that in the BL, GL, and SL, respectively. The total SOC and SOC associated in WSA of various sizes were the highest at a soil depth of 0–20 cm. In addition, the SOC contents of the WSA increased as the soil aggregate sizes decreased. The SOC contents of the WSA < 0.25 mm were highest except in the bare land, and the SOC contents of the aggregates < 0.25 mm, which ranged from 18.85 to 41.08 %, comprised the majority of the total aggregate SOC contents. The woodland and grassland facilitated WSA stability and SOC protection, thus, promoting the natural restoration of vegetation by reducing artificial disturbances could effectively restore the ecology of and prevent soil erosion in karst regions.

The role of Ca-organic interactions in soil aggregate stability .III. Mechanisms and models

Soil Research ◽  
1989 ◽  
Vol 27 (2) ◽  
pp. 411 ◽  
Author(s):  
M Muneer ◽  
JM Oades
Keyword(s):  
Organic Matter ◽  
Organic Materials ◽  
Surface Soil ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
Soil Aggregate Stability ◽  
Colloidal Aggregates ◽  
Clay Aggregates ◽  
Binding Mechanisms

Serial additions of glucose after drying-wetting cycles led to substantial aggregation of the surface soil from a red-brown earth. Addition of glucose and Ca compounds resulted in up to 80% of the soil bound in particles >2000�m with only a small portion of the soil in particles 4 0 �m. Treatment of the soils with Na4P2O7 caused dispersion of most of the clay but did not disrupt larger aggregates. More disaggregation was caused by treatments with HCI (0.02 M and 0.1 M), indicating the presence of pyrophosphate-resistant binding mechanisms which were presumed to be due to Ca bridging. Addition of Ca to the soil reduced the efficiency of extraction of organic materials by NaOH. This effect was eliminated by a pretreatment with 1 M HCl, indicating a 'bridging' effect of Ca between polycarboxylic macromolecules (humic acids) and clays. The role of Ca in clay and organic matter flocculation, the bridging of clay aggregates to organic materials and interactions of these colloidal aggregates with the biologic cycle is illustrated in some pictorial models.

scholarly journals Separation and Characterization of the Active Soil-Aggregating Agent Present in Distillery Slops

1969 ◽  
Vol 51 (4) ◽  
pp. 304-308
Author(s):  
Raúl Pérez Escolar
Keyword(s):  
Active Material ◽  
Aggregate Stability ◽  
Recovery Process ◽  
Insoluble Fraction ◽  
Soil Aggregate ◽  
Laboratory Studies ◽  
Soil Aggregate Stability ◽  
Stabilizing Agents ◽  
Percent Protein

Information resulting from laboratory studies is presented to show the nature of the soil-aggregating and stabilizing agents present in rum distillery slops. It was found that the main agents were constituents of the 80-percent alcohol-insoluble fraction of the rum distillery slops as shown by determining its soil-aggregate-stability activity. Fractionation of the active material indicated that 6 percent of it was a mannose-bearing polysaccharide, 7 percent protein, and the rest, 87 percent, or main constituent, was a caramel. This one results from the sucrose recovery process at the sugar factory and is not attacked by yeast in the molasses fermentation process.

Dynamics of soil aggregate stability as induced by potassium in a soil-plant system

2021 ◽  
pp. 1-9
Author(s):  
Surachet Aramrak ◽  
Natthapol Chittamart ◽  
Worachart Wisawapipat ◽  
Wutthida Rattanapichai ◽  
Mutchima Phun-Iam ◽  
...  
Keyword(s):  
Aggregate Stability ◽  
Soil Aggregate ◽  
Soil Aggregate Stability ◽  
Plant System
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