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.

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 Comparison of wheat and safflower cultivation areas in terms of total carbon and some soil properties under semi-arid climate conditions

2015 ◽  
Vol 7 (1) ◽  
pp. 1007-1024
Author(s):  
B. Turgut
Keyword(s):  
Organic Matter ◽  
Physical Properties ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Soil Physical Properties ◽  
Matter Content ◽  
Total Carbon ◽  
Arid Climate ◽  
Soil Layers ◽  
Semi Arid

Abstract. The aim of this study was to compare the soils of the wheat cultivation area (WCA) and the safflower cultivation area (SCA) within semi-arid climate zones in terms of their total carbon, nitrogen, sulphur contents, particle size distribution, aggregate stability, organic matter content, and pH values. This study presents the results from the analyses of 140 soil samples taken at two soil layers (0–10 and 10–20 cm) in the cultivation areas. At the end of the study, it has been established that there were significant differences between the cultivation areas in terms of soil physical properties such as total carbon (TC), total nitrogen (TN), total sulphur (TS) contents and pH, while only the TN content resulted in significantly different between the two soil layers. Moreover significant differences were identified in the cultivation areas in terms of soil physical properties including clay and sand contents, aggregate stability and organic matter content, whereas the only significant difference found among the soil layers was that of their silt content. Since safflower contains higher amounts of biomass than wheat, we found higher amounts of organic matter content and, therefore, higher amounts of TN and TS content in the soils of the SCA. In addition, due to the fact that wheat contains more cellulose – which takes longer to decompose – the TC content of the soil in the WCA were found to be higher than that of the SCA. The results also revealed that the WCA had a higher carbon storage capacity.

scholarly journals The status of phosphorus and other fertility parameters in soils of Puerto Rico

1969 ◽  
Vol 90 (3-4) ◽  
pp. 145-157 ◽  
Author(s):  
David Sotomayor-Ramírez ◽  
Gustavo A. Martínez
Keyword(s):  
Organic Matter ◽  
Puerto Rico ◽  
Soil Fertility ◽  
Temporal Dynamics ◽  
Organic Matter Content ◽  
Tropical Soils ◽  
Matter Content ◽  
Soil Test ◽  
Commercial Laboratory ◽  
Soil Fertility Status

There is a need to quantitatively assess the soil fertility status of tropical soils. Descriptive summaries help describe the effectiveness of liming programs, nutritional limitation in soils and the relative risk of off-field nutrient transport. A database of 1,168 soil test results collected from 1989 to 1999 from nearly 400 cultivated farms in Puerto Rico was used. Samples were analyzed for pH, organic matter (Walkley-Black method), extractable phosphorus (P) (Olsen and Bray 1), and exchangeable bases (NH4Oac method) by a commercial laboratory. Thirty-six percent of the samples had acidity problems (pH <5.5). Twenty-three percent of the samples had low organic matter content (<20 g/kg), and 16% had high category (>40 g/kg) values. Fifty-three and 56% of the samples showed a need to fertilize with magnesium (Mg) and potassium (K), respectively, because they had values below the suggested critical levels of 2.5 cmolc/kg for soil exchangeable Mg and of 0.4 cmolc/kg for K. On the basis of current soil fertility criteria, P fertilization would be required in 69% of the samples with pH less than 7.3, but only in 28% of the samples with pH greater than or equal to 7.3. Although the soils grouped with pH >7.3 had a greater proportion of samples in the "extremely high" soil test P category, the potential environmental impact may be lessened because the climatic and topographic conditions where these soils occur favor less runoff. Follow-up studies are needed to assess the spatial variability and the temporal dynamics of the nutritional status of soils of Puerto Rico. 

Mobility of metsulfuron-methyl in tropical soils

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1291 ◽  
Author(s):  
B. S. Ismail ◽  
K. Kalithasan
Keyword(s):  
Organic Matter ◽  
Soil Column ◽  
Organic Matter Content ◽  
Tropical Soils ◽  
Matter Content ◽  
Fresh Weight ◽  
Downward Movement ◽  
Natural Conditions ◽  
Metsulfuron Methyl ◽  
Rainfall Total

The mobility of metsulfuron-methyl in 5 soil series with different organic contents was determined in a greenhouse as well as under natural conditions. In these studies, the movement and biological activity of metsulfuron-methyl were determined by the bioassay method using long bean as a bioassay species. Bioactivity and movement of the herbicide down the soil profile were inversely related to the organic matter content of the soil. Phytotoxic levels of metsulfuron-methyl were restricted to the 10-cm depth of the column containing Selangor Series soil except when it received 40 mL of water daily (depth, 10–15 cm). In Munchung Series, the phytotoxic level was also mainly in the 5–10 cm layer. However, when the column received 40 mL daily or every 4 days, the residue was detected in 15–20 cm and 10–15 cm zones, respectively. The phytotoxic level moved downward to the 20–25 cm layer both in Sogomana and Holyrood Series when 40 mL of water was given daily. A phytotoxic level of metsulfuron herbicide was detected in the 20–25 cm layer when the soil column containing Serdang Series was leached with 40 mL of water every 4 days or with 20 mL daily; the phytotoxic level was detected at a depth of 25–30 cm when this soil was watered daily with 40 mL. The downward movement of metsulfuron under natural conditions showed a pattern similar to that found under simulated conditions. Phytotoxic effects of the residue could be detected in the 25–30 cm and 15–20 cm zone of Serdang and Holyrood Series, respectively, after exposure to 20 days of rainfall (total 111·9 mm). Phytotoxic residue in both Sogomana and Munchung Series soil was detected in the 10–15 cm layer, and in the 5–10 cm layer for Selangor Series soil, after exposure to 20 days of rainfall. After exposure to 40 days of rainfall (total 152·8 mm) under natural conditions, the residue could be detected in the 15–20 cm layer of Selangor Series. The phytotoxic level moved deeper in soil with low organic matter after exposure to 40 days of rainfall. Fresh weight reduction was greater in the 20–30 cm layer in Serdang Series than in the top layer.

Comparison of alternative farming systems. III. Soil aggregate stability

1993 ◽  
Vol 8 (1) ◽  
pp. 27-33 ◽  
Author(s):  
J.L. Jordahl ◽  
D.L. Karlen
Keyword(s):  
Soil Water ◽  
Soil Aggregates ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Farming Systems ◽  
Animal Manure ◽  
Matter Content ◽  
Water Stability ◽  
Alternative Farming ◽  
Alternative Practices

AbstractQuantitative studies are needed to separate the real and supposed benefits of alternative farming practices. Our objective was to learn how conventional and alternative practices on adjacent farms in central Iowa affected the water stability of soil aggregates. We collected samples of Clarion loam (fine-loamy, mixed, mesic Typic Hapludoll) from adjacent 16 ha fields in fall 1990 and spring 1991. Aggregate stability was determined by wet-sieving and by measuring turbidity of soil-water suspensions. The combined effects of alternative practices resulted in greater water stability of soil aggregates, higher soil organic matter content, and lower bulk density compared with conventional practices. The components of the alternative system that were mainly responsible for these differences were: rotations that included oat and hay crops; ridge-tillage; and additions of 45 Mg/ha of a mixture of animal manure and municipal sludge during the first 3 years of each 5 year rotation. The more favorable soil physical conditions, shown by increased water stability of soil aggregates, presumably will improve soil water regimes and reduce long-term soil erosion losses from the alternatively managed fields.

PHYSICAL PROPERTIES OF GLEYSOLIC SOILS IN THE LOWLANDS OF QUEBEC

1979 ◽  
Vol 59 (1) ◽  
pp. 69-78 ◽  
Author(s):  
C. R. DE KIMPE ◽  
G. R. MEHUYS
Keyword(s):  
Organic Matter ◽  
Pore Diameter ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Total Porosity ◽  
Matter Content ◽  
Soil Series ◽  
Mean Values ◽  
Small Pore ◽  
Agricultural Areas

Clay-rich soils were sampled in the agricultural areas of Montreal, Quebec and Lake St-Jean. Undisrupted soil blocks and bulk samples were taken by horizon in the Ste-Rosalie, Kamouraska and Normandin soil series. Aggregate stability increased with the organic matter content. Bulk density was generally highest in the B horizons. Porosity ranged from 39 to 56% of the total soil volume and the most representative pore diameter varied from 0.706 to 0.048 μm with the largest diameter being found in the Ap horizons. The distribution of porosity among large, medium and small pores in the Ste-Rosalie soil differed from that in the Kamouraska and Normandin soils. In the former, medium pores accounted for only a few percent of total porosity, while the pores were more evenly distributed in the latter soils. Medium pore contents decreased, while small pore contents increased, with increasing clay contents. No significant relationship was observed between large pores and clay percentages. Hydraulic conductivity, with mean values ranging from 3.5 to 109.3 cm/h, was significantly related to the large pore class.

scholarly journals Sorption and Desorption of Tembotrione and its Metabolite AE 1417268 in Soils with Different Attributes

2019 ◽  
Vol 37 ◽  
Author(s):  
A.T. FARIA ◽  
C.A. FIALHO ◽  
M.F. SOUZA ◽  
N.M. FREITAS ◽  
A.A. SILVA
Keyword(s):  
Organic Matter ◽  
High Performance ◽  
Organic Matter Content ◽  
Clay Content ◽  
Tropical Soils ◽  
Matter Content ◽  
Direct Relation ◽  
Carryover Effects ◽  
Physical Attributes ◽  
Low Levels

ABSTRACT: Tembotrione is registered in Brazil for maize and is used in large areas of the country in each harvest. In recent years, producers have reported carryover effects of this herbicide in succeeding crops to maize. This fact can be attributed to tembotrione recommendations without knowing their interactions with tropical soils colloids. In this study, using high-performance liquid chromatography, it was possible to evaluate the influence of chemical and physical attributes on the sorption and desorption of tembotrione, as well as its metabolite AE 1417268, on seven soils from different regions of Brazil. The coefficients referring to sorption and desorption, as well as the hysteresis index (Kf, 1/n and H) of tembotrione and its metabolite were influenced by pH, clay content and organic matter. In soil samples with low levels of clay and organic matter, values of sorption coefficients were reduced as pH increased. The desorption of tembotrione and its metabolite in all soils were low, mainly in the clayey ones and in soils with higher organic matter content. The sorption of tembotrione and its metabolites varies with the attributes of soil, presenting a direct relation with clay and organic matter contents and an inverse one with soil pH. The desorption of tembotrione and its metabolite decreased with the increase in clay and organic matter contents in the evaluated soils.

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