SOME CHEMICAL PROPERTIES OF SOIL ORGANIC MATTER AND OF SESQUIOXIDES ASSOCIATED WITH AGGREGATION IN SOILS

Knowledge on variations in vertical, horizontal and temporal characteristics of the soil chemical properties under eucalyptus stumps left in the soil is of fundamental importance for the management of subsequent crops. The objective of this work was to evaluate the effect of eucalyptus stumps (ES) left after cutting on the spatial variability of chemical characteristics in a dystrophic Yellow Argisol in the eastern coastal plain region of Brazil. For this purpose, ES left for 31 and 54 months were selected in two experimental areas with similar characteristics, to assess the decomposition effects of the stumps on soil chemical attributes. Soil samples were collected directly around these ES, and at distances of 30, 60, 90, 120 and 150 cm away from them, in the layers 0-10, 10-20 and 20-40 cm along the row of ES, which is in-between the rows of eucalyptus trees of a new plantation, grown at a spacing of 3 x 3 m. The soil was sampled in five replications in plots of 900 m² each and the samples analyzed for pH, available P and K (Mehlich-1), exchangeable Al, Ca and Mg, total organic carbon (TOC) and C content in humic substances (HS) and in the free light fraction. The pH values and P, K, Ca2+, Mg2+ and Al3+ contents varied between the soil layers with increasing distance from the 31 and 54-monthold stumps. The highest pH, P, K, Ca2+ and Mg2+ values and the lowest Al3+ content were found in the surface soil layer. The TOC of the various fractions of soil organic matter decreased with increasing distance from the 31 and 54-month-old ES in the 0-10 and 10-20 cm layers, indicating that the root (and stump) cycling and rhizodeposition contribute to maintain soil organic matter. The C contents of the free light fraction, of the HS and TOC fractions were higher in the topsoil layer under the ES left for 31 months due to the higher clay levels of this layer, than in those found under the 54-month-old stumps. However, highest C levels of the different fractions of soil organic matter in the topsoil layer reflect the deposition and maintenance of forest residues on the soil surface, mainly after forest harvest.

Download Full-text

Properties of soil organic matter of Plaggic Anthrosols from Northwest Germany, Northwest and North Russia

Archives of Agronomy and Soil Science ◽

10.1080/03650340802637733 ◽

2009 ◽

Vol 55 (5) ◽

pp. 477-492 ◽

Cited By ~ 8

Author(s):

Olga Kalinina ◽

Oleg Chertov ◽

Marina Nadporozhskaya ◽

Luise Giani

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Northwest Germany ◽

Properties Of Soil

Download Full-text

Accumulation of diazinon in Indian spinach under different doses of rice hull

Dhaka University Journal of Biological Sciences ◽

10.3329/dujbs.v26i2.46393 ◽

2017 ◽

Vol 26 (2) ◽

pp. 125-131

Author(s):

Fahmida Akhter ◽

Didar Ul Alam ◽

Monira Begum ◽

Naushad Alam

Keyword(s):

Organic Matter ◽

Organic Matter Content ◽

Chemical Properties ◽

Matter Content ◽

Rice Hull ◽

Vegetable Crops ◽

Soil Organic Matter Content ◽

Positive Effect ◽

Different Doses ◽

Properties Of Soil

An experiment was conducted to determine the effect of diazinon pesticide on some chemical properties of soil and to evaluate the accumulation of diazinon in Indian spinach (Basilla alba) under different doses of rice hull. Diazinon application had a positive effect to reduce the electrical conductivity (EC) of soil. Values of pH were found to decrease with the addition of diazinon. Diazinon had no effect on soil organic matter content although addition of rice hull increased organic matter content in soil with time. Plant analysis showed that the application of rice hull restricted the uptake of diazinon and continuously decreased with time. Therefore, rice hull could be used to control the uptake of diazinon pesticide by short duration vegetable crops. Dhaka Univ. J. Biol. Sci. 26(2): 125-131, 2017 (July)

Download Full-text

Mechanisms of improving coastal saline-alkali soil by periphyton

10.22541/au.161115527.78762010/v1 ◽

2021 ◽

Author(s):

Ye Zhu ◽

Tianyun Shao ◽

Yujie Zhou ◽

Xiumei Gao ◽

Xiaohua Long ◽

...

Keyword(s):

Organic Matter ◽

Enzyme Activity ◽

Soil Organic Matter ◽

Relative Abundance ◽

Ph Value ◽

Chemical Properties ◽

Functional Genes ◽

Control Soil ◽

Alkali Soil ◽

Unplanted Soil

Periphyton plays an indispensable role in coastal saline-alkali land, but its function is poorly understood. Soil physical and chemical properties (pH value, salinity, soil organic matter), enzyme activity and microbial diversity (based on 16s rDNA, ITS and functional genes) were measured in periphyton formed on rice-growing coastal saline-alkali soil modified by a new type of soil conditioner. The results showed that the content of organic matter and catalase activity in periphyton were significantly higher than in the unplanted control soil. Soil pH and salinity were decreased in periphyton compared to the unplanted control soil. Based on the relative abundance, bacterial genera Desulfomicrobium, Rhodobacter, cyanobacterium_scsio_T−2, Gemmatimonas, and Salinarimonas as well as fungal genus Fusarium were more abundant in periphyton than the unplanted control soil. In terms of functional genes, the cbbM and cbbL sequencing showed higher abundance of Hydrogenophaga, Rhodovulum, Magnetospira, Leptothrix, and Thiohalorhabdus, whereas the nifH sequencing indicated higher abundance of Cyanobacteria in the periphyton compared to the unplanted soil. The relative abundance and community structure of soil microorganisms were improved by periphyton, thus reducing soil salinity and pH, increasing soil organic matter and enzyme activity. This indicated that the periphyton can improve the conditions and offer a suitable environment for plant growth in coastal saline-alkali soil.

Download Full-text

Thermal stability of soil organic matter responds to long-term fertilization practices

Biogeosciences Discussions ◽

10.5194/bgd-3-309-2006 ◽

2006 ◽

Vol 3 (2) ◽

pp. 309-320 ◽

Cited By ~ 2

Author(s):

J. Leifeld ◽

U. Franko ◽

E. Schulz

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Mineral Fertilization ◽

Scanning Calorimetry ◽

Organic C ◽

Fertilization Experiment ◽

Thermal Stability Of ◽

Dsc Thermograms ◽

Properties Of Soil

Abstract. We used differential scanning calorimetry (DSC) to infer thermal properties of soil organic matter (SOM) in the static fertilization experiment in Bad Lauchstädt, Germany, which has been established in 1902. Four treatments (null N, change from null to manuring in 1978 NM, change from manuring to null in 1978 MN, and permanent manure and mineral fertilization since 1902 M) were sampled in 2004. Soil organic carbon contents were highest for M (2.4%), lowest for N (1.7%), and similar for MN and NM (2.2%). DSC thermograms were characterized by three peaks at around 354, 430, and 520°C, which were assigned to as thermally labile and stable SOM and combustion residues from lignite, respectively. DSC peak temperatures were relatively constant among treatments, but peak heights normalized to the organic C content of the soil were significantly different for labile and stable SOM. Labile C was higher for M>MN=NM=N, and stable C decreased in the order N=NM>MN=M, showing that agricultural depletion of SOM increases the share of thermally stable C. Lignite-derived C was not affected by management, suggesting a homogeneous deposition across treatments.

Download Full-text

Effect of Tillage and Cover Crop on Fluometuron Adsorption and Degradation under Controlled Conditions

Weed Science ◽

10.1017/s0043174500077067 ◽

1994 ◽

Vol 42 (4) ◽

pp. 629-634 ◽

Cited By ~ 18

Author(s):

Blake A. Brown ◽

Robert M. Hayes ◽

Donald D. Tyler ◽

Thomas C. Mueller

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Soil Ph ◽

Cover Crop ◽

Soil Depth ◽

Organic Matter Content ◽

Chemical Properties ◽

Exchange Capacity ◽

Matter Content ◽

No Till

Fluometuron adsorption and degradation were determined in soil collected at three depths from no-till + no cover, conventional-till + no cover, no-till + vetch cover, and conventional-till + vetch cover in continuous cotton. These combinations of tillage + cover crop + soil depth imparted a range of organic matter and pH to the soil. Soil organic matter and pH ranged from 0.9 to 2.5% and from 4.7 to 6.5, respectively. Fluometuron adsorption was affected by soil depth, tillage, and cover crop. In surface soils (0 to 4 cm), fluometuron adsorption was greater in no-till + vetch plots than in conventional-tilled + no cover plots. Soil adsorption of fluometuron was positively correlated with organic matter content and cation exchange capacity. Fluometuron degradation was not affected by adsorption, and degradation empirically fit a first-order model. Soil organic matter content had no apparent effect on fluometuron degradation rate. Fluometuron degradation was more rapid at soil pH > 6 than at pH ≤ 5, indicating a potential shift in microbial activity or population due to lower soil pH. Fluometuron half-life ranged from 49 to 90 d. These data indicate that tillage and cover crop may affect soil dissipation of fluometuron by altering soil physical and chemical properties that affect fluometuron degrading microorganisms or bioavailability.

Download Full-text

Soil Organic Matter Quality From Soils Cropped by Traditional Peasants

Sustainable Agriculture Research ◽

10.5539/sar.v3n4p63 ◽

2014 ◽

Vol 3 (4) ◽

pp. 63

Author(s):

Luciano Pasqualoto Canellas ◽

Riccardo Spaccini ◽

Natalia De Oliveira Aguiar ◽

Fabio Lopes Olivares

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Root Growth ◽

High Performance ◽

Chemical Properties ◽

Size Exclusion ◽

Native Forest ◽

Organic Matter Quality ◽

African Descendants ◽

Exclusion Chromatography

In this work we have analyzed soil samples from Oxisols collected from two traditional communities, one formed by Guarany Indians at South of Brazil and other by African descendants on North of Rio de Janeiro State, Brazil. The content and fractional composition of humus was investigated and the isolated humic acids (HAs) were characterized by elemental composition, 13C solid-state nuclear magnetic resonance, and high-performance size exclusion chromatography. The bioactivity of HAs was evaluated considering the effects on root growth of maize seedlings. Chemical properties from adjacent soils under native forest were used as control samples. The local field sites matching the traditional cropping requirements, were characterized by higher soil chemical fertility and soil organic matter hydrophobicity, as compared to the land plots considered as inadequate by rural peasants. The HAs from cropped soils revealed significant differences in respect to content, hydrophobicity, biostimulation and molecular dimension. Although all humic extracts promoted, both, root growth and the stimulation of lateral root emergence over control, the HAs from preferential local sites, revealed a larger bioactivity response on root stimulation even at lower concentration. The assessment of soil quality issued by local farmers, showed a valuable fitting with bio-chemical fertility indicators and SOM hydrophobicity.

Download Full-text