The effects of cultivation on the composition of organic-matter and structural stability of soils

Soil Research ◽  
1995 ◽  
Vol 33 (6) ◽  
pp. 975 ◽  
Author(s):  
A Golchin ◽  
P Clarke ◽  
JM Oades ◽  
JO Skjemstad
Keyword(s):  
Organic Matter ◽  
Chemical Composition ◽  
Organic Carbon ◽  
Organic Materials ◽  
Aggregate Stability ◽  
Soil Samples ◽  
Modulus Of Rupture ◽  
Dispersible Clay ◽  
Different Soils

Soil samples were obtained from the surface horizons of five untilled sites and adjacent sites under short- and long-term cultivation. The soil samples were fractionated based on density and organic materials were concentrated in various fractions which enabled comparative chemical composition of the organic materials in cultivated and uncultivated sites by solid-state C-13 CP/MAS NMR spectroscopy. Changes in the nature of organic carbon with cultivation were different in different soils and resulted from variations in the chemistry of carbon inputs to the soils and a greater extent of decomposition of organic materials in cultivated soils. Differences in the chemical composition of organic carbon between cultivated and uncultivated soils resided mostly in organic materials occluded within aggregates, whereas the chemistry of organic matter associated with clay particles showed only small changes. The results indicate a faster decomposition of O-alkyl C in the cultivated soils. Wet aggregate stability, mechanically dispersible clay and modulus of rupture tests were used to assess the effects of cultivation on structural stability of soils. In four of five soils, the virgin sites and sites which had been under long-term pasture had a greater aggregate stability than the cultivated sites. Neither total organic matter nor total O-alkyl C content was closely correlated with aggregate stability, suggesting that only a part of soil carbon or carbohydrate is involved in aggregate stability. The fractions of carbon and O-alkyl C present in the form of particulate organic matter occluded within aggregates were better correlated with aggregate stability (r = 0.86** and 0.88**, respectively). Cultivation was not the dominant factor influencing water-dispersible clay across the range of soil types used in this study. The amount of dispersible clay was a function of total clay content and the percentage of clay dispersed was controlled by factors such as clay mineralogy, CaCO3 and organic matter content of soils. The tendency of different soils for hard-setting and crusting, as a result of structural collapse, was reflected in the modulus of rupture (MOR). The cultivated sites had significantly higher MOR than their non-tilled counterparts. The soils studied had different MOR due to differences in their physical and chemical properties.

scholarly journals Higher Long-Term Soil Moisture Increases Organic Carbon Accrual Through Microbial Conversion of Organic Inputs

2021 ◽  
Author(s):  
Itamar Shabtai ◽  
Srabani Das ◽  
Thiago Inagaki ◽  
Behrooz Azimzadeh ◽  
Carmen Martínez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Chemical Composition ◽  
Organic Carbon ◽  
Fold Increase ◽  
Sodium Dithionite ◽  
Sodium Pyrophosphate ◽  
Microbial Conversion ◽  
High Moisture

High long-term soil moisture may either stimulate or inhibit soil organic carbon (SOC) losses through changes to mineral and chemical composition, and resultant organo-mineral interactions. Yet, the trade-off between mineralization and accrual of SOC under long-term variation in unsaturated soil moisture remains an uncertainty. In this study, we tested the underexplored relationships between long-term soil moisture and organo-mineral chemical composition, and its implications for SOC persistence. The results provide new insights into SOC accrual mechanisms under different long-term moisture levels commonly observed in well-drained soils. Differences in long-term mean volumetric water content ranging from 0.4 - 0.63 (v/v) on fallow plots in an experimental field in New York, USA, were positively correlated with SOC contents (R2 = 0.228; P = 0.019, n = 20), mineral-associated organic matter (MAOM) (R2 = 0.442; P = 0.001; n = 20) and occluded particulate organic matter (oPOM) contents (R2 = 0.178; P = 0.033; n = 20). Higher long-term soil moisture decreased the relative content of sodium pyrophosphate extractable Fe (R2 = 0.33; P < 0.005; n = 20), increased that of sodium dithionite extractable Fe (R2 = 0.443; P < 0.001; n = 20), and increased the overall importance of non-crystalline Al pools (extracted with sodium pyrophosphate and hydroxylamine extractable) for SOC retention. Higher long-term soil moisture supported up to a four-fold increase in microbial biomass (per unit SOC), and lower C:N ratios in MAOM fractions of high-moisture soils (from C:N 9.5 to 9, R2 = 0.267, P = 0.011, n =20). This was reflected by a 15% and 10% greater proportion of oxidized carboxylic-C to aromatic-C and O-alkyl C, respectively, as measured with 13C-NMR, and a more pronounced FTIR signature of N-containing proteinaceous compounds in high-moisture MAOM fractions, reflective of microbial metabolites. SOC accrual increased with increasing soil moisture (P = 0.019), exchangeable Ca2+ (P = 0.013), and pyrophosphate-extractable Al content (P = 0.0001) and Al/Fe ratio (P = 0.017). Taken together, our results show that high long-term soil moisture resulted in SOC accrual by enhancing microbial conversion of plant inputs to metabolites that interact with reactive minerals.

scholarly journals Higher Long-Term Soil Moisture Increases Organic Carbon Accrual Through Microbial Conversion of Organic Inputs

2021 ◽  
Author(s):  
Itamar Shabtai ◽  
Srabani Das ◽  
Thiago Inagaki ◽  
Behrooz Azimzadeh ◽  
Carmen Martínez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Chemical Composition ◽  
Organic Carbon ◽  
Fold Increase ◽  
Sodium Dithionite ◽  
Sodium Pyrophosphate ◽  
Microbial Conversion ◽  
High Moisture

High long-term soil moisture may either stimulate or inhibit soil organic carbon (SOC) losses through changes to mineral and chemical composition, and resultant organo-mineral interactions. Yet, the trade-off between mineralization and accrual of SOC under long-term variation in unsaturated soil moisture remains an uncertainty. In this study, we tested the underexplored relationships between long-term soil moisture and organo-mineral chemical composition, and its implications for SOC persistence. The results provide new insights into SOC accrual mechanisms under different long-term moisture levels commonly observed in well-drained soils. Differences in long-term mean volumetric water content ranging from 0.4 - 0.63 (v/v) on fallow plots in an experimental field in New York, USA, were positively correlated with SOC contents (R2 = 0.228; P = 0.019, n = 20), mineral-associated organic matter (MAOM) (R2 = 0.442; P = 0.001; n = 20) and occluded particulate organic matter (oPOM) contents (R2 = 0.178; P = 0.033; n = 20). Higher long-term soil moisture decreased the relative content of sodium pyrophosphate extractable Fe (R2 = 0.33; P < 0.005; n = 20), increased that of sodium dithionite extractable Fe (R2 = 0.443; P < 0.001; n = 20), and increased the overall importance of non-crystalline Al pools (extracted with sodium pyrophosphate and hydroxylamine extractable) for SOC retention. Higher long-term soil moisture supported up to a four-fold increase in microbial biomass (per unit SOC), and lower C:N ratios in MAOM fractions of high-moisture soils (from C:N 9.5 to 9, R2 = 0.267, P = 0.011, n =20). This was reflected by a 15% and 10% greater proportion of oxidized carboxylic-C to aromatic-C and O-alkyl C, respectively, as measured with 13C-NMR, and a more pronounced FTIR signature of N-containing proteinaceous compounds in high-moisture MAOM fractions, reflective of microbial metabolites. SOC accrual increased with increasing soil moisture (P = 0.019), exchangeable Ca2+ (P = 0.013), and pyrophosphate-extractable Al content (P = 0.0001) and Al/Fe ratio (P = 0.017). Taken together, our results show that high long-term soil moisture resulted in SOC accrual by enhancing microbial conversion of plant inputs to metabolites that interact with reactive minerals.

Soil organic carbon dynamics under long-term sugarcane monoculture

Soil Research ◽  
1999 ◽  
Vol 37 (1) ◽  
pp. 151 ◽  
Author(s):  
J. O. Skjemstad ◽  
J. A. Taylor ◽  
L. J. Janik ◽  
S. P. Marvanek
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Samples ◽  
Resonance Spectroscopy ◽  
13C Nuclear Magnetic Resonance ◽  
Potential Impact ◽  
Soil Organic Carbon Dynamics

Comparisons of soil samples from virgin sites or sites recently planted to sugarcane (new) with sites that had been under cane production for many years (old) were made to investigate the potential impact of cane production on soil organic carbon (OC) levels and chemistry. The comparisons showed that very little change had occurred in total OC and in ‘light’ fraction (<1·6 Mg/m3). Increasing pyrophosphate extractability throughout the profile at some sites, as a result of cultivation, however, suggested that the organic matter generally became more ‘humified’ with long-term cane production. Evidence is presented for a redistribution of OC within profiles under cane production. Old, well-established cane sites had soils with lower OC levels in the surface horizons and higher levels in the subsoils relative to new sites. The overall chemistry of the soil organic matter, as indicated by solid state 13C nuclear magnetic resonance spectroscopy, did not change significantly at each site even though between site differences were large. Some soils contained substantial amounts of charcoal which was of pre-cane origin. In some of the coarse-textured soils, smaller amounts of charcoal produced during the burning of cane appeared to accumulate below the A1 horizons in the profiles. It also appeared likely that the redistribution of carbon in the upper horizons of some soils resulted from the movement of charcoal within the profile, probably as a result of tillage.

scholarly journals Impact of soil use on aggregate stability and its relationship with soil organic carbon at two different altitudes in the Colombian Andes

2019 ◽  
Vol 37 (3) ◽  
pp. 263-273
Author(s):  
Efraín Francisco Visconti-Moreno ◽  
Ibonne Geaneth Valenzuela-Balcázar
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Aggregate Stability ◽  
Tropical Climate ◽  
Mineral Particle ◽  
Organic Carbon Content ◽  
Rice Soils ◽  
Organic Matter Pool ◽  
Different Altitudes

The stability of soil aggregates depends on the organic matter, and the soil use and management can affect the soil organicmatter (SOM) content. Therefore, it is necessary to know therelationship between aggregate stability and the content of SOMin different types of soil use at two different altitudes of theColombian Andes. This study examined the conditions of soilaggregate stability expressed as a distribution of the size classes of stable aggregates (SA) and of the mean weighted diameter of the stable aggregates (MWD). To correlate these characteristics with the soil organic carbon (OC), we measured the particulate organic matter pool (POC), the OC associated with the mineral organic matter pool (HOC), the total organic carbon content (TOC), and the humification rate (HR). Soils were sampled at two altitudes: 1) Humic Dystrudepts in a cold tropical climate (CC) with three plots: tropical mountain rainforest, pastures, and crops; 2) Fluvaquentic Dystrudepts in a warm tropical climate (WC) with three plots: tropical rainforest, an association of oil palm and pastures, and irrigated rice. Soils were sampled at three depths: 0-5, 5-10 and 10-20 cm. The physical properties, mineral particle size distribution, and bulk density were measured. The content of SA with size>2.36 mm was higher in the CC soil (51.48%) than in the WC soil (9.23%). The SA with size 1.18-2.36 mm was also higher in the CC soil (7.78%) than in the WC soil (0.62%). The SA with size 0.60-1.18 mm resulted indifferent. The SA with size between 0.30 and 0.60 mm were higher in the WC soil (13.95%) than in the CC soil (4.67%). The SA<0.30 mm was higher in the WC soil (72.56%) than in the CC soil (32.15%). It was observed that MWD and the SA>2.36 mm increased linearly with a higher POC, but decreased linearly with a higher HR. For the SA<0.30 mm, a linear decrease was observed at a higher POC, while it increased at a higher HR.

scholarly journals Long-Term Effect of Soil Use and Management on Organic Carbon and Aggregate Stability

2018 ◽  
Vol 42 (0) ◽  
Author(s):  
Neuro Hilton Wolschick ◽  
Fabrício Tondello Barbosa ◽  
Ildegardis Bertol ◽  
Bárbara Bagio ◽  
Danieli Schneiders Kaufmann
Keyword(s):  
Organic Carbon ◽  
Aggregate Stability ◽  
Term Effect ◽  
Long Term Effect

scholarly journals Effect of Tillage System and Organic Matter Management Interactions on Soil Chemical Properties and Biological Activity in a Spring Wheat Short-Time Cultivation

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7451
Author(s):  
Barbara Breza-Boruta ◽  
Karol Kotwica ◽  
Justyna Bauza-Kaszewska
Keyword(s):  
Organic Matter ◽  
Biological Activity ◽  
Organic Carbon ◽  
Spring Wheat ◽  
Chemical Properties ◽  
Soil Samples ◽  
Available Phosphorus ◽  
Organic Carbon Content ◽  
Tillage System ◽  
Short Time

Properly selected tillage methods and management of the available organic matter resources are considered important measures to enable farming in accordance with the principles of sustainable agriculture. Depending on the depth and intensity of cultivation, tillage practices affect soil chemical composition, structure and biological activity. The three-year experiment was performed on the soil under spring wheat (cv. Tybalt) short-time cultivation. The influence of different tillage systems and stubble management on the soil’s chemical and biological parameters was analyzed. Organic carbon content (OC); content of biologically available phosphorus (Pa), potassium (Ka), and magnesium (Mg); content of total nitrogen (TN), mineral nitrogen forms: N-NO3 and N-NH4 were determined in various soil samples. Moreover, the total number of microorganisms (TNM), bacteria (B), actinobacteria (A), fungi (F); soil respiratory activity (SR); and pH in 1 M KCl (pH) were also investigated. The results show that organic matter amendment is of greater influence on soil characteristics than the tillage system applied. Manure application, as well as leaving the straw in the field, resulted in higher amounts of organic carbon and biologically available potassium. A significant increase in the number of soil microorganisms was also observed in soil samples from the experimental plots including this procedure.

scholarly journals Properties of Humic Acids in Meadow Soils Irrigated With the Slope-And Flooding System

2021 ◽  
Author(s):  
Magdalena Banach-Szott ◽  
Andrzej Dziamski
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
Soil Samples ◽  
Hydrophobic Properties ◽  
Irrigation Ditch ◽  
Ft Ir ◽  
Degree Of Maturity

Abstract The aim of the research has been to determine the effect of many-year irrigation of unique grasslands on the properties of humic acids defining the quality of organic matter. The research was performed based on the soil (Albic Brunic Arenosol, the A, AE and Bsv horizons) sampled from Europe’s unique complex of permanent grasslands irrigated continuously for 150 years, applying the slope-and-flooding system; the Czerskie Meadows. The soil samples were assayed for the content of total organic carbon (TOC) and the particle size distribution. HAs were extracted with the Schnitzer method and analysed for the elemental composition, spectrometric parameters in the UV-VIS range, hydrophilic and hydrophobic properties and the infrared spectra were produced. The research results have shown that the HAs properties depended on the depth and the distance from the irrigation ditch. The HAs of the A horizon of the soils were identified with a lower “degree of maturity”, as reflected by the values of atomic ratios (H/C, O/C, O/H), absorbance coefficients, and the FT-IR spectra, as compared with the HAs of the Bsv horizon. The HAs molecules of the soils sampled furthest from the irrigation ditch were identified with a higher degree of humification, as compared with the HAs of the soils sampled within the closest distance. The results have demonstrated that many-year grassland irrigation affected the structure and the properties of humic acids.

scholarly journals Chemical composition of soil organic carbon changed by long-term monoculture cropping system in Chinese black soil

2018 ◽  
Vol 64 (No. 11) ◽  
pp. 557-563 ◽  
Author(s):  
Yunfa Qiao ◽  
Shujie Miao ◽  
Yingxue Li ◽  
Xin Zhong
Keyword(s):  
Chemical Composition ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Relative Proportion ◽  
Cropping System ◽  
Black Soil ◽  
Chemical Compositions ◽  
Crop Species ◽  
Rotation System

Monoculture is common to meet commodity grain requirements in Northeast China. The effect of long-term monoculture on chemical composition of soil organic carbon (SOC) remains unclear. This study was done to evaluate how changes in chemical compositions of SOC responded to long-term monoculture. To achieve this objective, the chemical compositions of SOC in maize-soybean rotation, continuous soybean and continuous maize were characterized with the nuclear magnetic resonance technique. Two main components, O-alkyl and aromatic C, showed a wider range of relative proportion in monoculture than rotation system across soil profiles, but no difference was observed between two monoculture systems. Pearson’s analysis showed a significant relationship between plant-C and OCH<sub>3</sub>/NCH, alkyl C or alkyl O-C-O, and the A/O-A was closely related to plant-C. The findings indicated a greater influence of monoculture on the chemical composition of SOC compared to rotation, but lower response to crop species.

Effects of agricultural management on dermosols in northern Tasmania

Soil Research ◽  
2002 ◽  
Vol 40 (1) ◽  
pp. 65 ◽  
Author(s):  
W. E. Cotching ◽  
J. Cooper ◽  
L. A. Sparrow ◽  
B. E. McCorkell ◽  
W. Rowley
Keyword(s):  
Organic Carbon ◽  
Microbial Biomass Carbon ◽  
Aggregate Stability ◽  
Infiltration Rate ◽  
Penetration Resistance ◽  
Agricultural Management ◽  
Structural Development ◽  
Laboratory Techniques ◽  
Carbon Concentrations

Attributes of 15 Tasmanian dermosols were assessed using field and laboratory techniques to determine changes associated with 3 typical forms of agricultural management: long-term pasture, cropping with shallow tillage using discs and tines, and cropping (including potatoes) with more rigorous and deeper tillage including deep ripping and powered implements. Soil organic carbon in the surface 75 mm was 7.0&percnt; under long-term pasture compared with 4.3&percnt; and 4.2&percnt; in cropped paddocks. Microbial biomass carbon concentrations were 217 mg&sol;kg, 161 mg&sol;kg, and 139 mg&sol;kg, respectively. These differences were negatively correlated with the number of years cropped. Greater bulk densities were found in the surface layer of cropped paddocks but these were not associated with increased penetration resistance or decreased infiltration rate and are unlikely to impede root growth. Long-term pasture paddocks showed stronger structural development and had smaller clods than cropped paddocks. Vane shear strength and penetration resistance were lower in cropped paddocks than under long-term pasture. Many soil attributes showed no significant differences associated with management. Including potatoes in the rotation did not appear to affect these dermosols, which indicates a degree of robustness in these soils. clay loams, organic carbon, soil strength, aggregate stability, land management, cropping.

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