Soil solution composition and aggregate stability changes caused by long-term farming at four contrasting sites in South Australia

Soil Research ◽  
1996 ◽  
Vol 34 (4) ◽  
pp. 511 ◽  
Author(s):  
R Naidu ◽  
S Mcclure ◽  
NJ Mckenzie ◽  
RW Fitzpatrick
Keyword(s):  
Organic Matter ◽  
Soil Solution ◽  
South Australia ◽  
Aggregate Stability ◽  
Fungal Hypha ◽  
Organic Carbon Content ◽  
Solution Composition ◽  
Horizon Scanning ◽  
Undisturbed Soils

The effect of long-term farming on the cation exchange capacity (CEC), organic carbon content, soil solution composition, and aggregate stability was investigated using contrasting soils from 4 sites in the Mid North of South Australia. Undisturbed and farmed profiles were characterised at each site. Farming led to a 10–50% decrease, approximately, in organic matter and CEC in the surface horizon. Scanning electron microscopic study of the surface and selected subsurface soils revealed poor aggregation, compaction, reduced porosity, and a decrease in aggregate particle size in the farmed surface soils. Intra-aggregate binding in the undisturbed soils appeared to be largely due to fungal hypha, with the roots largely contributing to inter-aggregate binding of soil particles. Electrical conductivity (EC) of soil solutions was generally 2–3 times higher in the undisturbed soils than farmed soils, suggesting increased leaching of ions associated with loss of tree cover. This was also supported by a decrease in the concentrations of mobile ions such as Cl-and Na+ in the farmed soils. The concentrations of Na+ and K+ decreased with farming leading to a decrease in the Gapon selectivity constant for Na–Ca and K–Ca exchange. The changes in soil solution composition together with the decline in organic matter concentrations resulted in increased sensitivity of soils to dispersion.

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.

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.

Organic matter mobilization as affected by soil-solution composition and prevailing clay minerals

2002 ◽  
Vol 33 (13-14) ◽  
pp. 2291-2299 ◽  
Author(s):  
Roberto S. Martínez ◽  
Pablo Zalba ◽  
María B. Villamil ◽  
Norman Peinemann
Keyword(s):  
Organic Matter ◽  
Clay Minerals ◽  
Soil Solution ◽  
Solution Composition

Influence of plant roots on rhizosphere soil solution composition of long-term contaminated soils

Geoderma ◽  
2010 ◽  
Vol 155 (1-2) ◽  
pp. 86-92 ◽  
Author(s):  
Kwon-Rae Kim ◽  
Gary Owens ◽  
Ravi Naidu ◽  
Soon-lk Kwon
Keyword(s):  
Soil Solution ◽  
Contaminated Soils ◽  
Rhizosphere Soil ◽  
Plant Roots ◽  
Solution Composition

Modelling dynamic interactions between soil structure and soil organic matter

2020 ◽  
Author(s):  
Nicholas Jarvis ◽  
Elsa Coucheney ◽  
Claire Chenu ◽  
Anke Herrmann ◽  
Thomas Keller ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Physical Properties ◽  
Management Practices ◽  
Animal Manure ◽  
Soil Bulk Density ◽  
Organic Carbon Content

&lt;p&gt;The aggregated structure of soil is known to reduce rates of soil organic matter (SOM) decomposition and therefore influence the potential for long-term carbon sequestration. In turn, the storage and turnover of SOM strongly determines soil aggregation and thus the physical properties of soil. The two-way nature of these interactions has not yet been explicitly considered in soil organic matter models. In this study, we present and describe a new model of these dynamic feedbacks between SOM storage, soil pore structure and soil physical properties. We show the results of a test of the model against measurements made during 61 years in a field trial located near Uppsala (Sweden) in two treatments with different OM inputs (bare fallow, animal manure). The model was able to successfully reproduce long-term trends in soil bulk density and organic carbon content (SOC), as well as match limited data on soil pore size distribution and surface elevation. The results suggest that the model approach presented here could prove useful in analyses of the effects of soil and crop management practices and climate change on the long-term potential for soil organic carbon sequestration.&lt;/p&gt;

scholarly journals Characterisation of soil organic matter in long-term fallow experiment with respect to the soil hydrophobicity and wettability

2008 ◽  
Vol 2 (No. 3) ◽  
pp. 96-103 ◽  
Author(s):  
T. Šimon
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Functional Groups ◽  
Farmyard Manure ◽  
Degradation Process ◽  
Conventional Tillage ◽  
Organic Carbon Content ◽  
Hydrophobicity Index ◽  
Time Period

Soil organic matter under different tillage and fertilisation systems of long-term fallow experiment established in 1958 in Prague was characterised in period of 1972&ndash;2004. This experiment consists of seven variants (control (no tillage, no manuring); farmyard manure compost (FYM); 2FYM; mineral fertilisation (NPK); 2NPK; reduced tillage (RT), and conventional tillage (CT)). In 1989, regular manuring and tillage were terminated and since then the plots have been maintained bare. Organic carbon content (C<sub>ox</sub>) was analysed and the hydrophobic (A) and hydrophilic (B) functional groups were determined using Fourier-transform infrared (FTIR) spectroscopy. Hydrophobicity index (HI) and soil wettability (A/B ratio) were assessed in the experimental variants. A high significant positive correlation (r = 0.976; P &lt; 0.05) was found, between hydrophobic functional groups (Band A) and C<sub>ox</sub>, hydrophilic functional groups (Band B) did not correlate with C<sub>ox</sub>. Soil wettability tended to decrease after the organic manuring was finished with the result that the values of A/B ratio were significantly different according to the farmyard manure doses applied. On the contrary, HI responded to organic manuring termination later on and no significant differences were found between different farmyard manure doses. In the variants without any fertilisation, a continual decrease in both soil wettability and hydrophobicity during the selected time period was found; the degradation process is going on in these variants.

scholarly journals Modelling Salinity and Sodicity Risks of Long-Term Use of Recycled Water for Irrigation of Horticultural Crops

Soil Systems ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 49
Author(s):  
Vinod Phogat ◽  
Dirk Mallants ◽  
Jirka Šimůnek ◽  
James W. Cox ◽  
Paul R. Petrie ◽  
...  
Keyword(s):  
Soil Solution ◽  
Crop Production ◽  
Root Zone ◽  
South Australia ◽  
Recycled Water ◽  
Management Scenarios ◽  
Management Options ◽  
Horticultural Crops ◽  
The Impact

Long-term use of recycled water (RW) for irrigation in arid and semiarid regions usually changes the soil solution composition and soil exchange characteristics, enhancing the risk for salinity and sodicity hazards in soils. This modelling study focuses on developing alternative management options that can reduce the potentially harmful impacts of RW use on the irrigation of wine grapes and almonds. The multicomponent UNSATCHEM add-on module for HYDRUS-1D was used to evaluate the impact of long-term (2018–2050) use of irrigation waters of different compositions: good-quality low-salinity (175 mg/L) water (GW), recycled water with 1200 mg/L salinity (RW), blended water of GW and RW in the 1:1 proportion (B), and monthly (Alt1) and half-yearly (Alt6) alternate use of GW and RW. The management options include different levels of annual gypsum applications (0, 1.7, 4.3, and 8.6 t/ha soil) to the calcareous (Cal) and hard red-brown (HRB) soils occurring in the Northern Adelaide Plain (NAP) region, South Australia. Additional management scenarios involve considering different leaching fractions (LF) (0.2, 0.3, 0.4, and 0.5) to reduce the salinity build-up in the soil. A new routine in UNSATCHEM to simulate annual gypsum applications was developed and tested for its applicability for ameliorating irrigation-induced soil sodicity. The 1970–2017 period with GW irrigation was used as a warmup period for the model. The water quality was switched from 2018 onwards to reflect different irrigation water qualities, gypsum applications, and LF levels. The data showed that the GW, B, Alt1, and Alt6 irrigation scenarios resulted in lower soil solution salinity (ECsw) than the RW irrigation scenario, which led to increased ECsw values (4.1–6.6 dS/m) in the soil. Annual gypsum applications of 1.7, 4.3, and 8.6 t/ha reduced pH, SAR, and ESP in both soils and reduced the adverse impacts of irrigation, especially in surface soils. A combination of water blending or cyclic water use with 3.8 t/ha annual gypsum applications showed promise for the SAR and ESP control. Additionally, irrigation with RW, a 0.2 LF, and annual gypsum applications limited the harmful salinity impacts in the soils. However, in the RW irrigation scenario, ECsw and ESP at the bottom of the crop root zone (90–120 cm depth) in the HRB soil were still higher than the wine grape and almond salinity thresholds. Thus, annual amendment applications, combined with the long-term use of blended water or cyclic use of RW and GW, represent a sustainable management option for crop production at the calcareous and hard red-brown soils.

Impact of long-term organic residue recycling in agriculture on soil solution composition and trace metal leaching in soils

2014 ◽  
Vol 499 ◽  
pp. 560-573 ◽  
Author(s):  
Philippe Cambier ◽  
Valérie Pot ◽  
Vincent Mercier ◽  
Aurélia Michaud ◽  
Pierre Benoit ◽  
...  
Keyword(s):  
Trace Metal ◽  
Soil Solution ◽  
Metal Leaching ◽  
Organic Residue ◽  
Solution Composition

Soil structural conditions of vineyards under two soil management systems

1985 ◽  
Vol 25 (2) ◽  
pp. 450 ◽  
Author(s):  
GJ Cock
Keyword(s):  
Root Growth ◽  
Sandy Loam ◽  
South Australia ◽  
Aggregate Stability ◽  
Soil Management ◽  
Penetration Resistance ◽  
Management Systems ◽  
Zero Tillage ◽  
Vineyard Soil

The soil structural conditions of two management systems of vineyard soil on Barmera Sandy Loam in the Riverland of South Australia were compared. Three years of zero cultivation and weed mulching were compared with long term winter cropping and cultivation between vines. Significant increases in 1 mm dry aggregates, aggregate stability and percentage of large pores were measured under zero tillage. Significant reductions also occurred for bulk density and penetration resistance of the 6-12 cm layer of the zero-tilled soil. The results suggest that infiltration, aeration and root growth of vines would improve under a long-term program of zero tillage and weed mulching.

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