The Restoration of a Structurally Degenerated Soil1

Telfair, D.; Garner, Murvel R.; Miars, David

doi:10.2136/sssaj1957.03615995002100020001x

Cited by 20 publications

(7 citation statements)

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“…While the role of plants in creating various soil structural features is well known, the mechanisms involved have not been precisely defined or quantified. Some of the studies on this subject include those of Horn and Dexter (1989), Semmel et al (1990), Telfair et al (1957) and Terpstra (1989). There still remains need for more and better understanding of the mechanisms underlying the dynamics of aggregation by plant roots.…”

Section: Introductionmentioning

confidence: 99%

Formation of aggregates by plant roots in homogenised soils

1992

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The influence of root growth and water regime on the formation of aggregates was studied in modified minirhizotrons under controlled conditions. Two soils, a black earth (67% clay) and a red-brown earth (19% clay) were ground and forced through a 0.5 mm sieve. Ryegrass, pea and wheat were grown for fifteen wetting and drying (wd) cycles for 5 months. Another set of minirhizotrons was not planted and served as a control. Measurements of aggregate size distribution (ASD), aggregate tensile strength (ATS), aggregate stability (AS), aggregate bulk density (ABD) and organic carbon (OC) were made on single aggregates of the 2-4 mm fraction.The results showed that aggregates of the black earth which has a high clay content and shrink/swell properties had more smaller aggregates with higher ATS, AS and ABD than those from the red-brown earth. It was also found that for both soils: (1) w/d cycles and higher root length density (RLD) increased the proportions of smaller aggregates and aggregate strength; (2) differences in the ability of the plant species to influence aggregation was evident and seemed to be related to the RLD. The RLD was in the order ryegrass > wheat > pea. Mechanisms likely to be involved in processes of aggregate formation and stabilization are discussed. They include cracking of soil due to tensile stresses generated during drying of a shrinking soil; changes in pore water pressure within the soil mass caused by water uptake by plant roots generating effective stresses; and biological processes associated with plant roots and root exudates.

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Section: Introductionmentioning

confidence: 99%

Formation of aggregates by plant roots in homogenised soils

1992

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“…Thus, W-D cycles can affect soil resistance measured by cone penetration, particle cohesion, internal friction, aggregate size and their mechanical stability (Rajaram and Erbach, 1999). These cycles can also result in aggregate formation in non-aggregated soils restoring the damaged structure of some soils (Telfair et al, 1957;Newman and Thomasson, 1979). According to Dexter (1988), W-D cycles affect directly soil aggregation due to the action of forces among soil particles and soil aggregates.…”

Section: Soil Structure Changes Due To Wetting and Drying Cyclesmentioning

confidence: 99%

Gamma-Ray Computed Tomography in Soil Science: Some Applications

Pires¹,

Cássaro²,

Bacchi³

et al. 2011

Computed Tomography - Special Applications

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“…Some authors have shown that sequences of W-D cycles can cause, for instance, aggregate formation in non-aggregated soils. It can in some circumstances regenerate structurally damaged soils and can induce, by increasing soil porosity, significant changes in SPS (Pagliai 1987, Sartori et al 1985, Newman and Thomasson 1979, Telfair et al 1957.…”

Section: Luiz F Pires Et Almentioning

confidence: 99%

Pore system changes of damaged Brazilian oxisols and nitosols induced by wet-dry cycles as seen in 2-D micromorphologic image analysis

Pires

Reichardt²,

Cooper³

et al. 2009

An. Acad. Bras. Ciênc.

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Soil pore structure characterization using 2-D image analysis constitutes a simple method to obtain essential information related to soil porosity and pore size distribution (PSD). Such information is important to infer on soil quality, which is related to soil structure and transport processes inside the soil. Most of the time soils are submitted to wetting and drying cycles (W-D), which can cause important changes in soils with damaged structures. This report uses 2-D image analysis to evaluate possible modifications induced by W-D cycles on the structure of damaged soil samples. Samples of three tropical soils (Geric Ferralsol, GF; Eutric Nitosol, EN; and Rhodic Ferralsol, RF) were submitted to three treatments: 0WD, the control treatment in which samples were not submitted to any W-D cycle; 3WD and 9WD with samples submitted to 3 and 9 consecutive W-D cycles, respectively. It was observed that W-D cycles produced significant changes in large irregular pores of the GF and RF soils, and in rounded pores of the EN soil. Nevertheless, important changes in smaller pores (35, 75, and 150 μm) were also observed for all soils. As an overall consideration, it can be said that the use of image analysis helped to explain important changes in soil pore systems (shape, number, and size distribution) as consequence of W-D cycles.

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The Restoration of a Structurally Degenerated Soil1

Cited by 20 publications

References 0 publications

Formation of aggregates by plant roots in homogenised soils

Formation of aggregates by plant roots in homogenised soils

Gamma-Ray Computed Tomography in Soil Science: Some Applications

Pore system changes of damaged Brazilian oxisols and nitosols induced by wet-dry cycles as seen in 2-D micromorphologic image analysis

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