scholarly journals Temporal Changes in Wet Aggregate Stability

1992 ◽  
Vol 35 (2) ◽  
pp. 493-498 ◽  
Author(s):  
G. A. Lehrsch ◽  
P. M. Jolley
2018 ◽  
Vol 98 (4) ◽  
pp. 738-742 ◽  
Author(s):  
L.L. Van Eerd ◽  
A.H. DeBruyn ◽  
L. Ouellette ◽  
D.C. Hooker ◽  
D.E. Robinson

Automated wet-sieving is preferred for this clay loam soil due to better sensitivity and savings (time and disposables) despite a larger capital investment. Rotations with greater frequency of winter wheat and no-till compared with conventional plow system had greater wet aggregate stability values, indicating better surface soil quality.


1993 ◽  
Vol 73 (4) ◽  
pp. 481-488 ◽  
Author(s):  
B. J. Zebarth ◽  
S. Freyman ◽  
C. G. Kowalenko

The use of inter-row ground covers has been suggested to reduce soil degradation in raspberry (Rubus idaeus L.) production. The effect after 6 yr of consistent inter-row management of ground covers or roto-tillage in raspberry on soil wet aggregate stability (WAS), bulk density, organic C and total N, and mineralizable nitrogen in the Fraser Valley of British Columbia was studied. Management treatments included no cover crop or cover crops of barley (Hordeum vulgare L.), sheep's fescue (Festuca ovina L.), perennial ryegrass (Lolium perenne L.), and white clover (Trifolium repens L.). A general pattern of perennial grasses > legume and barley > control was observed for soil WAS. Some quantitative and qualitative differences in the organic component of the soil profile to 30 cm were detected among management treatments. The differences were not statistically strong because the changes were small relative to the large pool present, but were relatively consistent overall. The white clover treatment tended to have more organic carbon, particularly in the subsurface, than the other treatments. The four treatments that included inter-row vegetation tended to have a greater amount of total and mineralizable N than the clean-tilled control. Crop vigour, as indicated by cane diameter, was reduced by the perennial grasses, but the inter-row management had only limited effects on berry yield. White clover appears to provide the best compromise between improving soil quality and minimizing competition with the berry crop. Key words: Wet aggregate stability, barley, sheep's fescue, perennial ryegrass, white clover


2020 ◽  
Vol 12 (5) ◽  
pp. 2071 ◽  
Author(s):  
Márcio R. Nunes ◽  
Douglas L. Karlen ◽  
Thomas B. Moorman

Tillage intensity affects soil structure in many ways but the magnitude and type (+/−) of change depends on site-specific (e.g., soil type) and experimental details (crop rotation, study length, sampling depth, etc.). This meta-analysis examines published effects of chisel plowing (CP), no-tillage (NT) and perennial cropping systems (PER) relative to moldboard plowing (MP) on three soil structure indicators: wet aggregate stability (AS), bulk density (BD) and soil penetration resistance (PR). The data represents four depth increments (from 0 to >40-cm) in 295 studies from throughout the continental U.S. Overall, converting from MP to CP did not affect those soil structure indicators but reducing tillage intensity from MP to NT increased AS in the surface (<15-cm) and slightly decreased BD and PR below 25-cm. The largest positive effect of NT on AS was observed within Inceptisols and Entisols after a minimum of three years. Compared to MP, NT had a minimal effect on soil compaction indicators (BD and PR) but as expected, converting from MP to PER systems improved soil structure at all soil depths (0 to >40-cm). Among those three soil structure indicators, AS was the most sensitive to management practices; thus, it should be used as a physical indicator for overall soil health assessment. In addition, based on this national meta-analysis, we conclude that reducing tillage intensity improves soil structure, thus offering producers assurance those practices are feasible for crop production and that they will also help sustain soil resources.


2006 ◽  
Vol 20 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Eleonora Bonifacio ◽  
Stefania Santoni ◽  
Gloria Falsone ◽  
Ermanno Zanini

2019 ◽  
Vol 99 (2) ◽  
pp. 222-225
Author(s):  
Ben W. Thomas ◽  
Derek Hunt ◽  
Shabtai Bittman ◽  
Kirsten D. Hannam ◽  
Aimé J. Messiga ◽  
...  

The lower Fraser Valley is one of the most intensively cropped regions in Canada. Yet, how soil health indicators respond to long-term intensive agricultural management is poorly documented in this region. Thus, we evaluated a suite of soil health indicators in response to 21 growing seasons of continuous silage corn (Zea mays L.) under conventional tillage or no-tillage (0–20 cm soil layer). Wet aggregate stability, available water capacity, active carbon (permanganate oxidizable, POXC), and extractable potassium and extractable magnesium were significantly greater with no-till than conventional tillage, whereas 8 of 13 indicators were similar. Soil health indicators responded more favourably to no-till than conventional tillage.


1991 ◽  
Vol 71 (1) ◽  
pp. 67-72 ◽  
Author(s):  
E. L. Dickson ◽  
V. Rasiah ◽  
P. H. Groenevelt

Variabilities in measured values of wet aggregate stability (WAS) of replicate samples of treatment exceeding that between treatments can create problems in interpreting treatment effects. The variabilities in WAS of replicate samples of treatment can be minimized by subjecting soil aggregates to a high vacuum fast prewetting technique. However, this technique is laborious and time consuming. In this paper the effect of four prewetting techniques: (1) and (2) high vacuum fast (HVFW) and slow (HVSW) wetting; (3) and (4) no vacuum (atmospheric) fast (NVFW) and slow wetting (NVSW) on the variations in WAS and coefficient of variation (CV) of WAS are reported. The measured values in WAS and CV of WAS for each soil varied with wetting rate and/or gas pressure used. The highest variation in WAS was found with NVFW, HVFW, NVSW and HVSW, respectively. For three out of four soils, the CV of WAS for NVSW technique was less than 2%, which was similar to that obtained under HVFW technique. Compared to HVFW technique, NVSW technique is simple, less laborious and less time consuming. Key words: Wet aggregate stability, prewetting techniques, vacuum wetting.


Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 218 ◽  
Author(s):  
J. M. Kirkham ◽  
B. A. Rowe ◽  
R. B. Doyle

Changes in the soil structure and hydraulic conductivity of an Acidic Red Ferrosol were measured in a long-term (1968–2003) fertiliser experiment on pasture in north-western Tasmania, Australia. Studies were initiated following observations of both softer soil surface and cracking on plots that had received 15 t/ha of ground agricultural limestone. Liming decreased penetration resistance and increased hydraulic conductivity. These structural improvements were associated with increased mean dry aggregate size, a small increase in wet aggregate stability, higher exchangeable calcium levels, and increased plant growth, but a 9% decrease in total soil organic carbon in the surface 50 mm. This decrease in organic carbon was not associated with deterioration in soil structure, as may have been anticipated. This was probably because total organic C was still 82 g/kg on unlimed plots. Decreases in soil penetration resistance due to liming increased the likelihood of pugging from livestock but may improve ease of tillage. This research demonstrates that liming can improve the structure of a well-aggregated Ferrosol as well as its previously reported effects of increasing soil pH and yields of pasture and barley despite decreasing organic C.


2014 ◽  
Vol 53 (9) ◽  
pp. 694-703 ◽  
Author(s):  
C. Buchmann ◽  
M. Meyer ◽  
G. E. Schaumann

1998 ◽  
Vol 13 (3) ◽  
pp. 132-137 ◽  
Author(s):  
Roger Lalande ◽  
Valentin Furlan ◽  
Denis A. Angers ◽  
Gilles Lemieux

AbstractWood residues are applied to soils to improve their organic matter content and related biological, physical, and chemical properties. We monitored the changes in soil total C and N content, the bacterial, fungal and actinomycetal populations, and microbial biomass and activity during 20 weeks in the first season following the application of chipped wood from twigs (CWT), and as residual effects during the second growing season on a loamy soil (coarse loamy, mixed, frigid, Humic Fragiorthod) in Sainte-Brigitte-des-Saults (Québec) Canada. Wet-aggregate stability and the content of nutrients of the soil also were determined. Adding CWT stimulated the bacterial and actinomycetal populations very rapidly (within 8 weeks); in the second season the effect was less pronounced and gradually disappeared. The most significant and long-lasting effect was on the fungal population in two consecutive years of observation, with increases of up to 24-fold. This stimulation of fungi possibly was responsible for the large and significant increase in wet-aggregate stability observed in the second year. The effect of CWT on alkaline phosphatase activity and total C and N was observed only in the second season. Someimmobilization was seen only in the season immediately following residue application. The addition of the CWT also supplied micronutrients, in particular Zn, which would make it a useful source of some elements in deficient soils. Application of CWT to this soil greatly improved its quality, as revealed by its biological, chemical, and physical attributes.


1996 ◽  
Vol 76 (4) ◽  
pp. 549-555 ◽  
Author(s):  
M. A. Arshad ◽  
K. S. Gill

There is an increased use of no-tillage (NT) methods in soils of the Peace River region of Alberta–British Columbia where a good proportion of acid soils exist. There is little information, however, on how crops, soils, and weeds respond to liming under different tillage intensities. A Hythe clay loam (Gray Luvisol; initial pH in CaCl2 ≈ 5) was limed (7.5 t ha−1) in May 1991. Field pea (Pisum sativum L.) yield, soil properties, and weed populations under conventional tillage (CT) and NT were monitored during three growing seasons (1993–1995). The pH of limed soil in the 0–10 cm layer ranged from 6.0 to 6.3. Liming slightly increased NO3-N, P and bulk density of soil, lowered exchangeable Al concentration and wet aggregate stability, and had no effect on NH4-N and penetration resistance. Liming increased the grain yield by 0.50 (22%) t ha−1 yr−1 in CT and by 0.55 (18%) t ha−1 yr−1 in NT. Aboveground dry matter (DM) increase of 1.37 (27%) t ha−1 yr−1 in CT and 1.72 (25%) t ha−1 yr−1 in NT was obtained due to liming. Populations of annual broadleaf, annual grass and perennial weeds were not affected by either liming or tillage. Reduced soil acidity and exchangeable Al in conjunction with increased NO3-N and P contributed to increased crop yield by liming under both CT and NT. Higher soil moisture in the NT contributed to increased yield in comparison to CT system, as other soil properties and weed population were not significantly affected by tillage. Key words: No tillage, Pisum sativum L., exchangeable aluminium, wet aggregate stability


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