Effects of soil modification and treading on pasture growth and physical properties of an irrigated red-brown earth

1985 ◽  
Vol 36 (6) ◽  
pp. 799 ◽  
Author(s):  
KB Kelly
Keyword(s):  
Bulk Density ◽  
Soil Profile ◽  
Surface Soil ◽  
Pore Space ◽  
Cumulative Effect ◽  
Soil Bulk Density ◽  
Pasture Production ◽  
Profile Modification ◽  
Penetrometer Resistance ◽  
Normal Soil

Lemnos loam, a red-brown earth used extensively for pasture production in northern Victoria, and its exposed subsoil (topsoil removed) were both subjected to surface cultivation and total profile modification. Total profile modification consisted of excavating and mixing the top 1.1 m of soil and incorporating gypsum (10 t ha-1), superphosphate (4.5 t ha-1) and ammonium nitrate (0.5 t ha-1) . A white clover-perennial ryegrass pasture was established. Treading by cattle was superimposed over these soil treatments. Exposure of the subsoil, as often occurs with laser landforming, reduced pasture growth by 30% compared with a normal soil profile. Modification of the exposed subsoil negated this effect. Modification of the normal soil profile had little effect on pasture production but did influence pasture composition. Treading had a cumulative effect with time, reducing pasture production by 6, 9 and 12% in 1981, 1982 and 1983, respectively. This occurred despite the precaution of allowing grazing only when the soil was dry. Profile modification resulted in increased pore space and root growth, and lowered bulk density and penetrometer resistance at depth. Treading increased surface soil bulk density, with penetrometer studies showing that this effect was confined to the top 0.15 m.

Forest Soil Compaction: Effect of Multiple Passes and Loadings on Wheel Track Surface Soil Bulk Density

1988 ◽  
Vol 5 (2) ◽  
pp. 120-123 ◽  
Author(s):  
Stephen G. Shetron ◽  
John A. Sturos ◽  
Eunice Padley ◽  
Carl Trettin
Keyword(s):  
Bulk Density ◽  
Soil Compaction ◽  
Surface Soil ◽  
Soil Bulk Density ◽  
Northern Red Oak ◽  
Wheel Drive ◽  
Density Values ◽  
Track Surface ◽  
Four Wheel Drive ◽  
Wheel Track

Abstract The change in wheel track surface soil bulk densities was determined after a mechanized thinning in a northern red oak stand. Mean bulk density values of the 0 to 5 cm surface of the wheel tracks immediately after felling, bunching, and skidding were: 0.80 g/cc on the high use areas; 0.77 g/cc on the low use areas; and 0.42 g/cc in the undisturbed areas. No significant differences in surface soil bulk densities were found between several loading treatments using a four-wheel drive articulated forwarder. The data indicate that initial passes of the equipment produce most of the disturbance. No significant recovery in wheel track soil bulk densities occurred during the year following harvest regardless of treatment. North. J. Appl. For. 5:120-123, June 1988.

Stocking intensity and pastoral production: I. Changes in the soil and vegetation of a sown pasture grazed by sheep at different stocking rates

1973 ◽  
Vol 81 (2) ◽  
pp. 193-204 ◽  
Author(s):  
J. P. Langlands ◽  
I. L. Bennett
Keyword(s):  
Soil Moisture ◽  
Bulk Density ◽  
Pore Space ◽  
Water Infiltration ◽  
Root Weight ◽  
Stocking Rate ◽  
Pasture Production ◽  
Basal Cover ◽  
Soil Pore Space ◽  
Stocking Rates

SummaryA Phalaris tuberosa and Trifolium repens pasture was grazed continuously at stocking rates varying from 2·5 to 37·1 sheep per ha between 1964 and 1969. During this period herbage availability and composition, basal cover, root weight, water infiltration, soil moisture content, bulk density and chemical composition of the soil were measured at intervals.As stocking rate was increased, herbage availability, root weight, basal cover, soil pore space and the rate of water infiltration declined, and bulk density and the nitrogen and calcium contents of the herbage on offer increased. In periods of below-average rainfall, soil moisture and nitrate levels were greater when herbage was of low availability.Herbage production was calculated from estimates of herbage consumption and of litter decomposition, and averaged 8·45 t dry matter/ha/year; it was insensitive to changes in stocking rate over the range from 2 to 22 sheep/ha. The ratio, herbage consumption/ pasture production increased by 0'045 per unit increase in stocking rate.

Spatial variability of soil porosity under reduced tillage in a Humo-Ferric Podzol

1995 ◽  
Vol 75 (1) ◽  
pp. 149-152 ◽  
Author(s):  
M. R. Carter
Keyword(s):  
Bulk Density ◽  
Prince Edward Island ◽  
Pore Space ◽  
Soil Bulk Density ◽  
Soil Sampling ◽  
Moisture Regime ◽  
Humid Climate ◽  
Soil Moisture Regime ◽  
Classical Statistics ◽  
Water Filled Pore Space

The spatial and random variability of soil bulk density, water-filled pore space and macroporosity, which are important indices of soil physical quality in a humid soil moisture regime, were studied in soil samples taken from direct-drilled rotations at Charlottetown, Prince Edward Island. Classical statistics indicated variation was low for bulk density (CV = 3.0–5.8%) and water-filled pore space (CV = 7.4–10.3%), and medium (CV = 15.7–29.6%) for macropore volume. Spatial variation determined using variograms indicated some degree of spatial structure. The ability of variograms to divide sample variance into random and spatial components allows improved estimation of soil sampling size and spacing. Key words: Geostatistics, soil sampling, direct-drilling, humid climate

scholarly journals Estimation of the density of the clay-organic complex in soil

2016 ◽  
Vol 30 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Ewa A. Czyż ◽  
Anthony R. Dexter
Keyword(s):  
Organic Matter ◽  
Bulk Density ◽  
Pore Space ◽  
Organic Matter Content ◽  
Soil Bulk Density ◽  
Matter Content ◽  
Gas Content ◽  
Effective Density ◽  
Organic Complex ◽  
Arable Soils

Abstract Soil bulk density was investigated as a function of soil contents of clay and organic matter in arable agricultural soils at a range of locations. The contents of clay and organic matter were used in an algorithmic procedure to calculate the amounts of clay-organic complex in the soils. Values of soil bulk density as a function of soil organic matter content were used to estimate the amount of pore space occupied by unit amount of complex. These estimations show that the effective density of the clay-organic matter complex is very low with a mean value of 0.17 ± 0.04 g ml−1 in arable soils. This value is much smaller than the soil bulk density and smaller than any of the other components of the soil considered separately (with the exception of the gas content). This low value suggests that the clay-soil complex has an extremely porous and open structure. When the complex is considered as a separate phase in soil, it can account for the observed reduction of bulk density with increasing content of organic matter.

Seasonal Dynamics of Surface Soil Bulk Density in a Forested Catchment

2015 ◽  
Vol 79 (4) ◽  
pp. 1163-1168 ◽  
Author(s):  
Adrienne C. Nottingham ◽  
James A. Thompson ◽  
Philip J. Turk ◽  
Qiuchen Li ◽  
Stephanie J. Connolly
Keyword(s):  
Bulk Density ◽  
Seasonal Dynamics ◽  
Surface Soil ◽  
Soil Bulk Density ◽  
Forested Catchment

INFLUENCE OF SOIL BULK DENSITY AND MATRIC PRESSURE ON SOIL RESISTANCE TO PENETRATION

1972 ◽  
Vol 52 (3) ◽  
pp. 477-483 ◽  
Author(s):  
H. F. MIRREH ◽  
J. W. KETCHESON
Keyword(s):  
Bulk Density ◽  
Three Dimensional ◽  
Soil Bulk Density ◽  
Soil Resistance ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Penetrometer Resistance ◽  
Loam Soil ◽  
Pass Through ◽  
Resistance To Penetration

Cylinders of a clay loam soil were adjusted to different bulk density and matric pressure combinations to study soil resistance to a penetrating probe. Regression analysis of the penetrometer data produced no evidence to reject a regression model of the form Y = β0X0 + β1X1 + β2X2 + β3X12 + β4X22 + β5X1X2 (where Y = penetrometer resistance, X1 = bulk density, X2 = matric pressure). A three-dimensional plot of the generated soil resistance values was constructed to illustrate the nature of the interaction. At any one bulk density in the range 1.0–1.5 g/cc, soil resistance values tended to pass through a maximum as soil moisture was removed over the matric pressure range 1.0–8.0 atm. The tendency was most pronounced at the lower bulk densities. Implications on root growth and soil management are briefly discussed.

scholarly journals Estimating soil water retention for wide ranges of pressure head and bulk density based on a fractional bulk density concept

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Huihui Sun ◽  
Jaehoon Lee ◽  
Xijuan Chen ◽  
Jie Zhuang
Keyword(s):  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Water Retention ◽  
Pore Space ◽  
Pressure Head ◽  
Soil Bulk Density ◽  
Residual Water ◽  
Soil Water Retention ◽  
Residual Water Content

Abstract Soil water retention determines plant water availability and contaminant transport processes in the subsurface environment. However, it is usually difficult to measure soil water retention characteristics. In this study, an analytical model based on a fractional bulk density (FBD) concept was presented for estimating soil water retention curves. The concept allows partitioning of soil pore space according to the relative contribution of certain size fractions of particles to the change in total pore space. The input parameters of the model are particle size distribution (PSD), bulk density, and residual water content at water pressure head of 15,000 cm. The model was tested on 30 sets of water retention data obtained from various types of soils that cover wide ranges of soil texture from clay to sand and soil bulk density from 0.33 g/cm3 to 1.65 g/cm3. Results showed that the FBD model was effective for all soil textures and bulk densities. The estimation was more sensitive to the changes in soil bulk density and residual water content than PSD parameters. The proposed model provides an easy way to evaluate the impacts of soil bulk density on water conservation in soils that are manipulated by mechanical operation.

scholarly journals Uncertainties in the prediction of spatial variability of soil CO2 emissions and related properties

2012 ◽  
Vol 36 (5) ◽  
pp. 1466-1475 ◽  
Author(s):  
Daniel De Bortoli Teixeira ◽  
Elton da Silva Bicalho ◽  
Alan Rodrigo Panosso ◽  
Luciano Ito Perillo ◽  
Juliano Luciani Iamaguti ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Respiration ◽  
Spatial Variability ◽  
Bulk Density ◽  
Ordinary Kriging ◽  
Co2 Emission ◽  
Pore Space ◽  
Soil Bulk Density ◽  
Soil Co2 ◽  
Soil Co2 Emission

The soil CO2 emission has high spatial variability because it depends strongly on soil properties. The purpose of this study was to (i) characterize the spatial variability of soil respiration and related properties, (ii) evaluate the accuracy of results of the ordinary kriging method and sequential Gaussian simulation, and (iii) evaluate the uncertainty in predicting the spatial variability of soil CO2 emission and other properties using sequential Gaussian simulations. The study was conducted in a sugarcane area, using a regular sampling grid with 141 points, where soil CO2 emission, soil temperature, air-filled pore space, soil organic matter and soil bulk density were evaluated. All variables showed spatial dependence structure. The soil CO2 emission was positively correlated with organic matter (r = 0.25, p < 0.05) and air-filled pore space (r = 0.27, p < 0.01) and negatively with soil bulk density (r = -0.41, p < 0.01). However, when the estimated spatial values were considered, the air-filled pore space was the variable mainly responsible for the spatial characteristics of soil respiration, with a correlation of 0.26 (p < 0.01). For all variables, individual simulations represented the cumulative distribution functions and variograms better than ordinary kriging and E-type estimates. The greatest uncertainties in predicting soil CO2 emission were associated with areas with the highest estimated values, which produced estimates from 0.18 to 1.85 t CO2 ha-1, according to the different scenarios considered. The knowledge of the uncertainties generated by the different scenarios can be used in inventories of greenhouse gases, to provide conservative estimates of the potential emission of these gases.

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