Soil bulk density effects on soil microbial populations and enzyme activities during the growth of maize (Zea mays L.) planted in large pots under field exposure

2002 ◽  
Vol 82 (2) ◽  
pp. 147-154 ◽  
Author(s):  
C. H. Li ◽  
B. L. Ma ◽  
T. Q. Zhang
Keyword(s):  
Zea Mays ◽  
Bulk Density ◽  
Enzyme Activities ◽  
Soil Compaction ◽  
Microbial Population ◽  
Soil Bulk Density ◽  
Microbial Populations ◽  
Growth Stages ◽  
Soil Microbial ◽  
Plant Growth Stages

Soil compaction associated with inappropriate maneuvering of field equipment, and/or modern cropping system negatively affect soil physical properties, and thus, may limit microbial activities and biochemical processes, which are important to nutrient bioavailability. An experiment was carried out using the pot-culture technique to determine the effect of bulk density on soil microbial populations and enzyme activities in an Eutric Cambisol sandy loam soil (United Nations’ classification) planted with maize (Zea mays L.) in the Experimental Farm of Henan Agricultural University, Henan, China (34°49′N, 113°40′E). Numbers of bacteria, fungi, and actinomycetes and the enzyme activities of invertase, polyphenol oxidase, catalase, urease, protease, and phosphatase were determined at various stages during the plant growing season. Microbial numbers were negatively and linearly related to soil bulk density. With increases in soil bulk density from 1.00 to 1.60 Mg m-3, total numbers of bacteria, fungi and actinomycetes declined by 26-39%. The strongest correlations between the soil microbial population and bulk density occurred at the plant growth stages of the 6 fully expanded leaf (V6) and anthesis (R1), with R2 > 0.90 (P< 0.01) for all three microorganism categories. Increasing soil bulk density was related quadratically to the activities of soil invertase and polyphenol oxidase, protease and catalase. It appears that the greatest activities of most soil enzymes occurred at a bulk density of 1.0 to 1.3 Mg m-3, which are optimum for most field crops. The plant growth stages also had an important impact on soil enzyme activities and microbial populations, with strong positive associations between soil microorganisms and enzyme activities with crop growth. Key words: Maize, soil enzymes, microbial population, soil compaction, bulk density, Zea mays

scholarly journals Linking Toluene Degradation with Specific Microbial Populations in Soil

1999 ◽  
Vol 65 (12) ◽  
pp. 5403-5408 ◽  
Author(s):  
Jessica R. Hanson ◽  
Jennifer L. Macalady ◽  
David Harris ◽  
Kate M. Scow
Keyword(s):  
Microbial Community ◽  
Microbial Population ◽  
Phospholipid Fatty Acid ◽  
Microbial Populations ◽  
Complex Environments ◽  
Toluene Degradation ◽  
Effective Technique ◽  
Soil Microbial ◽  
Isotope Tracer ◽  
Plfa Analysis

ABSTRACT Phospholipid fatty acid (PLFA) analysis of a soil microbial community was coupled with 13C isotope tracer analysis to measure the community’s response to addition of 35 μg of [13C]toluene ml of soil solution−1. After 119 h of incubation with toluene, 96% of the incorporated13C was detected in only 16 of the total 59 PLFAs (27%) extracted from the soil. Of the total 13C-enriched PLFAs, 85% were identical to the PLFAs contained in a toluene-metabolizing bacterium isolated from the same soil. In contrast, the majority of the soil PLFAs (91%) became labeled when the same soil was incubated with [13C]glucose. Our study showed that coupling13C tracer analysis with PLFA analysis is an effective technique for distinguishing a specific microbial population involved in metabolism of a labeled substrate in complex environments such as soil.

Soil compaction under varying rest periods and levels of mechanical disturbance in a rotational grazing system

2011 ◽  
Vol 91 (6) ◽  
pp. 957-964 ◽  
Author(s):  
C. Halde ◽  
A. M. Hammermeister ◽  
N. L. Mclean ◽  
K. T. Webb ◽  
R. C. Martin
Keyword(s):  
Bulk Density ◽  
Soil Compaction ◽  
Penetration Resistance ◽  
Soil Bulk Density ◽  
Intensive Treatment ◽  
Rotational Grazing ◽  
Pasture Management ◽  
Soil Penetration Resistance ◽  
Rest Periods ◽  
Grazing System

Halde, C., Hammermeister, A. M., McLean, N. L., Webb, K. T. and Martin, R. C. 2011. Soil compaction under varying rest periods and levels of mechanical disturbance in a rotational grazing system. Can. J. Soil Sci. 91: 957–964. In Atlantic Canada, data are limited regarding the effect of grazing systems on soil compaction. The objective of the study was to determine the effect of intensive and extensive rotational pasture management treatments on soil bulk density, soil penetration resistance, forage productivity and litter accumulation. The study was conducted on a fine sandy loam pasture in Truro, Nova Scotia. Each of the eight paddocks was divided into three rotational pasture management treatments: intensive, semi-intensive and extensive. Mowing and clipping were more frequent in the intensive than in the semi-intensive treatment. In the extensive treatment, by virtue of grazing in alternate rotations, the rest period was doubled than that of the intensive and semi-intensive treatments. Both soil bulk density (0–5 cm) and penetration resistance (0–25.5 cm) were significantly higher in the intensive treatment than in the extensive treatment, for all seasons. Over winter, bulk density decreased significantly by 6.8 and 3.8% at 0–5 and 5–10 cm, respectively. A decrease ranging between 40.5 and 4.0% was observed for soil penetration resistance over winter, at 0–1.5 cm and 24.0–25.5 cm, respectively. The intensive and semi-intensive treatments produced significantly more available forage for grazers annually than the extensive treatment. Forage yields in late May to early June were negatively correlated with spring bulk density.

scholarly journals A Comparison of Soil Compaction Associated with Four Ground-Based Harvesting Systems

2011 ◽  
Vol 28 (4) ◽  
pp. 194-198 ◽  
Author(s):  
Oscar Bustos ◽  
Andrew Egan
Keyword(s):  
Bulk Density ◽  
Forest Soils ◽  
Soil Compaction ◽  
Group Selection ◽  
Soil Bulk Density ◽  
Soil Productivity ◽  
Equipment Selection ◽  
Farm Tractor ◽  
Harvesting Systems

Abstract A study of soil compaction associated with four harvesting systems—a forwarder working with a mechanized harvester and a rubber-tired cable skidder, a farm tractor, and a bulldozer, each of them coupled with a chainsaw felling—was conducted in a group selection harvest of a mixed hardwood stand in Maine. The bulldozer system was associated with the highest percentage differences in soil bulk density measured in machine tracks (16.9%), trail centerlines (15.7%), and harvested group selection units (13.1%) versus adjacent untrafficked areas, whereas the forwarder system was associated with the lowest percentage differences in soil bulk density measured in machine tracks (3.5%), trail centerlines (1.2%), and harvested group selection units (6.3%) versus adjacent untrafficked areas. Results will help to inform loggers and foresters on equipment selection, harvest planning, and the conservation of forest soils and soil productivity.

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.

scholarly journals Aspen and white spruce productivity is reduced by organic matter removal and soil compaction

2012 ◽  
Vol 88 (03) ◽  
pp. 306-316 ◽  
Author(s):  
Richard Kabzems
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Bulk Density ◽  
Soil Compaction ◽  
Forest Floor ◽  
Mineral Soil ◽  
White Spruce ◽  
Soil Bulk Density ◽  
Post Treatment ◽  
Organic Matter Removal

Declines in forest productivity have been linked to losses of organic matter and soil porosity. To assess how removal of organic matter and soil compaction affect short-term ecosystem dynamics, pre-treatment and year 1, 5 and 10 post-treatment soil properties and post-treatment plant community responses were examined in a boreal trembling aspen (Populus tremuloidesMichx.)-dominated ecosystem in northeastern British Columbia. The experiment used a completely randomized design with three levels of organic matter removal (tree stems only; stems and slash; stems, slash and forest floor) and three levels of soil compaction (none, intermediate [2-cm impression], heavy [5-cm impression]). Removal of the forest floor initially stimulated aspen regeneration and significantly reduced height growth of aspen (198 cm compared to 472–480 cm) as well as white spruce (Picea glauca [Moench] Voss) height (82 cm compared to 154–156 cm). The compaction treatments had no effect on aspen regeneration density. At Year 10, heights of both aspen and white spruce were negatively correlated with upper mineral soil bulk density and were lowest on forest floor + whole tree removal treatments. Recovery of soil properties was occurring in the 0 cm to 2 cm layer of mineral soil. Bulk density values for the 0 cm to 10 cm depth remained above 86% of the maximum bulk density for the site, a soil condition where reduced tree growth can be expected.

Phosphorus acquisition from compacted soil by hyphae of a mycorrhizal fungus associated with red clover (Trifolium pratense)

1997 ◽  
Vol 75 (5) ◽  
pp. 723-729 ◽  
Author(s):  
Xiao-Lin Li ◽  
Jun-Ling Zhang ◽  
Eckhard George ◽  
Horst Marschner
Keyword(s):  
Bulk Density ◽  
Soil Compaction ◽  
Trifolium Pratense ◽  
Mycorrhizal Fungus ◽  
Red Clover ◽  
Arbuscular Mycorrhizal ◽  
Soil Bulk Density ◽  
Root Surface ◽  
P Uptake ◽  
Compacted Soil

The influence of an arbuscular mycorrhizal fungus, Glomus mosseae, on the adverse effects of soil compaction on growth and phosphorus (P) uptake of red clover was studied in a model experiment. The pots used in the experiment had three compartments, a central one with a soil bulk density of 1.3 g ∙ cm−3 and two outer compartments with three different levels of soil bulk density (1.3, 1.6, or 1.8 g ∙ cm−3). The soil in the outer compartments was fertilized with P and was either freely accessible to roots and hyphae, or separated by nets and accessible to hyphae only. At a soil bulk density of 1.3 g ∙ cm−3, mycorrhizal plants did not absorb more P than nonmycorrhizal plants except when access of roots to the outer compartments was restricted by nets. At high soil bulk density, root growth was drastically decreased. However, hyphae of G. mosseae absorbed P even from highly compacted soil, and induced a P-depletion zone of about 30 mm from the root surface. In consequence, at higher soil bulk density shoot P concentration and the total amount of P in the shoot were higher in mycorrhizal than in nonmycorrhizal plants. This experiment showed that hyphae of G. mosseae are more efficient in obtaining P from compacted soil than mycorrhizal or nonmycorrhizal roots of red clover. Key words: arbuscular mycorrhiza, phosphorus, red clover (Trifolium pratense L.), soil bulk density, soil compaction.

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