scholarly journals Groundcovers, Organic and Inorganic Mulches, and Masonry Surfaces Differentially Affect Establishment and Root Zone Characteristics of Urban Trees

2009 ◽  
Vol 35 (5) ◽  
pp. 232-240
Author(s):  
Michael Arnold ◽  
Garry McDonald
Keyword(s):  
Root Growth ◽  
Root Zone ◽  
Soil Surface ◽  
Bare Soil ◽  
Urban Trees ◽  
Recycled Paper ◽  
Cercis Canadensis ◽  
Soil Temperatures ◽  
Survival And Growth ◽  
Bare Soils

Three experiments investigated the effects of various groundcovers on establishment of redbuds [Cercis canadensis L. var. texensis (S. Watson) M. Hopkins ‘Alba’] and baldcypress [Taxodium distichum (L.) Rich.]. The first experiment involved eight surface treatments. Controls were bare soil. Remaining treatments were pine bark mulch; Asian jasmine [Trachelospermum asiaticum (Siebold & Zucc.) Nakai]; St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze]; decorative gravel; recycled paper mulch; decorative brick pavers; or seasonal rotations of herbaceous annuals. Other experiments compared brick-on-sand treatments ranging in color from light blonde to dark charcoal with bare soil on establishment of redbuds or baldcypress. Most organic and living soil surface covers were preferable to bare soils, however, some inorganic surface covers were detrimental to tree growth. Paving surfaces adversely affected survival, shoot or root growth, but differences were species dependent. Soil moisture, pH, and bulk density did not appear to be limiting under pavers, but substantial seasonal fluctuations in soil temperatures were observed. Light and medium bricks reflected more photosynthetically active radiation than dark bricks or bare soil. Atmospheric temperatures were greatest above dark and medium bricks. Root growth decreased as darkness of brick color increased. Redbud survival and growth were more adversely affected than with baldcypress

scholarly journals 597 Tree Establishment and Soil Surface Covers

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 550A-550
Author(s):  
Garry V. McDonald ◽  
Michael A. Arnold
Keyword(s):  
Elevated Temperatures ◽  
Root Zone ◽  
Soil Surface ◽  
Bare Soil ◽  
Pine Bark ◽  
Recycled Paper ◽  
Trunk Diameter ◽  
Cercis Canadensis ◽  
Water Potentials ◽  
Better Than

The purpose of this study is to determine the effects of a variety of commonly used soil surface covers on the establishment of Cercis canadensis L. var. texensis (Wats.) Rose. `Alba'. Containerized 23.3-L trees were planted into 1.1 × 1.5-m plots separated by metal landscape edging in 20-cm-deep raised beds constructed of exterior treated landscape timbers. Eight soil surface treatments were imposed with five replicates each. Controls included bare soil with no cover. The remaining seven treatments consisted of 8-cm depth of pine bark mulch, Trachelospermum asiaticum (Siebold & Zucc.) Nakai on 30-cm centers mulched with 8 cm of pine bark, solid sodded Stenotaphrum secundatum (Walt.) Kuntze, 8 cm of decorative gravel, 3 cm of recycled paper mulch, brick pavers underline with 5 cm of coarse builders sand (brick-on-sand), and seasonal color mulched with 8 cm of pine bark. The color rotation for summer, fall / winter, and spring is Catharanthus roseus (L.) G. Don, Viola × wittrockiana Gams., and Petunia × hybrida Hort. Vilm.-Andr., respectively. Preliminary data indicates that mulching with pine bark resulted in similar or slightly increased trunk diameter growth over that of bare soil. Brick-on-sand and the recycled paper mulch had smaller increases in trunk diameter than the other treatments. Mid-day leaf water potentials of most treatments were similar to bare soil, but the mid-day water potentials of trees mulched with recycled paper were among the most negative. All treatments except brick-on-sand trees recovered as well or better than trees in the bare soil by the next morning. Poor predawn water potential recovery of brick-on-sand trees may be due to the elevated temperatures observed in their root zone. Bare soil, recycled paper mulch, and the annual treatments had the most negative soil moisture tensions on average. The bare soil may be due to increased evaporative loose over mulched soils. The large biomass of vinca as the season progressed may account for the more negative readings in the annual seasonal color plots.

scholarly journals Time Series Analysis of Soil Freeze and Thaw Processes in Indiana

2008 ◽  
Vol 9 (5) ◽  
pp. 936-950 ◽  
Author(s):  
Tushar Sinha ◽  
Keith A. Cherkauer
Keyword(s):  
Air Temperature ◽  
Water Cycle ◽  
Soil Surface ◽  
Bare Soil ◽  
Cold Season ◽  
Freezing And Thawing ◽  
Soil Frost ◽  
Significance Level ◽  
Freeze Thaw ◽  
Soil Temperatures

Abstract Seasonal cycles of freezing and thawing influence surface energy and water cycle fluxes. Specifically, soil frost can lead to the reduction in infiltration and an increase in runoff response, resulting in a greater potential for soil erosion. An increase in the number of soil freeze–thaw cycles may reduce soil compaction, which could affect various hydrologic processes. In this study, the authors test for the presence of significant trends in soil freeze–thaw cycles and soil temperatures at several depths and compare these with other climatic variables including air temperature, snowfall, snow cover, and precipitation. Data for the study were obtained for three research stations located in northern, central, and southern Indiana that have collected soil temperature observations since 1966. After screening for significant autocorrelations, testing for trends is conducted at a significance level of 5% using Mann–Kendall’s test. Observations from 1967 to 2006 indicate that air temperatures during the cold season are increasing at all three locations, but there is no significant change in seasonal and annual average precipitation. At the central and southern Indiana sites, soil temperatures are generally warming under a bare soil surface, with significant reductions in the number of days with soil frost and freeze–thaw cycles for some depths. Meanwhile, 5-cm soils at the northernmost site are experiencing significant decreases in cold season temperatures, as an observed decrease in annual snowfall at the site is counteracting the increase in air temperature. Seasonal mean maximum soil temperatures under grass cover are increasing at the southernmost site; however, at the central site, it appears that seasonal minimum soil temperatures are decreasing and the number of freeze–thaw cycles is increasing.

Understanding mechanisms of reduced annual weed emergence in alfalfa

Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 876-885 ◽  
Author(s):  
H. R. Huarte ◽  
R. L Benech Arnold
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Bare Soil ◽  
Winter Period ◽  
Soil Temperatures ◽  
Bull Thistle ◽  
Weed Emergence ◽  
Selection Of

Field experiments were carried out at the Facultad de Agronomía, Universidad de Buenos Aires, Argentina (34°25′S, 58°25′W), to evaluate the possibility of reducing weed seedling emergence through the use of alfalfa cultivars with low levels of winter dormancy and by increasing plant density from 200 to 400 plants m−2. It was hypothesized that these treatments would alter the temperature regime and the red (R)–far-red (FR) ratio of radiation to which seeds were exposed. Responses to management treatments were recorded for bull thistle, cotton thistle, plumeless thistle, tall rocket, mustard, curly dock, and pigweed. During the alfalfa establishment year, pigweed and curly dock emergence was reduced by the nondormant cultivar established at high density. This reduction disappeared when soil beneath the canopy was fitted with heaters that mimicked bare-soil temperatures. Crop canopy presence during the establishment year was not effective in reducing mustard, cotton thistle, bull thistle, plumeless thistle, and tall rocket emergence. During the second and third years after crop establishment, the canopy of the nondormant alfalfa cultivar was effective in reducing germination of weed seeds placed on the soil surface during fall and winter. In contrast, the winter-dormant cultivar allowed the establishment of weeds during the winter period. These reductions in weed emergence were associated with a modification in the R–FR ratio perceived by the seeds located at the soil surface and could largely be removed by using FR filters to increase the R–FR ratio. These results suggest that the selection of a nondormant cultivar combined with an increase in plant density could effectively reduce weed populations in alfalfa.

scholarly journals Oversummer Survival of Monilinia vaccinii-corymbosi in Relation to Pseudosclerotial Maturity and Soil Surface Environment

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 723-730 ◽  
Author(s):  
K. D. Cox ◽  
H. Scherm
Keyword(s):  
Soil Moisture ◽  
Ground Cover ◽  
Soil Surface ◽  
Field Capacity ◽  
Bare Soil ◽  
Sole Source ◽  
Early Summer ◽  
Soil Temperatures ◽  
Maturity Degree ◽  
Surface Environment

Pseudosclerotia (infected, mummified fruit) on the orchard floor act as oversummering and overwintering structures and the sole source of primary inoculum of Monilinia vaccinii-corymbosi, the causal agent of mummy berry disease of blueberry. Survival of pseudosclerotia may be affected by their maturity (degree of stromatization), which can vary considerably at the time of fruit abscission in early summer, and by variations in the soil surface environment. From July through October in 2 years, survival of pseudosclerotia of varying initial maturity (expressed as the proportion of fruit containing mature, melanized entostromata; immature, nonmelanized entostromata; or undifferentiated mycelia) was investigated in the laboratory relative to soil surface temperature and soil moisture content and in the field in relation to shading (full sun versus 50% shade) and ground cover (bare soil versus grass). In the laboratory, oversummer survival, expressed as the percentage of intact pseudosclerotia at the end of the experiment, was higher for cool soil temperatures (approximately 15°C), soils drier than field capacity, and pseudosclerotia containing mature entostromata. In the field, survival was related solely to initial maturity of pseudosclerotia and was highest for pseudosclerotia containing mature entostromata. Shading or grass ground cover did not significantly (P > 0.05) affect oversummer survival, presumably because they did not greatly modify soil temperature or soil moisture. When individual, intact pseudosclerotia were tested for viability using fluorescein diacetate staining, a linear relationship (r = 0.982, P < 0.0001, n = 90) between viable and intact pseudosclerotia was observed, supporting the use of the percentage of intact pseudosclerotia as a measure of oversummer survival.

The role of mulch and its architecture in modifying soil temperature

Soil Research ◽  
1988 ◽  
Vol 26 (2) ◽  
pp. 269 ◽  
Author(s):  
KL Bristow
Keyword(s):  
Surface Temperature ◽  
Surface Soil ◽  
Soil Surface ◽  
Bare Soil ◽  
Minor Importance ◽  
Maximum Surface ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Maximum Surface Temperature

Both the quantity and architecture of a surface mulch affect its performance in modifying the soil microenvironment. In this paper, temperature under two simple mulch architectures is compared and contrasted with that of bare soil in a tropical environment. In mulch treatments the quantities of mulch per unit area were similar, but elements in one treatment were horizontal (forming a 5 cm layer) while in the other they were vertical (forming a 22 cm layer). Temperatures were recorded for several days as the soil dried following a storm which saturated the mulch and surface soil. The bare soil dried more rapidly than that with mulch, so that by the fourth day its hourly maximum surface temperature was 8�C higher, and that at 2 5 cm depth was 3�C higher, than soil temperatures under the mulch. Significant differences in soil temperatures under the two mulch treatments only appeared several days later, as subtle differences in the partitioning of energy by the two mulch canopies became more apparent with drier conditions. By the twelfth day, the maximum surface temperature under the vertical mulch was 7�C higher than that under the horizontal mulch. Minimum soil temperatures were never more than 2.5�C different between the bare and mulched treatments and converged with drying. In both mulch treatments, the mulch elements near the soil surface experienced greater temperature extremes than those at the top of the mulch layer. The range in element temperature was slightly greater in the horizontal mulch treatment than in the vertical mulch treatment, where the element temperatures were more closely tied to air temperatures. The first few days following rain are crucial for seedling establishment in the semi-arid tropics and it appears from this study that mulch architecture is of minor importance during this period.

scholarly journals Bare Soil Surface Moisture Retrieval from Sentinel-1 SAR Data Based on the Calibrated IEM and Dubois Models Using Neural Networks

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3209 ◽  
Author(s):  
Hamid Reza Mirsoleimani ◽  
Mahmod Reza Sahebi ◽  
Nicolas Baghdadi ◽  
Mohammad El Hajj
Keyword(s):  
Neural Networks ◽  
Soil Surface ◽  
Bare Soil ◽  
Equation Model ◽  
Second Step ◽  
Surface Moisture ◽  
The Neural Networks ◽  
Radar Backscattering ◽  
Single Polarization ◽  
Bare Soils

The main purpose of this study is to investigate the performance of two radar backscattering models; the calibrated integral equation model (CIEM) and the modified Dubois model (MDB) over an agricultural area in Karaj, Iran. In the first part, the performance of the models is evaluated based on the field measurement and the mentioned backscattering models, CIEM and MDB performed with root mean square error (RMSE) of 0.78 dB and 1.45 dB, respectively. In the second step, based on the neural networks (NNS), soil surface moisture is estimated using the two backscattering models, based on neural networks (NNs), from single polarization Sentinel-1 images over bare soils. The inversion results show the efficiency of the single polarized data for retrieving soil surface moisture, especially for VV polarization.

Improving suppression of Meloidogyne spp. by Purpureocillium lilacinum strain 251

Nematology ◽  
2014 ◽  
Vol 16 (6) ◽  
pp. 711-717 ◽  
Author(s):  
Gita Parajuli ◽  
Gita Parajuli ◽  
Robert Kemerait ◽  
Gita Parajuli ◽  
Robert Kemerait ◽  
...  
Keyword(s):  
Cover Crops ◽  
Soil Surface ◽  
Bare Soil ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Crimson Clover ◽  
Purpureocillium Lilacinum ◽  
Soil Temperatures ◽  
Meloidogyne Spp ◽  
Nematode Eggs

The fungus Purpureocillium lilacinum (syn. Paecilomyces lilacinus) is marketed for control of plant-parasitic nematodes in several countries. Our objectives in this study were to determine whether suppression of Meloidogyne spp. by P. lilacinum strain 251 was affected by the crop plant and whether growing winter cover crops such as rye and crimson clover would improve suppression of M. incognita on cotton by the fungus. All experiments were conducted in a glasshouse using non-sterilised field soil. To determine the relative efficacy of P. lilacinum on cotton (Gossypium hirsutum), peanut (Arachis hypogaea) and maize (Zea mays), four concentrations of P. lilacinum (NemOut™) were applied in furrow: 336, 252, 168 and 0 g ha−1. Although the fungus reduced numbers of eggs of Meloidogyne spp. on all crops, percentage suppression was lower on maize than on cotton and peanut at all inoculum levels of P. lilacinum. When rye and crimson clover were grown in pots for 30 days and then killed with a herbicide prior to applying P. lilacinum and M. incognita and planting cotton, the fungus failed to suppress numbers of nematode eggs when the surface residues of the cover crops were removed. However, when the residues were left on the soil surface, percentage suppression (49% for clover and 63% for rye) was greater than when the soil was left fallow (36%). The residues could have created conditions that were more conducive than bare soil to the fungus, such as lower soil temperatures and increase moisture retention.

Soil temperature and the energy balance of vegetative mulch in the semi-arid tropics. II. Dynamic analysis of the total energy balance

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 515 ◽  
Author(s):  
PJ Ross ◽  
J Williams ◽  
RL Mccown
Keyword(s):  
Energy Balance ◽  
Soil Water ◽  
Water Loss ◽  
Crop Production ◽  
Soil Surface ◽  
Bare Soil ◽  
Lower Atmosphere ◽  
Water Losses ◽  
Total Energy Balance ◽  
Soil Temperatures

Soil temperatures and water losses under killed vegetative mulch canopies are examined in the context of no-tillage crop production, using a numerical dynamic model of the soil, canopy and lower atmosphere. Both liquid and vapour movement in the soil are included, as are free and forced convection in the canopy. The predictions of the model for a clay loam soil are as follows. Medium and heavy mulches reduce the water loss over six days by 1.4 and 2.7 mm respectively, the reduction occurring while the soil surface is wet. This small effect is important in giving seedlings an extra 2 or 3 days for establishment. Water loss from bare soil and under a medium mulch is limited by soil resistance even on the first day of evaporation from initially wet soil. Mulch canopies that intercept 80 and 50% of incoming radiation can keep surface soil temperatures within 10 and 20�C respectively of ambient, whereas bare soil temperatures may rise 30�C above ambient. A moderate wind reduces soil temperatures under a mulch only a few degrees, but cools the canopy much more. A rough soil surface helps cool the soil. Water losses and soil temperatures are little affected by a 50% change in soil water diffusivity or thermal conductivity. An extensive mulched area results in temperatures well above those observed on small plots surrounded by transpiring vegetation, which maintains cool air above the mulch. A simplified form of the model, which incorporates only a single mulch layer and which ignores effects of wind, yields soil temperatures which are not greatly different from those generated by the more complex model for wind speeds below 1 ms-1 at canopy height.

Effect of irrigation on soil oxygen status and root and shoot growth of wheat in a clay soil

1985 ◽  
Vol 36 (2) ◽  
pp. 171 ◽  
Author(s):  
WS Meyer ◽  
HD Barrs ◽  
RCG Smith ◽  
NS White ◽  
AD Heritage ◽  
...  
Keyword(s):  
Root Growth ◽  
Root Zone ◽  
Pore Space ◽  
Soil Surface ◽  
Control Treatment ◽  
Water Control ◽  
Undisturbed Soil ◽  
Soil Oxygen ◽  
Maximum Root ◽  
And Control

Two watering treatments (flood and control) were applied to undisturbed (bulk density �? 1.6 mg mm-3 ) and repacked �? 1.2 mg mm-3 ) cylinders of Marah clay loam. The cylinders (0.75 m o.d. by 1.4 m deep) were housed in a lysimeter facility. Wheat (cv. Egret) was grown in the cylinders and the soil was either kept well watered with frequent small amounts of water (control treatment) or subjected to three separate periods, ranging from 4 to 72 h, of surface inundation (flood treatment). The greater pore space and better drainage of the repacked soil ensured that its average level of soil oxygen (O2) was about three times that of the undisturbed soil. Nevertheless, inundation of the soil surface for either 48 or 72 h rapidly decreased soil O2 levels in both soils. Root growth in these soils appeared to be slowed when soil O2 levels became less than 15% of the maximum that would occur in dry, aerated soil. Root growth ceased in both repacked and undisturbed soil cores after a 48-h flooding, when the soil O2 status was probably < 10% of the maximum. Root growth was greatest in the repacked soil with controlled water additions. The ranking of treatments, by either root intercept counts or O2 status, were the same. Leaf and stem growth were not very sensitive to the root zone conditions, but this may have been due to the advanced stage of plant growth when the treatments were applied and to the generally low nitrogen status of all treatment plants. There was a 44% reduction in yield from the best to the worst aerated soil treatment. The data show that if soil O2 levels become low as the result of flooding, root growth of wheat will stop and grain yield will be substantially decreased. Greatly improved aeration of these fine-textured soils is only possible if both the internal drainage properties of the soil are improved and prolonged periods of surface inundation are avoided.

scholarly journals Soil Management Affects Shoot and Root Growth, Nutrient Availability, and Water Uptake of Young Peach Trees

1991 ◽  
Vol 116 (2) ◽  
pp. 238-241 ◽  
Author(s):  
D.M. Glenn ◽  
W.V. Welker
Keyword(s):  
Root Growth ◽  
Water Use ◽  
Tall Fescue ◽  
Prunus Persica ◽  
Ground Cover ◽  
Soil Surface ◽  
Bare Soil ◽  
Soil Conditions ◽  
Shoot And Root Growth ◽  
Peach Trees

We determined how differences in peach tree water use and shoot and root growth due to ground cover treatments are affected by tree response and soil conditions in the adjacent soil environment. Ground cover combinations of bare soil (BS), a killed K-31 tall fescue sod (KS), a living Poa trivialis sod (PT), and a living K-31 tall fescue sod (LS) were imposed on 50% of the soil surface in greenhouse studies. The ground cover on 50% of the soil surface influenced root and top growth of the peach trees [Prunus persica (L) Batsch], water use, and NO3-N levels in the opposing 50%, depending on the competitiveness of the cover crop (LS vs. PT and KS) and characteristics of the soil (BS vs. KS). Tree growth was allometrically related to root growth.

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