The relationship between surface fractal dimension and soil water content at permanent wilting point

Soil water availability to the plants is a range of water content between the field capacity and the permanent wilting point (PWP) conditions. The PWP is defined as the lower limit of soil water content that the plant can extract water from the soil as indicated by the symptoms of wilting plants. This is because plant roots are unable to penetrate the soil micropores that contain the water. The study aims to analyze the effects of arbuscular mycorrhizal fungi (AMF) and compost in enhancing soil water absorption by the plant when the water content is close to the permanent wilting point. Four doses of AMF (0, 5, 10 and 15 g.plant-1) and three doses of coffee pulp-made compost (0, 5 and 10 ton.ha-1) were arranged according to a randomized complete block design with three replicates. Results showed that the application of AMF significantly enabled the plant to improve water uptake when the soil water content was about at the permanent wilting point conditions. The AMF addition of 15 g.plant-1 significantly prolonged the growing period of chili to wither and the plant showed the wilting symptoms at the soil water content of 5 to 7% lower than the no-AMF plants. Improved water uptake under water stress conditions was attributed to increases in the root colonization by AMF.

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SIMPLE DEVICE FOR ESTIMATING SOIL WATER CONTENT AT PERMANENT WILTING POINT

Acta Horticulturae ◽

10.17660/actahortic.2003.613.21 ◽

2003 ◽

pp. 163-168

Author(s):

P. Bussiéres ◽

J. Hostalery ◽

A. Battilani

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Simple Device ◽

Permanent Wilting Point ◽

Wilting Point

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The relationship between soil emissivity and soil reflectance under the effects of soil water content

Physics and Chemistry of the Earth Parts A/B/C ◽

10.1016/j.pce.2018.11.006 ◽

2019 ◽

Vol 110 ◽

pp. 133-137 ◽

Cited By ~ 2

Author(s):

Jing Tian ◽

Shangkun Song ◽

Honglin He

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

The Relationship ◽

Soil Reflectance

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The relationship between solar radiation interception and soil water content in a tropical deciduous forest in Mexico

CATENA ◽

10.1016/s0341-8162(98)00121-0 ◽

1999 ◽

Vol 36 (1-2) ◽

pp. 153-164 ◽

Cited By ~ 50

Author(s):

L Galicia ◽

J López-Blanco ◽

A.E Zarco-Arista ◽

V Filips ◽

F Garcı́a-Oliva

Keyword(s):

Solar Radiation ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Deciduous Forest ◽

Tropical Deciduous Forest ◽

Radiation Interception ◽

The Relationship

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Canopy Solar-Induced Chlorophyll Fluorescence and Its Link to Transpiration in a Temperate Evergreen Needleleaf Forest during the Fall Transition

Forests ◽

10.3390/f13010074 ◽

2022 ◽

Vol 13 (1) ◽

pp. 74

Author(s):

Weiwei Cong ◽

Kaijie Yang ◽

Feng Wang

Keyword(s):

Chlorophyll Fluorescence ◽

Soil Temperature ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Air Temperature ◽

Pearson Correlation ◽

Evergreen Forest ◽

Spatiotemporal Resolution ◽

The Relationship

Northern hemisphere evergreen needleleaf forest (ENF) contributes a significant fraction of global water exchange but regional transpiration (T) observation in ENF ecosystems is still challenging. Traditional remote sensing techniques and terrestrial biosphere models reproduce the transpiration seasonality with difficulty, and with large uncertainties. Solar-induced chlorophyll fluorescence (SIF) emission from vegetation correlates to photosynthesis at multiple spatial and temporal scales. However, how SIF links to transpiration of evergreen forest during seasonal transition is unclear. Here, we explored the relationship between canopy SIF and T retrieved from ground observation towers in ENF. We also examined the role of meteorological and soil factors on the relationship between SIF and T. A slow decrease of SIF and T with a fast reduction in photosynthetically active radiation (PAR), air temperature, vapor pressure deficit (VPD), soil temperature and soil water content (SWC) were found in the ENF during the fall transition. The correlation between SIF and T at hourly and daily scales varied significantly among different months (Pearson correlation coefficient = 0.29–0.68, p < 0.01). SIF and T were significantly linearly correlated at hourly (R2 = 0.53, p < 0.001) and daily (R2 = 0.67, p < 0.001) timescales in the October. Air temperature and PAR were the major moderating factors for the relationship between SIF and T in the fall transition. Soil water content (SWC) influenced the SIF-T relationship at an hourly scale. Soil temperature and VPD’s effect on the SIF-T relationship was evident at a daily scale. This study can help extend the possibility of constraining ecosystem T by SIF at an unprecedented spatiotemporal resolution during season transitions.

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A Microcontact Model Developed for Asperity Heights With a Variable Profile Fractal Dimension, a Surface Fractal Dimension, Topothesy, and Non-Gaussian Distribution

STLE/ASME 2008 International Joint Tribology Conference ◽

10.1115/ijtc2008-71086 ◽

2008 ◽

Author(s):

Jen Luen Liou ◽

Jen Fin Lin

Keyword(s):

Fractal Dimension ◽

Cross Sections ◽

Fractal Dimensions ◽

Surface Fractal Dimension ◽

Surface Fractal ◽

Deformation Regime ◽

Circular Contour ◽

The Mean ◽

Non Gaussian ◽

The Relationship

The cross sections formed by the contact asperities of two rough surfaces at an interference are island-shaped, rather than having the commonly assumed circular contour. These island-shaped contact surface contours show fractal behavior with a profile fractal dimension Ds. The surface fractal dimension for the asperity heights is defined as D and the topothesy is defined as G. In the study of Mandelbrot, the relationship between D and Ds was given as D = Ds+1 if these two fractal dimensions are obtained before contact deformation. In the present study, D, G, and Ds are considered to be varying with the mean separation (or the interference at the rough surface) between two contact surfaces. The D-Ds relationships for the contacts at the elastic, elastoplastic, and fully plastic deformations are derived and the inceptions of the elastoplastic deformation regime and the fully plastic deformation regime are redefined using the equality of two expressions established in two different ways for the number of contact spots (N).

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Soil water response to rainfall in a dune-interdune landscape in Horqin Sand Land, northern China

Soil and Water Research ◽

10.17221/142/2018-swr ◽

2019 ◽

Vol 14 (No. 4) ◽

pp. 229-239 ◽

Cited By ~ 1

Author(s):

Xueya Zhou ◽

Dexin Guan ◽

Jiabing Wu ◽

Fenghui Yuan ◽

Anzhi Wang ◽

...

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Northern China ◽

Water Dynamics ◽

Soil Water Dynamics ◽

Water Recharge ◽

Sand Land ◽

Horqin Sand Land ◽

The Relationship

Soil water dynamic is considered an important process for water resource and plantation management in Horqin Sand Land, northern China. In this study, soil water content simulated by the SWMS-2D model was used to systematically analyse soil water dynamics and explore the relationship between soil water and rainfall among micro-landforms (i.e., top, upslope, midslope, toeslope, and bottomland) and 0–200 cm soil depths during the growing season of 2013 and 2015. The results showed that soil water dynamics in 0–20 cm depths were closely linked to rainfall patterns, whereas soil water content in 20–80 cm depths illustrated a slight decline in addition to fluctuations caused by rainfall. At the top position, the soil water content in different ranges of depths (20–40 and 80–200 cm) was near the wilting point, and hence some branches, and even entire plants exhibited diebacks. At the upslope or midslope positions, the soil water content in 20–80 or 80–200 cm depths was higher than at the top position. Soil water content was higher at the toeslope and bottomland positions than at other micro-landforms, and deep caliche layers had a positive feedback effect on shrub establishment. Soil water recharge by rainfall was closely related to rainfall intensity and micro-landforms. Only rainfalls > 20 mm significantly increased water content in > 40 cm soil depths, but deeper water recharge occurred at the toeslope position. A linear equation was fitted to the relationship between soil water and antecedent rainfall, and the slopes and R<sup>2</sup> of the equations were different among micro-landforms and soil depths. The linear equations generally fitted well in 0–20 and 20–40 cm depths at the top, upslope, midslope, and toeslope positions (R<sup>2</sup> value of about 0.60), with soil water in 0–20 cm depths showing greater responses to rainfall (average slope of 0.189). In 20–40 cm depths, the response was larger at the toeslope position, with a slope of 0.137. In 40–80 cm depths, a good linear fit with a slope of 0.041 was only recorded at the toeslope position. This study provides a soil water basis for ecological restoration in similar regions.

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The Effect of Earthworm (Lumbricus terrestrisL.) Population Density and Soil Water Content Interactions on Nitrous Oxide Emissions from Agricultural Soils

Applied and Environmental Soil Science ◽

10.1155/2010/737096 ◽

2010 ◽

Vol 2010 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Andrew K. Evers ◽

Tyler A. Demers ◽

Andrew M. Gordon ◽

Naresh V. Thevathasan

Keyword(s):

Population Density ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Agricultural Soils ◽

Lumbricus Terrestris ◽

Nitrous Oxide Emissions ◽

Research Station ◽

Significant Difference ◽

The Relationship

Earthworms may have an influence on the production ofN2O, a greenhouse gas, as a result of the ideal environment contained in their gut and casts for denitrifier bacteria. The objective of this study was to determine the relationship between earthworm (Lumbricus terrestrisL.) population density, soil water content andN2Oemissions in a controlled greenhouse experiment based on population densities (90 to 270 individualsm−2) found at the Guelph Agroforestry Research Station (GARS) from 1997 to 1998. An experiment conducted at considerably higher than normal densities of earthworms revealed a significant relationship between earthworm density, soil water content andN2Oemissions, with mean emissions increasing to 43.5 gha−1day−1at 30 earthworms 0.0333 m−2at 35% soil water content. However, a second experiment, based on the density of earthworms at GARS, found no significant difference inN2Oemissions (5.49 to 6.99 gha−1day−1) aa a result of density and 31% soil water content.

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