Measuring Soil Porosity

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Measuring soil porosity Viti-note Summary: Soils need large pores and channels for Equipment adequate aeration and good drainage. • Equipment Shovel, fuse wire (0.1mm and 0.5mm Large pores that can be seen by the diameter), recording sheet and pen. • Timing human eye are known as macropores. • Method Mesopores and micropores are too small to be visible: they are respectively Timing responsible for storing plant available water and holding the water that is This measurement is best undertaken unavailable to plant roots. The movement when soil sampling is conducted. See of air through micropores is very slow. Taking soil samples. For good plant growth, the soil needs a balance of macro-, meso- Method and micropores. Soils with too many micropores will drain poorly and this Extract a moist sample of soil and on will result in waterlogging. Clay subsoils an undisturbed face on a clod, select a often restrict water movement to depth representative 25 mm2 section (i.e. 25 and have a low porosity. Therefore, the mm x 25 mm). Count all pores in the size porosity of the subsoil is often a good range 0.1-0.5mm using the 2 wires as a indicator of potential waterlogging of guide. Repeat 3 times at each site/depth. the surface soil. NOTE: IF THE TOPSOIL IS VERY CRUMBLY Soil management can modify the (FRIABLE), THEN THE MACROPOROSITY IS porosity of a soil. Tillage and trafficking, GOOD, EVEN THOUGH IT IS DIFFICULT TO particularly of wet soil, can destroy COUNT THE NUMBER OF PORES. macro- and mesopores, while cover Optimal values are given in the table crops and mulches can maintain and below. stabilise these pores. There is a simple field method to measure soil porosity by counting the number of pores on a face Other topics in this of a clod of soil. This is described below. Viti-Notes series include: • Measuring the infiltration rate of water into soil using the ring Table 1. Irrigation classification and rate of soil water conductivity at varying soil pore levels. infiltrometer method *See Cockroft for details • A method for examining grapevine root systems Number of soil pores Soil water conductivity Irrigation classification (25 mm x 25 mm) (mm/h)* • Soil moisture monitoring • Measuring soil porosity 10 0.6 Poor • Measuring soil strength 15 1.3 Acceptable for irrigation • A method for assessing 20 2.3 “ soil structure • Taking soil samples 25 3.5 “ • Measuring soil pH 30 4.9 Good for irrigation • Measuring soil salinity 40 8.5 “ • Measuring organic carbon in soil 50 12.9 Excellent page 1 Vineyard Activity Guides. Measuring soil porosity. AWRI ©2010. RTP 0054. Measuring soil porosity Acknowledgement The Australian Wine Research Institute would like to acknowledge: • Cooperative Research Centre for Viticulture (CRCV) and all involved in the VitiNotes series (1996 – 2006). Further information • Nicholas, P. 2004. Soil, irrigation and nutrition. Adelaide: Winetitles. • Cockroft B, 1970. Estimation of soil permeability from counts of visible pores, Australian Journal of Experi- mental Agriculture and Animal Husbandry 10 (45), pp 460-1. Product or service information is provided to inform the viticulture sector about available resources and should not be interpreted as an endorsement. page 2 Vineyard Activity Guides. Measuring soil porosity. AWRI ©2010. RTP 0054. .

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Global Hydrogeology Maps (GLHYMPS) of Permeability and Porosity
UVicSPACE: Research & Learning Repository _____________________________________________________________ Faculty of Engineering Faculty Publications _____________________________________________________________ A glimpse beneath earth’s surface: Global HYdrogeology MaPS (GLHYMPS) of permeability and porosity Tom Gleeson, Nils Moosdorf, Jens Hartmann, and L. P. H. van Beek June 2014 AGU Journal Content—Unlocked All AGU journal articles published from 1997 to 24 months ago are now freely available without a subscription to anyone online, anywhere. New content becomes open after 24 months after the issue date. Articles initially published in our open access journals, or in any of our journals with an open access option, are available immediately. © 2017 American Geophysical Unionhttp://publications.agu.org/open- access/ This article was originally published at: http://dx.doi.org/10.1002/2014GL059856 Citation for this paper: Gleeson, T., et al. (2014), A glimpse beneath earth’s surface: Global HYdrogeology MaPS (GLHYMPS) of permeability and porosity, Geophysical Research Letters, 41, 3891–3898, doi:10.1002/2014GL059856 PUBLICATIONS Geophysical Research Letters RESEARCH LETTER A glimpse beneath earth’s surface: GLobal 10.1002/2014GL059856 HYdrogeology MaPS (GLHYMPS) Key Points: of permeability and porosity • Mean global permeability is consistent with previous estimates of shallow crust Tom Gleeson1, Nils Moosdorf 2, Jens Hartmann2, and L. P. H. van Beek3 • The spatially-distributed mean porosity of the globe is 14% 1Department of Civil Engineering, McGill University, Montreal, Quebec, Canada, 2Institute for Geology, Center for Earth • Maps will enable groundwater in land 3 surface, hydrologic and climate models System Research and Sustainability, University of Hamburg, Hamburg, Germany, Department of Physical Geography, Faculty of Geosciences, Utrecht University, Utrecht, Netherlands Correspondence to: Abstract The lack of robust, spatially distributed subsurface data is the key obstacle limiting the T.
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