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growobservatory.org
growobservatory.org
You need:
- A glass jar
- A trowel
- A spade
- Some paper
- A 2mm sieve
- A mortar
- A permanent
marker
- A ruler
- A teaspoon of
SHMP Sodium hexametaphosphate )
How to measure Soil texture and stone content growobservatory.org - - PowerPoint PPT Presentation
How to measure Soil texture and stone content growobservatory.org - - PowerPoint PPT Presentation
How to measure Soil texture and stone content growobservatory.org You need: A glass jar A trowel A spade Some paper A 2mm sieve A mortar A permanent marker A ruler A teaspoon of SHMP Sodium
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The jar must be 13 cm tall, or taller. The jar must have flat sides down to the bottom – as flat as possible.
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The diameter of the jar must be
- min. 8-9 cm.
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Step 1
Prepare your jar
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- Make a 3cm mark and a
13cm mark from bottom up.
- Label 3cm mark “soil” and
the 13cm mark “water”.
- If your jar is about 13cm tall
in total, label lid with “13cm water”.
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Step 2
Dig your soil
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20cm 20cm Dig a hole 20 cm in diameter and 10-15 cm deep.
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- Take out the soil and set
aside.
- Cleanly cut one side of
the hole so that it is smooth and evenly vertical.
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Clean side with your hands. 10 10-15 15cm cm
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Step 3
Estimate stone content
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10cm 10cm Estimate stone content visually with help of diagrams. Or take out soil from the wall and estimate stone content visually with help of diagrams and by touching.
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First, eliminate the
- ptions that seem the
least likely. Then, weigh the other options and decide on your final approximate estimate.
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Step 4
Soil sampling
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Take a large enough soil sample from the dug-up pit, from between 5-15cm depth.
Large enough depends on the size of your jar and on how many stones and debris are in your soil. Once stones and debris are removed, you should be able to fill your jar with compressed soil up to the 3cm mark.
2 soil samples from 2 different spots in northern Austria
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Dry the soil first, especially if you have wet, dense and heavy soils. When dry, separate soil particles until there are no crumbs left – with a mortar or a similar tool.
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IMPORTANT – be very gentle, do not break apart stones or grind smaller particles!
!
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Step 5
Sieve soil and revisit stone content
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Sieve the separated soil particles through a 2mm sieve and revisit stone content estimates.
Soil sample 1 Soil sample 2
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Fill your jar with the soil, compress, up to the 3cm mark.
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Step 6
Fill with water and make solution
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Fill the jar with water:
- completely (13cm
jars) or
- up to the 13cm mark
(>13cm jars). Close the lid and shake firmly!
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After shaking, you may now see a gap between the 13cm mark and the water level in the jar. Close the gap by filling with water.
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Remove floating organic matter and debris. Add a teaspoon of SMHP, stir well, close the lid and firmly shake again.
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When finished, bring the jar some-where,… …, where you can access it easily and where it can sit for a couple of days.
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Step 7
Explore how sediment settles
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Let sit for 3 days and shake firmly at least twice a day.
This helps completely dissolve the smallest soil particles.
After shaking the jar every day, you can observe and get an idea on how the different components of your soil settle with different speeds.
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Slightly tilt your jar backwards to better see the line between the first layer to settle (sand) and the
- ther particles,
which are still dissolved in the water.
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Or rotate the jar horizontally to explore the line between the settled layer and the remaining soil solution.
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Step 8
Measure and record sediment layers
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Wait 2 minutes until the SAND layer has settled. Mark level of sand. After three days of shaking, firmly shake your jar one last time and place on an even surface. Do not move the jar from now on.
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Now, let sit in an even spot for 5 hours. Wait 5 hours until the SILT layer has settled. Mark level of silt.
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The silt layer may compresses further after 5 hours. If you can observe this, correct the silt mark.
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Now, let sit in an even spot for at least 24 hours for the CLAY layer to settle. If the water is still cloudy after 24 hours, wait longer.
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When water is clear, make final mark for level of clay.
Note that the water is dark but clear in the right jar.
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Measure the height of each layer in mm. SAND (from bottom up) SILT (from sand to silt mark) CLAY (from silt to clay mark)
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Step 9
Record your results
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SOIL TEXTURE Sand: _______mm Silt: _______mm Clay: _______mm STONE CONTENT 0% 1-5% 6-15% 16-40% 41-80% >80%
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