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<p>Bulk density is essentially determined by the soil texture and compaction. Soils with no compaction are simply described by texture that then provides particle type, and size distribution, that create bulk density.</p>
<p>Low bulk density soils, such as "engineered" structural soils for landscape projects, sometimes do not provide enough resistance to movement of roots when large loads are applied. This is often due to low particle density and high organic matter content and resulting relatively large pore space.</p>
<p>Structural soils are not to be compacted but seem to fail trees on many occasions. Structural soils have been known to allow tree failure (what is really a soil failure) with stories out of Europe.</p>
<p>I would check the work by Nina Bassuk as a starting point for references.</p>
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<p>Michael</p>
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<p id="reply-intro">On 2025-03-25 21:44, Mike James via CANUFNET wrote:</p>
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<p class="v1MsoNormal">It is received wisdom that trees need to be planted in soils that are lightly tamped to:</p>
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<li class="v1MsoListParagraph" style="margin-left: 0in; mso-list: l0 level1 lfo1;">provide some resistance and support for tree roots</li>
<li class="v1MsoListParagraph" style="margin-left: 0in; mso-list: l0 level1 lfo1;">prevent settlement of root balls</li>
<li class="v1MsoListParagraph" style="margin-left: 0in; mso-list: l0 level1 lfo1;">prevent large airgaps that disconnect root/soil contact</li>
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<p class="v1MsoNormal">However, I cannot find any independent, scholarly research that proves this through case studies or comparative empirical testing.</p>
<p class="v1MsoNormal">Almost all of the research is about too much compaction.</p>
<p class="v1MsoNormal">I can’t find any research that shows the effect of totally uncompacted loose soil (no tamping) on tree health and stability.</p>
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<p class="v1MsoNormal">I am reaching out to the community to see if you can provide me with links to research you might be aware of on this topic.</p>
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<p class="v1MsoNormal">Thank you in advance. </p>
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<p class="v1MsoNormal"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; color: black; mso-ligatures: none;"> </span></p>
<p class="v1MsoNormal"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; color: black;"><img id="v1Picture_x0020_1" style="width: 1.8437in; height: 1.0104in;" src="cid:174300919167e435a7921d9953210726@kos.net" width="177" height="97" /></span></p>
<p class="v1MsoNormal"><span style="font-size: 12.0pt;"><img id="v1Picture_x0020_2" style="width: 3.125in; height: .7291in;" src="cid:174300919167e435a7922f6773058578@kos.net" width="300" height="70" /></span><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; color: black; mso-ligatures: none;"></span></p>
<p class="v1MsoNormal"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; color: black; mso-ligatures: none;"><a href="https://www.youtube.com/@Deeproot/videos" target="_blank" rel="noopener noreferrer"><span style="color: #467886;">DeepRoot - YouTube</span></a></span><span style="font-family: 'Calibri',sans-serif;"></span></p>
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