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| Munkholm, Lars; Schjønning, Per; Kay, Bev D.. |
| Tensile failure of soil is desirable in tillage. Soil tensile strength estimates most often are obtained from compression tests of dry aggregates. As tillage is performed under moist conditions, it would be highly relevant to measure tensile strength at high water contents. Plough-layer soil was sampled in a compacted soil (PAC) and in a non-compacted reference soil (REF). Tensile strength was measured in a new direct tension test using undisturbed soil cores (4.45 cm in diameter and 5.00 cm in height) adjusted to either -50 or -100 hPa matric potential. The air-filled pore space, a, was determined from water retention measurements. Air permeability, Ka, was determined at -30, -100 and -300 hPa matric potentials and from these measurements an index of... |
| Tipo: Journal paper |
Palavras-chave: Soil quality. |
| Ano: 2002 |
URL: http://orgprints.org/36/1/nymanus.pdf |
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| Munkholm, Lars J.; Kay, Bev D.. |
| The effect of water regime on aggregate-tensile strength, rupture energy, and friability index was studied in two experiments on sandy loam soils (Glossic Phaeozem/WRB 1998). In Exp. 1, soil from a long-term, 5-yr crop rotation receiving animal manure (dairy farm and grass, DFG) was compared with a soil (continuous cereal crop, CCC), which had grown almost continuous cereals and not received animal manure. In Exp. 2, soil from compacted plots (PAC) and uncompacted reference plots (REF) was sampled. The soil was air-dried and separated into four aggregate-size classes (i.e., 1–2, 2–4, 4–8, and 8–16 mm). Aggregate-tensile strength and rupture energy were measured on air-dry aggregates and on aggregates adjusted to -10, -30, -100, -350 kPa, and -166 MPa... |
| Tipo: Journal paper |
Palavras-chave: Soil quality. |
| Ano: 2002 |
URL: http://orgprints.org/31/1/SSSAJ_--_Munkholm_and_Kay_66_%283%29_702.htm |
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