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| Registros recuperados: 12 | |
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| Munkholm, Lars J.; Schjønning, Per; Debosz, Kasia; Jensen, Henry E.; Christensen, Bent T.. |
| Current concern for soil quality has stimulated research on soil biological and chemical properties. In contrast, the mechanical behaviour of soil is somewhat neglected. We have examined the effects on soil mechanical properties of more than 100years of contrasting fertilization employing three treatments from the Askov long-term experiment: UNF (unfertilized), NPK (mineral fertilized) and AM (animal manured). We have measured tensile strength of aggregates when air-dry and when adjusted to 10, 30 and 100kPa pressure potential. Four aggregate size classes were investigated (1-2, 2-4, 4-8 and 8-16mm diameter). Soil fragmentation was characterized in the field using a drop-shatter test. Bulk soil strength was determined in the field using a shear vane and a... |
| Tipo: Journal paper |
Palavras-chave: Soil. |
| Ano: 2002 |
URL: http://orgprints.org/32/1/j.1365-2389.2002.00424.x.pdf |
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| Munkholm, Lars J.; Schjønning, Per; Rasmussen, Karl J.. |
| Optimisation of soil tilth is of paramount importance in organic plant production in order to enhance crop growth. Non-inversion and reduced tillage systems are often claimed to be preferable for organic farming. The purpose of this study was to evaluate the early stage effects of converting a mouldboard-ploughed soil to a non-inversion tillage system. A multi-level experimental strategy including in situ, on-site and laboratory methods was followed in order to relate quantitative measures of soil physical properties directly to soil behaviour in the field. A non-inversion deep soil loosening (0¯35 cm) tillage system (NINV) was compared to a conventional mouldboard ploughing and harrowing tillage system (CONV). The experimental site was located on an... |
| Tipo: Journal paper |
Palavras-chave: Soil quality. |
| Ano: 2001 |
URL: http://orgprints.org/39/1/manus.pdf |
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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; Schjønning, Per; Rasmussen, Karl J. |
| Organic farmers often claim positive effects of non-inverting and reduced tillage systems. There is a need of quantifying tilth characteristics in the former plough layer of soil converted to such tillage systems. A non-inverting tillage system (NINV) was tested in a field experiment conducted on a Danish sandy loam soil. It included deep loosening and shallow intensive cultivation and was compared to a conventional ploughing-harrowing tillage system (CONV). A hierarchical analytical procedure was applied in studies of soil fragmentation and soil strength characteristics for the 7-14 cm soil layer. A visual description was carried out and ease of fragmentation was evaluated in the field using a soil drop test. Soil strength was measured in the field with... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Soil quality; Soil tillage. |
| Ano: 2000 |
URL: http://orgprints.org/57/1/Istro.pdf |
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| Schjønning, Per; Rasmussen, Karl J.; Munkholm, Lars J.; Nielsen, Peter S.. |
| I perioden 1996 til 2000 gennemførtes et markforsøg med forskellige jordbearbejdnings-systemer på Den økologiske Forsøgsstation Rugballegaard. Forsøgsarealet blev omlagt til økologisk drift i forbindelse med projektets start i 1996. Undersøgelserne gennemførtes i et fem-marks skifte, der ligeledes blev kørt ind i forbindelse med projektet. Det drejer sig om et såkaldt blandet sædskifte med byg/ært m. udlæg, 1. års kløvergræs, 2. års kløvergræs, havre og vinterhvede. Forsøget blev anlagt i fem marker (B1-B5), hvilket indebærer, at alle skiftets afgrøder blev dyrket hvert år. Fire forskellige jordbearbejdningssystemer blev undersøgt i et randomiseret blokforsøg med 4 blokke. De fire behandlinger omfattede to systemer med pløjning, nemlig led A med 20 cm... |
| Tipo: Report |
Palavras-chave: Soil quality; Weed management; Soil tillage; Soil biology. |
| Ano: 2002 |
URL: http://orgprints.org/188/1/djfm82.pdf |
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| Schjønning, Per; Lamandé, M.. |
| Titlen kan lyde som en vittighed: jorden skal bære trafikken,- den skal være bæredygtig. Men driftsmetoder, der skader jorden vedvarende er ikke bæredygtige. Og nutidens maskiner giver skader. Man kunne også stille spørgsmålet, om man kan tale om ”økologisk trafik”? Økologerne har været foregangsmænd/-kvinder hvad angår udfasning af pesticider og mineralsk gødning. Budskabet i denne artikel er, at der ligger en tilsvarende udfordring og venter mht vores trafik i marken. |
| Tipo: Report chapter |
Palavras-chave: Soil quality; Soil tillage; Buildings and machinery. |
| Ano: 2012 |
URL: http://orgprints.org/27257/6/27257.pdf |
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| Elmholt, Susanne; Munkholm, Lars J.; Debosz, Kasia; Schjønning, Per. |
| During the last decades Denmark has experienced a growing interest in low-input farming systems like organic farming. These systems rely on a high soil fertility to maintain nutrient availability and plant health. Soil aggregation contributes to this fertility, because it is crucial to soil porosity, aeration and infiltration of water. This paper reports a study of two pairs of differently managed, neighboring fields. The aim was to elucidate long-term effects of the different farming systems on physical and biological variables with influence on bonding and binding mechanisms of soil aggregation. Each pair consists of an organically grown dairy farm soil, based on a forage crop rotation system, including grass (Org-FCS(G)) and a conventionally managed... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Soil quality; Production systems; Soil biology. |
| Ano: 2000 |
URL: http://orgprints.org/49/1/manus3ny.pdf |
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| Schjønning, Per; Munkholm, Lars J.; Debosz, Kasia; Elmholt, Susanne. |
| Soil quality is often used as a qualitative, general term. However, quantification is an important feature of the scientific approach to nature. On the other hand, addressing specific soil parameters as indicators of soil quality includes a reduction of the whole soil system. Therefore, results obtained by specialized methodologies ought to be evaluated by methods integrating the soil characteristics in situ. In this presentation, results are given from an investigation of the tilth of two differently managed loamy soils. One of the soils had been managed for decades with a forage crop system (labeled FCS), which included fertilization with farmyard manure, while the other had been grown with a continuous cereal system (labeled CCS), receiving no input of... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Soil quality; Research methodology and philosophy. |
| Ano: 2000 |
URL: http://orgprints.org/51/1/manus4.pdf |
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| Registros recuperados: 12 | |
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