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| Registros recuperados: 25 | |
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| Munkholm, L.J.; Schjønning, P.; Rasmussen, K.J.; Tanderup, K.. |
| Despite more than 30 years of research and practical experience the interest in shallow tillage and especially direct drilling has remained low in Scandinavia. Excessive compaction of the topsoil layer is one of the major problems encountered when adapting shallow tillage and direct drilling in particular. The purpose of this study was to evaluate temporal and spatial effects of two different direct drilling techniques on bulk density and penetration resistance in the near seed environment. A sandy loam growing small grain cereals was followed during the first 3 years after conversion from conventional tillage to direct drilling to reveal short-term changes in soil structure. A field experiment with four blocks was conducted in 1999–2001 where a... |
| Tipo: Journal paper |
Palavras-chave: Soil quality Production systems Soil tillage Cereals; Pulses and oilseeds. |
| Ano: 2003 |
URL: http://orgprints.org/729/1/dirdrill2003.pdf |
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| Munkholm, L.J.. |
| Mange års pløjning med traktorhjulet i furebunden samt færdsel med tunge maskiner har betydet, at skadelig pakning af underjorden er et udbredt og tiltagende problem i Danmark. Undersøgelser ved Danmarks JordbrugsForskning viser, at stort set alle danske jorde har et fortættet jordlag under pløjedybden - en såkaldt pløjesål. Mange steder er jorden også pakket længere ned som følge af kørsel med tunge maskiner. Alt andet lige er skadelig pakning et alvorligt problem under økologiske dyrkningsforhold, hvor det vigtigt at bibeholde og fremme en velfungerende og sund jord. Der findes en bred vifte af redskaber, der forholdsvis effektivt løsner en pakket underjord, hvis løsningen vel at mærke foretages under tørre forhold. Alligevel viser de fleste forsøg, at... |
| Tipo: Newspaper or magazine article |
Palavras-chave: Soil quality; Soil tillage. |
| Ano: 2003 |
URL: http://orgprints.org/1562/1/ljmklumme1.doc |
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| Munkholm, L.J.; Schjønning, P.. |
| Sustainable soil management requires that the structural degradation is balanced or exceeded by regeneration. Our objective was to investigate the vulnerability of topsoil structure to stress exerted by intensive tillage or traffic. The study addressed the short-term stability to disturbance as well as the recovery (resilience) within a year. A field experiment was conducted in a randomized block design on a humid sandy loam in 1997-1999. Each year, either compaction from a heavy tractor (PAC) or puddling by intensive rotary cultivation (PUD) produced a severe impact on topsoil structure. The PAC and PUD treatments were carried out on wet soil in early spring. The mechanical treatments were referenced by plots (REF), which were left undisturbed until the... |
| Tipo: Journal paper |
Palavras-chave: Soil quality; Production systems; Soil tillage; Farming Systems; Crop husbandry. |
| Ano: 2004 |
URL: http://orgprints.org/1508/1/Struct_vuln_subm.doc |
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| Schjønning, P.; Munkholm, L.J.; Elmholt, S.; Olesen, J.E.. |
| Management-induced depletion in soil organic carbon (SOC) may create critical tilth conditions for arable farming. We investigated the short-term effect of crop rotation and addition of animal manure on SOC fractions, the dispersibility of soil clay, the length of fungal hyphae, wet aggregate stability, tensile strength of dry aggregates, and the pore size distribution, gas diffusivity and permeability of undisturbed bulk soil. SOC fractions were measured in whole-soil samples and in 1-2 mm air-dried aggregates. Plough layer soil was sampled five and six years after the start of a field experiment with different cropping systems at two loamy sand soils (Foulum, ~9% clay and Flakkebjerg, ~14% clay). A soil drop test was performed in the field to evaluate in... |
| Tipo: Journal paper |
Palavras-chave: Crop combinations and interactions; Soil biology; Soil quality; Soil tillage; Composting and manuring. |
| Ano: 2007 |
URL: http://orgprints.org/7750/1/7750.pdf |
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| Schjønning, P.; Munkholm, L.J.; Moldrup, P.; Jakobsen, O.H.. |
| Long-term cultivation of soils for arable crops and without application of organic manure is thought to reduce the soil quality for crop production. We studied the porosity of two sandy loam soils from organic dairy farms with a ley cropping system and compared them with a conventionally managed dairy farm growing arable crops only and an arable soil receiving only mineral fertilizers, respectively. Saturated hydraulic conductivity, water retention characteristics, air diffusivity and air permeability were determined in the plough layer of the soil. The soil of one of the organic dairy farms contained many more earthworm burrows and had a significantly larger hydraulic conductivity than the counterpart soil of the conventionally managed dairy farm. In... |
| Tipo: Journal paper |
Palavras-chave: Soil quality; Soil biology. |
| Ano: 2002 |
URL: http://orgprints.org/44/1/manus2.pdf |
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| Schjønning, P.; de Jonge, L.W.; Munkholm, L.J.; Moldrup, P.; Christensen, B.T.; Olesen, J.E.. |
| Soil organic carbon (OC) influences clay dispersibility, which affects soil tilth conditions and the risk of vertical migration of clay colloids. No universal lower threshold of OC has been identified for satisfactory stabilization of soil structure. We tested the concept of clay saturation with OC as a predictor of clay dispersibility and soil friability. Soil was sampled three years in a field varying in clay content (~100 to ~220 g kg-1 soil) and grown with different crop rotations. Clay dispersibility was measured after end-over-end shaking of field-moist soil and 1-2 mm sized aggregates either air-dried or rewetted to -100 hPa matric potential. Tensile strength of 1-2, 2-4, 4-8 and 8-16 mm air-dried aggregates was calculated from their compressive... |
| Tipo: Journal paper |
Palavras-chave: Soil quality. |
| Ano: 2011 |
URL: http://orgprints.org/18939/4/18939.pdf |
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| Schjønning, P.; Jørgensen, M.H.; Olesen, J.E.; Rasmussen, G.; Munkholm, L.J.; Melander, B.. |
| Der er fra det danske landbrugserhverv formuleret ønske om, at der iværksættes en bedre rådgivning omkring gennemførelse af reduceret jordbearbejdning, herunder direkte såning (FRDK, bl.a. ved mødet i Forskningskontoret 18. januar 2001). Problemstillingen har interesse for såvel konventionelle som økologiske jordbrugere, idet reduceret bearbejdning af jorden som udgangspunkt er positivt for jordkvaliteten. Der er gennemført en lang række undersøgelser omkring reduceret jordbearbejdning og direkte såning i Danmark. En række forhold har dog til dels gjort disse resultater forældede. Det skyldes bl.a. den politisk bestemte udvikling i de dyrkede afgrøder, herunder i særlig grad sædskiftet, som har stor betydning for reduceret jordbearbejdning. De gennemførte... |
| Tipo: Report |
Palavras-chave: Production systems; Soil tillage; Farming Systems; Soil. |
| Ano: 2001 |
URL: http://orgprints.org/730/1/redj_not.doc |
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| Registros recuperados: 25 | |
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