Search results for " compaction"

Isolated non-compaction, stroke and trabecular meshwork fibrosis

2009

APPLICAZIONE DI UN PROTOTIPO DI MOTOVANGATRICE PER PRESERVARE LA FERTILITÀ DEL SUOLO

Negli ambienti caratterizzati da forti pendenze o sistemati a terrazze, nell’ambito delle lavorazioni superficiali, viene impiegato diffusamente il motocoltivatore provvisto di zappatrice rotativa. Tuttavia, l’effetto dell’uso ripetuto della zappatrice per lavorazione del terreno ha una notevole influenza sulle caratteristiche del terreno, che si presenta finemente polverizzato, soffice e astrutturato. Al fine di limitare tali inconvenienti, è stata progettata dalla sezione Meccanica del Dipartimento Scienze Agrarie e Forestali dell’Università di Palermo, in collaborazione con la ditta costruttrice Agrotec di Padova, una macchina innovativa semovente provvista di organi di lavoro del tipo a…

Long-term monitoring of soil bulk density and erosion rates in two Prunus Persica (L) plantations under flood irrigation and glyphosate herbicide tre…

2021

Abstract Early season fruit production for the northern European market is highly intensive in fertilization, machinery, irrigation and the use of herbicides. Those conditions increase the soil losses and soil compaction and threaten the Sustainable Goals for Development of the United Nations by 2030. Long-term soil erosion measurements are necessary to determine the sustainability of agriculture managements. Moreover, soil erosion on flood irrigation land is a topic that request more surveys and research as rainfed sloping terrains attracted all the attention of scientists and research investment. Improved Stock Unearthing Method (ISUM) was applied to two 15 years-old herbicide treated fie…

Testing Soil Encasing Materials for Measuring Hydraulic Conductivity of a Sandy-Loam Soil by the Cube Methods

2008

The Cube Method (CM) and the Modified Cube Method (MCM) were developed for measuring vertical (K v ) and horizontal (K h ) saturated hydraulic conductivity of a single soil sample. By these methods, a cube of soil is carved out in situ and a suitable material is applied to enclose the cube in a tightly fitting casing before moving the sample to the laboratory. Problems may be associated with the use of gypsum, originally used to encase soil. The suitability of molten wax and expandable polyurethane foam to encase a soil cube was tested for a sandy-loam soil. Wax-treated samples yielded lower conductivity results than untreated samples by a maximum factor of 3.7. The observed discrepancies w…

A system for the real-time geo-referenced measurement of soil parameters

2011

The aim of this research is to develop a system for accurately measuring in real-time, collecting and processing a high amount of geo-referenced data of soil physical-mechanical parameters, e.g. cone penetrometer resistance, index of soil compaction, and draft force. The system for measuring the soil cone penetrometer resistance is comprised of a load cell, connected to a rod, ending with a cone, and is mounted on a frame, fixed to the front part of a tractor. The system for measuring the draft force required to till the soil is comprised of a load cell, mounted on the hitch hook of a tool carrier, towed by the tractor. Moreover, in order to test the usefulness of the system with different …

Mapping of penetrometer resistance in relation to tractor traffic using multivariate geostatistics

2007

Abstract The traffic of agricultural machines can cause soil compaction and high variability of soil structure, both along normal lines and along those parallel to the field plane. The aim of this work was to investigate the potential of an electronic penetrometer, a GPS, a GIS and geostatistical techniques for mapping soil compaction. In July 2003 soil cone penetrometer resistance was measured using a semi-automatic electronic penetrometer in a sandy-silt soil (Vertic Xerochrept) of inland Sicily where a three-year rotation wheat ( Triticum durum Desf.)–wheat–tomato ( Solanum lycopersicum L.) was practiced. The measurements were carried out along three parallel 3-m long transects, from the…

Early response ofQuercus roburseedlings to soil compaction following germination

2018

Logging operations using heavy machinery effect changes in soil characteristics due to compaction; such conditions can negatively influence seedling development. In stands managed on the basis of close-to-nature silviculture or continuous cover forestry, successful establishment of natural regeneration after logging is important to ensure the proper functioning of a forest ecosystem, to promote soil recovery, and to prevent and mitigate land degradation processes (such as soil erosion, mudflow, waterlogging, and landslides) related to soil compaction and rutting. This work aimed to assess the early response of Quercus robur seedlings to soil compaction during the first 1.5 months after germ…

Multivariate geostatistics for assessing and predicting soil compaction

2005

The aim of this research is to investigate the potential of geostatistical techniques for understanding and evaluating the spatial variability of soil compaction, caused by the traffic of agricultural machines and/or the action of tillage implements. Soil cone penetrometer resistance was measured in a field of inland Sicily, along a transect of 3 m length, from the soil surface until 70 cm depth. The 3D mean maps showed a random variation on the surface and a high spatial correlation among penetrometer resistance data measured at different depths. The map corresponding to five tractor passes showed the largest extension of the areas characterised by the highest values of penetrometer resist…

Systems for evaluating the correlation between soil cone penetrometer resistance and shear strength

2008

The aim of this research is to study possible correlations between soil compaction (and related soil cone penetrometer resistance measurements) and shear strength normal to the field plane, required to cut the soil with a subsoiler. A measurement system for sensing the soil cone penetrometer resistance was built mounting, on a frame fixed to the front part of a tractor, a rod and a penetration cone with a load cell. A load cell, mounted on the tractor drawbar, pulling a subsoiler, allowed to measure the shear strength normal to the field plane, required to cut the soil. Both load cells were connected, through a display, to a portable computer, where a software was used for acquiring the dat…

Ventricular dysfunction and number of non compacted segments in non compaction: Non-independent predictors.

2010

Abstract Background Isolated ventricular noncompaction (IVNC) is characterized by multiple prominent trabeculations and deep intertrabecular recesses. Some reports prove that the chronic heart failure may occur in approximately half of the patients. In this report we investigate the correlation between the number of non compacted segments and entity of systolic dysfunction from the registry and subregistries of the SIEC. Method To identify the correlation between ventricular dysfunction and number of segments involved in non compaction we evaluated a consecutive series of 238 patients affected by non compaction, from the SIEC (Societa Italiana di Ecografia Cardiovascolare) registry. The ave…