Search results for "soil water"

A comparison of extraction procedures for water-extractable organic matter in soils

2014

The characteristics of dissolved organic matter (DOM) in soils are often determined through laboratory experiments. Many different protocols can be used to extract organic matter from soil. In this study, we used five air-dried soils to compare three extraction methods for water-extractable organic matter (WEOM) as follows: (i) pressurised hot-water-extractable organic carbon (PH-WEOC), a percolation at high pressure and temperature; (ii) water-extractable organic carbon (WEOC), a 1-hour end-over shaking; and (iii) leaching-extractable organic carbon (LEOC), a leaching of soil columns at ambient conditions. We quantified the extraction yield of organic carbon; the quality of WEOM was charac…

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…

An open-source instrumentation package for intensive soil hydraulic characterization

2020

International audience; We present a new open-source and modular instrumentation package composed of up to ten automatic in- filtrometers connected to data acquisition systems for automatic recording of multiple infiltration experiments. The infiltrometers are equipped with differential transducers to monitor water level changes in a Mariotte re- servoir, and, in turn, to quantify water infiltration rates. The data acquisition systems consist of low-cost components and operate on the open-source microcontroller platform Arduino. The devices were tested both in the laboratory and on different urban and agricultural soils in France and India. More specifically, we tested three procedures to t…

The use of soil water retention curve models in analyzing slope stability in differently structured soils

2017

Abstract This study analyzes whether and at what rate the parameterization of the Soil Water Retention Curve (SWRC) affects the analysis of shallow slope stability for differently structured unsaturated soils. Advanced empirical or physically-based equations of SWRCs have been proposed in literature to describe soil systems characterized by the so-called bimodal porous domain. In unsaturated soils, SWRC affects the stability assessment in two ways. It influences the resistance properties in terms of shear strengths, which depend on the soil water suction; and it affects the hydrological process modeling (e.g. infiltration) directly influencing soil moisture patterns and indirectly influenci…

Mulching practices for reducing soil water erosion: A review

2016

Abstract Among the soil conservation practices that are used, mulching has been successfully applied to reduce soil and water losses in different contexts, such as agricultural lands, fire-affected areas, rangelands and anthropic sites. In these contexts, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas of the world. Although the beneficial effects of mulching are known, further research is needed to quantify them, especially in areas where soil erosion by water represents a severe threat. In the literature, there are still some uncertainties about how to maximize the effectiveness of mulching to reduce the soil and water loss rates. Given the serious…

The role of pedogenic overprinting in the obliteration of parent material in some polygenetic landscapes of Sicily (Italy)

2016

Abstract Many soils older than the Holocene have experienced several changes, and possess properties that may be due to the complex effect of several stages of soil development; these soils are called polygenetic. It is still rather unclear, however, if, as time elapses, pedogenic processes tend to diverge generating different soils, or converge towards increasingly similar soils. We studied five pedons (37°60′N, 13°90′E) exposed to present weathering simultaneously since the Holocene but located on Upper Miocene or Holocene parent material. Their XRD and FTIR clay mineralogy reveal an overall homogeneity; smectites, calcite and gypsum reach the thermodynamic equilibrium, a slight undersatu…

Taxonomic and environmental implication of pedotechnique in large scale farming

2016

Abstract Human activities that involve deep modifications of the soils and a substantial deterioration of their features are numerous and very diverse. Such activities are considered as pedotechniques and, in large-scale farming, are used only under the boost of significant economic returns. In these last decades, the pedotechniques used to tailor soils suitable for table vine cultivation in the Acate valley (Sicily, Italy), not only led to objective difficulties in the classification of these deeply transformed soils but also, to several environmental hazards. In this work after considering the pedotechniques used in tailoring suitable soil for table vine cultivation, we propose to introdu…

Soil type and soil preparation influence vine development and grape composition through its impact on vine water and nitrogen status

2018

The influence of soil type and preparation on vine development and grape composition was investigated in a 50 ha estate located in Saint-Emilion (Bordeaux, France) and planted predominantly with Merlot. Part of the vineyard was planted down the slopes and another part of the vineyard was planted on terraces, where soils were profoundly modified through soil preparation. Grape composition (berry weight, sugar, total acidity, malic acid and pH), vigor (pruning weight), vine nitrogen status (Yeast Available Nitrogen (YAN) in grapes) and vine water status (δ13C) was measured at a very high density grid of 10 data points per hectare. Water deficit was globally weak over the estate because of hig…

Cover crops and pruning in Bobal and Tempranillo vineyards have little influence on grapevine nutrition

2016

ABSTRACT Cover crops may improve vineyard soil properties, grapevine nutrient status and berry composition, however, factors such as cover crop type, annual rainfall, climate and irrigation may change their effects on vineyards. From 2008 to 2011, the effects of a non-permanent cover crop and two pruning techniques on soil as well as vine nutrients and grapevine performance of two vineyards (cv. Tempranillo and cv. Bobal) were evaluated. For that purpose, two legumes were sown in inter-rows of hand-pruned vines in February and were tilled at flowering. Soil tillage, or cover cropping, was combined with either light pruning or severe pruning to study foliar nutrient variations. Soil N, P, K …

Influence of soil surface sealing and hydrophobicity on water infiltration

Nella tesi viene affrontato lo studio dell’impatto dei fenomeni di sealing superficiale e di idrofobicità sui processi di infiltrazione dell’acqua nel suolo. A tal fine vengono utilizzati diversi tipi di esperimenti infiltrometrici che consentono di determinare le modificazioni delle proprietà idrauliche del suolo indotte da questi due fenomeni permettendo di valutare così le loro ripercussioni negative sui processi idrologici. The thesis aims at investigating the effects of soil sealing and hydrophobicity on the water infiltration process. Different field infiltrometric techniques are applied at this end due to their ability to characterize modifications of soil hydraulic properties that d…