Search results for "soil"

On the variation of the correction factor of surface velocity with the measurement vertical for shallow flows over rough beds

2023

Considering that water flow energy affects the detachment of soil particles, the transport and deposit of the detached particles, the flow velocity is a key variable governing the soil erosion processes at the hillslope scale. The simple dye-tracer technique for measuring mean flow velocity can be applied in non-controlled field applications for which some measurement difficulties (e.g. due to sediment transport, and shallow flows) can occur. The correction factor is usually obtained as the ratio between the mean velocity, deriving from measurements of flow discharge and water depth, and surface velocity. Alternatively, the possibility of using the velocity profile in a given vertical to de…

Subsurface drip irrigated potato (Solanum tuberosum L.) with saline water under Tunisian climate

2012

Field experiment was conducted at the Higher Institute of Agronomy of Chott Meriem (Tunisia) during the growing season (2011/2012) to investigate the effects of water quality on water‘s dynamic in soil (water potential, soilcmoisture distribution, water’s stock in soil) and water use efficiency (WUE) to produce potato (Solanum tuberosum L.). Irrigation management treatments were fresh (1 dS m-1) and saline waters (4 dS m-1). Subsurface drip irrigation was used, a rate of 4 L h-1 applied at the same irrigation duration and interval. The results indicate that water content is more uniform using the saline water varies from 15 to 23% than treatment varies from 10 to 26%. The recorded changes o…

An approach to assess soil salinisation in a catchment of south-western Sicily

2008

Mapping soil compaction measuring cone penetrometer resistance

2003

The quickest way for monitoring soil compaction differences in a field is measuring cone penetrometer resistance. Soil compaction can be significantly spatially variable, depending on the amount and distribution of the traffic of agricultural machines in the field. Therefore, it could be useful to measure soil compaction on a localised basis, in order to produce maps of the damages caused by the traffic of agricultural machines and/or the action of tillage implements. Aim of this paper is to present a system developed by the Department I.T.A.F. for the geo-referenced measurement of cone penetrometer resistance and for mapping soil compaction. This system was built fitting a minitransporter …

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…

General framework for assessing the risks for in-soil organisms exposed to Plant Protection Products (PPP)

2017

The Panel on Plant Protection Products and their Residues (PPR) has been tasked by EFSA to revise the SANCO guidance Document on Terrestrial Ecotoxicology which is currently used for conducting the risk assessment for terrestrial non-target organisms, except for birds and mammals and non-target arthropods. For each group of organisms, the PPR Panel first summarises the science behind the respective risk assessment in a scientific opinion and, in a second step, EFSA will develop practical guidance on how to perform the risk assessment. The main scope of the revision is to take into consideration: (i) the entry into force of the Regulation 1107/2009 replacing the Directive 91/414/EEC; (ii) th…

Antimycotic activity of Bacillus amyloliquefaciens against fungi of vineyards soil origin

2009

Preliminary investigations on grapevines (cv Catarratto) with symptoms of “esca” allowed the isolation of different bacterial colonies (Alfonzo et al, 2009). A Gram-positive, spore forming isolate, able to inhibit fungal growth, was subjected to identification. On the basis of the whole 16S rRNA gene sequence, it showed a similarity of 99% with Bacillus amyloliquefaciens. There are numerous reports on the antagonistic activity of this species towards several phytopathogenic microorganisms. For this reason, the potential of the bacterial strain against the fungi commonly associated to the soil of vineyards (Alternaria alternata, Aspergillus ochraceus, Aspergillus carbonarius, Cladosporium cl…

Effects of Humic Substances and Soya Lecithin on the Aerobic Bioremediation of a Soil Historically Contaminated by Polycyclic Aromatic Hydrocarbons (…

2004

The high hydrophobicity of polycyclic aromatic hydrocarbons (PAHs) strongly reduces their bioavailability in aged contaminated soils, thus limiting their bioremediation. The biodegradation of PAHs in soils can be enhanced by employing surface-active agents. However, chemical surfactants are often recalcitrant and exert toxic effects in the amended soils. The effects of two biogenic materials as pollutant-mobilizing agents on the aerobic bioremediation of an aged-contaminated soil were investigated here. A soil historically contaminated by about 13 g kg(-1) of a large variety of PAHs, was amended with soya lecithin (SL) or humic substances (HS) at 1.5% w/w and incubated in aerobic solid-phas…

Valorization of Citrus spp. Cultivars cultivated in Sicily for the industrial use of citrus derivatives and in particular for potential alternative u…

2021

[ES] En esta tesis doctoral se discuten una serie de cuestiones científicas relacionadas con a la producción y el procesamiento de algunas especies de cítricos de especial relevancia en Sicilia y en el área mediterránea. Los objetivos se centran en estudiar la trazabilidad y sostenibilidad de la producción de algunas especies de cítricos, así como encontrar nuevas aplicaciones a los subproductos y productos de desecho de la industria, con el fin de mejorar su rentabilidad. Por lo tanto, los temas que se desarrollarán serán los siguientes: caracterización de los compuestos bioactivos presentes en aceites esenciales y en el hidrolato de diferentes especies de cítricos; seguimiento del efecto …

Coil homogeneity and the effect of rotor filling on the spectral resolution

2009

Spectral resolution depends upon the length (N) of the transform interval: N=F/ f, where f is the smallest frequency difference which can be distinguished at a given sampling frequency F. f depends on the signal width, which, in turn, is influenced by the relaxation time of the sampled signal. Relaxation time is affected by the external magnetic field and the applied pulse sent to the sample through the transmitter/receiver coil. The pulse length homogeneity throughout this coil is a major factor affecting NMR resolution and also the sensitivity of the measurement. So far, this fact is only considered when small sample amounts are used, where care should be taken to place the sample in the …