Search results for "Soil C"

Soil quality indicators as affected by a long term barley-maize and maize cropping systems

2011

Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L.) and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L.) with Italian ryegrass (R3) and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1) the high input level (H), done as a conventional tillage, 2) the low input level (L), where the tillage was replaced by harrowing and the…

Effects of pentachlorophenol in forest soil: a microcosm experiment for testing ecosystem responses to anthropogenic stress

1996

Changes in the structure and function of a soil decomposer community and growth of birch (Betula pendula) due to chemical contamination were studied in laboratory microcosms. Sodium pentachlorophenate (PCP) was added to the humus layer of a simulated forest soil at three nominal concentrations (0, 50 and 500 mg kg-1 dry mass). After two growing periods (48 weeks), there were more small soft-bodied mites, but less collembolans and microbial biomass, in the higher PCP concentration treatment than in the other treatments. Number of enchytraeids were significantly reduced and fungal-feeding nematodes became extinct in the soil with the higher PCP concentration. Soil respiration did not change d…

Contamination of soil by copper affects the dynamics, diversity, and activity of soil bacterial communities involved in wheat decomposition and carbo…

2009

ABSTRACT A soil microcosm experiment was conducted to evaluate the influence of copper contamination on the dynamics and diversity of bacterial communities actively involved in wheat residue decomposition. In the presence of copper, a higher level of CO 2 release was observed, which did not arise from greater wheat decomposition but from a higher level of stimulation of soil organic matter mineralization (known as the priming effect). Such functional modifications may be related to significant modifications in the diversity of active bacterial populations characterized using the DNA stable-isotope probing approach.

Cropping system influente on soil carbon isotopic pedogenic carbonates

2004

Testing assumptions and procedures to empirically predict bare plot soil loss in a Mediterranean environment

2014

Empirical prediction of soil erosion has both scientific and practical importance. This investigation tested USLE and USLE-based procedures to predict bare plot soil loss at the Sparacia area, in Sicily. Event soil loss per unit area, Ae, did not vary appreciably with plot length, λ, because the decrease in runoff with λ was offset by an increase in sediment concentration. Slope steepness, s, had a positive effective on Ae, and this result was associated with a runoff coefficient that did not vary appreciably with s and a sediment concentration generally increasing with s. Plot steepness did not have a statistically detectable effect on the calculations of the soil erodibility factor of bot…

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…

Survey of the mean pressure exerted by a wide range of tractors on the soil

2010

In order to predict the mean pressure exerted by a vehicle tyre on the soil, in 1984 Plackett suggested measuring the contact area of a tyre on a hard surface. The model proposed by Hallonborg in 1996, based on the “super ellipse theory”, provided the best results in terms of prediction of the tyre-soil contact area. In this study 82 4WD tractors with different power, mass and age of manufacture were surveyed. Relying on their technical features, the contact area of the front and rear tyres of each tractor and, therefore, their pressure on the soil was calculated, in order to assess the attention paid by manufacturers to soil compaction. The results of this survey showed that the mean press…

Different Type Clay Amendments for Lead Immobilization in Contaminated Soils

2014

Contamination with lead in soil is a crucial problem in industrial and military sites. Immobilization of lead by natural and modified clay as soil amendment can be an effective solution to this problem. Quaternary and Devonian clays were chosen for modification with NaCl, CaCl2, FeOOH and Ca10(PO4)6(OH)2 in different proportions of Ca/P equimolar ratio to test and compare immobilization efficiency of lead (II) on raw and modified clays by using a batch leaching test. The aim of the study is to compare different types of raw and modified clays as soil amendments by lead immobilization properties.

Devonian Clay Modification for the Improvement of Heavy Metal Sorption Properties

2013

Contamination with heavy metals is an important problem as bioaccumulation effects of those are creating direct and indirect hazards to environment and human health. Contaminated soil remediation can be done by various technologies and using of soil amendments is the one. Clay modification experiments were done to study heavy metal sorption from spiked solutions and leaching from contaminated soils. The aim of this paper is to give an overview of Devonian clay modification possibilities in order to improve heavy metal sorption capacity and immobilization options. Modification was done by using Ca, Na salts, HNO 3 (protonated forms), Fe-oxyhydroxide. Research has shown better sorption due to…

Aspects and problems of changing economic utilization of the land in Italy and the corresponding soil consumption

2013

The study moves from the observation that, in the last fifty years (1961-2010) the territory of our country, like those of other countries with advanced economies, has undergone extensive economic processes of change in the use of land, mostly due to a strong reduction of Agricultural Area Use (AAU), whose consistency - on the basis of official statistics (National Statistics Institute) and, in particular, the results of the General Census of Agriculture - is estimated at around 7,8 million hectares, from 20, 7 million hectares in 1961 to 12,9 million in 2010. It should be noted in fact that the intensity of the processes of reduction of the UAA was much greater in the first three decades, …