SOIL ENZYME ACTIVITIES RECOVERY AFTER ORGANIC TREATMENTS OF DEGRADED AREAS WITHIN VINEYARDS

Soil enzymes were used to assess the impact of different treatments applied in four farms, each one with three vineyards as replicates, on soil functionality. 8 enzymes related to C, N, S and P cycling were measured and functional diversity indexes were estimated. Three treatments were compared: compost, green manure and dry mulching with respect to degraded and non-degraded soil. The four vineyards showed different enzymatic patterns and response to treatments. Vineyards with the largest difference between degraded and non-degraded soil have benefited more largely from the treatments. In particular, dry mulching seemed to be more effective than green manure or compost, with the exception of San Disdagio. However, the effect the short term

Altitude and vegetation affect soil organic carbon, basal respiration and microbial biomass in apennine forest soils

Both altitude and vegetation are known to affect the amount and quality of soil organic matter (SOM) and the size and activity of soil microbial biomass. However, when altitude and vegetation changes are combined, it is still unclear which one has a greater effect on soil chemical and biochemical properties. With the aim of clarifying this, we tested the effect of altitude (and hence temperature) and vegetation (broadleaf vs pine forests) on soil organic carbon (SOC) and soil microbial biomass and its activity. Soil sampling was carried out in two adjacent toposequences ranging from 500 to 1000ma.s.l. on a calcareous massif in central Italy: one covered only by Pinus nigra J.F. Arnold forests, while the other covered by Quercus pubescens Willd., Ostrya carpinifolia Scop. and Fagus sylvatica L. forests, at 500, 700 and 1000 m a.s.l., respectively. The content of SOC and water-extractable organic carbon (WEOC) increased with altitude for the pine forests, while for the broadleaf forests no trend along the slope occurred, and the highest SOC and WEOC contents were observed in the soil at 700 m under the Ostrya carpinifolia forest. With regard to the soil microbial community, although the size of the soil microbial biomass (Cmic) generally followed the SOC contents along the slope, both broadleaf and pine forest soils showed similar diminishing trends with altitude of soil respiration (\u3a3CO2-C), and \u3a3CO2-C:WEOC and \u3a3CO2-C:Cmic ratios. The results pointed out that, although under the pine forests' altitude was effective in affecting WEOC and SOC contents, in the soils along the broadleaf forest toposequence this effect was absent, indicating a greater impact of vegetation than temperature on SOC amount and pool distribution. Conversely, the similar trend with altitude of the microbial activity indexes would indicate temperature to be crucial for the activity of the soil microbial community

Flexural characterization of a novel recycled-based polymer blend for structural applications

The use of recycled plastic in construction fields, among others, is becoming a turning point for resolving significant related problems such as resource management, sustainability and plastic waste generation. Hence, in the context of sustainability, the "Three R’s": reduce, reuse and recycle, are getting more attention day after day. There has been a huge surge in the recycling and reuse of plastic composites due to their eco-friendliness, lightweight, life cycle superiority and low cost. However, because of a lack of knowledge of their performance and behavior, their application is still limited in the real world. The aim of this research is to understand the behavior of recycled plastic and derive its material properties which can be used in the design of structural and non-structural elements. In the present study, three stiffened plates are manufactured from 80% of recycled plastic (around 50% of recycled Polypropylene rPP, and around 50% of High Density Polyethylene PEHD with a little part of Low Density Polyethylene PELD) and 20% of virgin polypropylene PP Copolymer. Three-point bending test is performed on the three specimens. In the experimental campaign, the behavior of these stiffened plates under pure bending loads has been studied. After that, the material properties are extracted from the data collected during the experiment using Ramberg–Osgood equation. Then, once implemented in finite elementcmodels, it was observed that the simulated material shows similar behavior to the one registered during the experiment. As a conclusion, the derived material properties show reliability and they can be used to study a design of a structural or non-structural component including recycled plastic

Amido termoplástico.

bitstream/CNPDIA-2009-09/11042/1/DOC30_2007.pd

Utilização de fibras vegetais para reforço de plásticos.

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