Clustering and percolation in lithium borate glasses

Journal URL: http://jcp.aip.org/jcp/staff.js

Soil Fungi-Plant Interaction

Computer modelling & simulatio

Integration of the regulated deficit irrigation strategy in a sustainable orchard management system

Irrigation in arid regions requires special attention to optimize the management of all components of the orchard system in order to increase water use efficiency and reduce environmental impacts (e.g. soil salinization, degradation of ground and surface waters). This six-year study reports the comparison of some orchard practices (soil and irrigation management, plant nutrition) routinely adopted by local farmers (conventional, C) with those interventions having the potential to save water and maximize water use efficiency in a peach orchard and therefore defined as sustainable (S). Due to the relative approach (C versus S) used in this study, classical statistical comparison of results could not be made. The S system included the application of regulated deficit irrigation (RDI) with specific crop coefficients to calculate the plant water requirement. The S system on average saved 1450 m3 ha-1 of water per year without affecting yield or fruit quality. The concept of economic water productivity (EWP) is discussed. We conclude that addressing some practices currently adopted by farmers could increase sustainability of irrigation and enhance (EWP) in peach tree orchards

Sustainable apricot orchard management to improve soil fertility and water use efficiency

This 4-year on-farm study reports the effects of different agricultural practices on yield and carbon input in an apricot orchard grown in Mediterranean area. Groups of plants under local orchard management (LOM) practices (i.e., soil tillage, removing of pruning residues, mineral fertilisers) were compared with plots under sustainable orchard management (SOM) actions (i.e., cover crop, no-tillage, compost application, mulching of pruning residues). In the SOM blocks, fertilization was based on plant demand and soil availability and irrigation volumes were calculated on the evapotranspiration values basis, while in the LOM plots fertilization and irrigation were empirically managed. Results show that yield was enhanced by 28% by SOM. In comparison with LOM plots, changed practices increased the amount of N, P, K annually incorporated into soil thus increasing their reservoir in the soil. The study demonstrates that appropriate crop management can increase the mean annual carbon soil inputs from about 1.5 t ha-1 to 9.0 t ha-1 per year

Soil water availability and relationship between canopy and roots in young olive trees (cv Coratina).

Trials were carried out in the Basilicata region (41°03’ N, 15°42’ E, Southern Italy) using ownrooted plants of the cultivar Coratina planted in 1992 at distances of 6 x 3 m. During 1992, the whole plot (about 7000 m2) was irrigated. From 1993 onwards, irrigation was suspended in part of the plot. A representative number of plants during 1992, 1993, 1994 and 1998 was destroyed in order to carry out dry weight measurements on roots and canopy. The ratio between root and leaf dry weight was always greater in nonirrigated plants compared to irrigated ones. Roots explored a soil volume ranged from 0.5 m3 in the first year to 16.8 m3 in the seventh year for irrigated plants and from 0.5 m3 to 13.4 m3 for non-irrigated ones. The study showed that in deep soil, with a greater capacity for water storage during the rainfall season, limited water supply (220-1350 m3 ha-1) during the first seven years from planting increased canopy growth by 79% compared to nonirrigated plants, but made little difference to root growth. In non-irrigated plants, canopy growth (but not root growth) was drastically reduced, as a defence strategy against water deficit, making for a better root/leaf ratio and consequently greater water availability for leaves

Contracepção oral de emergência: crenças, conhecimentos e consumo nos estudantes do Instituto Politécnico de Lisboa

Em Portugal, o recurso à contracepção oral de emergência (COE) tem aumentado nos últimos anos, sobretudo nas faixas etárias mais jovens. Constituindo os conhecimentos e crenças de um indivíduo factores determinantes do seu comportamento em determinado domínio, importa abordá-los no âmbito da COE, de forma a identificar os processos que presidem à adopção deste tipo de contracepção e, a partir daí, delinear estratégias de intervenção. Objectivo do estudo: identificar e caracterizar as práticas contraceptivas dos estudantes, sobretudo no que concerne à COE, bem como as suas crenças e conhecimentos sobre este método contraceptivo