Evaluation of organic matter stability during the composting process of agroindustrial wastes.

Composting of wastes from citrus industrial processing (pastazzo and sludge) was studied in order to evaluate the evolution of organic matter during the process and to individuate chemical and/or biochemical techniques able to set the stability of the final product. Composts from two open-air piles of different composition were sampled every month during the whole period of composting (5 months) and the organic matter of each sample was characterised by chemical and biochemical techniques. Humification rate (HR%) and humification index (HI) were determined. Extracted organic matter of six samples collected for each compost was investigated by isoelectric-focusing technique (IEF). The biochemical analysis was based on the study of C-mineralisation after the addition of each collected sample to soil. Results obtained clearly demonstrated organic matter evolution during composting processes. Humification rates increased and humification indexes decreased over time, while extracted organic matter showed electrophoretic behaviour typical of stabilised organic compounds. Moreover, mineralisation patterns confirmed the increased level of organic matter stability during the composting process

Evaluation of grapevine water status from trunk diameter variations

We evaluated the usefulness of short-term trunk diameter variations (TDV) as water stress indicator in field-grown grapevines cv. Tempranillo. Two indices were calculated from TDV, maximum daily trunk shrinkage (MDS), and trunk growth rate (TGR). The seasonal evolution of both indicators was compared with occasional determinations of pre-dawn leaf water potential and stem water potential, measured at early morning (Ψ s em ) and at midday (Ψ s md ) in irrigated and non-irrigated vines. In the second season, the effect of crop load on the vine water status indicators was also studied. Crop load did not affect either the vine water relations or the TDV. All water potential determinations had much lower variability and were more sensitive than both MDS and TGR to water restrictions. The ability of both indices to detect plant water stress varied largely depending upon the phenological period. In fact, MDS and TGR were only able to detect vine water stress during a short period of time before veraison. During this period, TGR was linearly related to both Ψ s em and Ψ s md , while for MDS a curvilinear, quadratic equation, better described the relationship with plant water status. After veraison no apparent relationship existed between plant water status and MDS or TGR. Hence, our results question the practical use of both MDS and TGR as variables to automate irrigation scheduling for grapevin

Effects of long term application of compost and poultry manure on soil quality of citrus orchards in Southern Italy.

A six-year study was carried out in an organically managed orange orchard located in Sicily (Southern Italy) to assess the effect of compost and organic fertilizers utilisation on soil quality. Adopting a randomized-block experimental design with three replicates, four treatments were carried out. In treatments 1 and 2, two different composts (C1 from distillery by products and C2 from livestock wastes) were applied. The plots of treatment 3 were fertilized using dried poultry manure. The control treatment was fertilized with mineral/synthetic fertilizers. In order to verify the hypothesis that composts and organic fertilizers improve soil fertility, soil quality was evaluated by selecting dynamic soil parameters, as indicators linked to C and N cycles. Total organic C, total N, C/N ratio, humified fraction, isoelectric focusing (IEF) of extracted organic matter, microbial biomass C, potentially mineralisable N under anaerobic conditions, potenzially mineralizable C, C mineralization quotient and metabolic quotient were determined for each sample. Furthermore, the Comunity level Physiological Profile (by Biolog tecnique) was defined, calculating derived functional biodiversity and versatility indexes. Parameters related to IEF and potentially mineralizable C showed significant differences among the treatments. Moreover, total C, total N and humification parameters tended to increase, while no differences were observed in biodiversity indexes. On these findings, it was concluded that composts and poultry manure only weakly affected soil properties, though they increased soil nutritive elements potentially available to crops

Soil fertility comparison among organic and conventional managed citrus orchards in Sicily.

In recents years, organic farming is expanding in Southern Italy and in the Mediterranean area, due to interest of consumers and EU agricultural policies. Evaluation of organic farming system introduction on soil quality and fertility status should be taken into account in order to define medium-long term environmental and agricultural strategies, on both locol and national scale. Soil physical, chemical and biological parameters represent effective tools to evaluate soil quality and changes in soil fertility status, as a consequence of different agronomic management (i.e. organic vs coventional). The aim of this work was to compare soil fertility of conventional and organic managed citrus Orchards, using specific soil system descriptors. The research was carried out in a Mediterranean environment (Sicil Region, Southern Italy), on Navelina and Tarocco orchards. Soil characteristics were analysed in 54 farms under both organic and conventional management. Farms were selected to obtain similar pairs (27) in the same environmental conditions. Moreover, orchards pairs were homogeneous for age, cultivar and rootsock to reduce effects not linked to soil management. For each soil, total organic carbon, total nitrogen, mineral NO3-N and NH4-N were determined. In addition, in order to evaluate biological fertility of the considered soils, carbon mineralisation and nitrogen mineralisation in anaerobic conditions were studied. Soils' humic fraction was at least characterised qualitatively by isoelectric focusing technique,to obtain information on soil organic matter stability. Potenzially mineralisable carbon and cumulative mineralised carbon determined on 21 days experimental trials differed significantly in organic and conventional soils. Since this significance was detected also for cumulative mineralised carbon after 7 days, probably C-mineralisation represents the more reliable and prompter indicator to discriminate soil biological fertility with respect to the other tested ones. Moreover, it should be remarked that some parameters (as total nitrogen content, mineralised carbon after 1 days and the more humified organic matter fraction), even if not yet significantly different, revealed a strong tendency to increase in organic managed soils, attesting that the organic citrus orchards can be considered systems able to conserve energy and store nutrients more than the conventional ones

¿Es posible mejorar la eficiencia en el uso del agua de un viñedo mediante un acolchado orgánico del suelo?

El objetivo de este trabajo fue evaluar el efecto que un acolchado orgánico del suelo (restos de poda) puede tener sobre la evapotranspiración del cultivo (ETc) de la vid con el fin de mejorar la eficiencia en el uso del agua. El estudio se realizó durante la campaña de 2015 en la finca “Las Tiesas”, Albacete (España). Las medidas se llevaron a cabo en un lisímetro monolítico de pesada ubicado en el centro de una parcela de vid (Vitis vinífera L., cv. Tempranillo) de 1 ha de superficie, y con cepas plantadas a un marco de 3 x 1,5 m y conducción en espaldera. Se llevaron a cabo tres ciclos de medidas, cada uno consistió en mantener el suelo desnudo durante los dos primeros días, los dos siguientes se cubrió la superficie del lisímetro con un acolchado orgánico (restos de poda de la vid) y los dos últimos días se cubrió el lisímetro con un acolchado inorgánico (lona de plástico). Los resultados indican que para la misma demanda evaporativa y fracción de cubierta vegetal, el acolchado orgánico redujo la ETc de la vid algo más de un 17%, mientras que el plástico la redujo un 25%. Los resultados obtenidos indican que con el acolchado orgánico sigue produciéndose una cierta evaporación de agua desde el suelo, pero se reduce considerablemente la ETc pudiéndose mejorar la eficiencia en el uso del agua.Ministerio de Economía y Competitividad FEDER AGL2014-54201-C4-4- RRTA 2011-00100-C05-04RTA 2014-00049-C05-0

Transferencia de resultados de investigación para el ahorro de agua y de la energía en comunidades de regantes a través del entorno de gestión integrada CORENET-COREGEST

En la actualidad se está produciendo un incremento en la demanda para realizar una gestión optimizada del agua y de la energía empleadas en el regadío. Esto ha dado lugar a una importante actividad de I+D con diferentes sistemas, productos y servicios, que comparten el objetivo de mejorar la aplicación del agua y/o de la energía. Sin embargo, el conocimiento generado choca con dificultades a la hora de transferir los resultados hacia los usuarios finales. Esto es debido, al menos en parte, a la necesidad de que las Comunidades de Regantes cambien su modelo de gestión y sean capaces de integrar los resultados de este conocimiento con los procesos normales de gestión que se emplean en las mismas. SERINA ha desarrollado la metodología y el Enterprsise Resource Planning (ERP) de gestión CORENET-COREGEST, que permite modernizar los procesos de gestión de las Comunidades de Regantes e integrar herramientas/sistemas/servicios externos generados por los centros de I+D con el objetivo de mejorar la gestión, fundamentalmente, del agua y de la energía. En este trabajo se muestran algunos casos que ilustran lo anterior y se explican las ventajas para las Comunidades de Regantes usuarias así como por los centros de I+D que han integrado sus productos en CORENET-COREGEST

Berry abscission is related to berry growth in Vitis labruscana 'Concord' and Vitis vinifera 'Riesling'

Research Note

Vine and soil-based measures of water status in a Tempranillo vineyard

Seasonal changes of leaf and stem water potential and midday stomatal conductance (gs) of Tempranillo grapevines were determined in irrigated and non-irrigated vines in 2003 and 2004. Leaf water potential was measured at pre-dawn (Ψpd) and at midday (Ψlmd), while stem water potential was measured in the early morning (Ψsem) and at midday (Ψsmd). At Ψpd to -0.54 MPa rain-fed and irrigated vines had similar midday Ψl and Ψs. This was due to both, stomatal closure and reduction of leaf area. Under these conditions, Ψpd and Ψsem were better water stress indicators than midday Ψ. In both years a close correlation was found between Ψpd and Ψsem. However, for a given Ψpd, Ψsem of vines was lower in 2004 than in 2003. This was probably due to the larger leaf area developed by vines in 2004. Stomatal conductance reflected reasonably well differences in the vine water status but its variability was much higher than that of Ψ. Moreover, the afternoon depression of stomatal conductance observed even in irrigated plots, indicates that measuring gs early in the morning is more convenient when assessing different treatments.

Effects of the whole vine versus single shoot-crop level on fruit growth in Vitis labruscana 'Concord'

The fruit growth response to the whole vine and single shoot crop level was studied in Vitis labruscana 'Concord' grown in the North-Eastern United States. In vines thinned to lower and higher yields (equivalent to 12 and 21 t·ha-1), different number of clusters per shoot were retained after cluster thinning one week after set. Results showed that the seasonal accumulation of berry dry weight, fruit fresh weight, and the berry total soluble solids at harvest were only affected by the whole vine crop level. This suggests that under the conditions of this experiment shoots are not autonomous in terms of carbon partitioning to the fruit. Hence, crop level effects on fruit development can be considered and modelled on a whole vine basis.

Modern trends of Citrus pruning in Italy

The citrus industry is at present increasingly oriented toward upgrading groves, discarding obsolete plantings and introducing new rootstock/scion combinations which are more tailored to local environmental conditions. A rise in production costs (but without a proportionate increase in profit) together with technological innovation have both led to many changes in citrus orchard management, and consequently there have been changes in cultural techniques. Many cultural and edaphic factors influence the choice of pruning frequency and intensity. The main goal of pruning is to reach a useful balance between yield and growth, and to reduce cultivation costs. Drastic pruning in young citrus trees with a vigorous vegetative habit causes an excess of shoot growth, thereby extending the juvenile stage and delaying fruiting. Adaptation of the technique to local conditions in bearing groves (species, cultivars, planting distances, etc.) is mandatory for pruning optimization. A fully mechanised approach to pruning leads to substantial changes in citrus grove management and sometimes to negative effects on yield. Functional integration of mechanical and assisted pruning seems to be the right choice for the Italian citrus industry