1,721,475 research outputs found
Prácticas pre-profesionales en el Tambo. Novedades sobre los sistemas de crianza artificial
Full text linkFil: Dichio, Luciana. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin
Orchard management to preserve soil fertility and improve the efficiency of water and mineral resources
No full textAn appropriate orchard management is a necessary condition for high quality production with respect to environmental aspects such as a) organic matter depletion, which leads to the desertification phenomenon; b) water shortage; c) soil alkalinization and salinization processes; d) aquifers pollution; e) nitrogen and carbon gas emissions. In this paper we discuss the most appropriate practices to preserve soil fertility and improve the efficiency of water and mineral resources. Soil incorporation of green manure, pruned material and mature compost can play an interesting role in reducing the chemical inputs in agriculture, improving the organic matter content of the soil and restoring its biological fertility. As regards an efficient use of water, it is important to consider: training system, plant architecture and the different distribution of light in the canopy, as well as the irrigation system and its management. The knowledge of the uptake of mineral elements and their partitioning in the different plant organs during the annual cycle, and reserves accumulation and mobilisation is necessary in order to synchronise the supply of nutrients with plant requests. The use of fertigation is recommended, as it combines efficient use of water resources with rational use of fertilisers. Finally, referring to the present knowledge on the matter, we will point out topics in which it will be necessary to invest resources in the future research projects
Actores sociales y perspectiva de continuidad de los tambos asociados a cooperativas de la zona de Rosario.
Full text linkDichio, Lucian
Dichio(RS).vp
No full textSummary We evaluated the osmotic adjustment capacity of leaves and roots of young olive (Olea europaea L.) trees during a period of water deficit and subsequent rewatering. The trials were carried out in Basilicata (40°24′ N, 16°48′ E) on 2-yearold self-rooted olive plants (cv. 'Coratina'). Plants were subjected to one of four drought treatments. After 13 days of drought, plants reached mean predawn leaf water potentials of -0.45 ± 0.015 MPa (control), -1.65 ± 0.021 (low stress), -3.25 ± 0.035 (medium stress) and -5.35 ± 0.027 MPa (high stress). Total osmotic adjustment increased with increasing severity of drought stress. Trees in the high stress treatment showed total osmotic adjustments ranging between 2.4 MPa at 0500 h and 3.8 MPa at 1800 h on the last day of the drought period. Osmotic adjustment allowed the leaves to reach leaf water potentials of about -7.0 MPa. Active osmotic adjustment at predawn decreased during the rewatering period in both leaves and roots. Stomatal conductance and net photosynthetic rate declined with increasing drought stress. Osmotic adjustment in olive trees was associated with active and passive osmotic regulation of drought tolerance, providing an important mechanism for avoiding water loss
L’irrigazione sostenibile in frutticoltura
No full textNonostante l’innovazione tecnologica abbia reso disponibili, fin dagli anni ’70, strumenti e materiali che permettono
l’ottenimento di una elevata efficienza dei metodi irrigui (90-95%), ancora oggi nel settore frutticolo si fa largo
uso di metodi con bassa efficienza (40-50%). Una prerogativa fondamentale per ottenere il massimo dell’efficienza
dei metodi irrigui a microportata è disporre di acqua a domanda in modo da garantire la gestione dell’irrigazione
con bassi volumi d’ adacquamento e turni brevi. Tale gestione permette di mantenere l’umidità del suolo a
livelli ottimali e controllare sia la nutrizione idrica che minerale delle piante. Inoltre in fase di progettazione dell’impianto
irriguo bisogna tenere in considerazione le caratteristiche pedo-climatiche, la quantità e la qualità dell’acqua
disponibile e le caratteristiche della specie coltivata. Le recenti conoscenze relative ai rapporti pianta-terreno-
atmosfera permettono di migliorare ulteriormente l’efficienza dell’uso dell’acqua da parte delle piante, prendendo
in considerazione la vocazionalità delle specie, cultivar e portinnesti, scegliendo l’architettura della chioma e
le tecniche innovative per la sua corretta gestione. Sono auspicabili azioni coordinate tra i servizi di Sviluppo agricolo,
i Consorzi d’irrigazione, le Associazioni dei produttori, i tecnici e gli imprenditori che operano nel settore agricolo,
per introdurre, alla luce delle attuali conoscenze, una nuova cultura dell’utilizzazione delle risorse idriche. Cultura
che dovrà puntare ad un uso sostenibile della risorsa acqua mediante la combinazione di fattori che riguardano
la scelta e la gestione del metodo irriguo e la conduzione della pianta e del suolo
- …
