Nowadays, the most used constituent for growing media in soilless cultivation is still peat. However, limitations related to their extraction cost, availability on the market from one year to the next and a possible environmental impact, pushed the research to focusing on possible alternative materials. By-products from production/transformation processes could represent a source of materials for growing media, with the general advantage of a circular economy. Different by-products: coir, compost, grape marc, hemp residues and wood fibers were considered. First part of research was focused on the evaluation of main physical, chemical and biological properties of coir, green compost, hemp residues and grape marc. Then materials were tested in a series of comparative cultivation trial (i.e. basil transplant cultivation). Coir showed interesting results, some properties (i.e. water retention and capillary rise), proved to be good, in particular with high percentages of coir pith (70% or more). Coir properly supported plants growth, providing same or better results when compared to peat. Some limitation were found for hemp residues (scarce hydraulic properties) and grape marc (high electric conductivity). The grape marc suitability as substrate increased washing marc to reducing salts concentration and mixing with materials with better physical characteristics (peat and coir). Research also evaluated the totally or partially peat replacement with wood fibers and different types of compost. Wood fibers and compost in peat-based substrates modified the physical properties of the growing media such as water retention and capillary rise, suggesting the need of an increase of irrigation frequency, when alternative substrate are use for ornamental production irrigated with ebb and flow system. According to the presented results, also fertilization and water management are pivotal for successful soilless cultivation.
La torba è il materiale più utilizzato per i substrati impiegati nelle coltivazioni fuori suolo. Tuttavia, limitazioni relative ai costi e ad un possibile impatto ambientale dell’estrazione, nonchè alla disponibilità sul mercato da un anno all’altro, spingono la ricerca ad interessarsi a materiali alternativi. Sottoprodotti da produzioni/processi di trasformazione, possono rappresentare una fonte di materiali, con i vantaggi legati all’economia circolare. La ricerca ha riguardato fibra e midollo di cocco, compost, residui di canapa, vinacce e fibre di legno. Nella prima parte è stata eseguita una valutazione delle proprietà fisiche, chimiche e biologiche per cocco, compost, canapa e vinacce. I materiali sono poi stati testati in prove di coltivazione. Miscele di fibra e midollo di cocco hanno mostrato spiccate proprietà idrauliche (ritenzione idrica e assorbimento capillare) che aumentano all’aumentare delle percentuali di midollo (70% e oltre). Fibra e midollo di cocco, sono risultati idonei alla coltivazione di alcune specie, con crescite uguali o maggiori rispetto alla torba. Limitazioni sono state riscontrate nell’utilizzo di canapa (scarse proprietà idrauliche) e vinacce (alta conducibilità elettrica). L’idoneità delle vinacce come substrato, è però aumentata dopo il lavaggio, (riduzione concentrazione salina) e la miscelazione con materiali con migliori caratteristiche fisiche (torba e midollo di cocco). L’utilizzo di fibre di legno e compost in sostituzione totale o parziale alla torba ha modificato le proprietà fisiche dei substrati (ritenzione idrica e risalita capillare), sottolineando la necessità di un aumento della frequenza irrigua, quando tali substrati vengono impiegati per la coltivazioni ornamentali irrigate con sistemi di flusso e riflusso. I risultati suggeriscono, inoltre, che lo studio e l’uso di materiali alternativi non può prescindere da fattori quali irrigazione e nutrizione, fondamentali per il successo della coltivazione fuori suolo.
Use of organic by-products as growing media in soilless cultivation / Pica, Francesco. - (2016 Feb 26).
Use of organic by-products as growing media in soilless cultivation
PICA, FRANCESCO
2016-02-26
Abstract
Nowadays, the most used constituent for growing media in soilless cultivation is still peat. However, limitations related to their extraction cost, availability on the market from one year to the next and a possible environmental impact, pushed the research to focusing on possible alternative materials. By-products from production/transformation processes could represent a source of materials for growing media, with the general advantage of a circular economy. Different by-products: coir, compost, grape marc, hemp residues and wood fibers were considered. First part of research was focused on the evaluation of main physical, chemical and biological properties of coir, green compost, hemp residues and grape marc. Then materials were tested in a series of comparative cultivation trial (i.e. basil transplant cultivation). Coir showed interesting results, some properties (i.e. water retention and capillary rise), proved to be good, in particular with high percentages of coir pith (70% or more). Coir properly supported plants growth, providing same or better results when compared to peat. Some limitation were found for hemp residues (scarce hydraulic properties) and grape marc (high electric conductivity). The grape marc suitability as substrate increased washing marc to reducing salts concentration and mixing with materials with better physical characteristics (peat and coir). Research also evaluated the totally or partially peat replacement with wood fibers and different types of compost. Wood fibers and compost in peat-based substrates modified the physical properties of the growing media such as water retention and capillary rise, suggesting the need of an increase of irrigation frequency, when alternative substrate are use for ornamental production irrigated with ebb and flow system. According to the presented results, also fertilization and water management are pivotal for successful soilless cultivation.File | Dimensione | Formato | |
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