Ciencia del Suelo (Dec 2017)
Sustratos: relación de poros con aire y agua adecuada para producir plantas florales en contenedor Nº10
Abstract
In Argentina a large part of the ornamental plant production is produced in containers, therefore, an important supply is the plant substrate. There is a variety of materials that could be used as a substrate, but its characterization and critical analysis of properties is a previous requirement. Among these, aeration capacity (AC) and water holding capacity (CRA) are outstanding; whose appropriate ranges depend on factors, such as the height of the container. Therefore, in this work we evaluated the appropriate range of substrate AC and CRA for the development of two varieties of Viola and Petunia in container Nº10, with drip irrigation, at two times of the year. Seven substrates made with Sphagnum peat and fine and medium pine bark compost were evaluated. pH, electrical conductivity, granulometry, density, EPT, CRA and CA were analyzed. Two trials with Viola and two with Petunia in containers Nº10 (377 cm³ and 7.5 cm in height) were made. At the end of each trial, the aerial and radical dry mass was measured per plant. Substrate pH was corrected, reaching values between 5.31 and 5.77. It was possible to obtain substrates with a differing AC/CRA relation (P<0.0001) for its later evaluation with plants but substrates with an even lower CA to complete the study were not obtained. The greater development of plants, based on the dry mass, was obtained in the substrate with AC /CRA ratio: 0.511, followed by substrates with 0.589 and 0.792 ratios, regardless of the time of the year. In conclusion, it is proposed that an appropriate substrate should have a CRA of minimum of 50% and an AC of maximum of 50%, provided that the EPT is greater than 85%.
