ISHS Acta Horticulturae 779: International Symposium on Growing Media
REGIONAL COMPONENTS USED AS GROWING MEDIA IN ARGENTINA |
| Authors: | O.R. Valenzuela, C.S. Gallardo, A.N. Kämpf |
| Keywords: | plant substrates, organic and inorganic components, physical and chemical properties, South America |
| Abstract:
This study describes samples of 57 materials commonly used for seedling production in Argentina, with the objective to reduce the lack of literature on plant substrates in this country. The organic samples include two types of subtropical peat, pine bark at different grades of decomposition, vermicompost of diverse origins and carbonized rice hulls; the inorganic samples include: mineral soil, sand and others. The following characteristics were determined in three repetitions: total porosity (TP), dry bulk density (Ds), particle density (Dp); water retention capacity (WRC) at 10 hPa, air-filled porosity (AP), pH-value (pH) and salinity (EC). The peat from Delta de Entre Rios is fibrous with pieces of grass and ferns still present, has a high value of TP (between 84 and 93% v/v) and 42%v of WRC. The peat from Concordia is more mineralized, dark colored, with high WRC (61%v), low pH (from 3.5 to 5.3) and EC value from 0.03 to 3 dS/m (25°C). Pine bark presents TP > 85%v with WRC varying between 30 and 49% v/v and pH from 3.5 to 5.6. Vermicompost is a very hetero¬geneous material, intensively used by small growers. The variability among the results was very significant (p < 0.001). The samples showed values of TP varying from 73 to 92%v and WRC between 20 and 66% v/v. Despite already in use as a component for plant substrates in Brazil, carbonized rice hulls remain almost unknown in Argentina, where its potential use should be studied, due to the local rice crop production. The very low WRC (ca. 20% v/v) of this material can be limiting for some uses. To conclude, this study opens a new line of investigation on qualified plant substrates to replace the present use of mineral soils and sand materials. | |
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