NURSERY GROWTH AND BIOMASS OF THE SEEDLINGS OF NINE TREE SPECIES PLANTED UNDER DIFFERENT POTTING MEDIA IN NORTHWEST ETHIOPIA

Abstract

The production of quality seedlings depends on the potting media. A nursery experiment was conducted in Pawe Agricultural Research
Centre, in the northwest part of Ethiopia in 2006. The study was aimed at investigating the impact of different potting media on biomass and growth
and also identifying the properties that influence seedlings’ nursery performance. Four types of potting media, three of them mixed from different
proportions (farm yard manure, forest soil, sand), and the local soil were compared. A factorial experiment was laid out in Randomized Complete
Block Design. ANOVA on growth and biomass data were performed for nine tree species using the GLM procedure of SPSS (Version 13). In most of the
studied species, the seedlings planted in potting media with the un-amended local soil showed significantly highest (p<0.05) shoot height, root collar
diameter, shoot and root biomass. The present results from biomass and growth analyses suggested that physical properties which determine plant
water relations are essential to seedling growth during dry spells of the year, when most nurseries of Ethiopian drylands produce tree seedlings. Under such conditions, potting media calibration should aim at amending physical properties such as total porosity and bulk density. The notion of enhanced seedling growth in substrates of high organic matter content should be carefully considered in nurseries of dry areas.