Evaluation of mineral nutrition and growth of Eucalyptus saligna seedlings raised on organic – enriched nursery potting media

Abstract

Forest soil is the convectional growth media used in raising seedlings in tree nurseries in Kenya. Poor growth media in tree nursery establishment has been reported as the major cause of poor seedling establishment in the nursery and after out planting. This study evaluated the potential of forest soil and organic mixtures as potting media for seedling establishment. The experiment was laid out in a completely randomized design with five treatments comprising of: Forest soil (Medium 1); Sawdust mixed with cattle manure in the ratio of 1:1 by weight (Medium 2); Forest soil mixed with cattle manure - sawdust mixture (1:1) in the ratio of 1:1 (Medium 3); Forest soil mixed with cattle manure - sawdust (1:1) mixture in the ratio of 1:2 (Medium 4); and Forest soil mixed with cattle manure - sawdust (1:1) mixture in ratio of 1:3 (Medium 5). The treatments were replicated three times in experimental plots of 100 seedlings per treatment. Seedlings were allowed to grow for 24 weeks while the growth parameters, foliar nutrient concentration and seedling mortality were monitored periodically during the study period. Enrichment of Forest soil with Sawdust and Cattle manure at various ratios increased nutrient concentrations in the media and enhanced growth and dry matter biomass compared to those with forest soil alone thus resulting to faster growth and increased nutrient uptake. There is need to develop strategies for mixing organic materials with forest soil which will improve decomposition and growth of seedlings and thereby reduce mining of forest soil.

Keywords: Cattle manure, Forest soil, Sawdust, Tree seedlings, Nutrient uptake