ISHS Acta Horticulturae 779: International Symposium on Growing Media
NITROGEN AND WATER HOUSEHOLD IN PEAT REDUCED GROWING MEDIA DURING CULTIVATION OF TREE NURSERY CROPS |
| Author: | H. Bohne |
| Keywords: | incubation test, N-immobilization, N-mineralization, N-uptake, organic fertilizer, available water, water tension |
| Abstract:
Container experiments with a peat-free and a peat-reduced substrate fertilized with Osmocote or an organic fertilizer were carried out. Cultivated plants were Weigela 'Bristol Ruby', Prunus laurocerasus 'Otto Leuken' and Forsythia × intermedia 'Lynwood'. Mineral N-content in the substrate, plant growth and N-uptake were measured during the vegetation period. Water tension was determined weekly. The air- and water-characteristics of the substrates were analyzed with the M-ISHS-method. Additionally, for the peat-free substrate an incubation and storage test were carried out. Available water was lower for the peat-free and peat-reduced substrate compared to white peat. The data of the incubation test (N-immobilization) gave no explanation for the effect of the peat-free substrate during the growth period, where former N-immobilization changed into N-mineralization processes. Interactions with fertilizers could be stated. In all treatments marketable plants could be produced. Fresh matter was higher in the white peat substrates than in the peat-free and peat-reduced substrates. However, N-immobilization is not regarded as a problem for plant growth at the beginning of the growth period since the increase of fresh matter and N-uptake starts only in late spring. Apart from the mineral N-content, also the high water tension in peat free or peat reduced substrates seems to be responsible for the reduction of growth. Especially organic fertilizers were not evenly distributed in the container due to the refertilization procedure. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
