Effect of Fertilization on the Nursery Growth and Outplanting Success of Two- Year-Old Containerized Scots Pine Seedlings

1990

16 S.

6 Abb., 7 Tab., 46 Lit. Ang.

Bandaufführung

2628

37238

The effect of fertilization on the development of Scots pine (Pinus sylvestris L.) seedlings grown on two commercial nursery peats was studied. Seedlings were grown in paper pots (FS 608; 196 cm3/pot, 80 pots/unit, 333 pots m-2) filled with two nursery peats, Vapo-400 Tree seedling peat or Sato ST-400, PP6. The growing and fertilizing schedule for the first year (1984) was similar for all seedlings (Table 1). In the beginning of the second growing season (1985) the fertilization was differentiated into three levels according to the electrical conductivity (EC) of peat water extract (Table 2) . Each treatment (peat x fertilization-combination) consisted of 30 seedlings trays with 80 seedlings in each tray. Fertilizers were applied 1-5 times a week in irrigation water with 0.1-0.4% concentration depending on the EC of the substrate and need of watering. In the beginning of the growing season granular fertilizers were also used in order to increase the EC to the targeted level; this was achieved in three weeks after start of fertilization (Fig. 1). The fertilizers and nutrients given during the second year are shown in Table 3 and Fig. 2. The seedlings were watered according to nursery practice and the moisture content of the peat substrate was checked once a week by watering the seedling trays to the targeted weight (8.0-9.0 kg, moisture content 39-46% in volume) weekly. Because of a rainy autumn, the weight of seedling units uncreased to 13 kg (65% in volume) at the end of September. EC and pH of the peat substrate were measured weekly and the nutrient concentration of peat water extract was measured 3 times during the first growing season and 6 times in the second. Nutrient concentration of needles was analyzed once at the end of the first growing season and 7 times during the second growing season. Morphological properties (10 seedlings/treatment) were measured 6 times during the second growing season. In addition mortality, damages, and number of lammas shoots were recorded from all seedlings and the heights of 100 seedlings/treatment were measured at the end of the second growing season. Outplanting performance of seedlings was tested both in the pot experiment and the field test. In the pot experiment seedlings grown in Vapo peat were planted on May 15, 1986 in plastic boxes filled with fine sand, and were watered weekly to the targeted moisture contents (75%, 50%, and 25% of water capacity). Fertilization-moisture combinations had 4 replications with 8 seedlings in each box. The experiment was conducted under a plastic cover to prevent the effect of rain. Morphological properties, dry weights and nutrient concentrations of needles were measured at the end of October. The field experiment was established on an abandoned agricultural loamy field.