Suo - Mires and peat vol. 29 no. 2 | 1978

In this study samples of both flark and forest peat from nutritionally similar sites were compared. Flark peat was found to be richer in nearly all nutrients, including the exchangeable ones, than the forest peat (Table 1). The most important reason for the difference may be that the trees and ground vegetation on a pine fen have taken up and retained a considerable part of nutrients. Microbes may, however, have fixed more nutrients on flark fen than on pine fen, for there were four times as many aerobic bacteria in flark peat than in forest peat. The peat required for the experiments came from Alajärvi fen in the Kivalo experimental area belonging to the Forest Research Institute. Peat was taken from two points, 30 metres apart. One sampling point was located on a flark fenlike bog and the other on a pine fen. Peat from the former will be called flark peat, from the latter forest peat. Thirty pots were filled with two peat types. Three pine seedlings grown in unfertilized garden peat were planted in every other pot and birch seedlings in the rest of the pots. Pine seedlings were grown in their pots in a greenhouse for about 12 moths and birch seedlings for about 10 months. At the end of the experiment the shoots were weighed, the length of roots measured and the root tips counted. Every fifth birch root branch in each pot was measured; while each pine root from every other pot was chosen for measurements. Results from the analysis lead to the assumption that flark peat, because of its richer nutrient content, may be better than forest peat as a substrate for the growth of Betula verrucosa and Scots pine. The final measurements showed that the growth of birch shoots and roots was much stronger on flark than on forest peat (Table 2). The growth of pine shoots showed a similar trend, although the difference was smaller. The investigation also included the forming of mycorrhizae in seedlings and corresponding nutrient uptake. A microscopic study of the slices from root tips revealed a rather weak ability of birch and pine to form mycorrhizae (Fig. 1). There^ were no marked differences in mycorrhizaf development of seedlings grown on flark or forest peat. Scanning electron microscopy showed that some root tips were enveloped by mycelium and that pines grown on flark peat displayed unidentified cell formations (Fig. 2). When comparing the influence of peat extracts and mixtures of nutrient solution on the growth of mycorrhizal fungi, it was detected that a fungus important for birch, Paxillus involutus, grew better in a solution containing extract from forest peat rather than flark peat (Table 3). Tricholoma flavo-brunneus yielded the opposite result in two experiments, in one of which the difference was statistically significant. The fungi important for pine, Cenococcum grani-forme and Boletus variegatus, grew better in a nutrient solution containing extract from forest peat. The growth of other involved mycorrhizal fungi (Amanita muscaria umbrina, E-57) was not significantly dependent on peat types. The examination of seedlings grown in 32P isotope solution showed that the phosphorus uptake was better from a pure nutrient solution than from a solution containing either of the two peat extracts (Table 4). The extract from flark peat, as compared to that of forest peat, harmed the phosphorus uptake of birch less; whereas pine reacted in the opposite way. Pine could on a peat substrate, however, take up phosphorus, applied at watering, better from flark peat than from forest peat. According to the results, peat from a flark fen was a good substrate for the initial development Betula verrucosa. The initial development of Scots pine was relatively much weaker on this peat substrate. The experiments utilizing peat extracts even imply that peat from a flark fen may contain, in its natural state, substances that harm the growth of mycorrhizal fungi on pine and the nutrient uptake of seedlings. More investigations, however, are necessary for any final conclusions.

• Paavilainen, Sähköposti: ei.tietoa@nn.oo

This study involves the determination of some kinetic parameters of the various peat samples. Also, the effect of the peat type and the degree of the humification to the kinetics of the pyrolysis was of interest. These experiments were performed both in the inert gas and in the air nitrogen gas mixture. The energy of the activation as well as the rate constant clarify the changes of the matter during the pyrolysis. These facts are met, if we want to distinguish the nature and the behaviour of the products formed in the pyrolysis. The kinetic parameters were calculated using two different methods, both giving the similar results. The reference substance employed was cellulose since it is one of the main components of the peat and its pyrolysis is well studied. We conclude, that the pyrolysis of the peat can be investigated assuming the first order kinetics. Further, the differences between the peat types were considerable which leads to the fact, that the selection of the peat type reflects the gaseous products formed during the pyrolysis and is important e.g. in the gasification studies.

• Tummavuori, Sähköposti: ei.tietoa@nn.oo
• Venäläinen, Sähköposti: ei.tietoa@nn.oo
• Nyrönen, Sähköposti: ei.tietoa@nn.oo

The article presents results of an experiment in which different sowing and planting methods were compared. The experi-ment was carried out in two experimental areas in Central Finland, the Lylynsuo and the Nuijaneva. The Lylynsuo area has been drained in 1969 and its pre-drainage peatland site type was an ordinary sedge bog. The Nuijaneva area has been drained in 1963 and its site type was a small-sedge bog. The experimental layout was the same in both areas: four planting and four sowing methods on five blocks. An experimental unit consisted of a pair of rows with 100 transplants or sowing spots. The methods used were. 1. Planting on intact peat surface 2. Planting on top of the furrow ridge made by a reforestation plow (see Fig. 1) 3. Planting on the side of the ridge nearest to the furrow 4. Planting on the other side of the ridge 5. Sowing on intact peat surface 6. Sowing on a 50 x 50 cm2 spot, from where the living moss had been removed 7. Sowing on a foot-pressed spot, on chopped peat spread out with Kopo spiral trencher 8. Sowing with sowing machine (see Fig. 2). The afforestation was made with Scots pine in the spring 1969. After planting and sowing, spot fertilization (30 g/trans- plant or sowing spot) was applied with compound fertilizer (15 % N, 25 % P2O5, 10 % K2O). Living transplants and sowing spots with seedlings were counted in the autumn 1969, in the spring 1970, in the autumn 1971, and in the autumn 1974. The height and the height growth of the transplants and seedlings were measured in 1971 and 1974, the height of the seed-lings in the machine-sown group only in 1971. The results are presented in the Figures 3— 5. Planting was successful with all the methods applied, with no significant differences between the methods. Sowing succeeded better in the Nuijaneva area than in the Lylynsuo. As can be seen, the results of sowing correlate with the competition from the surface vegetation, which is greater in the Lylynsuo area. The transplants were significantly higher and their height growth greater in the three turf planting methods (2—4) than in the method of planting on intact peat surface. Height growth of seedlings was the best on the chopped peat (method 7) and the poorest on the intact surface. Results from the two experimental areas are quite similar. Taking into account the age diffe-rence of the seedlings and the transplants, the seedlings are either growing almost as well as the transplants or are only a year or two behind in development.

• Mannerkoski, Sähköposti: ei.tietoa@nn.oo