Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 2332

P. Gyurko and L. Varga; [Neuere Untersuchungen uber die Mikrobiologische Wirkung der Tiefdungung von Sandboden] (Recent investigations of the Microbiological Effects of deep Manuring Sand-soils). Acta.Agronomica Acad.Sci.Hung. VIII:313-341, 1958

Reprint

In File

Notes

Authors have investigated the effect of deep manuring on the microflora and microfauna of the soils in the variations of the experiments conducted at Orszentmiklos by Egerszegi on loose clacarious sand-soil. The samples were taken on November 30, 1955 when the vegetative period had come to an end and the ecological conditions in the soil corresponded to those in winter. Authors have established the amount of aerobic and anaerobic bacteria and of microscopic fungi in 31 layers taken from seven soil sections, as well as the number of nitrifying, denitrifying and cellulose-decomposing (aerobic, anaerobic) bacteria. The result were compared among themselves and with data obtained from soil layers taken from control plots. The quantity of the microfauna and its species were determied from 16 layers taken from four plots. The results have shown that the use of deep manuring as suggested by Egerszegi considerably increases the number of microorganisms in the sandy soil. An increment in the number of species constituting the microfauna can also be observed. By deep dressing with farmyard manure the soil becomes, so to say, inoculated with masses of microorganisms. Under favourable ecological conditions the species of the microfauna thus introduced survive for years and mix up with the species originally found there. The manure layers having much higher water content than sand layers contain the relatively largest masses of microfauna and microflora. In the course of one or two year the 20 to 30 cm thick sand layer between manure layers becomes conspicuously rich in microorganisms. After three to four years the microfauna in the sand layer attains the number of those populating the manure layers whereas the members of the microflora, though thriving in the intermediate sand layer, fail to come up to the number of those in the manure layers. Nutrients seem to filtrate from the stable-manure layers into the sand layers which, having a more constant water content and temperature, becomes an extremely favourable medium for microorganisms. As against surface dressing, the effect of deep manuring can be demonstrated by means of microbiological investigations even after four to five years. In soils improved by deep manuring the amount of microflora and microfauna is high in the manure layers after dressing, whereas later the number of microorganisms increases in the sand layer and decreases in the manure layers. After four to five years this difference gradually equalizes. The number of cellulose-decomposing bacteria in deep manured soils is always higher than in the control soils. The nitrifying bacteria were found to be present in relatively small numbers. On the other hand, probably owing to nitrates easily dissolving in water, the denitrifying bacteria were found in large quantities along the whole section of soils improved by deep manuring. The species of the microfauna are in general polysaprobic organisms. They are closely connected with the bacteria as can be seen when comparing Tables 1, 2 and 3.