Studies on certain physical soil properties in long-term soil cultivation experiments on a brown forest soil in Godollo

Changes in soil physical properties during the 1997 vegetation period were studied under favourable nutrient supply conditions in a long-term soil cul tivation experiment set up in 1994. The growing site was a rust-brown fores t soil with moderate fertility, a shallow topsoil and moderate nutrient sup plies. The present paper evaluates the effect of five soil cultivation vari ants on thr, total porosity, volume mass, moisture dynamics and water reten tion curves (pF curves) of the soil. Analysis of variance between the treatments indicated that in all the treat ments differences due to the cultivation effect could only be observed in t he 0-40 cm layer. The application of direct drilling and disking over a num ber of years resulted in significantly larger Volume mass values and lower total porosity values compared with techniques involving soil turning and l oosening. It was found that the direct effect of cultivation on the pF curves could o nly be demonstrated at the beginning of the vegetation period in the low su ction force range. By the middle of the vegetation period (June) no signifi cant differences could be observed between the water retention values measu red at different suction forces. The indirect effect of cultivation was obs erved at the end of the vegetation period (August). The integrated effect of soil cultivation on various physical soil paramete rs was characterised using measured soil moisture dynamics. Statistically s ignificant differences were found between the soil moisture values in the p loughed layer. During the period examined the soil was driest after direct drilling, which is recommended in the literature as a way of reducing moist ure losses. The highest moisture values were recorded after ploughing combi ned with loosening. The results prove that results obtained under different climatic conditions on different types of soil cannot be extrapolated; whe rever possible, measurements should be made on the actual site.