Biological activity of soil is an important factor of productivity from agronomy and ecology standpoint as well as sensitive indicator of anthropogenic impact. Present day concern regarding a great attention for its investigations in World, because that connected with rapid anthropogenic destruction of soil, attached to a pollution of atmosphere and emissions of motor transport, a waste disposal and etc. Four soil sites to highway Vilnius - Kaunas - Klaipėda, near Giraitė (Kaunas district) and Kryžkalnis (Raseiniai district) have been selected for experiment: 20 m form roadside and heavily influenced emissions of motor transport (I and III objects), 350 m form roadside and background pollution (II and IV objects). Soil samples for analyses of soil biological activity were taken from soil profile at depth 0-10, 20-25, 39-43, 56-61, 78-83 and 95-100 cm, according genetic soil horizon. United soil samples for replication were taken from soil site at same depth. The experimental data showed that in both soils a significantly decrease of urease activity in soil under the influence from highway: 20 m from roadside it was 2-3 times lower then 350 m. However, the activity of sacharase and dehydrogenase was influenced less. On contrary, soil respiration intensity increases when distance to highway decreases. Comparison of both soils biological activity shows that oxidation - reduction processes were more intensive in Luvisols (Giraitė, Kaunas district) and hydrolysis processes... [to full text]

Two long-term fertilization trials were established in 1966 on a Calc(ar)i-Epihypogleyic Luvisol at LUA Experimental station (Kaunas district). Experimental data of the period 2004 – 2005 presented in the paper shows the impact of long-term fertilization of mineral and organic fertilizers, its combinations on soil biological activity. Experimental data shows that the influence of various rates of fertilizers and their combinations on enzyme activity and respiration intensity was different. Hydrolases - urease and sacharase - activity more influenced by using mineral fertilizers, whereas oxidoreductases – dehydrogenases – activity more influenced by using mineral and organic fertilizers. Mineral fertilizers increased urease activity by on average 12 percent, whereas sacharase activity was not influenced, compared with unfertilized. The application of organic and mineral fertilizers increased activity of thus enzymes, accordingly 33 and 7 percent. In the second trial, treated with organic and mineral fertilizers, dehydrogenase activity was significantly influenced by application only rate of and 100 t ha-1 of manure per crop rotation. Under application of only mineral fertilization dehydrogenase activity in soil increased, compared with unfertilized. Average data of two years investigations under application of mineral – organic fertilizers and its combinations show that soil respiration intensity was significantly influenced by application only rate of N100P60K60. Key... [to full text]