B. N. DHANANJAYAALUR, ASHOK S.B. G. PRAKASHR. L. RAGHUNATHA REDDYB. R. PREMALATHAH. M. PRUTHVI RAJ2024-01-042024-01-042021-01UHS18PGM1133https://krishikosh.egranth.ac.in/handle/1/5810205696A study was undertaken to assess the fertility status of surface soils under different periods of eucalyptus cultivation (12, 24 and 48 years) and restoration (2, 6 and 10 years) and compared with adjacent croplands having no history of eucalyptus cultivation. The results revealed that the soils under eucalyptus plantation showed high bulk density and low water holding capacity as compared to restored and cropland plots. Further, bulk density was increased while water holding capacity was decreased with increasing the cultivation period of eucalyptus. Soils under eucalyptus plantation were acidic in reaction and contained less total soluble salts. The soil acidity was increased while total soluble salts content was decreased with prolonging the cultivation period of eucalyptus. The available major nutrients except sulphur and total bacterial and actinomycetes counts were low in soils under eucalyptus plantation and were decreased with prolonging the cultivation period of eucalyptus. The available Fe, Mn, Zn and Cu contents including total fungal counts were relatively more in soils under eucalyptus plantation than restored and cropland plots and were increased with prolonging the period of eucalyptus cultivation. A study on vertical distribution of nutrients in eucalyptus, restored and cropland plots indicated that the available major and micronutrients contents were decreased with depth except Mn content. A study on allelopathic effect of eucalyptus tree parts aqueous extracts on seed germination and seedling growth of finger millet and tomato revealed that the germination of tomato seeds was more inhibited than finger millet seeds. Further, fresh leaves aqueous extract has pronounced more inhibitory effect on seed germination and seedling growth attributes of finger millet and tomato followed by consortium of fresh leaves, juvenile stem bark and root extracts while least inhibition was noticed in root extract at all levels of concentration tried.EnglishThesis