Nitrogen use efficiency and life cycle of root nodules in alfalfa after different mineral fertilization and soil cultivation practices were studied. Field trial was conducted in the Institute of Forage Crops, Pleven, Bulgaria on leached chernozem subsoil type and no irrigation. The next treatments were tested: i) for fertilization as follows: N0P0K0 (control); N60P100K80 (an accepted technology...

Ninety, day old broiler chicks were arranged into 5X3X6 pattern to investigate the effect of exclusion of Cobalt, Iron and Copper from the mineral mixture. Five dietary groups (T1 to T5) were assigned basal diets containing 2800 kcal ME/kg and 22% CP (Starter) and 20% (Finisher) for a total duration of 6 weeks. The chicks in T1 were fed commercial mineral mixture, T2 were supplemented with mine...

In recent years stable isotopes of metallic and semi-metallic elements have become popular as tracers in studies of nutrition and metabolism. There are several recent reviews on the use of stable isotopes of the mineral elements (Janghorbani & Young, 1980; Janghorbani et af . 1985). The orientation of these reviews has tended toward neutron-activation analysis in conjunction with the faecal iso...

In recent years stable isotopes of metallic and semi-metallic elements have become popular as tracers in studies of nutrition and metabolism. There are several recent reviews on the use of stable isotopes of the mineral elements (Janghorbani & Young, 1980; Janghorbani et af . 1985). The orientation of these reviews has tended toward neutron-activation analysis in conjunction with the faecal iso...

Microbial biomass nitrogen and carbon were studied in long-term field experiments with continuous cultivation of silage maize and with crop rotation. a positive effect of organic fertilizers on the microbial biomass nitrogen and the carbon content in soil was observed. Statistically significant effect of organic fertilizers on the higher content of microbial biomass C and n was established in t...

The Chah-Shaljami polymetal ore deposit contains heavy metal anomalies in various mineralization zones. Geochemical distribution and correlation of elements in surficial soilsindicate that sulfide, sulfate, sulfosalt and silicate mineral occurrences (e.g. Pyrite, chalcopyrite, galena, sphalerite, molybdenite, enargite, hornblend and biotite) in mineralization and stockwork zones resulted in the...