The influence of city sludge fertilization upon the symbiotic fixation at alfalfa

Abstract

Neutralization of the city sludge with the help of soil considered a cleaning biological station is one of perspective, the most important upon the environment with the increase of the agricol production. In the new socio economic conditions from Romania, manure is to found less and less due to the decreasingof the animal number, and the way they are exploited, replacing manure with the sludge from the treatment of used waters is an alternative due to the sure advantages of using sludge as fertilizer. The aim of this present paper is represented by the determination of the nitrogen symbiotically fixed at the alfalfa culture fertilized with sludge from the station of cleaning water at Tetarom Cluj with manure, within an experiment with eight variants. Following the appliance of city sludge there was noticed an increase of the nitrogen quantity symbiotically fixed at the fertilized variants with sludge from the cleaning water stations, and in direct corelation with it, a significant increase of the dry matter quantitaty /ha.