Balachandran, P VSaraswathi, PKAU2020-06-032020-06-031989http://krishikosh.egranth.ac.in/handle/1/5810146937PGAn investigation on the urease activity of rice soils of Kerala was conducted at the College of Horticulture, Vellanikkara during the period 1987-1989. Representative soil samples were collected from six rice soils of Kerala, namely , laterite karppadam, kari, kayal, kole and black soil . The kinetics of urease activitywas worked out employing Lineweaver-Burk equation of double reciprocal plot. The effect of different factors like pH, soil submergence and rice rhizosphere on soil urease activity was investigated . A comparision of the efficiency of the different methods of urease assay was also made. The radioassay and autoradiograph of the plants which were allowed to absorb 14 C - urea were also done.enThesis