Abstract

A field experiment was conducted during kharif 2010 on sandy loam soil at Students’ Farm, College of Agriculture, Rajendranagar to study the different nitrogen sources (inorganic nitrogen, vermicompost and poultry manure) and their integration effect on soil dehydrogenase, phoaphatase (acid and alkaline) and urease activities in tomato at vegetative, flowering and harvest stages. Significantly highest urease activity of 234.0, 288.8 and 126.7 μg of NH4+-N released/5 g soil/2 h with the combined application of 75% RDNF+25% VC, significantly highest dehydrogenase activity of 161.0, 177.1 and 133.4 μg of TPF produced/g soil/d, the highest acid phosphatase activity of 35.23, 48.55, 25.55 μg of PNP released/g soil/h and the highest alkaline phosphatase activity of 65.07, 88.64, 71.27 μg of PNP released/g soil/h were obtained at vegetative, flowering and harvest stages, respectively, with the combined application of 50% VC and 50% PM. All three enzyme activities were increased from the vegetative to flowering stage and later showed decrease from flowering to harvest stage.