The activity of azotobacter in different soil types from Malta

Abstract

Biological Nitrogen fixation is a process where atmospheric nitrogen is converted to ammonia by microorganisms collectively known as diazotrophs. Diazotrophs carry out this process either in the free living state or when associated with certain types of flora and fauna. An important free living diazotroph which received substantial attention through the years is Azotobacter. The contribution towards nitrogen input in agricultural soil and its effect on crop production has been studied with inconclusive results. The scope of this project was to study the distribution and growth of Azotobacter in different soil types from Malta. The soil paste method was carried with soil with contrasting characteristics and the number, type and characteristics of colonies produced on the pastes were noted. This study could not establish clearly whether the distribution and growth of Azotobacter in soil depends solely on soil type since there were similarities as well as differences in the growth pattern both in soils of the same series and between soils of different series.