Population dynamics of Azotobacter chroococcum in wheat and paddy fields with different degrees of agricultural intensification in plains of Northern India

Abstract

Microbial population in soil is determined by the soil factors, characteristics, composition and environment. Intensification of agriculture in recent years has changed the composition and structure of soil. High input of N. P. K. based fertilizers, pesticides, mechanical tillage, irrigation practices and high yielding crop varieties have changed the soil environment, either inhibiting indigenous microflora or supporting the growth of new type of microflora. The free living nitrogen fixers (Azotobacter sp. etc) have been adversely affected by the change. For the purpose of study three sites were selected from wheat and rice fields and different degrees of agricultural intensification were employed. The study of these sites shows that the population of Azotobacter chroococcum varied with different degrees of agricultural intensification.