State in brief about the Fungi
It is heterotrophic plants, larger than the bacteria. Those that live on the dead tissues of organic substances are called saprophytic. They play a important role in soils and plant nutrition. The number of fungi may vary from 105 to 106 per gram of soil and the number is less than that of bacteria but the total mass is probably of the order of that of bacteria. The environmental factors which influence the occurrence, distribution and activity of soil fungi are more or less the similar as those of soil bacteria, except that fungi dominate in acid soils. As these soil organisms are aerobic and heterotrophic, they require an abundant supply of oxygen and organic matter in soil. Thus, due to the aeration factor, the number of fungi in coarse textured soil is more than that in fine textured clay soil. Optimum soil reaction lies among pH 4.5 and 6.5. However, some soil fungi can tolerate a pH as high as 9.0.