Effects of Burning Crop Residues and Drenched the Soil with Water on the Populations of the Bacteria, Thiobacillus spp. and the Fungus, Trichoderma spp. in the Open Fields

Burning crop residues and/or drenched fields with water is one of the most common methods for controlling weeds and plant diseases in Iraq that farmers use after the wheat and barley harvest season every year. It is known that the soil contains many microorganisms that coexist with the roots of plants, such as fungi and symbiotic bacteria. This study aimed to show the effect of soil burning harvest residues or drenched with water on the population density of Trichoderma spp. fungus and Thiobacillus spp. bacteria. The results of the experiment showed that the burning process negatively affects the population density of microorganisms in the soil, which live at a level of 10 cm below the soil surface. The results indicated that there was a clear and significant difference between the treatments, like the burning of harvest residues or drenched of the soil, which reduced the population density of the tested microorganisms in the experiments.