Ecophysiology of the plant-rhizosphere system

The rhizosphere is the site of organic deposition and the generator of habitat and resource heterogeneity for soil organisms. Plants can modify their rhizosphere through nutrient, moisture and O-2 uptake from the rhizosphere, rhizo-deposition and production of root exudates. As a result, rhizosphere chemical (pH, nutrient solubility, O-2, CO2 and other chemicals), physical (moisture and aeration), and biological (soil pathogens, beneficial microorganisms and allelopathy) characteristics will be changed or modified. Rhizosphere microorganisms have positive or negative effects on plant growth and morphology by affecting the plant hormone balance, plant enzymatic activity, nutrient availability and toxicity, and competition with other plants. Plants modify the rhizosphere and as a result will modify the community.