Rhizosphere, an Approach to Management the Soil around the Roots

The rhizosphere is a microecological zone in direct proximity of plant roots. The theoretical extent of the rhizosphere is dependent on the zone of influence of the plant roots and associated microorganisms. The rhizosphere is a metabolically busier, faster moving, more competitive environment than the surrounding soil. The rhizosphere include three zones which are defined based on their relative proximity to and thus influence from the root: Endorhizosphere,Rhizoplane and Ectorhizosphere. The rhizodeposites include: Root Exudates, Secretion, Lysates and Gaseous Compounds. Compounds in root exudates assist plants in accessing nutrients by acidifying or changing the redox condition within the rhizosphere or directly chelating with the nutrient. As the soil dries and its hydraulic potential decrease, exudates will subsequently begin to lose water to soil. When this occurs, the surface tension of the exudates decreases and its viscosity increases. In addition, as viscosity increase, the resistance to movement of soil particles in contact with exudates will increase, and a degree of stabilization within the rhizosphere will be achieved. Traditional nutrient management strategy was highly dependent on external chemical fertilizer input, but ignored exploring biological potential of efficient acquisition and use of soil nutrient resources by plants intrinsically. Rhizosphere is the key center of interactions among plants, soils and microorganisms; the chemical and biological processes occurring in the rhizosphere not only determine mobilization and acquisition of soil nutrients, but also control nutrient use efficiency by crops. The rhizosphere management strategy lays emphasis on maximizing the efficiency of root and rhizosphere processes in nutrient acquisition towards high-yield and high-efficiency sustainable crop production by optimizing nutrient supply in root zone, regulating root morphological and physiological traits, and manipulating rhizosphere processes and interactions.