Transformation of short-range order minerals in maize (Zea mays L.) rhizosphere

Under nutrient stress, low molecular weight organic acids are released in rhizosphere, which dissolve the crystalline layered silicate minerals and subsequently some short range order (SRO) minerals may be formed. To analyze this hypothesis, a controlled greenhouse experiment was conducted with three contrasting soils belonging to Alfisols, Inceptisols and Vertisols order in two phases, viz. Sorghum-sudangrass depletion and test crop experiment on maize. The SROs were measured by selective dissolutions. The results indicate that, NaOH extractable amorphous ferri-alumino silicate was higher in rhizosphere, whereas mild extractant extractable SRO dissolution was increased due to fertilization and rhizospheric effect. Fourier transform infrared band showed changes in 3400-3600/cm region (adsorbed water) and Si-O stretching vibration (1000/cm). This information will provide a new insight in formation of SROs under the rhizospheric environment.