Rhizosphere Effects of Melocanna baccifera on Soil Microbial Properties under Different Fallow Phases Following Shifting Cultivation

Rhizosphere plays an important role in regulating soil fertility and nutrient cycling in different ecosystems. Bamboos are important secondary successional plants in fallow land that have strong impact on the soil fertility of different fallow lands. The main objectives of the present study is to examined the rhizosphere effects of bamboo (Melocanna baccifera) on soil microbial properties (soil organic carbon, SOC; total nitrogen, TN; microbial biomass C and N, MBC and MBN; dehydrogenase activity, DHA; acid phosphatase activity, APA; β-glucosidase activity, GSA) in rhizosphere (RS) and bulk soil (BS) in shifting cultivation stand with different fallow phase (2 years old, FP-2; 5 years old, FP-5; and 10 years old fallow, FP-10) in Mizoram. The result indicated that soil microbial properties were significantly higher (p<0.05) in RS compared to BS. Further, the level of microbial properties significantly increases in longer fallow (FP-10) compared to shorter fallow (FP-2 and FP-5). On contrary, magnitude of rhizosphere effect of M. baccifera was greater in shorter fallow phase compared to longer fallow phase for all microbial properties except in APA and GSA. It was concluded that the rhizosphere effect of bamboo in shorter fallow is microbial mediated under C and nutrient limited conditions and in longer fallow the same is regulated by the accumulated organic matter and the available nutrients. Further studies are needed to assess the changes in secondary successional plant rhizosphere microbes under different fallow phases.