Effects of three different cropping system on diversity of soil bacterial community

Effects of different cropping system on diversity of soil bacterial community were studied by using denatured gradient gel electrophoresis (DGGE) analysis. Results showed that the numbers and strength of the bands from DGGE profiles varied with the different cropping system, especially the distinguished bands were different. The bacterial community diversity, the richness index and the evenness index showed the effects of the rice vegetable cropping system (RVCs) the fallow rotation cropping system (FRCs) the vegetable continuous cropping system (VCCs) in the soil layer of 0-15 cm, but FRCs＞RVCs＞VCCs in the soil second layer of 15-30 cm. The UPGMC cluster analysis indicated that the system of RVCs and RRCs plays the differential role to the components. RVCs and VCCs systems were related with the principal components factor 1, but the FRCs system showed highly related with the principal components factor 2. Based on these results, the bacterial community diversity was closely related with planting system and the changed cropping system possibly played an important role in the soil bacterial community diversity.