Soil chemical and biological fertility, microbial community structure and dynamics in successive and fallow sugarcane planting systems

Sugarcane yields are declining under successive planting (monoculture) compared to other planting systems in Florida Histosols. To evaluate soil properties related to the sugarcane yield decline, an on-farm study was conducted on soil chemical, biological, and microbial indicators variation with soil samples collected from successive green cane or burnt cane harvest, flooded fallow, and rice and sweetcorn rotation planting sites. Overall, harvest residue incorporated in the soil in green cane harvest and corn rotation increased organic matter, total carbon and C:N ratios which resulted in higher microbial biomass parameters and total PLFA biomass. However, successive planting with burnt cane harvest reduced total soil carbon and hence microbial biomass. Findings suggested that these parameters should be considered for further research to determine specific causes of sugarcane yield decline in successive planting.