Results Sucrose content and theoretical production The available stalk number per hectare, stalk diameter, single stalk weight and theoretical production find more of plant cane were found to be significantly (P ≤ 0.05) higher than those of ratoon cane. However, there were no significant differences in the sucrose content and stalk height of the 2 types of cane (Table 1). Table 1 The agronomic characters, theoretical sugar content and yield of plant cane and ratoon cane   Sucrose content (%) Available stalk number (hm-2) Stalk height (cm) Stalk diameter (cm) Single stalk weight (kg) Theoretical production (kg/hm2) Plant cane 12.86±0.63a 67311.06±555.17a

312.0±1.53a 2.97±0.009a 1.96±0.02a 131785.5±393.7a Ratoon cane 13.59±0.36a 61541.54±826.24b 325.3±9.17a 2.77±0.066b 1.78±0.10b 109404.8±6641.4b Note: Data are means ± SE. Different letters in columns show significant differences determined by Tucky’s test (P ≤ 0.05). Soil enzyme activity Except for polyphenol oxidase, the other enzymes, i.e. invertase, urease, phosphomonoesterase and peroxidase

activities were found to be significantly higher in plant cane soil, than in ratoon cane soil or control soil. There were no significant differences in invertase and peroxidase activities between the control and ratoon cane soils. However, the control soil had significantly lower urease and phosphomonoesterase activities than ratoon cane soil (Table 2). Table 2 Soil enzyme activities in rhizospheric soils from the study sites   Invertase a Urease b Phosphomonoesterase c Polyphenol oxidase Small Molecule Compound Library d Peroxidase d Control soil 0.21±0.034b 0.020±0.0009c 0.12±0.0091c 0.85±0.074a 1.91±0.101b Plant cane soil 0.62±0.033a 0.047±0.0023a 0.41±0.0042a 1.18±0.074a 2.50±0.208a Ratoon cane soil 0.33±0.020b 0.038±0.0013b 0.27±0.0108b 0.88±0.164a 1.88±0.024b Note: Data are means ± SE. Different letters in columns show significant differences Clostridium perfringens alpha toxin determined by Tucky’s test (P ≤ 0.05). a μmol glucose g-1 soil h-1; b μmol urea g-1 soil h-1; c μmol p-nitrophenol g-1 soil h-1;

d μmol pyrogallol g-1 soil h-1. Microbial community dynamics assessed by BIOLOG analysis The average well-color development (AWCD) of the carbon substrates for all soil samples using the BIOLOG ECO microplates indicated that the change in AWCD increased with an increase in incubation time during the 168 h incubation period (Figure 1). The AWCD followed the sequence, plant cane (NS) > ratoon cane (RS) > control (CK), at almost every time point monitored. Plant cane soil showed the largest rates of substrate utilization while ratoon cane soil displayed significantly lower rates. Furthermore, CLPP diversity and evenness, evaluated with the data from 96 h incubation, were found to be significantly lower in ratoon cane soil than in plant cane soil.