Compost and Biochar to Promote Soil Biological Activities under Sweet Potatoes Cultivation in a Subtropical Semiarid Region

Figure 3

Soil enzyme activity and microbial biomass P during the growing season of sweet potatoes at preplanting and 39, 48, and 92 days after planting. Error bars represent ± one standard error (n = 3). Values followed by the same lowercase letter are not significantly different within the same sampling date, and means followed by the same uppercase letter are not significantly different across sampling dates within the same treatment. Means followed by asterisk () are significantly different than prefertilization mean ( < 0.05). There were no significant differences between the treatments within each sampling date for MBP, alkaline phosphatase, and acid phosphatase. DAP = days after planting.

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