Abstract
This study was aimed at clarifying the optimum effective soil layer depth for field improvement in a limestone area. Three experimental areas (15m×12m) with different effective soil layer depths (40cm, 60cm and 80cm) were prepared in the same field and sugar cane was planted under conditions of irrigation and non-irrigation. After the harvesting of sugar cane, the sugar production, which was calculated by multiplying the cane weight by the sucrose content, was compared among all conditions.
As a result, the effective soil layer depth with the highest production was different for conditions of irrigation and non-irrigation. The effective soil layer depth of 80cm gave the best production in the non-irrigated condition and that of 60cm gave the best production in the irrigated condition. Therefore, we concluded that effective soil layer depth for field improvement with an irrigation system in a limestone area had better be 60cm.
