Masanori Yanase

Growth characteristics and yield of carrots grown in a soil ridge with a porous tube for soil aeration in a wet lowland

The growth characteristics and yield of carrots grown in a soil ridge with an aeration treatment were compared with those of carrots grown in a conventional ridge as a control under wet lowland field conditions. For the aeration treatment, a plastic porous tube was placed in the soil ridge. Water depth between the ridges in the aeration treatment and the control was kept at 20 mm throughout the growing period in order to imitate the wet soil conditions in tropical and subtropical lowlands. The fresh and dry weights of the storage root were 1.9 and 1.7 times greater, respectively, in the aeration treatment than in the control. The maximum root length in the aeration treatment was 1.8 times greater than in the control. The length of the leaf lamina and the leaf area per plant were greater in the aeration treatment than in the control. The fresh and dry weights of the total phytomass per plant were approximately 1.6 times greater in the aeration treatment than in the control. The fresh weight of the above-ground part was 1.3 times greater in the aeration treatment than in the control. The net photosynthetic rate and edible biomass index were greater in the aeration treatment than in the control. Carrot production in wet lowlands is possible if adequate aeration of the soil ridges is provided.