Transplanting by side contact method of plug seeding increased the root development after transplanting on wet sheet culture compared to conventional bottom contact transplanting. This method was applied to field experiment of two truss cropping system of tomato. As a result, transplanting by side contact method of plug seeding increased the rate of fruits setting by 42%, the root dry weight by 14% finally and sugar content of tomato fruits by 15% compared to conventional transplanting.

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Plowing is an effective tillage system for crop cultivation in large-sized paddy fields and large-scale farming. Plowing reduces gas phase in the soil and increases soil hardness at depths of more than 5 cm below the surface as compared with the conventional system of rotary tilling. We investigated root distribution and activity of two maize (Zea mays L.) hybrids grown by plowing or rotary tilling in an upland maize field converted from a paddy field in Andosol. There was no significant difference in aboveground dry weight and nitrogen absorption between the plowing and rotary tilling treatments. In addition, we found no significant difference in bleeding rate, a parameter indicating root activity, between the two tillage systems. However, the percentage of roots with lengths ranging from 0-5 cm was higher and root depth index was smaller in the plowing treatment than in the rotary tilling treatment. These results indicate that the root activity of maize subjected to plowing treatment is similar to that in maize subjected to rotary tilling, although the root system in the former treatment is shallower than that in the latter.

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