Abstract: Taking Japonica rice cultivar Wuyunjing 24 as test material, this paper studied the effects of different planting modes on the growth and development characteristics of rice in Tai Lake area of East China. Four treatments were installed, i.e., direct seeding on June 1, direct seeding on June 17, manual transplanting, and mechanical transplanting. Different planting modes had significant effects on the rice growth period, with the duration of the growth period being the longest under manual transplanting, followed by mechanical transplanting, and direct seeding. The rice yield was the highest under mechanical transplanting, and the lowest under direct seeding. At the early growth stage of rice, the biomass under manual transplanting was high, while that under mechanical transplanting was relatively low. At maturing stage, the biomass under direct seeding on June 17 was the lowest, while that under mechanical transplanting and manual transplanting was nearly the same. At early growth stage, the leaf area index was higher under manual transplanting than under other treatments; at heading stage, there was no significant difference in leaf area index among the treatments; at late growth stage, the leaf area index declined quickly under direct seeding, but increased significantly under manual transplanting and mechanical transplanting. Throughout the whole growth period, the photosynthetic potential under direct seeding was the lowest. Direct seeding on June 1 and manual transplanting promoted the rice growth rate at early growth stage, but direct seeding on June 17 increased the rice growth rate significantly at late growth stage. Mechanical transplanting increased the amount of α-NA per unit dry weight of root at rice heading stage significantly. Manual transplanting and direct seeding on June 1 increased the leaf chlorophyll content at tillering and jointing stages, while mechanical transplanting promoted the leaf chlorophyll content from heading stage to maturing stage. In sum, under mechanical transplanting, the rice growth period was relatively long, rice grew well at early growth stage, and, the leaf area index, photosynthetic potential, leaf chlorophyll content, and root activity were higher at middle and late growth stages, which was beneficial to gain the high and steady rice grain yield.

Key words: nutrient reabsorption efficiency, leaf, litter, herbaceous plant, vegetation recovery.