# The fate of fertilizer nitrogen applied to the paddy field and its absorption by rice plant part 7 relationships between the absorption of nitrogen by the rice plants and the growth of the plants

##### Takashashi, J.; Wada, G.; Shoji, S.

#### Japanese Journal of Crop Science 45(2): 220-225

#### 1976

Accession: 006676005

The rate of N absorption was greatest just before the neck mode differentiation stage throughout all the growth stages. The greatest rate of N absorption at this stage was positively correlated to the length of culms, the sum of lengths of lower 3 internodes, the sum of lengths of upper 3 leaf blades (excepting those of the plots of N topdressing) and the number of spikelets per panicle (except those of the plots of no basal N, N topdressing at the neck node differentiation stage and at the stage of reduction division), respectively. The amount of plant N per unit area at the early stage of spikelet differentiation was positively correlated to the number of panicles per unit area. The amount of N in plant per unit area at the ear mergence was positively correlated to the number of spikelets per unit area. To obtain optimum growth, the rate of N absorption by rice plants must be decreased just before neck node differentiation stage and be increased at the other growth stages. Early transplanting and high plant density improved N absorption and increased yield per unit area.