Effect of Nitrogen Applications on the Growth and Primary Production of Soybean Population

질소구배에 따른 대두개체군의 생장 및 일차생산성

Growth analytical and primary productivity experiments of soybean populations were conducted with special references to the development of productive structures and environmental conditions of nitrogen levels $(N_1,\; control:\; N_2,\; 6.67gN/\textrm m^2:\; N_3,\;13.34\textrm {gN/m}^2)$. The maximum amounts in LAI for $N_1,\; N_2\; and\; N_3$ stand were 17.3, 19.0 and 18.5; in total standing grops, 1570, 1785 and 1704gDM/$\m^2$; in total net productions, 543, 648 and 636gDM/$\m^2$, respectively. The maximum CGR attanined were 208, 237 and 272 gDM$\m^2$/week, while the mean EU was 2.55, 2.92 and 2.84% N1, N2 and N3, respectively. The total nitrogen standing quantity attained 53.4, 71.8 and 59.8 gN/$\m^2$ at the maximum standing crop period. The net nitrogen absorption rates showed highly significant differences among nitrogen treatments, i.e., 1.34, 10.77 and 13.22 mg/g/day for $N_1,\; N_2\; and \;N_3$ stand, repsectively.

무시비구, 질소시비구(6.67gN/$m^2$) 및 과질소비구(13.34gN/$m^2$)의 질소구배처리에 따른 대두개체군의 생육과정별 제 생장해석적특징 및 일차생산성을 비교검토하였다. 질소시비구 및 과질소시비구에서는 대조구에 비해 8~10배의 순질소흡수율과 비교적 높은 생산성 및 최대 LAI의 도달이 2주정도 빨리 나타났고 SLA의 증가를 보였으나, 근립의 형성은 1/3~1/4의 감소를 보였다. 그러나, H, F/C, T/R, RGR, NAR, 및 CGR 등 생장해석적특징에는 큰 유의차가 없었다.