질소시비량이 쇠무릎의 생육 및 건물수량에 미치는 영향

Abstract

To determine the optimum N rate in Jeju island for utricle and root production of Achyranthes japonica Nakai, a medicinal plant, the plants were grown at two plant densities (50 and 100 hills/㎡, two plants per hill; main plots) at six N application rates (0, 6, 12, 18, 24, and 30 ㎏/10a; split plots) in 2001. there was no significant interaction between plant density and N application rate for all measured agronomic characters. Main root length and roots per hill were 5 and 52% grater, respectively, but N content of stover was lower under lower plant density compared to higher plant density. The other characters were not affected by plant density. N application rate did not significantly affect main stem diameter, spikes per hill, spike length, utricles per spike, main root length and diameter, and utricle N content. As N rate increased from 0 to 30 ㎏/10a, SPAD values and stover N content increased linearly from 35.0 to 40.5 and 1.09 to 1.38%, respectively, and plant hight, branches per hill, stover, utricle and root dry matter yields, roots per hill, and top N yield increased quadratically. Spikes per hill were increased in a cubic manner with increased N application rates. N application rate for the maximum dry matter yield of utricle and root in A. japonica was estimated to be 21 ㎏ N/10a.