A native cultivar of Japanese millet [Echinochloa crusgalli var. frumentacea (Roxb.) W. F. Wight) was grown with N rates of 0, 50, 100, 150, 200, and 250 ㎏/㏊ from 31 May to 6 September in 1999 to determine the optimum N rate for forage production ...
A native cultivar of Japanese millet [Echinochloa crusgalli var. frumentacea (Roxb.) W. F. Wight) was grown with N rates of 0, 50, 100, 150, 200, and 250 ㎏/㏊ from 31 May to 6 September in 1999 to determine the optimum N rate for forage production in a volcanic ash soil of Jeju island. Half of N fertilizer rate was applied at planting and half at 60 days after planting. Days to heading increased from 84 to 90 days as nitrogen rate increased from 0 to 250㎏/㏊. Plant height increased from 144 to 183 cm with increasing nitrogen rate. However, there was no significant difference between 200 and 250 ㎏ N/㏊ for the two characteristics. Increasing N rate from 0 to 250 ㎏/㏊ increased dry matter (DM) yield from 6.76 to 12.67 MT/㏊, crude protein yield from 0.47 to 1.21 MT/㏊, and total digestible nutrients (TDN) yield from 3.46 to 7.18 MT/㏊. However, no significant differences in these yields were found between 200 and 250 ㎏ N/㏊. Nitrogen uptake increased from 75.1 to 194.2 ㎏/㏊ but N use efficiency decreased from 90.0 to 65.2 ㎏ DM/㎏ N with increasing N from 0 to 250 ㎏/㏊. As N rate increased from 0 to 250 ㎏/㏊, CP and TDN contents increased from 6.9 to 9.6% and from 51.3 to 56.7%. respectively. while crude fiber content decreased from 39.5 to 35.9%. Ether extract and nitrogen free extract contents increased up to 200 ㎏ N/㏊ and then did not significantly increase with the further increase in N rate. Crude ash content decreased up to 200 ㎏ N/㏊ and then did not significantly decrease with the further increase in N rate. Based on the these findings, the optimum N rate for forage production of Japanese millet seems to be about 200 ㎏/㏊ in volcanic ash soils of Jeju island.