The purpose of this study was to assess the forage productivity and nutritive value of kenaf at different fertilizer application amounts and various stages of maturity. The experiment was conducted from May to September 2020, the amount of 80 kg of kenaf seed/ha was supplied with different types and amounts of nitrogen fertilizer and the plants were harvested at 10-day intervals from different harvesting dates (24th August and 3rd, 13th, 23rd September). According to the different fertilizer types and application amounts, the highest kenaf height was recorded in the inorganic fertilizer amounts of 200 and 250 kg N/ha and the fresh and DM yield were significantly improved in the inorganic nitrogen amount of 250 kg N/ha. The highest CP and TDN content in the leaf was achieved in the inorganic fertilizer amounts of 150 and 200 kg N/ha, respectively; and the highest TDN content in the stem was also found in the inorganic fertilizer amount of 200 kg N/ha. According to the different harvesting dates, the highest DM ratio was found in the harvesting date of 13th September, the leaf ratio increased with advanced maturity, whereas the stem ratio decreased significantly and the highest DM yield of kenaf was recorded in the harvesting dates of 13th and 23rd September. Besides, the highest CP, CF, CA, ADF, NDF and TDN content in the leaf as influenced by different harvesting dates was 15.4, 31.8, 10.2, 22.1, 34.7 and 76.5%, respectively, and the CP, CA, ADF and TDN in stem decreased significantly with advanced maturity of kenaf. In conclusion, the optimal fertilizer amounts and the appropriate harvesting dates for a high forage yield and high-quality kenaf as livestock feed were the inorganic fertilizer application amounts of 200-250 kg N/ha and from 13th and 23rd September, respectively.

The aim of this present study was to investigate the impact of different seeding rate and nitrogen fertilizing levels on the seed yield and feed value of oats(Avena sativa L.) grown in Gyeongbuk area for two years. The experiment was arranged in split plot design with 3 main plots(100, 130 and 160 kg of seed/ha) and 4 subplots(0, 50, 70 and 90 kg N/ha), with 3 replicates. Heading, flowering, and maturing dates of oats sown in spring 2017, delayed by two days compared to that of spring 2016, and the plant height of spring 2017 were significantly shorter than that of spring 2016(18.1 ~ 23.4 cm). In addition, the highest number of stems and number of panicles according to different seeding rate and nitrogen fertilizing levels were achieved with the seeding rate of 160 kg/ha and 90 kg of N/ha in 2016 and 2017, respectively. In case of seed yield as affected by different seeding rate, the highest seed yield was achieved with a seeding rate of 130 kg/ha(p<0.05), and based on nitrogen fertilizing levels, the highest yield was obtained in 50 kg of N/ha compared to others. The crude fiber(CF), neutral detergent fiber(NDF) and total digestible nutrients(TDN) of oats cultivated and harvested in spring 2016 and 2017 according to different sowing rate were the highest in the seeding rate of 130 kg/ha. The crude protein(CP) content and total digestible nutrients(TDN) of 2016-2017 as influenced by nitrogen fertilizer levels were the highest in the nitrogen fertilizer level of 90 and 50 kg N/ha, respectively. In conclusion, the proper seeding rate and the optimal nitrogen fertilizing level in Gyeongju, Gyeongbuk province were considered to be the most appropriate in 130 kg/ha and 50 kg of N/ha, respectively.