Effects of nitrogen application on plant growth and forage yield in seasonal growing alfalfa
Providing adequate nitrogen (N) fertilizer is essential for high yields of alfalfa (Medicago sativa L.) in the seasonal cultivation system in southeastern China.For purpose of measuring the optimum N application rate during seedling growth and spring rapid growth period of alfalfa, the response of seedling growth to different N application rate (0, 4, 8, 12, 16 and 20 mmol N L-1) was investigated at 38 days after N treatment in a pot experiment, and the influence of four N treatments (60, 120,180 and 240 kg N ha-1) on forage yield, yield components and N content of leaf (% DW) was investigated in a two years field experiment.The results showed that seedling growth was enhanced significantly (P < 0.05) with increasing N application rate when N application was less than 8 mmol N L-1, then stabilized on the peak when N application changed from 8 to 16 mmol N L-1, and tended to decrease at 20 mmol N L-1.The N content of seedling was 2.9-3.3% when growth response stabilized to N application.Plant height, leaf area per plant, shoot DW and DW yield were the greatest at the application of 180 kg N ha-1, meanwhile N content of leaf was 3.08-3.15%.The results indicated that N content of seedling or leaf may be used as the indicator for N application in alfalfa cultivation, and 2.9-3.3% is a critical value.
alfalfa nitrogen application rate nitrogen content
Kai Zheng Zheng Xue Kun Zhang Yixin Shen
College of Grassland Science, Nanjing Agricultural University, Nanjing, 210095, China
国际会议
The 5th China-Japan-Korea Grassland Conference(第五届中-日-韩国际草地会议)
长春
英文
103-104
2014-08-20（万方平台首次上网日期，不代表论文的发表时间）