3JACKSON L E, STIVERS L J, WARDEN B T, et al. Crop nitrogen-utilization and soil nitrate loss in a lettuce field[J]. Fert Res, 1994, 37(2): 93-105.
4LISHUYI, ZHENGHUIDINA, LIAOXINRONG,et al. Effects of middle and trace element fertilizers on yield and nitrate in Brassica chinensis [J]. Journal of Horticultural Science and Biotechnology, 1999,74(4): 458-463.
5Lishuyi, zhenghuidian, liaoxinrong, et al. Effects of middle and trace element fertilizers on yield and nitrate in Brassica chinensis[J]. Journal of Horticultural Science and Biotechnology, 1999, 74 (4): 458-463.
