3Luo Y, Meyerhoff PA, Loomis RS. Seasonal patterns and vertical distributions of fine roots of alfalfa[J]. Field Crops Research, 1995, 40(2): 119- 127.
4Alam M, Trooien T P, Dumler T J, et al. Using subsurface drip irrigation for alfalfa[J]. Journal of the American Water Resources Association, 2002, 38(6): 1715- 1721.
