共 215 条
[111]
Ladd J. N., 1988, Advances in nitrogen cycling in agricultural ecosystems, P113
[113]
LAMPKIN N, 1990, ORGANIC FARMING, P89
[115]
LINDEN B, 1993, SWED J AGR RES, V23, P161
[116]
LLOYD A, 1992, ASPECTS APPL BIOL, V30, P243
[118]
LOHNIS F, 1910, HDB LANDWIRTSCHAFTLI