围封对黄土高原草地土壤铵态氮和硝态氮的影响
, 郭丁Effects of fencing on contents of soil ammonium nitrogen and nitrate nitrogen in the Loess Plateau, northern China
Liao Sheng-xiang1 , Ren yun-tao1 , Yuan Xiao-bo1 , Li Xu-dong1 , Guo Ding1 , Li Jin-bo2 , Fu Hua
, Guo Ding