^pKey;
Laboratory;
of;
Soil;
and;
Sustainable;
Agriculture,;
Institute;
of;
Soil;
Science,;
Chinese;
Academy;
of;
Sciences,;
Nanjing;
210008,;
China;
^pUniversity;
of;
Chinese;
Academy;
of;
Sciences,;
Beijing;
100049,;
China;
(NH4)2SO4; 硝化抑制; 土壤酸化; 中国南方; 尿素氮; 老成土; 土壤pH值; 土壤硝化作用;