Abstract:The effect of applying chlorine-containing chemical fertilizers on paddy field ecosystems is becoming a matter of concern in China with the extensive application of fertilizers such as KCl and NH_4Cl. Thus, a long-term field experiment was established in 1975 at Qiyang Red Soil Experimental Station, Hunan Province to investigate this problem. The application rates of Cl~- in 3 treatments (CK, Low Cl and High Cl) were 0, 352, 1032 kg/ha·yr, respectively. Soil Samples in 1975 to 1997 and rice plant samples i...