Fixed Ammonium Content and Maximum Capacity of Ammonium Fixation in Major Types of Tillage Soils in Hunan Province,China  

作　　者：ZHANG Yang-zhu HUANG Shun-hong WAN Da-juan HUANG Yun-xiang ZHOU Wei-jun ZOU Ying-bin 

机构地区：[1]College of Resources and Environment, Hunan Agricultural University, Changsha 410128, P.R.China [2]College of Metallurgical Science and Technology, Central South University, Changsha 410083, P.R.China [3]College of Resources and Environment Sciences, Hunan Normal University, Changsha 410081, P.R.China [4]Institute of Rice, Hunan Agricultural University, Changsha 410128, P.R.China

出　　处：《Agricultural Sciences in China》2007年第4期466-474,共9页中国农业科学（英文版）

摘　　要：In order to understand the status of fixed ammonium, fixed ammonium content, maximum capacity of ammonium fixation, and their influencing factors in major types of tillage soils of Hunan Province, China, were studied with sampling on fields, and laboratory incubation and determination. The main results are summarized as follows： （1） Content of fixed ammonium in the tested soils varies greatly with soil use pattern and the nature of parent material. For the paddy soils, it ranges from 135.4 ± 57.4 to 412.8±32,4 mg kg^-1, with 304.7±96.7 mg kg^-1 in average; while it ranges from 59.4 to 435.7 mg kg^-1, with 230.1 ± 89.2 mg kg^-1 in average for the upland soils. The soils developed from limnic material and slate had higher fixed ammonium content than the soils developed from granite. The percentage of fixed ammonium to total N in the upland soils is always higher than that in the paddy soils. It ranges from 6.1 ±3.6% to 16.6±4.6%, with 14.0% ±5.1% in average for the paddy soils and it amounted to 5.8±2.0% to 40.1 ± 17.8%, with 23.5 ± 14.2% in average for upland soils. （2） The maximum capacity of ammonium fixation has the same trend with the fixed ammonium content in the tested soils. For all the tested soils, the percentage of recently fixed ammonium to maximum capacity of ammonium fixation is always bellow 20% and it may be due to the fact that the soils have high fertility and high saturation of ammonium-fixing site. （3） The clay content and clay composition in the tested soils are the two important factors influencing their fixed ammonium content and maximum capacity of ammonium fixation. The results showed that hydrous mica is the main 2：1 type clay mineral in 〈 0.02 mm clay of the paddy soils, and its content in 0.02-0.002 mm clay is much higher than that in 〈 0.002 mm clay of the soils. The statistical analysis showed that both the fixed ammonium content and the maximum capacity of ammonium fixation of the paddy soils were positively correlated with the total 2：1 type clay minerIn order to understand the status of fixed ammonium, fixed ammonium content, maximum capacity of ammonium fixation, and their influencing factors in major types of tillage soils of Hunan Province, China, were studied with sampling on fields, and laboratory incubation and determination. The main results are summarized as follows： （1） Content of fixed ammonium in the tested soils varies greatly with soil use pattern and the nature of parent material. For the paddy soils, it ranges from 135.4 ± 57.4 to 412.8±32,4 mg kg^-1, with 304.7±96.7 mg kg^-1 in average; while it ranges from 59.4 to 435.7 mg kg^-1, with 230.1 ± 89.2 mg kg^-1 in average for the upland soils. The soils developed from limnic material and slate had higher fixed ammonium content than the soils developed from granite. The percentage of fixed ammonium to total N in the upland soils is always higher than that in the paddy soils. It ranges from 6.1 ±3.6% to 16.6±4.6%, with 14.0% ±5.1% in average for the paddy soils and it amounted to 5.8±2.0% to 40.1 ± 17.8%, with 23.5 ± 14.2% in average for upland soils. （2） The maximum capacity of ammonium fixation has the same trend with the fixed ammonium content in the tested soils. For all the tested soils, the percentage of recently fixed ammonium to maximum capacity of ammonium fixation is always bellow 20% and it may be due to the fact that the soils have high fertility and high saturation of ammonium-fixing site. （3） The clay content and clay composition in the tested soils are the two important factors influencing their fixed ammonium content and maximum capacity of ammonium fixation. The results showed that hydrous mica is the main 2：1 type clay mineral in 〈 0.02 mm clay of the paddy soils, and its content in 0.02-0.002 mm clay is much higher than that in 〈 0.002 mm clay of the soils. The statistical analysis showed that both the fixed ammonium content and the maximum capacity of ammonium fixation of the paddy soils were positively correlated with the total 2：1 type clay miner

关 键 词：Hunan Province tillage soils paddy soil upland soil fixed ammonium maximum capacity of ammonium fixation 

分 类 号：S155.92[农业科学—土壤学] S155.4[农业科学—农业基础科学]