不同土地利用方式下紫色土中铵的容量和强度(Q/I)关系  

QUANTITY-INTENSITY RELATIONSHIP OF AMMONIUM IN PURPLE SOILS DIFFERENT IN LAND USE

作　　者：袁俊吉[1] 彭思利[1] 余祥宇[1] 蒋先军[1] 谢德体[1] 

机构地区：[1]西南大学资源环境学院,重庆400716

出　　处：《土壤学报》2011年第6期1180-1188,共9页Acta Pedologica Sinica

基　　金：重庆市自然科学基金项目(CSTC-2008BA1024);教育部"新世纪优秀人才计划"项目(NCET-08-0817);国家自然科学基金项目(40871112)资助

摘　　要：研究了4种土地利用方式下(水田、旱地、林地、菜地)紫色土(紫色湿润雏形土)和紫色水稻土(紫色水耕人为土)NH4+的容量和强度(Q/I)关系。结果表明:紫色土和紫色水稻土NH4+Q/I曲线的曲线部分均出现在NH4+的活度比(ARNH4)较低时,表明土壤存在非交换性NH4+(或专性吸附的NH4+)的释放。紫色土和紫色水稻土NH4+的潜在缓冲容量(PBC)为71.47～203.7 cmol kg-1(mol L-1)-1/2;土壤活性NH4+(-ΔNH40)为0.029 5～0.089 7 cmol kg-1,NH4+的平衡活度比(AR0NH4)为0.187×10-3～1.255×10-3(mol L-1)1/2;土壤专性吸附位点(NH4-sas)为0.010 6～0.118 5 cmol kg-1。相关分析和通径分析表明,土壤小于0.002 mm黏粒含量与NH4+PBC及NH4-sas均呈极显著正相关(p<0.01),小于0.002 mm黏粒对PBC的影响主要是间接作用(间接通径系数为0.585),但对NH4-sas则有强烈的直接作用;有机碳与-ΔNH40和AR0NH4均呈极显著正相关(p<0.01),但是有机碳对-ΔNH40有较大的直接效应(直接通径系数为0.966),而对AR0NH4的影响主要以间接效应为主。土壤-ΔNH40与交换性NH4+数值接近且呈极显著相关(r=0.876 4,n=8,p<0.01),而AR0NH4与交换性NH 4+亦呈极显著相关(r=0.983 7,n=8,p<0.01)。土壤小于0.002 mm黏粒和有机碳的差异是导致不同土地利用方式下紫色土交换性NH4+以及Q/I参数的差异的主要原因,交换性NH4+标志的NH4+有效性指标与由Q/I关系得到的NH4+有效性指标类似。Quantity-intensity （Q/I） relationships of NH4＋ in purple soils and purple paddy soils different in land use （paddy field, dry land, woodland and vegetable plot） were studied. It was found that in both 0 - 20 cm and 20- 40 cm layers of the two soils the curve of NH4 Q/I relationships were observed only when NH4 activity ratios in the soils were low, suggesting release of nonexchangeable （or specifically adsorbed） NHf in the soils NH4＊ in the two soils ranged from 71.47 to 203.7 cmol kg-1 （mol L-1） -1/2 in potential buffering capacity （PBC） , from 0. 029 5 to 0. 089 7 cmolo kg-1 in labile NH4 （ -△NH4）, from 0. 187 ×10-3 to 1. 255 ×10-3（ mol L-1）1/2 in equilibrium activity ratio （ARNN4） and from 0. 010 6 - 0. 118 5 cmol kg-1 in specific adsorption sites （ NH4-sas）. Correlation analysis and path analysis indicate that the content of clay （ 〈0. 002 mm） is in extremely significant positive relationship with both PBC and NH4-sas（p 〈0.01 ）. The effect of clay （ 〈 0. 002 mm） is mainly indirect on PBC （ indirect path coefficient, 0. 585） , but strong and direct on NH4 Positive linear relationships were observed of organic C with - △NH4 and ARNH4 in all soil samples. The effect of organic C is high and direct on - △NH4 （direct path coefficient, 0. 966）, but indirect on - △NH4. The concentration of exchangeable NH4＋ is positively related to - △NH4 （ r = 0. 876 4, n = 8, p 〈 0.01 ） and they are approximate in value. Moreover, exchangeable NH4 is also positively related to ARNH4 （r = 0. 983 7, n = 8, p 〈 0.01 ）. This study clearly demonstrates that differences between the soils in clay and organic C are the main reason for the differences in exchangeable NH4 and Q/I parameters between purple soils different in land use. The use of exchangeable NH4 as indicator of NH4 availability has a similar effect as the use of Q/I relationships.

关 键 词：紫色土 容量和强度关系 非交换性NH4+ 通径分析 

分 类 号：S153[农业科学—土壤学]