Abstract: In order to study the effects of acidified soil on indexes of roots physiological properties,roots activity,absorption area,activity of POD and SOD and indexes of nitrogen utilization efficiency of late rice to discuss the influence approach of acidified soil on nitrogen utilization efficiency of late rice,experiments were conducted in fields with different pH in Changsha,Hunan Province,with 7 acid-sensitive late rice varieties with different nitrogen sensibility screened from former tests as materials.The results showed that activity,total absorption area,active absorption area and POD activity of roots of all varieties decreased in acidified paddy soil,while the decreasing significance was related to types of nitrogen sensibility of varieties.In common,the decrease of nitrogen-sensitive varieties was very significant,that of nitrogen-intermedia varieties was significant,while that of nitrogen-obtuse varieties was not significant.The roots SOD activity at booting and full heading stage of all varieties was significantly decreased by acidified soil,while that at filling stage was affected unclearly.The nitrogen accumulation,nitrogen utilization efficiency in common,nitrogen fertilizer efficiency and nitrogen physiological efficiency of all varieties were decreased in acidified field in common,in which the decreasing significance of the former three indexes was related to types of nitrogen sensibility of varieties,that is to say,the decrease of nitrogen-sensitive varieties was very significant,that of nitrogen-intermedia varieties was significant,while that of nitrogen-obtuse varieties was not significant.The decrease of nitrogen physiological efficiency of all varieties was very significant,which was not related to types of nitrogen sensibility of varieties.Correlation analysis between roots physiological indexes and nitrogen utilization efficiency indexes showed that the correlation between roots POD activity,roots activity and nitrogen utilization efficiency indexes was more evident,so we could preliminarily confirm that effect of acidified soil on nitrogen utilization efficiency of late rice was mainly realized by affecting roots POD activity and roots activity.

Key words: Late rice, Acidified soil, Root physiological property, Nitrogen utilization efficiency

CLC Number: 

• S511.01

• S143.1