摘要
以山东茶园土壤为研究对象,采用室内好气培养法,分析了恒定湿润和干湿交替模式下土壤氮素转化特征。结果表明:(1)至培养结束时,恒湿模式下60%WHC处理土壤净矿化量和净硝化量较高;脲酶和亚硝酸还原酶活性较强。20%WHC处理下土壤净矿化速率、净硝化速率严重受到抑制。(2)干湿交替模式下复水后土壤净矿化量、净硝化量以及酶活性得到增强,并出现“脉冲”式变化。(3)2种模式下氮素损失均为N_(2)O排放量大于NH 3挥发量。N_(2)O排放量与土壤含水量呈正比,NH_(3)挥发量与土壤含水量呈反比。干湿交替均增强土壤N 2O和NH_(3)排放量。(4)结构方程模型(SEM)揭示土壤含水量通过直接或间接作用影响土壤氮素转化(p<0.001),脲酶显著影响恒湿模式下土壤氮素转化(p<0.001),而亚硝酸还原酶在2种模式下均显著负影响氮素转化(p<0.001)。研究结果有助于更好地调节茶园生态系统中土壤管理及氮肥的使用。
In this study,the characteristics of nitrogen transformation in tea garden soil of Shandong Province were analyzed by indoor aerobic culture.Soil N transformation and enzymes activities in constant wet and dry/wet cycle conditions were measured.The results showed that:(1)The net mineralization quantity and net nitrification quantity,the activities of urease and nitrite reductase were the highest in the 60% WHC treatment at the end of incubation.The net mineralization and net nitrification rates were seriously inhibited in 20% WHC treatment.(2)In dry/wet cycle treatment,net mineralization quantity,net nitrification quantity and enzymes activities increased and the change of“pulse”pattern appeared.(3)N_(2)O emission was greater than NH_(3) volatilization in both models.N_(2)O emission was directly proportional to soil water content,while NH_(3) volatilization was inversely proportional.Dry wet alternation enhanced N_(2)O and NH_(3) emissions.(4)The structural equation model revealed that soil water content affected soil N transformation(p<0.001);urease significantly improved soil N transformation in constant wet treatment(p<0.001),while nitrate reductase inhibited N transformation(p<0.001)in constant wet and dry/wet cycle models.These results might help to better regulate soil management and the use of N fertilizer in the tea garden ecosystem under different water supply conditions.
作者
于淑华
张丽霞
谢雪迎
韩晓阳
YU Shuhua;ZHANG Lixia;XIE Xueying;HAN Xiaoyang(College of Horticulture Science and Engineering,Shandong Agriculture University,Taian,Shandong 271018;State Key Laboratory of Crop Biology,Taian,Shandong 271018;Shandong Provincial Key Laboratory of Applied Microbiology,Ecology Institute,Qilu University of Technology(Shandong Academy of Sciences),Jinan 250000)
出处
《水土保持学报》
CSCD
北大核心
2021年第4期289-298,共10页
Journal of Soil and Water Conservation
基金
山东省自然科学基金项目(ZR201807060561)。
关键词
水分模式
茶园土壤
氮素转化
water regime
tea garden soil
nitrogen transformation
