不同年限旱改水稻田土壤有机氮矿化对外源氮素的响应  

Effects of Temperature and Nitrogen Addition on Soil Organic Nitrogen Mineralization in Nanniwan Paddy Field

作　　者：赵满兴[1,2,3] 王欣 马文全 周韩冰 李硕 马丹妮 李祥东 ZHAO Manxing;WANG Xin;MA Wenquan;ZHOU Hanbing;LI Shuo;MA Danni;LI Xiangdong(College of Life Sciences,Yan′an University,Yan′an 716000,Shaanxi,China;Shaanxi Key Laboratory of Research and Utilization of Resource Plants on the Loess Pateau,Yan′an 716000,Shaanxi,China;Key Laboratory of Applied Ecology of Loess Plateau in Shaanxi Higher Education Institutions,Yan′an 716000,Shaanxi,China)

机构地区：[1]延安大学生命科学学院,陕西延安716000 [2]陕西省黄土高原资源植物研究与利用省市共建重点实验室,陕西延安716000 [3]黄土高原应用生态陕西省高等学校重点实验室,陕西延安716000

出　　处：《四川农业大学学报》2025年第2期332-340,共9页Journal of Sichuan Agricultural University

基　　金：国家自然科学基金(41761068);陕西省自然科学基础研究面上项目(2024JC-YBMS-239)。

摘　　要：【目的】为了探讨南泥湾不同年限旱改水稻田土壤有机氮矿化对外源氮素的响应,分析土壤供氮能力及其特征。【方法】以南泥湾水稻种植基地不同年限旱改水稻田(0 a、5 a、25 a、78 a)土壤为研究对象,采用室内49 d淹水密闭-间歇淋洗培养方法,研究土壤有机氮矿化特征。【结果】在30℃培养条件下,不同氮添加水平下土壤氮累积矿化量表现为0 a>78 a>25 a>5 a,并随着氮添加量的增加而升高。0~20 cm土层土壤氮累积矿化量显著高于20~40 cm土层(P<0.05)。氮矿化速率呈现出培养前期快、后期慢的趋势,随培养时间的延续而下降,最终趋于平稳,其中N1、N2、N3氮添加条件下前7 d分别占矿化总量的32.50%、54.04%和65.68%,0~20 cm土层土壤矿化速率也高于20~40 cm土层。而土壤矿化率则表现为5 a、25 a高于78 a、0 a。N0(土壤氮素矿化势)则随着年限的增加而增加,随着氮添加量的增加而增加。0~20 cm土层N0高于20~40 cm土层(P<0.05)。N_(0)与全氮、碱解氮表现为极显著正相关关系(P<0.01),与土壤C/N呈极显著负相关关系(P<0.01)。【结论】外源氮素添加促进了不同旱改水年限稻田土壤氮素矿化,且氮添加水平越高增加越明显。【Objective】This study aims to analyze the soil nitrogen supply capacity and characteristics,reveal the patterns of soil nitrogen evolution,and provide a theoretical basis for soil utilization and fertilizer management in northern Shaanxi.【Method】The characteristics of soil organic nitrogen mineralization were investigated using a 49-day indoor watering-hermetic-intermittent leaching culture method in the paddy fields(0 a,5 a,25 a,78 a)at Nanniwan rice planting base.【Result】The soil cumulative nitrogen mineralization at 30℃followed the order:0 a>78 a>25 a>5 a,and it increased with the increase of nitrogen supplemental level.The cumulative nitrogen mineralization in 0-20 cm soil layer was significantly higher than that in 20-40 cm soil layer(P<0.05).The rate of nitrogen mineralization showed a fast trend in the early stage and slow trend in the late stage,and decreased with the culture time,and finally stabilized.The N1,N2 and N3 nitrogen mineralization before 7 d accounted for 32.50%,54.04%,and 65.68%of the total.The mineralization rate of 0-20 cm soil layer was also higher than that of 20-40 cm soil layer.The soil mineralization rate of 5 a and 25 a were higher than 78 a and 0 a.N0 increased with the increase of age and increased with the increase of nitrogen addition.N_(0)in 0-20 cm soil layer was higher than that in 20-40 cm soil layer(P<0.05).N0 was positively correlated with total nitrogen and alkali hydrolyzed nitrogen(P<0.01),and negatively correlated with soil C/N(P<0.01).【Conclusion】Soil nitrogen mineralization was significantly increased by nitrogen addition,with the increase being more pronounced at higher levels of nitrogen addition.

关 键 词：水稻 半干旱区 旱改水 氮矿化 氮添加 

分 类 号：S153.6[农业科学—土壤学]