摘要
为探讨长期不同施肥与耕作条件下土壤与径流中氮磷化学计量关系变化。在紫色土坡耕地设5个处理:顺坡耕作无施肥(对照,CK)、顺坡耕作+化肥有机肥混施(T1)、顺坡耕作+单施化肥(T2)、顺坡耕作+1.5倍单施化肥增量(T3)和横坡耕作+单施化肥措施(T4),每个处理均设3个重复,分析2008—2017年土壤总氮(TN_(S))、总磷(TP_(S))含量与化学计量TN_(S)∶TP_(S),以及83场产流事件径流总氮(TN_(W))、总磷(TP_(W))浓度及化学计量TN_(W)∶TP_(W)的变化特征。结果表明:CK处理TN_(S)、TP_(S)含量与T1处理差异不显著,但显著低于T2、T3、T4处理,主要是因为化肥施用显著提高土壤氮磷含量。各处理间TN_(S)∶TP_(S)无显著差异,其平均值为3.55~4.79,CV值为0.39~0.94,表明施肥对于多年间土壤氮磷比并无显著影响。CK处理的TN_(W)浓度显著高于其他施肥处理;T1处理TN_(W)浓度与T2处理差异不显著,但显著高于T3、T4处理。CK处理TP_(W)浓度与T2、T3、T4处理差异不显著,但显著低于T1处理。CK处理的TN_(W)∶TP_(W)显著高于各施肥处理,而各施肥处理间TN_(W)∶TP_(W)差异不显著,各处理平均值为25.48~56.83,CV值为1.11~1.80,均属于强变异,施肥显著降低径流氮磷比,并稳定次降雨事件间的差异。年平均TN_(W)与TN_(S)、TN_(W)与TN_(S)∶TP_(S)、TP_(W)与TN_(S)、TP_(W)与TN_(S)∶TP_(S)之间均呈显著线性正相关,径流N流失浓度受土壤N含量的显著影响,但年平均TN_(S)∶TP_(S)与TN_(W)∶TP_(W)关系不显著。施肥与耕作可解耦土壤与径流氮磷化学计量关系,研究结果可为农业面源污染防治提供理论依据。
In order to study the changes of nitrogen and phosphorus stoichiometry in soil and runoff under long-term fertilization and tillage,five treatments(three replicates were set in each treatment)were set up on the sloping land of purple soil∶downslope tillage without fertilization(CK),downslope tillage with mixed application of chemical fertilizer and organic fertilizer(T1),downslope tillage with chemical fertilizer(T2),downslope tillage with 1.5 times increment of chemical fertilizer(T3),and contour tillage with fertilizer(T4),to analyze the change characteristics of soil total nitrogen(TN_(S)),soil total phosphorus(TP_(S))and TN_(S)∶TP_(S),runoff total nitrogen(TN_(W)),runoff total phosphorus(TP_(W))and TN_(W)∶TP_(W) in 83 runoff-producing events during 2008-2017.The results showed that the contents of TN_(S) and TP_(S) in CK treatment were not significantly different from those in T1 treatment,but significantly lower than those in T2,T3 and T4 treatment.The main reason was that the application of chemical fertilizer significantly increased the content of nitrogen and phosphorus in soil.The mean value of TN_(S)∶TP_(S) was 3.55~4.79,and the CV value was 0.39~0.94,indicating that fertilization had no significant effect on N/P ratio.The concentration of TN_(W) in CK treatment was significantly higher than that in other fertilization treatments,and the concentration of TN_(W) in T1 treatment was not significantly different from that in T2 treatment,but significantly higher than that in T3 and T4 treatment.The TP_(W) concentration of CK treatment was not significantly different from that in T2,T3,T4 treatment,but significantly lower than that in T1 treatment.The TN_(W)∶TP_(W) of CK treatment was significantly higher than that in fertilization treatments,but there was no significant difference in TN_(W)∶TP_(W) among fertilization treatments.The mean values of each treatment was 25.48~56.83,and the CV value was 1.11~1.80.Fertilization significantly reduced the N/P ratio in runoff and stabilized the difference between rainfall events.Annual mean TN_(W) and TP_(W) were both significantly positively correlated with annual mean TN_(S) and TN_(S)∶TP_(S),indicating runoff N loss concentration was significantly affected by soil N content,while annual mean TN_(S)∶TP_(S) and TN_(W)∶TP_(W) were not significantly correlated.Fertilization and tillage could decouple the relationship between nitrogen and phosphorus stoichiometry in soil and runoff.The results can provide theoretical basis for the prevention and control of agricultural non-point source pollution.
作者
张海香
李天阳
何丙辉
吴小雨
杜映妮
ZHANG Haixiang;LI Tianyang;HE Binghui;WU Xiaoyu;DU Yingni(College of Resources and Environment,Southwest University,Chongqing 400715)
出处
《水土保持学报》
CSCD
北大核心
2023年第3期281-287,共7页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(U20A20326)
中央高校基本科研业务费专项(SWU-KT22060)
重庆市教育委员会科学技术研究项目(KJQN202100212)。
关键词
施肥与耕作
土壤养分
化学计量
径流流失
紫色土
fertilization and tillage
soil nutrient
stoichiometric characteristics
runoff loss
purple soil
作者简介
第一作者:张海香(1998-),女,硕士研究生,主要从事土壤侵蚀与流域治理研究。E-mail:zhx990119@163.com;通信作者:何丙辉(1966-),男,教授,博士生导师,主要从事水土保持研究。E-mail:hebinghui@swu.edu.cn。
