长期施肥和耕作下紫色土坡耕地土壤C、N、P和K化学计量特征  

Stoichiometric Characteristics of Purple Sloping Cropland Under Long-term Fertilization and Cultivation

作　　者：杜映妮 李天阳 何丙辉 贺小容 付适 DU Ying-ni;LI Tian-yang;HE Bing-hui;HE Xiao-rong;FU Shi(Key Laboratory of Eco-environment in the Three Gorges Reservoir Region,Ministry of Education,College of Resources and Environment,Southwest University,Chongqing 400715,China;Bishan Eco-environment Monitoring Station of Soil and Water Conservation,Chongqing 402760,China)

机构地区：[1]西南大学资源环境学院,三峡库区生态环境教育部重点实验室,重庆400715 [2]重庆市璧山区水土保持监测站,重庆402760

出　　处：《环境科学》2020年第1期394-402,共9页Environmental Science

基　　金：农业部公益性行业科研项目(201003014-6-3);国家自然科学基金项目(41771312);中央高校基本科研业务费专项(SWU118079)

摘　　要：阐明长期施肥和耕作对坡耕地土壤C、N、P和K含量及其化学计量比的影响,将有助于深刻理解土壤C和养分元素循环过程及其相互作用机制,对施肥管理及农业面源污染防治具有重要意义.在紫色土坡耕地(坡度为15°)建立15个小区(长8 m×宽4 m),设置5个处理(每个处理3次重复):顺坡无施肥处理(对照,CK)、顺坡复合施用有机肥和化肥处理(T1)、顺坡单施化肥处理(T2)、顺坡单施化肥增量处理(T3)和横坡单施化肥处理(T4),比较各处理0~10 cm及10~20 cm土层的C、N、P和K含量及其化学计量变化特征.结果表明,各处理土壤C、N和P差异显著(P <0. 05),均表现为T1> T3> T4> T2>CK,施肥处理下K含量差异不显著(P> 0. 05),但均显著高于对照处理(P <0. 05),表现为T4> T3> T2> T1> CK.各处理土壤的C∶N在10~20 cm土层中差异显著(P <0. 05),表现为T4> T3> T1> CK> T2;而C∶P则在0~10 cm土层差异显著(P <0. 05),表现为T1> T3> CK> T4> T2;各处理土壤的C∶K、N∶P、N∶K和P∶K在不同土层中均差异显著(P <0. 05),其中C∶K、N∶K和P∶K表现为T1> T3> T4> T2> CK,N∶P表现为T1> CK> T4> T3> T2.土壤的C、N、P和K含量及其化学计量比均随土层加深而递减.试验区土壤C、N和P含量属中等变异,变异系数(CV)分别为37. 50%、38. 91%和25. 35%,K含量属弱变异,CV为5. 03%.化学计量比中,C∶N和C∶P属弱变异,CV分别为7. 52%和14. 38%,C∶K、N∶P、N∶K和P∶K属中等变异,CV分别为35. 62%、17. 01%、37. 24%和44. 78%.土壤C、N、P和K含量及化学计量比之间存在显著正相关(P <0. 05).试验区土壤N∶P平均值为2. 09,低于中国土壤平均水平(9. 3).研究表明紫色土坡耕地土壤N为养分限制因子,而复合施用有机肥和化肥可有效缓解紫色土坡耕地N缺乏的状况.Clarification of the effects of long-term fertilization and cultivation on soil organic carbon( C),nitrogen( N),phosphorus( P),and potassium( K) contents and their stoichiometric ratios can contribute to existing research on the C and nutrient biogeochemical cycles and their interacting mechanisms. Such information is also of great significance to fertilization management and for the control of non-point pollution. Fifteen plots( 8 m long,4 m wide) were set up on a representative purple hillslope( 15°) . Five treatments( three replications) were used on the plots: i) no fertilizer with downslope cultivation( CK),ii) combined application of manure and fertilizer with downslope cultivation( T1),iii) chemical fertilizers with downslope cultivation( T2),iv) chemical fertilizer with increasing fertilization with downslope cultivation( T3),and v) chemical fertilizer with contour cultivation( T4). The C,N,P and K contents and their ratios in the five treatments corresponding to 0-10 cm and 10-20 cm soil depths were compared. The results showed that C,N and P contents for the different treatments were differed significant and could be ranked: T1 > T3 > T4 > T2 > CK( P< 0. 05). K content was not significantly different among the four fertilizations( P > 0. 05) but was significantly higher than the CK treatment( P < 0. 05),and could be ranked: T4 > T3 > T2 > T1 > CK. The C∶ N ratios in the five treatments were significantly different( P < 0. 05) at a soil depth of 10-20 cm( T4 > T3 > T1 > CK > T2). The C∶ P ratios in the five treatments were significantly different( P < 0. 05) at a soil depth of 0-10 cm( T1 > T3 > CK > T4 > T2). The C∶ K,N∶ P,N∶ K,and P∶ K ratios for the five treatments at both of the soil depths showed significant differences( P < 0. 05),and the C∶ K,N∶ K,and P∶ K were ranked as T1 > T3 > T4 > T2 >CK,whereas the N∶ P ratio was ranked as T1 > CK > T4 > T3 > T2. The C,N,P,and K contents and their stoichiometric ratios decreased with increasing soil depth. Soil C,N and P in the study sit

关 键 词：施肥和耕作 化学计量特征 碳含量 养分因子 紫色土 

分 类 号：X171[环境科学与工程—环境科学]