不同覆盖作物对砂姜黑土剖面硝态氮动态的影响  

Effects of different cover crops on nitrate dynamics in Shajiang black soil profile

作　　者：徐静怡 张中彬[2] 王玥凯 赵馨雅 孙海军 郭自春 彭新华[2,3] XU Jingyi;ZHANG Zhongbin;WANG Yuekai;ZHAO Xinya;SUN Haijun;GUO Zichun;PENG Xinhua(College of Forestry/Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China;State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Tropical Crops,Hainan University,Haikou 570228,China)

机构地区：[1]南京林业大学林学院/南方现代林业协同创新中心,南京210037 [2]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京210008 [3]中国科学院大学,北京100049 [4]海南大学热带作物学院,海口570228

出　　处：《农业环境科学学报》2023年第10期2281-2290,共10页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(41771264,31972518);中国科学院青年创新促进会项目(2021311)。

摘　　要：为探究不同覆盖作物整个生育期内[覆盖作物播种后(2021年11月5日)、营养生长期(2022年3月12日)和生殖生长期(2022年5月5日)]砂姜黑土剖面中硝态氮的动态变化,本研究在安徽省龙亢农场典型砂姜黑土区设置压实(Compacted,C)与不压实(Non-compacted,NC)处理,并裂区设置冬季休闲(Con)、苜蓿(Alf)、油菜(Rap)、萝卜+毛苕子混播(Rhv)4个处理,动态监测0~120 cm土层中土壤硝态氮含量、储量和植株地上地下生物量及其氮素积累量。结果表明:整个覆盖作物生长季,Alf、Rap、Rhv处理土壤硝态氮含量持续下降,各处理0~120 cm土层平均分别下降43.3%、53.9%、57.5%。营养生长期与生殖生长期3个覆盖作物处理(除生殖生长期不压实条件下Rhv处理)硝态氮储量均较Con处理降低(P<0.05),且营养生长期的平均降幅(压实52.7%,不压实60.7%)高于生殖生长期(压实40.2%,不压实35.6%)。营养生长期,不压实条件下Alf处理土壤硝态氮储量是Rap和Rhv处理的1.41倍(P<0.05)。生殖生长期,压实与不压实条件下3个覆盖作物处理土壤硝态氮储量间无显著差异。营养生长期,Alf处理地上部生物量和氮素累积量低于Rap处理(P<0.05),地下部生物量和氮素累积量低于Rhv处理(P<0.05);但生殖生长期,Alf处理地上和地下部氮素累积量均显著高于Rap和Rhv处理(P<0.05)。相关分析表明,土壤中硝态氮储量与覆盖作物生物量以及氮素累积量呈负相关(P<0.05),表明覆盖作物对氮的吸收利用是土壤硝态氮下降的主要原因。综上,与Con处理相比,Alf、Rap和Rhv处理均可以有效降低土壤剖面中残余硝态氮,但Alf处理在前期生长缓慢,降低土壤剖面硝态氮的能力低于Rap与Rhv处理。因此,在砂姜黑土区种植油菜或萝卜+毛苕子更有利于降低覆盖作物生长期的硝态氮淋溶风险。The objective of this study was to evaluate the effects of different cover crops on reducing nitrate(NO_(3)^(-)-N)accumulation along the soil profile of Shajiang black soil throughout the growth period(2021.11 after sowing;2022.03 during the nutritional growth period;and 2022.05 during the reproductive growth period).Four treatments,including winter fallow(Con),alfalfa(Alf),oilseed rape(Rap),and mixed radish and hairy vetch(Rhv),were conducted under both compacted(C)and non-compacted(NC)conditions at Longkang farm,Anhui Province.The dynamics of the soil NO_(3)^(-)-N content and NO_(3)^(-)-N storage were measured along the 0-120 cm soil profile by interval sampling.The aboveground and belowground crop biomasses and their nitrogen accumulation were also determined.Our results showed that the NO_(3)^(-)-N content along the 0-120 cm soil profile continuously decreased by 43.3%,53.9%,and 57.5%under the Alf,Rap,and Rhv treatments,respectively,throughout the growing season.During the nutritional and reproductive growth periods,the soil NO_(3)^(-)-N storage was significantly reduced in all three cover crop treatments compared with that in the Con treatment under both compacted and non-compacted conditions(except the Rhv treatment in the non-compacted soil during the reproductive growth period,P<0.05),with a higher average reduction during the nutritional growth period(compacted:52.7%and non-compacted:60.7%)than that during the reproductive growth period(compacted:40.2%and non-compacted:35.6%).During the nutritional growth period,the soil NO_(3)^(-)-N storage in the Alf treatment was 1.4 times higher than those in the Rap and Rhv treatments under the non-compacted condition(P<0.05).Meanwhile,during the reproductive growth period,soil NO_(3)^(-)-N storage showed no significant difference among the three cover crop treatments under both compacted and non-compacted conditions.The aboveground biomass and N accumulation in the Alf treatment were significantly lower than those in the Rap treatment during the nutritional growth

关 键 词：砂姜黑土 覆盖作物 土壤硝态氮 生物量 植株氮素累积 

分 类 号：S153.6[农业科学—土壤学]