摘要
基于2个氮水平(低氮和高氮)下连续种植6年的玉米单作、马铃薯单作及玉米马铃薯间作田间定位试验,采用湿筛法对土壤进行团聚体分级,并测定各粒级全钾、交换性钾和非交换性钾含量,研究氮水平和种植模式对土壤团聚体相关钾素分配的影响。结果表明:土壤团聚体以中团聚体(0.25~2 mm)为主,所分配钾素占土壤钾储量60.6%~65.0%。种植模式和施氮量显著影响团聚体非交换性钾含量和储量,但对全钾、交换性钾无显著影响。高氮水平下,间作比单作加权值提高大团聚体(>2 mm)全钾和非交换性钾储量57.6%和73.6%,中团聚体(0.25~2 mm)全钾和非交换性钾储量21.1%和41.5%。间作增加了玉米钾吸收,但降低了马铃薯钾吸收量。除马铃薯单作外,>0.25 mm团聚体的交换性钾、非交换性钾占比与作物钾吸收量呈显著正相关。总之,间作和施氮可提高土壤中较大粒级团聚体非交换性钾和全钾储量,对促进土壤钾素保存和持续供应有积极意义。
We examined the effects of N application rate and cropping pattern on the distribution of soil aggregate-associated K in a 6-year field experiment of maize monocropping,potato monocropping and intercropping of maize and potato under two nitrogen(N)application rates(low N and high N).Soil aggregates were classified using wet sieving method,and the contents of total potassium(K),exchangeable K and non-exchangeable K in each aggregate were measured.The results showed that soil aggregates were mainly composed of medium-sized aggregates(0.25-2 mm).The allocated K in medium-sized aggregates accounted for 60.6%-65.0%of soil total K reserves.The cropping pattern and N application rate significantly affected the content and reserve of aggregate-associated non-exchangeable K,but did not affect that of total K and exchangeable K.Under high N application level,intercropping significantly increased the reserves of total K and non-exchangeable K by 57.6%and 73.6%for large-sized aggregates(>2 mm),and 21.1%and 41.5%for medium-sized aggregates(0.25-2 mm),respectively,compared with the weighted average of monocropping.Intercropping increased the K uptake by maize,but reduced that of potato.Except for the potato monocropping,the proportion of exchangeable K and non-exchangeable K in aggregates(>0.25 mm)was significantly positively correlated with crop K uptake in monocropping(except for potato monocropping)and intercropping systems.In conclusion,intercropping and N application could increase the non-exchangeable K and total K reserves of largersized aggregates in soil,with positive consequences on the preservation and sustainable supply of soil K.
作者
伊文博
王顶
李欢
何澍然
赵平
龙光强
YI Wen-bo;WANG Ding;LI Huan;HE Shu-ran;ZHAO Ping;LONG Guang-qiang(College of Resources and Environment,Yunnan Agricultural University,Kunming 650201,China;Yunnan Science Observation Station for Cultivated Land Conservation of the Ministry of Agriculture and Rural Affairs,Yunnan Agricultural University,Kunming 650201,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第2期392-401,共10页
Chinese Journal of Ecology
基金
国家自然科学基金项目(41967004)
云南省农业联合专项(2017FG001-027)
云南省重点研发计划(2018BB015)
云南省中青年后备人才项目(2017HB027)资助。
关键词
间作
施氮量
钾形态
团聚体
intercropping
nitrogen application rate
potassium form
aggregate
