垄作免耕对水稻根系特性和氮磷钾养分累积的影响  

Root characteristics and accumulation of nitrogen, phosphorus, and potassium in rice plants cultivated under three different systems

作　　者：万琪慧 马黎华[1] 蒋先军[1] WAN Qi-hui;MA Li-hua;JIANG Xian-jun(College of Resources and Environment,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学资源环境学院

出　　处：《草业学报》2019年第10期44-52,共9页Acta Prataculturae Sinica

基　　金：国家重点研发计划子课题(2016YFD0300901);国家自然科学基金项目(51509214)资助

摘　　要：依托稻田免耕长期定位试验,研究了垄作免耕对Y两优6号水稻根系特性、氮、磷、钾养分累积和产量的变化。研究主要涉及冬水田(中稻-冬水田)、垄作免耕(中稻-油菜)和水旱平作(中稻-油菜)对水稻4个生育时期(分蘖期、拔节期、抽穗期和成熟期)和根系特性,以及水稻根、茎、叶和穗的氮、磷、钾浓度及累积量的影响。结果表明,垄作免耕的实际产量达8750.8 kg·hm-2,显著高于水旱平作与冬水田(P<0.05)。在拔节期,垄作免耕水稻根系的根长密度和根表面积及比根长均显著高于水旱平作(P<0.05)。在抽穗期,垄作免耕根表面积最高达1.74 cm 2·cm-3,分别比冬水田和水旱平作提高了3.37%和6.71%;且垄作免耕水稻茎秆氮、磷、钾累积量分别较水旱平作提高了49.26%、33.20%和59.70%。相较于常规平作,垄作免耕水稻抽穗期茎叶的磷含量没有显著差异,而茎叶中氮、磷、钾累积量显著增加(P<0.05);氮、磷、钾养分累积速率显著提高(P<0.05),说明在养分累积的关键时期,垄作免耕能显著提高氮、磷、钾的吸收、分配和累积。在成熟期,垄作免耕水稻籽粒中氮累积量比冬水田和水旱平作显著提高了24.80%和14.30%。在分蘖-抽穗期,垄作免耕水稻的N∶K最低、K∶P最高,表明垄作免耕能显著提高水稻生长前中期对钾的吸收利用和分配。综上,垄作免耕不仅可以增加水稻的根长密度和根表面积,在抽穗期显著提高水稻对氮、磷、钾的累积,整个生育期对钾的吸收利用明显优于水旱平作和冬水田,为水稻高产提供可参考的依据。The aim of this study was to determine the effects of different cultivation methods on the root characteristics of rice(Oryza sativa),the accumulation of nitrogen(N),phosphorus(P)and potassium(K)in rice plants at different growth stages,and rice yield.The rice variety Y Liangyou 6 was grown in soil containing sufficient amounts of N,P,and K.The design was based on a long-term field experiment(initiated in 1990),with three treatments:flooded paddy field(FPF),conventional paddy-upland rotation tillage(CT),and combined ridge and no-tillage(RNT).The actual yield of the RNT system was 8750.8 kg·ha-1,significantly higher than the yields from the CT and FPF systems(P<0.05).The rice root length density,root surface area,and specific root length were higher significantly in RNT than in CT at the elongation stage(P<0.05).Compared with the root surface area in the FPF and CT systems,that in RNT was increased by 3.37%and 6.71%,respectively,at the heading stage(1.74 cm 2·cm-3).The RNT system increased rice stem N,P,and K contents by 49.26%,33.20%,and 59.70%compared with their respective contents in CT at the heading stage.There was no significant difference in the P content of stems and leaves of rice among the three tillage methods,but NPK accumulation was significantly higher in rice plants in the RNT treatment than in those in the CT treatment(P<0.05)at the heading stage.The accumulation rate of NPK in rice plants was significantly higher(P<0.05)in the RNT treatment than in the other treatments at the heading stage,indicating that the accumulation of N,P,and K was significantly increased under RNT.Compared with the N content in mature rice grains in FPF and CT,that in RNT was increased by 24.80%and 14.30%,respectively(P<0.05).The lowest N∶K and highest K∶P were in the RNT treatment from the tillering to the heading stage,which meant that the absorption,utilization,and distribution of K in rice was significantly improved by the combined ridge cultivation no-tillage system.In conclusion,rice plants cultivated under the

关 键 词：养分吸收 根系特性 耕作模式 水稻 

分 类 号：S51[农业科学—作物学]