摘要
倒伏是限制长江流域直播油菜高产稳产的关键因素之一,水稻秸秆还田后,氮肥运筹通过碳氮代谢和茎秆结构影响油菜抗倒性能。本研究采用裂区设计,以华油杂62为材料,基于稻-油轮作定位试验,研究秸秆管理耦合氮肥运筹对高密度直播油菜抗倒性的影响。以秸秆还田处理为主区(R0为秸秆不还田, R1为全量还田),以氮肥运筹为副区, CK为240 kg hm^(-2)的常规施氮量及基肥∶苗肥∶薹肥∶花肥=6∶4∶0∶0, N1、N2、N3、N4均为减氮20%,但基肥∶苗肥∶薹肥∶花肥分别为10∶0∶0∶0、6∶4∶0∶0、6∶2∶2∶0和6∶2∶0∶2,研究不同处理对成熟期油菜茎秆细胞壁成分、茎秆硅钙含量及花期茎秆显微结构等指标的影响。结果表明,相较于秸秆不还田,秸秆还田后,油菜成熟期地上部鲜重增加29.1%,茎秆抗折力增加23.3%,茎秆纤维素、总木质素、果胶、硅、钙含量分别显著(P<0.05)增加了26.3%、3.4%、30.6%、45.0%和9.5%,茎秆强度和韧性显著增强,但油菜株高、地上部鲜重的增幅大于茎秆抗折力增幅,导致倒伏指数平均增加了7.9%。合理的氮肥运筹可提高茎秆质量,从而降低倒伏指数。秸秆还田下N3处理使田间实际倒伏角度较常规施氮处理降低2.6%,茎秆抗折力增加15.2%,倒伏指数降低10.2%,优于其他处理。其机理是该处理显著增加了茎秆纤维素、果胶和钙含量及花期茎秆皮层厚度、表皮厚度、维管束长、横截面积、维管束数目以及维管束面积,显微结构排列更加合理,抗倒性显著增强。因此,在长江流域水稻秸秆还田和油菜高密直播条件下,以全生育期施氮192 kg hm^(-2)(基肥∶苗肥∶薹肥=6∶2∶2)为推荐施肥方案,可以减少氮肥投入,增强茎秆的抗倒伏能力,提高机械收获效率,实现高产抗倒协同的目标。
Lodging is a major constraint limiting the yield and stability of direct-seeded rapeseed in the Yangtze River Basin.Straw incorporation from the preceding rice crop can influence lodging resistance in rapeseed by affecting carbon-nitrogen metabolism and stem morphology,especially when combined with tailored nitrogen management strategies.In this study,a split-plot design was used with the rapeseed hybrid Huayouza 62,based on a long-term rice-rapeseed rotation field experiment.The main plots comprised straw incorporation treatments(R0:no straw incorporation;R1:full straw incorporation).Subplots consisted of nitrogen application regimes:CK(conventional nitrogen rate of 240 kg hm^(-2) with basal:seedling fertilizer ratio 6:4:0:0)and four 20%-reduced nitrogen treatments(N1,N2,N3,N4),maintaining identical total nitrogen reduction but differing fertilizer ratios(basal:seedling:bolting:flower fertilizer stages):N1(10:0:0:0),N2(6:4:0:0),N3(6:2:2:0),and N4(6:2:0:2).The effects of these treatments on stem cell wall composition at maturity,stem silicon and calcium content,and stem anatomical structure at flowering were evaluated.Compared with no straw return,full straw incorporation significantly increased aboveground fresh biomass by 29.1%and stem breaking strength by 23.3%.Increases were also observed in stem contents of cellulose(26.3%),total lignin(3.4%),pectin(30.6%),silicon(45.0%),and calcium(9.5%)(P<0.05),contributing to improved stem strength and toughness.However,the gains in plant height and biomass outpaced the improvements in stem strength,leading to a 7.9%average increase in the lodging index.Appropriate nitrogen allocation strategies improved stem structural quality and reduced lodging risk.Notably,the N3 treatment(192 kg hm^(-2),applied as 6:2:2:0)under full straw return conditions reduced the actual lodging angle by 2.6%,increased stem breaking strength by 15.2%,and decreased the lodging index by 10.2%compared to the conventional treatment.These improvements were attributed to significant increases in stem cellulose,pectin,and calcium contents,as well as enhanced anatomical characteristics at flowering,including greater cortex and epidermis thickness,increased vascular bundle length and area,and a higher number of vascular bundles.A more uniform vascular bundle arrangement further contributed to improved stem mechanical strength and lodging resistance.Therefore,under high-density direct-seeded rapeseed cultivation with rice straw incorporation in the Yangtze River Basin,an optimized nitrogen regime of 192 kg hm^(-2)(basal:seedling:bolting=6:2:2)is recommended.This strategy not only reduces nitrogen input but also enhances stem strength and lodging resistance,thereby improving mechanical harvest efficiency while maintaining high yield and structural resilience.
作者
朱家宝
王先领
樊友众
王宗铠
蒯婕
汪波
王晶
徐正华
赵杰
周广生
Zhu Jia-Bao;Wang Xian-Ling;Fan You-Zhong;Wang Zong-Kai;Kuai Jie;Wang Bo;Wang Jing;Xu Zheng-Hua;Zhao Jie;Zhou Guang-Sheng(College of Plant Science and Technology,Huazhong Agricultural University/Key Laboratory of Crop Ecophysiology and Farming System for the Middle Reaches of the Yangtze River,Ministry of Agriculture and Rural Affairs,Wuhan 430070,Hubei,China;Hongshan Laboratory,Wuhan 430070,Hubei,China)
出处
《作物学报》
北大核心
2026年第1期233-248,共16页
Acta Agronomica Sinica
基金
国家重点研发计划项目(2021YFD1901205)资助。
关键词
油菜
秸秆还田
氮肥运筹
倒伏指数
茎秆成分
显微结构
rapeseed
straw incorporation
nitrogen management
lodging index
stem composition
microstructure
