秸秆隔层及水肥管理对芥菜生长、产量和水氮利用的影响

Effects of Straw Interlayer and Water-Nitrogen Management on Mustard Production in Growth,Yield,and Water-Nitrogen Utilization

研究秸秆还田及其水肥配套技术,可为秸秆资源化利用和水肥管理提供借鉴。采用桶栽试验,研究秸秆隔层及水氮管理对芥菜光合、产量及水肥利用的影响。对比分析不同秸秆埋深(0 cm、10 cm、20 cm)、灌水定额(17 mm、21 mm、25 mm)和施氮量(230 kg/hm^(2)、287 kg/hm^(2)、344 kg/hm^(2))耦合作用下对芥菜叶绿素相对含量(SPAD值)、光合参数、荧光参数、产量、干物质量、灌溉水利用效率(IWUE)和氮肥偏生产力(PFPN)的影响效果和变化规律,分析探讨各指标的影响因素及其影响机制,确定芥菜生长的最优秸秆隔层埋深及水氮组合。结果表明,施氮量和秸秆隔层埋深分别为芥菜光合作用(除Ci)、产量、干物质量(除根部干物质量)和PFPN的主、次影响因素,且两者均影响显著(P<0.05);高施氮量(344 kg/hm^(2))和秸秆埋深20 cm可显著提升芥菜光合作用、产量、干物质量和IWUE;灌水定额对IWUE影响极显著(P<0.01),两者呈反比,但对芥菜其他生长指标影响不显著(P>0.05);PFPN与施氮量亦呈反比,秸秆隔层对PFPN的影响优于秸秆覆盖。因此,秸秆隔层埋深20cm能促进芥菜的生长、产量、干物质量和水肥利用效率的提升,秸秆隔层埋深10 cm效果较差;秸秆还田条件下,80%~120%Iw对芥菜生长和产量影响不明显;适当增施氮肥可促进芥菜生长及产量提升,但增量20%效果并不显著。综上,秸秆隔层埋深20cm、灌水定额17mm和施氮量287kg/hm^(2)为芥菜生长的最优组合。

To provide a reference for straw resource utilization and water and fertilizer management,researches on straw management and technology of water and fertilizer support are necessary..In this study,we compared and analyzed the effects and changes of different factors on mustard growth.These factors include straw burial depth(0 cm,10 cm,20 cm),irrigation amount(17 mm,21 mm,25 mm),and nitrogen application amount(230 kg/hm^(2),287 kg/hm^(2),344 kg/hm^(2)).We looked at the impact on SPAD,photosynthetic parameters,fluorescence parameters,yield,dry matter quality,IWUE,and PFPN of mustard.Our analysis helped us determine the optimal straw burial depth and water-nitrogen combination for mustard growth.We also identified the influencing factors and explained the reasons behind each index.The results indicated that nitrogen application rate and straw burial depth were the primary and secondary influencing factors for photosynthesis(except Ci),yield,dry matter weight(except root dry matter weight),and PFPN of mustard.Both factors have significant effects(P<0.05).Increasing nitrogen application rate and straw burial depth by 20 cm increases photosynthesis,yield,and IWUE of mustard significantly.Irrigation amount has an inverse significant effect on IWUE(P<0.01),but no significant effect on other growth indicators of mustard(P>0.05).The PFPN is inversely proportional to the nitrogen application rate,and effect of straw interlayer on PFPN is superior to straw mulching.Therefore,a straw burial depth of 20 cm promoted the growth,yield,and water-fertilizer utilization efficiency of mustard,while the effect of a straw burial depth of 10 cm is poorer.Under the condition of straw returning,80%~120%Iw has no obvious effect on the growth and yield of mustard.Properly increasing the amount of nitrogen fertilizer could enhance the growth and yield of mustard,but a 20%increase has no significant effect.The results show that the optimal combination for mustard growth is a straw burial depth of 20 cm,an irrigation amount of 17 mm and a nitrogen application rate of 287 kg/hm^(2).This combination could achieve efficient utilization of straw,increase the yield and efficiency of mustard,and save water for irrigation.