中国农业科学 ›› 2014, Vol. 47 ›› Issue (10): 1929-1938.doi: 10.3864/j.issn.0578-1752.2014.10.006

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

盆栽条件下土壤无机氮浓度对大豆结瘤、固氮和产量的影响

 严君, 韩晓增   

  1. 中国科学院东北地理与农业生态研究所黑土区农业生态(院)重点实验室,哈尔滨 150081
  • 收稿日期:2013-07-24 出版日期:2014-05-20 发布日期:2013-09-04
  • 通讯作者: 韩晓增,Tel:0451-86602940;E-mail:xzhan@neigaehrb.ac.cn
  • 作者简介:严君,Tel:0451-86648128;E-mail:yanjun985625@163.com
  • 基金资助:

    国家自然科学基金项目(41201246,41371296)、现代农业产业技术体系建设专项资金(CARS-04)

Effect of Soil Inorganic N Concentrations on the Nodulation, N2 Fixation and Yield in Soybean in a Pot Experiment

 YAN  Jun, HAN  Xiao-Zeng   

  1. Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081
  • Received:2013-07-24 Online:2014-05-20 Published:2013-09-04

摘要: 【目的】大豆结瘤固氮和产量对氮肥的反应不同,实际上是由于大豆共生固氮系统及其根系系统对土壤无机氮浓度的感知不同造成的。通过对不同土壤无机氮浓度下大豆结瘤、固氮及产量影响的研究,探索能提高大豆产量、结瘤和固氮的土壤无机氮浓度,即掌握土壤无机氮浓度与大豆共生固氮和产量的数量关系,为调控氮肥施用量及施用时期、预测氮肥对大豆共生固氮能力和产量的影响提供理论依据。【方法】采用盆栽土培试验方法,分别在第一片复叶充分生长(V2期)、始花期(R1期)、始荚期(R3期)和始粒粒(R5期)一次性施用不同量的氮肥,从而形成不同无机氮浓度的土壤。利用获得的不同无机氮浓度土壤为供试土壤,对各生育时期根瘤数量、干重和固氮酶活性及成熟期产量及其构成因子进行调查,明确大豆根瘤固氮和产量对土壤无机氮浓度的响应,掌握土壤无机氮浓度与氮肥及与大豆固氮和产量的数量关系。【结果】不同时期土壤无机氮浓度处理下的根瘤干重、数量和固氮酶活性均随着大豆生育时期的推进在R4期时达到最大值。R6期时大豆平均根瘤干重、数量和固氮酶活性均表现为:V2期>R5期>R3期>R1期,较CK处理根瘤平均干重分别下降15%、18%、17%和32%;根瘤数量下降13%、18%、19%和20%;固氮酶活性下降19%、22%、23%和32%。不同生育时期土壤无机氮浓度与R6期大豆根瘤干重、数量和固氮酶活性间均具有显著的线性负相关关系,即土壤无机氮浓度越大对根瘤干重、数量和固氮酶活性的抑制作用越大。大豆干物质积累量和产量的变化趋势均表现为:R1期>R3期>V2期>R5期。除R5期不同土壤无机氮浓度处理与CK处理间的生物量和产量差异不显著外,V2、R1和R3期不同土壤无机氮浓度处理,均显著地促进大豆生物量和产量的增加。不同生育时期处理均以N3和N4处理的生物量、株高、株荚数、株荚重、株粒重显著高于其它处理。V2期土壤无机氮浓度对大豆固氮能力和产量的影响最大,而R1期土壤无机氮浓度对大豆生长和产量的影响最大。不同生育时期不抑制大豆固氮同时还提高大豆产量的土壤无机氮浓度不同:V2期土壤无机氮浓度达到135.8 mg•kg -1;R1期土壤无机氮浓度为58—91 mg•kg-1;R3期土壤无机氮浓度为29.4—62.8 mg•kg -1;在R5期土壤无机氮浓度达到102.3 mg•kg -1。【结论】大豆对氮肥的反应主要取决于土壤无机氮浓度的大小,而土壤无机氮浓度大小的调节,除了与氮肥施用量有关外还与大豆的生育时期有关系,可以根据农业生产和科学试验的需要进行调节。其中V2期土壤无机氮浓度对大豆根瘤数量、干重和固氮酶活性的影响大于其它生育时期土壤无机氮浓度处理;而R1期土壤无机氮浓度对大豆生物量和产量的影响大于其它生育时期土壤无机氮浓度处理。

关键词: 土壤无机氮 , 根瘤 , 固氮能力 , 产量 , 黑土

Abstract: 【Objective】 The response of N2 fixation and yield to N fertilizer, even with same N application rate, gives varying and contradicting results. The contradicting results depend on the perception of the system of soybean nitrogen fixation and root to the soil inorganic N concentration. The nodulation, fixation and yield of soybean with different soil inorganic N concentrations were studied to find the reasonable soil inorganic N concentration for promoting soybean yield, nodulation and fixation. i.e. to master the quantified relationship between soil inorganic N concentration, nodulation and fixation. Then it will have a significant theory and production meaning for adjusting N application rate, timing, and forecasting the effect of N fertilizer on the fixation and yield. 【Method】A pot experiment was conducted to study the effects of different soil inorganic nitrogen concentrations, which derived from total fertilizer N (as urea) applied at vegetative stage (V2), at early blooming stage (R1), at early podding stage (R3) and at grain filling stage (R5), on the ability of N2 fixation and yield, by measuring the nodule number, biomass and nitrogenase activity and yield components. Through the research, the response of soybean nodulation and yield to soil inorganic N concentration cleared, and thus mastering the quantity relationship between soil inorganic N concentration and N application, nodulation and yield, and then providing a theoretical basis for agriculture production and scientific research. 【Result】 The nodule number, biomass and nitrogenase activity of soybean reached peak at R4 stage, while decreased at R6 stage, and the nodule number, biomass and nitrogenase activity were in order of V2>R5>R3>R1. The nodule biomass decreased by 15%, 18%, 17% and 32% compared to that of CK. The nodule number decreased by 13%, 18%, 19% and 20%. The nitrogenase activity decreased by 19%, 22%, 23% and 32%. Meanwhile, there were significant negative linear correlations between nodule number, biomass and nitrogenase activity at R6 stage and the concentration of soil inorganic nitrogen. Moreover, The trends of dry matter accumulation and yield were expressed as an order of R1>R3>V2>R5. Except the treatments at R5 had no significant correlations with the treatment of CK, the other treatments had a significant promoted effect on dry matter accumulation and yield. The treatment of N3 had the highest dry matter accumulation, plant height, pod number, pod dry weight and yield than the other treatments at different growth stages. The soil inorganic N concentration at V2 stage had a significant effect on nodulation and the ability of nitrogen fixation, and that at R1 stage had a significant effect on growth and yield. There were different threshold values of soil inorganic nitrogen concentration at different growth stages. The soil inorganic N concentration should be reached 135.8 mg•kg -1 at V2 stage, 58-91 mg•kg -1 at R1 stage; 29.4-62.8 mg•kg -1 at R3 stage; 102.3 mg•kg -1 at R5 stage to promote soybean nitrogen fixation and yield. 【Conclusion】 The response of N2 fixation and yield to N fertilizer mainly depended on the soil inorganic N concentration which was affected by N fertilizer application rate and timing. The soil inorganic N concentration was adjusted by agriculture production and scientific experiment. The nodule number, biomass and nitrogenase activity were significantly affected by the soil inorganic N concentration at V2 stage than that at the other growth stages, while the biomass and yield were significantly affected by the soil inorganic N concentration at R1 stage than that at other growth stages.

Key words: soil inorganic nitrogen , nodule , N2 fixation , yield , black soil