玉米产量和氮肥利用效率与土壤基础生产力的关系
发布时间：2018-04-02 23:33
本文选题：土壤基础生产力 切入点：玉米 出处：《内蒙古农业大学》2017年硕士论文
【摘要】：粮食增产长期刚性需求和当前化肥农药"零增长"的发展背景下,以更少氮肥投入获得更高产量需要挖掘土壤生产潜力。但提升土壤基础生产力(ISP)能否协同提高玉米产量和氮肥利用效率(NUE)尚不明确。定量化解析ISP与玉米产量及NUE的关系及其生态生理机制,探讨影响ISP的主控因子,将为依靠地力提升实现玉米产量与NUE协同提升提供基础性依据。本研究立足于内蒙古自治区从东到西较大跨度下ISP的差异,采用多生态区定位联网试验,通过土壤管理模式(常规管理,CP;地力提升,IISP)×密度(6.0万株/hm2、8.25万株/hm2、10.5万株/hm2)×施氮量(0 kg/hm2、220kg/hm2)交互,创造不同氮效率群体,系统分析了土壤基础生产力与产量和NUE的关系及其土壤生态与作物生理过程。主要研究结果如下:(1)提升土壤基础生产力可实现玉米产量和氮肥效率协同提高。当ISP提升到8.7 t/hm2以上时,可实现产量和PFPN同步提高;当ISP提升到10 t/hm2以上时,可实现产量与NUE同步提高。高密和低氮群体在较高ISP水平下可获得较高产量,说明提升ISP是增密减氮增产的重要基础。(2)土壤有机质含量、有效氮含量、土壤氮矿化量、土壤氮表观损失(N losses)与水分利用效率(WUE)是影响ISP和施氮产量主要因素;而NUE主要受土壤氮矿化量、N losses和WUE影响;土壤有机质含量间接影响土壤有效氮水平、氮素矿化能力和水分涵养能力,是影响ISP的核心。IISP模式显著提高土壤氮矿化量(16.0%),显著降低N losses(11.4%),显著提高WUE(12.9%),其较佳的土壤水氮环境是其高产高效的重要基础。(3)ISP低于10t/hm2时,土壤供氮能力不足使施氮产量增速低于ISP增速,NUE随ISP明显降低;ISP提高到10t/hm2以上时,土壤供氮能力不是制约因子后,ISP提升协同优化了源库比和花后营养器官碳氮转运能力,通过提高千粒重和氮肥生理效率(NIE)实现产量和NUE系统提高。施氮量与密度互作对ISP与产量和NUE的关系的显著影响,以及土壤管理模式×施氮量×密度的显著互作效应,说明通过地力提升实现玉米产量和氮效率协同提高需要结合增密减氮等其他措施,发挥其与氮密的综合互作效应。(4)基于当前的玉米产量水平,若使产量与氮肥生产效率(PFPN)协同提高15%,ISP需提高到10 t/hm2,在此情境下土壤氮矿化量和WUE将达99.1 kg/hm2和27.2kg hm-2 mm-1,N losses 则为 117.3 kg/hm2;所需施氮量为 206.1kg/hm2,将较 8.7t/hm2 的ISP水平节氮46.4%。若使产量与PFPN协同提高30%,ISP需提高至11.6 t/hm2,此时的土壤氮矿化量和WUE将达119.4 kg/hm2和32.7kg hm-2 mm-1,而N losses将降低至96.7kg/hm2;所需施氮量则降低为176.1kg/hm2,将较8.7t/hm2的ISP水平节氮67.4%。
[Abstract]:Under the background of long-term rigid demand for increasing grain yield and "zero growth" of chemical fertilizer and pesticide, it is necessary to tap the potential of soil production to obtain higher yield with less nitrogen input.However, it is not clear whether ISP can increase maize yield and N use efficiency.The quantitative analysis of the relationship between ISP and maize yield and NUE and its ecological physiological mechanism, and the discussion of the main controlling factors affecting ISP, will provide the basic basis for realizing the synergistic enhancement of maize yield and NUE by soil fertility enhancement.Based on the difference of ISP between east and west in Inner Mongolia Autonomous region, this study adopts multi-ecological location networking test.Different nitrogen efficiency groups were created by interaction of soil management model (conventional management system) 脳 density (60000 / hm ~ (2), 82500 / hm ~ (2), 105000 / hm ~ (2)) 脳 N application rate of 0 kg / hm ~ (2) ~ (2) kg 路hm ~ (2) / hm ~ (2).The relationship between soil basic productivity and yield and NUE, soil ecology and crop physiological process were systematically analyzed.The main results are as follows: (1) improving soil basic productivity can achieve synergistic improvement of maize yield and nitrogen fertilizer efficiency.When ISP is raised above 8.7 t/hm2, the output and PFPN can be increased synchronously, and when ISP is raised to more than 10 t/hm2, the output can be increased synchronously with NUE.High density and low nitrogen population can obtain higher yield at higher ISP level, indicating that increasing ISP is an important basis for increasing density and decreasing nitrogen yield. 2) soil organic matter content, available nitrogen content, soil nitrogen mineralization amount, soil organic matter content, available nitrogen content and soil nitrogen mineralization amount.The apparent loss of soil nitrogen (N) and water use efficiency (Wue) were the main factors affecting ISP and N application yield, while NUE was mainly affected by N mineralization, N losses and WUE, and soil organic matter content indirectly affected soil available nitrogen level.姘礌鐭垮寲鑳藉姏鍜屾按鍒嗘兜鍏昏兘鍔，
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