【作者】 赵琳；

【导师】 李世清； 冯佰利；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2005， 硕士

【摘要】 在黄土高原南部年降水量628.8mm 左右的半湿润区以红油土为供试土壤,在杨凌西北农林科技大学农作一站于2003 年-2004 年进行大田试验,供试品种为小偃22,研究不同施氮水平(设不施氮和每公顷施氮120kg　等2 个水平)、不同栽培模式(设常规栽培、地膜覆盖、垄沟栽培、垄播覆膜等4 种栽培模式)对冬小麦个体-群体的调控以及对产量影响的集成效应。通过研究,得到以下主要结论:　1.　施氮和栽培模式对功能叶氮素,特别是对生育后期功能叶氮素含量的影响,是影响源同化能力的基础。研究结果表明,施氮能够显著增加小麦各生育期旗叶含氮量,在拔节期其影响效果最为明显;进入灌浆和成熟期,影响效果减弱。不同栽培模式对叶片含氮量的作用没有氮肥的影响效果明显。垄播覆膜和地膜栽培两种栽培模式下的旗叶含氮量在灌浆期和成熟期均高于其它处理,特别是垄播覆膜在灌浆期的效果较为明显,比对照(常规栽培)分别增加12%和29%,施氮和栽培模式对叶绿素含量的影响基本与对旗叶含氮量的影响一致。越冬期、返青期、拔节期和开花期施氮绿叶面积比不施氮分别增加23.4%、20.7%、15.3%和8.9%,氮肥对绿叶面积影响以苗期影响最为显著;地膜覆盖和垄播覆膜栽培模式下绿叶面积明显高于常规栽培,以垄播覆膜栽培模式下小麦绿叶面积最大。施氮能够显著增加开花期、灌浆旗和成熟期净光合速率,施氮比不施氮分别增加7.8%、15.9%和7.2%。　各栽培模式间旗叶净光合速率存在极显著差异(P<0.01),其中垄播覆膜栽培条件下旗叶净光合速率最大,为16.291μmolCO2m-2.s-1;地膜覆盖、垄播覆膜与垄沟栽培与常规栽培模式间存在极显著差异(P<0.01);垄播覆膜和地膜覆盖差异不显著。　相关分析进一步证明,增加功能叶含氮量,特别是生育后期含氮量,对增加籽粒产量具有重要作用。功能叶含氮量增加,有利于增加叶绿素含量和提高光合速率,因此功能叶含氮量是影响源同化能力的基础。在本研究中,除施氮能够显著增加功能叶含氮量外,地膜覆盖、垄播覆膜和垄沟栽培均能显著增加功能叶含氮量,并以地膜覆盖和垄播覆膜尤为显著。　2.　施氮和栽培模式主要通过影响群体分蘖、叶面积和地上部生物量,而影响小麦群体结构。无论在何种栽培模式,施氮均能显著增加群体分蘖数;不同栽培模式,其群体分蘖数也不同:常规栽培、地膜覆盖、垄沟栽培和垄播覆膜栽培的群体分蘖数分别为378 个/m2、405 个/m2、452 个/m2和512 个/m2,垄播覆膜、垄沟栽培和地膜覆盖分别比常规栽培增加26%、16%、7%,可见,采用垄播覆膜栽培最有利于增加单位面积小麦群体分蘖数。相关分析表明,群体分蘖数与子粒产量有密切的正相关关系,因此在一定范围内增加群体分蘖数有利于提高籽粒产量。地上部生物量与籽粒产量呈显著正相关关系。在施氮与不施氮2 种条件下,小麦地上部生物量随生育期的动态变化趋势基本一致,均表现为在灌浆前持续增加,灌浆到收获,呈下降趋势。不同栽培模式,其地上部生物量累积不同。覆膜后植更多还原

【Abstract】 The field experiment was conducted at the first Agronomy Research Farm, Northwest Sci-tech University of Agriculture and Forest in Yang ling, which were in the south part of Loess Plateau with about 628.8mm precipitation each year. Xiaoyan 22 was used as indicating crops to study the relationship between individual and colony of winter wheat and yield in different planting modes(control-C, plastic sheet-mulching-PSM, ridge-furrow tillage-RFT and plastic sheet-mulching on ridge-PSMR) and different nitrogen fertilizer application(no nitrogen application and nitrogen application 120kg/hm2). The main results showed as follows: 1. The effects of nitrogen fertilizer and planting modes on the flag leaf, especially in the growth anaphase, were the basis of assimilation ability of source. Results showed that nitrogen fertilizer were able to increase the nitrogen content of flag leaf significantly, especially at jointing stage. But during filling stage and maturing stage, it increased slowly. The effects of planting modes were less than nitrogen fertilizer. The flag leaf nitrogen content of PSMR and PSM were higher than the other two planting modes, during the filling stage and maturing stage, especially the effects of PSM were obvious in the filling stage. They individually increased 12% and 29% comparing to C. The effects of nitrogen fertilizer and planting modes on chlorophyll were almost the same as on the flag leaf nitrogen content. The area of green leaf under the condition of nitrogen fertilizer were increased to 23.4%,20.7%,15.3% and 8.9% comparing to non-nitrogen fertilizer. At seeding stage, reviving stage , jointing stage and anthesis stage, the effects of nitrogen fertilizer on the area of green leaf are the largest at seeding stage. PSM and PSMR’s green leaf area were higher than C significantly. PSMR’s green leaf areas were the largest. Nitrogen fertilizer can significantly increased flag leaf’s photosynthetic rate. At jointing stage, filling stage and maturing stage, they increased to 7.8%, 15.9% and 7.2% than non-nitrogen application. The changes of Pn were significantly different at 0.01 in different planting modes. PSMR’s Pn were the largest, 16.291μmolCO2m-2.s-1. Correlation analysis showed that increased flag leaf’s nitrogen content were beneficial to grain yield, especially in the growth anaphase. Increasing flag leaf’s nitrogen content were beneficial to increasing chlorophyll and Pn. So flag leaf’s nitrogen content are the basis of assimilation ability. Study showed that not only nitrogen fertilizer can increased flag leaf’s nitrogen content significantly, but also PSM, PSMR and RFT can increased it significantly, especially PSM AND PSMR. 2. Nitrogen fertilizer and planting modes mainly affected canopy tiller, leaf area and biomass over-ground, so as to affect colony structure. In every planting modes, nitrogen fertilizer can increase colony tiller significantly. The colony tiller were different in different planting modes. C, PSM, RFT and PSMR’s colony tiller individually were 378/m2,405/m2,452/m2 and 512/m2. PSMR,RFT and PSM increased 26%,16% and 7% comparing to C. We can see that PSMR was the most beneficial to increase colony tiller per area. Correlation analysis showed that colony tiller and grain yield were positive correlation. So we can increase colony tiller to some extent to increase grain yield. Biomass over-ground were the same as whether using nitrogen or not. They were all increased in the initial filling stage, and then decreased in filling stage and harvest time. Biomass over –ground were different in different planting modes. They were higher comparing to the non-mulching. The biomass over-ground sequence from large to small was PSMR, RFT, PSM and C. The effects of nitrogen fertilizer on dry matter accumulation were different. PSMR’s dry matter accumulation were higher than PSM at harvest time, so it was beneficial to increase grain yield. From the colony tiller and biomass considering, PSMR and PSM were the best planting modes. To the RFT, colony tiller on ridge had close relation with sheet-mulching. PSMR could increase the colony tiller significantly. LAI was increased at the first and then decreased. The largest LAI was 1.919 in anthesis and the least was 1.292 in mature. The changes of LAI were significantly different at 0.01 in different nitrogen treatment. Nitrogen fertilizer could increased 20% to LAI. PSMR and RFT’s LAI were higher than the other two planting modes, but DIFN was reverse. The DIFN became small from mature to anthesis. RFT and PSMR’s DIFN were significantly different at 0.01 from the other two planting modes. C’s DIFN was the largest without nitrogen, PSM’s DIFN was the least with nitrogen. 3. Nitrogen fertilizer and planting modes affected the root characteristic significantly, but the relation between the ratio of root to shoot and root biomass with grain yield were not different significant. The root weight were gradually increased from reviving stage to booting stage. It reached maximum at booting stage. Besides PSM, nitrogen fertilizer didn’t affect the root weight significantly. PSM, RFT and PSMR’s root biomass were larger than C’s in reviving stage. But after jointing stage, PSM and PSMR’s root biomass were almost the same as C’s, even less than C’s. that perhaps were affected by the dying of the root. The root quantity per plant were significant different in different planting modes in reviving stage. C and PSM’s root quantity were more. PSM and PSMR’s root quantity per plant were decreased significantly when entering into booting stage. Nitrogen fertilizer made the ratio of root to shoot decreased. The changes of the ratio of root to shoot were significantly different at 0.01 in different planting modes. The ratio of root to shoot’s sequence from large to small was RFT, PSMR, C and PSM. Correlation analysis showed that the ratio of root to shoot were negative relation to grain yield, but not significantly. Dry weight of root have nothing with grain yield. 4. Nitrogen fertilizer and planting modes could affect grain yield through spike quantity and 1000 kernel dry weight. Study showed that grain yield’s sequence from large to small was PSMR, RFT, PSM and C. They individually increased to 27%,20% and 9% comparing to C. The different level reached to 0.01.PSMR’s spike quantity were largest. Nitrogen fertilizer can significantly affect spike quantity and 1000 kernel dry weight, but not affected kernel quantity per spike significantly. However, planting modes can affect sink volume per spike significantly. Nitrogen also can affect the HI(harvest index) significantly. It can increase 10% to HI. Study showed that PSMR’s grainyield were largest, 8899kg/hm2. The NUE(nitrogen use efficiency)’s sequence from large to small is PSMR, RFT PSM and C. PSMR’s NUE increased 37% comparing to C’s NUE.更多还原