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1.
【目的】阐明夏播玉米大豆间作对小麦玉米轮作体系产量、吸氮量、土壤含水量和硝态氮残留的影响,明确间作地上部和地下部因素对间作优势的相对贡献率,为优化资源配置、提高土地生产力提供科学依据。【方法】2011年6月至2012年10月,在河北省徐水县代表性农田设置玉米单作(T1)、大豆单作(T2)、玉米与大豆间作根部不分隔(T3)、玉米与大豆间作根部分隔(T4)4个处理,并对关键生育时期的作物生长、土壤水分和硝态氮含量进行实时观测。【结果】相对作物单作种植模式,间作产量优势明显,玉米大豆间作种植的土地当量比(LER)大于1,间作模式总吸氮量(256.1 kg·hm-2)显著高于玉米单作种植(159.7 kg·hm-2)。玉米大豆间作主要通过促进玉米生长和氮素吸收来提高间作系统生产能力,其中地上部因素对间作玉米生物量、产量和吸氮量提高的贡献率分别为81.6%、83.4%和75.7%,而地下部因素的贡献率仅为18.4%、16.6%和24.3%。间作玉米条带土壤含水量显著低于单作玉米,隔根间作玉米土壤含水量显著低于不隔根间作玉米,单作大豆与间作大豆土壤含水量无显著差异,隔根对间作大豆土壤含水量无显著影响。相对单作种植,间作系统降低了玉米收获后各层土壤硝态氮含量,而提高了大豆条带土壤硝态氮含量;相对不隔根处理,间作隔根对玉米土壤硝态氮含量影响不大,但降低了间作大豆土壤硝态氮含量。夏季无论是单作种植还是间作种植,其后茬小麦产量和吸氮量均无显著差异,但间作可以显著降低小麦收获后土壤硝态氮残留量(P<0.05),相对玉米单作,间作种植的后茬小麦收获后0-100 cm土层硝态氮残留量降低了87.2 kg·hm-2,其中地上部因素贡献率为77.5%,地下部因素对此贡献仅为22.5%。【结论】夏播间作种植产量优势明显,间作模式整体吸氮量高于玉米单作,其中地上部因素对间作优势的贡献大于地下部因素,并且夏播间作种植对后茬小麦产量和吸氮量均无显著影响。相对单作种植,间作种植降低了玉米条带土壤含水量而对大豆条带无显著影响,间作玉米条带土壤硝态氮含量显著降低而大豆条带土壤硝态氮含量显著提高,但间作系统当季及后茬作物收获后的整体土壤硝态氮残留显著降低。  相似文献   

2.
To ascertain the possibility of cultivating maize using biological nitrogen fixation (BNF) by leguminous green manure crops in maize/leguminous green manure intercropping systems, BNF and nitrogen (N) transfer were studied in Xining and Wuwei, two typical northwestern Chinese cities. The experimental treatments included monocultured maize, monocultured green manures (hairy vetch and common vetch), and their intercropping systems. The proportions of N derived from the atmosphere (%Ndfa) in intercropping systems were not significantly different from that in monocultured green manure systems at either experimental site, except for that in hairy vetch (HV) in Xining. The amount of N derived from the atmosphere (Ndfa) of common vetch (CV) significantly decreased from 1.16 and 1.10 g/pot in monoculture to 0.77 and 0.55 g/pot when intercropped with maize, in Xining and Wuwei, respectively, and the Ndfa of HV when intercropped significantly decreased from 1.02 to 0.48 g/pot in Xining. In the intercropping systems in Xining and Wuwei, the amounts of N transferred (Ntransfer) from CV to maize were 21.54 and 26.81 mg/pot, accounting for 32.9 and 5.9% respectively of the N accumulation in maize, and the values of Ntransfer from HV to maize were 39.61 and 46.22 mg/pot, accounting for 37.0 and 23.3%, respectively, of the N accumulation in maize. Path analysis showed that soil nutrient and green manure biomass were mainly related to Ndfa, and that δ15N had a primary relationship with Ntransfer. We found that 5.9–37.0% of N accumulation in maize was transferred from green manures, and that the N transfer ability to maize of HV was higher than that of CV. In conclusion, intercropping with leguminous green manures provided a feasible way for maize to effectively utilize biologically fixed N.  相似文献   

3.
AMF与隔根对紫色土上玉米||大豆种间氮竞争的影响   总被引:4,自引:0,他引:4  
【目的】旨在探究紫色土上接种丛枝菌根真菌(arbuscular mycorrhizal fungus,AMF)和不同间作模式对玉米(Zea mays L.)和大豆(Glycine max L.)作物种间相对竞争能力及氮(N)营养竞争比率的影响,为AMF调控菌根作物间的养分资源利用和竞争作用提供科学依据。【方法】论文通过温室内盆栽试验,设置3种不同间作模式(不分隔、尼龙网分隔、塑料布分隔)和不同AMF处理(不接种(NM)、接种Glomus etunicatum(G.e)),分析比较了玉米和大豆植株生长和氮营养状况,量化AMF和间作模式对玉米和大豆的种间竞争能力和氮营养竞争比率的影响。【结果】相同间作条件下,玉米始终具有较强的竞争优势,大豆处于竞争劣势,其中G.e不分隔处理下,玉米相对大豆的种间竞争能力和氮营养竞争比率最大。无论接种与否,玉米植物氮含量、氮吸收量和根系生物量在3种间作模式下均表现为不分隔模式尼龙网分隔模式塑料布分隔模式,大豆恰恰表现出相反的趋势。与NM处理相比,接种AMF显著提高玉米相对大豆的种间竞争能力和氮营养竞争比率,其中,不分隔模式下,玉米地上部和根系生物量分别增加20.48%和23.50%,玉米地上部和根系氮吸收量分别提高64.20%和37.60%。对于根际土壤碱解氮而言,G.e-不分隔处理显著提高了玉米和大豆植物对土壤有效氮的吸收,而显著降低了其根际土壤碱解氮含量,减少了土壤碱解氮残留。【结论】不同间作模式下的玉米和大豆竞争能力有所不同,但玉米对氮的竞争能力始终大于大豆,且外源AMF也显著提高了玉米相对大豆的种间竞争能力和氮营养竞争比率。表明AMF在调控间作植物间的资源利用和维持农田作物多样性方面具有重要的生态学意义。  相似文献   

4.
 以小麦蚕豆间作方式为研究对象,通过根系分隔技术,主要研究了在小麦蚕豆根系不分隔(I)、尼龙网分隔(M)和塑料膜分隔(P)3种根系分隔条件下,供氮水平(N0,N0.05,N0.1和N0.2)对小麦生长和白粉病病害发生的影响。结果表明,施氮显著提高了间作小麦的生物量。在3种不同的根系分隔方式下(I,P和M),N0.05水平小麦地上部的生物量分别比N0水平增加了59.9%,62.6%和58.6%。随着供氮水平的提高,小麦白粉病的发病率和病情指数均明显增加,在3种根系分隔方式下,分别增加337.1%~1213.6%,766.3%~1750.1%和130.7%~1061.0%。但根系不分隔处理(Ⅰ)的间作小麦对白粉病的抗病能力较强,在高氮水平下(N0.2)病情指数和发病率均低于根系完全分隔处理(P)。  相似文献   

5.
大豆根构型在玉米/大豆间作系统中的营养作用   总被引:23,自引:0,他引:23  
 运用根构型不同的大豆品种与玉米进行间作,比较大豆根构型在玉米/大豆间作系统中的营养作用。结果表明,玉米与大豆间作具有明显的间作优势,间作作物的生物量、氮磷含量都显著好于单作。玉米与浅根型大豆品种巴西10号间作,间作优势大于与深根型大豆品种本地2号。说明大豆根构型在玉米/大豆间作系统中具有十分重要的作用。间作系统的氮磷养分竞争比率表明,玉米/大豆这类豆科/禾本科间作组合的优势主要来自对氮的优势性吸收,而玉米与不同基因型大豆间作的优势差异则主要来源于对土壤磷吸收的差异。浅根型大豆品种不仅有利于两种间作作物对土壤磷的吸收,同时还有利于对氮的吸收。  相似文献   

6.
Legume cultivars affect N uptake, component crop growth, and soil physical and chemical characteristics in maize–legume intercropping systems. However, how belowground interactions mediate root growth, N fixation, and nodulation of different legumes to affect N uptake is still unclear. Hence, a two-year experiment was conducted with five planting patterns, i.e., maize–soybean strip intercropping (IMS), maize–peanut strip intercropping (IMP), and corresponding monocultures (monoculture maize (MM), monoculture soybean (MS), and monoculture peanut (MP)), and two N application rates, i.e., no N fertilizer (N–) and conventional N fertilizer (N+), to examine relationships between N uptake and root distribution of crops, legume nodulation and soil N availability. Results showed that the averaged N uptake per unit area of intercrops was significantly lower than the corresponding monocultures. Compared with the monoculture system, the N uptake of the intercropping systems increased by 31.7–45.4% in IMS and by 7.4–12.2% in IMP, respectively. The N uptake per plant of intercropped maize and soybean significantly increased by 61.6 and 31.8%, and that of intercropped peanuts significantly decreased by 46.6% compared with the corresponding monocultures. Maize and soybean showed asymmetrical distribution of roots in strip intercropping systems. The root length density (RLD) and root surface area density (RSAD) of intercropped maize and soybean were significantly greater than that of the corresponding monocultures. The roots of intercropped peanuts were confined, which resulted in decreased RLD and RSAD compared with the monoculture. The nodule number and nodule fresh weight of soybean were significantly greater in IMS than in MS, and those of peanut were significantly lower in IMP than in MP. The soil protease, urease, and nitrate reductase activities of maize and soybean were significantly greater in IMS and IMP than in the corresponding monoculture, while the enzyme activities of peanut were significantly lower in IMP than in MP. The soil available N of maize and soybean was significantly greater increased in IMS and IMP than in the corresponding monocultures, while that of IMP was significantly lower than in MP. In summary, the IMS system was more beneficial to N uptake than the IMP system. The intercropping of maize and legumes can promote the N uptake of maize, thus reducing the need for N application and improving agricultural sustainability.  相似文献   

7.
施氮量对间作小麦蚕豆根系分泌槲皮素和橙皮素的影响   总被引:1,自引:0,他引:1  
刘英超  肖靖秀  汤利  郑毅 《中国农业科学》2017,50(16):3092-3100
【目的】系统探讨间作条件下,不同施氮水平不同生育期小麦和蚕豆根系分泌槲皮素和橙皮素的动态变化及累积特征,为进一步探明间作增产控病机制提供依据。【方法】通过盆栽试验,采用小麦与蚕豆根系尼龙分隔(MB)和塑料分隔(PB)两种间作种植模式,测定间作小麦蚕豆不同氮水平(低氮1/2N:常规施氮量的一半;常规施氮N;高氮3/2N:常规施氮量的1.5倍)条件下,不同生育期根系分泌槲皮素和橙皮素数量。【结果】施氮水平和间作体系根系不同分隔方式影响作物生物量和根冠比。随着施氮量增加,小麦和蚕豆生物量增加45%—62.5%和3.2%—18.9%,根冠比降低33.8%—47.3%和11.8%—26.9%;与塑料分隔相比,相同施氮水平条件下,作物生长60 d时,尼龙分隔小麦和蚕豆生物量分别提高4.2%—25%、19%—38.6%,随生长天数增加差异逐渐不显著。间作根系不同分隔方式和施氮量均能影响小麦蚕豆根系槲皮素和橙皮素的分泌量。随施氮量增加,小麦蚕豆槲皮素和橙皮素分泌量减少,与低氮条件相比,常规施氮和高氮条件下,小麦槲皮素分泌量减少了23.4%和62.3%,橙皮素分泌量减少了32.2%和64.5%;蚕豆槲皮素分泌量减少了35.4%和44.1%,橙皮素减少了11.9%和23.9%。相同氮水平条件下,尼龙分隔小麦蚕豆槲皮素和橙皮素分泌量高于塑料分隔,低氮和常规施氮条件下,尼龙分隔小麦槲皮素的分泌量分别高于塑料分隔15.3%和27.1%,橙皮素的分泌量分别高于塑料分隔21%和13.7%;蚕豆根系尼龙分隔槲皮素分泌量高于塑料分隔34.6%和56.6%,橙皮素高于塑料分隔16.9%和5.1%;高氮条件下两种根系分隔方式之间差异不显著。【结论】间作根系不同分隔方式影响小麦和蚕豆根系槲皮素和橙皮素的分泌,但这种影响受施氮水平的调控,低氮和常规施氮条件下,尼龙分隔小麦和蚕豆根系槲皮素和橙皮素分泌量高于塑料分隔,高氮条件下差异不显著。  相似文献   

8.
通过大田试验,在高、中、低供水水平和根系部分分隔(尼龙网隔根)、完全分隔(塑料布隔根)、不分隔条件下,探讨玉米间作豌豆的产量和水分利用特征,以期为通过调控根间作用提高间作水分利用效率(WUE)提供依据。结果表明,9个间作处理的LER处于1.13~1.42,即间作较单作具有明显的产量优势。两种作物地上互作对间作产量的贡献率为15.7%~17.2%,根系空间生态位重叠对产量的贡献率占0.9%~3.4%,地下互作对间作增产的贡献率为82.6%~86.1%,供水水平相对较高时利于间作优势的发挥。玉米间作豌豆耗水量较相应单作高24.8%~28.8%。供水水平较低且存在作物生长带间水分迁移时,根系空间生态位重叠有利于降低群体耗水量。间作WUE较单作平均高27.5%~38.3%,高供水间作处理的WUE高于中、低灌水处理。无论是完全隔根还是部分隔根,间作WUE较未隔根处理显著下降,且尼龙网隔根间作的WUE最低。间作作物地下水分的带间迁移、根系空间生态位的适度重叠是提高作物WUE的重要途径。  相似文献   

9.
通过根系分隔的盆栽试验,研究了地下部分隔对小麦//蚕豆间作系统中蚕豆的养分吸收和斑潜蝇发生的影响。结果表明:根系完全分隔处理蚕豆的生物量和N、P、K吸收量均高于其余2种分隔方式,在各个生育期,根系完全分隔处理与不分隔处理间差异均显著。根系分隔方式还影响了蚕豆斑潜蝇的发生,蚕豆斑潜蝇的发生均表现为根系不分隔(I)<尼龙网分隔(M)<完全分隔(P)。说明根系的相互作用,对蚕豆斑潜蝇的发生有一定的减轻作用。  相似文献   

10.
Planting grass and legume mixtures on improved grasslands has the potential advantage of realizing both higher yields and lower environmental pollution by optimizing the balance between applied N fertilizer and the natural process of legume biological nitrogen fixation. However, the optimal level of N fertilization for grass-legume mixtures, to obtain the highest yield, quality, and contribution of N2 fixation, varies with species. A greenhouse pot experiment was conducted to study the temporal dynamics of N2 fixation of alfalfa(Medicago sativa L.) grown alone and in mixture with smooth bromegrass(Bromus inermis Leyss.) in response to the addition of fertilizer N. Three levels of N(0, 75, and 150 kg ha–1) were examined using 15N-labeled urea to evaluate N2 fixation via the 15 N isotope dilution method. Treatments were designated N0(0.001 g per pot), N75(1.07 g per pot) and N150(2.14 g per pot). Alfalfa grown alone did not benefit from the addition of fertilizer N; dry matter was not significantly increased. In contrast, dry weight and N content of smooth bromegrass grown alone was increased significantly by N application. When grown as a mixture, smooth bromegrass biomass was increased significantly by N application, resulted in a decrease in alfalfa biomass. In addition, individual alfalfa plant dry weight(shoots+roots) was significantly lower in the mixture than when grown alone at all N levels. Smooth bromegrass shoot and root dry weight were significantly higher when grown with alfalfa than when grown alone, regardless of N application level. When grown alone, alfalfa's N2 fixation was reduced with N fertilization(R2=0.9376, P=0.0057). When grown in a mixture with smooth bromegrass, with 75 kg ha–1 of N fertilizer, the percentage of atmospheric N2 fixation contribution to total N in alfalfa(%Ndfa) had a maximum of 84.07 and 83.05% in the 2nd and 3rd harvests, respectively. Total 3-harvest %Ndfa was higher when alfalfa was grown in a mixture than when grown alone(shoots: |t|=3.39, P=0.0096; root: |t|=3.57, P=0.0073). We believe this was due to smooth bromegrass being better able to absorb available soil N(due to its fibrous root system), resulting inlower soil N availability and allowing alfalfa to develop an effective N2 fixing symbiosis prior to the 1st harvest. Once soil N levels were depleted, alfalfa was able to fix N2, resulting in the majority of its tissue N being derived from biological nitrogen fixation(BNF) in the 2nd and 3rd harvests. When grown in a mixture, with added N, alfalfa established an effective symbiosis earlier than when grown alone; in monoculture BNF did not contribute a significant portion of plant N in the N75 and N150 treatments, whereas in the mixture, BNF contributed 17.90 and 16.28% for these treatments respectively. Alfalfa has a higher BNF efficiency when grown in a mixture, initiating BNF earlier, and having higher N2 fixation due to less inhibition by soil-available N. For the greatest N-use-efficiency and sustainable production, grass-legume mixtures are recommended for improving grasslands, using a moderate amount of N fertilizer(75 kg N ha–1) to provide optimum benefits.  相似文献   

11.
非豆科植物根际联合固氮作用广泛存在于水稻、玉米等根际,在农作物节肥增产方面具有巨大的应用潜力。施氏假单胞菌A1501是一株分离自水稻根际的模式联合固氮菌,接种该菌对水稻和玉米均具有良好的促生效果。为了进一步研究根际固氮与促生效果的关系,利用突变型泌铵固氮菌株(1568/pVA3)和转基因氮高效利用玉米品系共同构建高效固氮体系,并在温室条件下进行促生及生物固氮量评价。播种60 d后对玉米生长量和微生物固氮量进行分析,结果表明:固氮施氏假单胞菌接种后氮高效利用和对照玉米品系的地上和地下部生物量都显著高于不接种对照,但是固氮菌接种对氮高效利用玉米和对照玉米的总生物量没有显著影响。氮高效利用玉米接种1568/pVA3菌株后,植株生物量较施肥处理提高25.5%,全氮含量较不接种对照增加39%,15N同位素稀释法测定生物固氮量为0.8 g·株-1;接种野生型后植株生物量较施肥处理提高24.8%,生物固氮量为0.64 g·株-1。研究结果表明,通过将固氮菌尤其是泌铵工程菌与氮高效利用玉米建立联合固氮体系可以显著提高根际固氮量和植株生物量,据估算每公顷可节省化肥约23%,而对照体系为7.5%。  相似文献   

12.
无芒雀麦和紫花苜蓿在(1:1)混播中的竞争与共存   总被引:3,自引:2,他引:1  
【目的】在豆科与禾本科牧草混播草地中不仅存在种内竞争也存在种间竞争,由于不同植物之间竞争力强弱不同,竞争的结果将出现一方逐渐消退,另一方逐渐占据优势的现象,因此研究豆科与禾本科牧草之间竞争与共存机制对于维持混播草地稳定高产具有重要意义。【方法】在温室栽培条件下设置3个氮肥水平(0, 75, 150 kg N·hm-2,记作N0, N75, N150)以及单播和混播两种种植模式(无芒雀麦单播,紫花苜蓿单播,无芒雀麦和紫花苜蓿1﹕1混播),采用相对生物量(RY)、相对密度(RD)、竞争率(CR)和相对产量总值(RYT)以及紫花苜蓿的固氮比例(%Ndfa)和转氮比例(%N Trans)等指标研究无芒雀麦和紫花苜蓿在1﹕1混播中的竞争关系与共存机制。【结果】施氮量从0增加到150 kg N·hm-2,单播中无芒雀麦的地上和地下生物量和分蘖数显著增加(P<0.05),而紫花苜蓿的地上和地下生物量和分枝数无显著变化(P>0.05)。在混播中无芒雀麦的地上和地下生物量和分蘖数也显著增加(P<0.05),在一定程度上抑制了紫花苜蓿的生物量和分枝数。另外,在混播中无芒雀麦以增加分蘖数的方式来扩张地上空间的能力要强于紫花苜蓿。无芒雀麦的单株生物量和分蘖数在混播模式下都极显著高于单播(P<0.01),而紫花苜蓿的单株生物量和分枝数在混播模式下极显著低于单播(P<0.01)。在混播中无芒雀麦的竞争率始终大于1.0,而紫花苜蓿的竞争率始终小于1.0,这说明无芒雀麦的竞争力要大于紫花苜蓿的竞争力,且在整个生育期中,无芒雀麦的竞争力逐渐减弱,而紫花苜蓿的竞争力逐渐增强。在N0处理下,第2次、第3次和第4次取样时,无芒雀麦和紫花苜蓿的相对产量总值(RYT)显著大于1.0(P<0.05),说明无芒雀麦和紫花苜蓿无明显的竞争效应,这主要归功于紫花苜蓿的生物固氮对无芒雀麦的贡献(地上部转移的氮素占无芒雀麦氮素含量的15.26%-29.92%)。在N75和N150处理下,其RYT值与1.0无显著差异(P>0.05)。另外,施入氮肥明显抑制了紫花苜蓿的生物固氮比例和对无芒雀麦的氮素转移的比例,导致混播中无芒雀麦和紫花苜蓿同时竞争土壤氮素和肥料氮。【结论】施入75和150 kg N·hm-2的氮肥增强了无芒雀麦的竞争力,而抑制了紫花苜蓿的生物固氮和对无芒雀麦氮素的转移,二者促进作用减弱,竞争效应增强。  相似文献   

13.
Nitrogen (N) is unevenly distributed throughout the soil and plant roots proliferate in N-rich soil patches. However, the relationship between the root response to localized N supply and maize N uptake efficiency among different genotypes is unclear. In this study, four maize varieties were evaluated to explore genotypic differences in the root response to local N application in relation to N uptake. A split-root system was established for hydroponically-grown plants and two methods of local N application (local banding and local dotting) were examined in the field. Genotypic differences in the root length response to N were highly correlated between the hydroponic and field conditions (r>0.99). Genotypes showing high response to N, ZD958, XY335 and XF32D22, showed 50–63% longer lateral root length and 36–53% greater root biomass in N-rich regions under hydroponic conditions, while the LY13 genotype did not respond to N. Under field conditions, the root length of the high-response genotypes was found to increase by 66–75% at 40–60 cm soil depth, while LY13 showed smaller changes in root length. In addition, local N application increased N uptake at the post-silking stage by 16–88% in the high-response genotypes and increased the grain yield of ZD958 by 10–12%. Moreover, yield was positively correlated with root length at 40–60 cm soil depth (r=0.39). We conclude that local fertilization should be used for high-response genotypes, which can be rapidly identified at the seedling stage, and selection for “local-N responsive roots” can be a promising trait in maize breeding for high nitrogen uptake efficiency.  相似文献   

14.
为西北1熟制灌区豆科/禾本科间作体系高产高效提供科学依据,于2007年在甘肃省农业科学院武威绿洲农业试验站设计了蚕豆/玉米间作体系的田间根系分隔试验,研究蚕豆/玉米2种作物间根系分隔和施氮对作物根系空间分布、根系形态的影响.采用根系行分隔法进行田间作物间根系分隔,并用根钻法采集根系.蚕豆和玉米根系主要分布分别在0~40 cm浅土层和0~60 cm土层,且间作玉米根系在60~120 cm比根系分隔的多,较深根系分布有利于玉米的后期竞争恢复生长.玉米根系可以占据蚕豆地下部空间,而蚕豆的根却较少到间作玉米的地下部空间.种间互作和施氮增加了玉米和蚕豆在纵向和横向2个尺度上的根重密度、根长密度、根表面积、根系体积.蚕豆玉米间作和施氮扩展了2种作物根系纵向和横向的空间生态位,改变了作物根系形态,从而增加了作物水分和养分吸收的有效空间.  相似文献   

15.
In China, the abuse of chemical nitrogen(N) fertilizer results in decreasing N use efficiency(NUE), wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enhance crop yield and improve resource use efficiency, especially in Southwest China. To optimize N utilization and increase grain yield, we conducted a two-year field experiment with single-factor randomized block designs of a maize-soybean intercropping system(IMS). Three N rates, NN(no nitrogen application), LN(lower N application: 270 kg N ha–1), and CN(conventional N application: 330 kg N ha–1), and three topdressing distances of LN(LND), e.g., 15 cm(LND1), 30 cm(LND2) and 45 cm(LND3) from maize rows were evaluated. At the beginning seed stage(R5), the leghemoglobin content and nitrogenase activity of LND3 were 1.86 mg plant–1 and 0.14 m L h–1 plant–1, and those of LND1 and LND2 were increased by 31.4 and 24.5%, 6.4 and 32.9% compared with LND3, respectively. The ureide content and N accumulation of soybean organs in LND1 and LND2 were higher than those of LND3. The N uptake, NUE and N agronomy efficiency(NAE) of IMS under CN were 308.3 kg ha–1, 28.5%, and 5.7 kg grain kg–1 N, respectively; however, those of LN were significantly increased by 12.4, 72.5, and 51.6% compared with CN, respectively. The total yield in LND1 and LND2 was increased by 12.3 and 8.3% compared with CN, respectively. Those results suggested that LN with distances of 15–30 cm from the topdressing strip to the maize row was optimal in maize-soybean intercropping. Lower N input with an optimized fertilization location for IMS increased N fixation and N use efficiency without decreasing grain yield.  相似文献   

16.
玉米行距配置对套作大豆生物量、根系伤流及养分的影响   总被引:5,自引:2,他引:3  
【目的】通过研究套作种植条件下,玉米不同行距配置对大豆生物量、根系伤流及其养分的影响,为玉米-大豆带状套作合理的群体配置提供理论依据。【方法】试验于2012—2013年采用单因素随机区组设计,以玉米-大豆带状套作种植中大豆为研究对象,固定玉米和大豆带宽200 cm,设置3个玉米窄行处理,分别是A1(20 cm+180 cm;窄行20 cm,宽行180 cm)、A2(40 cm+160 cm)和A3(60 cm+140 cm)。两行大豆种植于玉米宽行中,行距40 cm;净作大豆为对照,行距70 cm,每个处理重复3次。在大豆第三节龄期(V3)、第五节龄期(V5)与盛花期(R2)分析玉米不同行距配置对套作大豆根系生物量、氮磷钾的积累、伤流强度及伤流液组分的影响。【结果】套作大豆地上地下生物量和根系氮磷钾养分积累随着玉米窄行行距的增加而降低,且显著低于净作对照(P0.05)。根系伤流强度在各处理下均随生育时期的推进而增加,同一生育时期伤流强度从A1到A3逐渐降低,但A1和A2处理差异不显著(P0.05)。A1处理下大豆根系伤流强度在V3、V5及R2期比净作处理平均低27.69%、26.11%和23.23%。除V5期大豆根系伤流组分铵态氮含量低于V3和R2期外,硝态氮、全磷、全钾、可溶性糖含量随大豆生育时期推进逐渐增加,且均低于净作对照。通过相关分析,大豆地上地下生物量与根系养分积累量、伤流强度及组分含量间均呈极显著正相关(P0.01)。【结论】在玉米-大豆带状套作种植中,行距配置的差异性导致大豆地上地下生物量和根系伤流强度的变化而影响根系养分的吸收和物质的转运。  相似文献   

17.
不同配置对辽西玉米‖花生间作系统氮素吸收利用的影响   总被引:1,自引:0,他引:1  
【目的】通过研究不同配置条件下玉米‖花生间作系统地上部氮含量和吸收量,结合间作系统花生结瘤固氮和土壤有效氮分布,明确不同配置下玉米‖花生间作体系对氮素的吸收利用特征,为玉米‖花生间作氮高效利用模式的区域筛选提供依据。【方法】本试验于2015—2016年在国家农业环境阜新观测实验站进行,设置玉米单作(M)、花生单作(P)、2行玉米4行花生间作(M2P4)和4行玉米4行花生间作(M4P4)模式,玉米单作及每种间作模式下设3种不同玉米种植密度(6、9和12株/m2),共10个处理,分析不同配置(行比和密度)玉米‖花生间作系统氮素吸收利用特征和优势。【结果】与单作相比,间作玉米和花生植株氮浓度变化并不明显,受作物占地比例影响,间作模式下玉米和花生的产量、氮产量均低于相应单作,且氮产量与间作生物产量表现相一致。玉米‖花生间作可以显著提高系统氮的吸收利用(氮吸收当量比NER>1),且主要归因于玉米的养分吸收优势(pNERm为0.63—0.80)。随着玉米行比和密度的增加NER也随之增大,其中M4P4模式(NER 1.06—1.22)的氮吸收要显著高于M2P4模式(NER 1.0—1.06)。在玉米‖花生间作系统中,玉米比花生更有竞争力(Amp>0),且竞争吸收氮养分能力也更强(CRmp>1),M4P4行比以及玉米增密有助于增强玉米对氮营养的竞争,增加系统氮养分吸收优势(△NU>0)以及间作养分对产量的贡献(C)。与玉米间作可促进花生结瘤固氮,M4P4行比配置下花生根瘤数量、单株根瘤重量和单个瘤重均高于M2P4配置,且以中、低密度处理为优。间作系统中土壤有效氮含量(Nmin)表现为花生条带土壤Nmin高于玉米条带,且单作花生土壤Nmin高于间作花生,而单作玉米土壤Nmin低于间作玉米。【结论】玉米‖花生间作可显著提高系统氮的吸收利用,其中玉米对系统氮吸收的贡献较大,适度增加玉米行比和密度有助于增加系统氮素吸收当量比、增强玉米对氮营养的竞争以及间作养分对产量的贡献。综合分析认为,本研究中M4P4-6和M4P4-8为玉米‖花生间作较佳配置,玉米花生种间互作对间作系统干物质量和花生生物固氮的促进,以及玉米在吸收氮养分上的强竞争能力是玉米‖花生间作具有氮素吸收利用优势的重要原因。  相似文献   

18.
Intercropping is an important agronomic practice. However, assessment of intercropping systems using field experiments is often limited by time and cost. In this study, the suitability of using the DeNitrification DeComposition(DNDC) model to simulate intercropping of maize(Zea mays L.) and soybean(Glycine max L.) and its aftereffect on the succeeding wheat(Triticum aestivum L.) crop was tested in the North China Plain. First, the model was calibrated and corroborated to simulate crop yield and nitrogen(N) uptake based on a field experiment with a typical double cropping system. With a wheat crop in winter, the experiment included five treatments in summer: maize monoculture, soybean monoculture, intercropping of maize and soybean with no N topdressing to maize(N0), intercropping of maize and soybean with 75 kg N ha~(–1) topdressing to maize(N75), and intercropping of maize and soybean with 180 kg N ha~(–1) topdressing to maize(N180). All treatments had 45 kg N ha~(–1) as basal fertilizer. After calibration and corroboration, DNDC was used to simulate long-term(1955 to 2012) treatment effects on yield. Results showed that DNDC could stringently capture the yield and N uptake of the intercropping system under all N management scenarios, though it tended to underestimate wheat yield and N uptake under N0 and N75. Long-term simulation results showed that N75 led to the highest maize and soybean yields per unit planting area among all treatments, increasing maize yield by 59% and soybean yield by 24%, resulting in a land utilization rate 42% higher than monoculture. The results suggest a high potential to promote soybean production by intercropping soybean with maize in the North China Plain, which will help to meet the large national demand for soybean.  相似文献   

19.
本文在三种施氮水平上对玉米大豆间作条件下大豆的根瘤形成及固氮等问题进行了研究。结果表明:与单作未施肥大豆相比,三种不同施肥水平上间作大豆的根瘤形成及固氮能力均有所降低,氮肥水平越高,下降越严重;间作条件下,大豆固氮活性的降低大于根瘤数和根瘤重,同样肥力水平下,玉米间作大豆的后茬作物产量显著低于单作大豆的后茬作物产量,而与单作玉米的后茬产量差异不大。与休闲地相比,无论大豆单作还是间作,其后茬产量都显著降低。因此种植大豆不是培肥地力而是消耗土壤肥力。间作大豆对玉米无促进作用,反而使玉米产量下降,对玉米植株含氮量影响不大。间作后作物总产量降低,但蛋白质产量和经济收益明显增加。  相似文献   

20.
不同铜浓度下玉米间作豌豆对土壤铜的吸收效应研究   总被引:1,自引:1,他引:0  
为探讨玉米间作模式对铜污染土壤的修复效果,通过盆栽实验研究了玉米||豌豆和玉米单作种植模式对不同铜浓度(0、100、200、400、600 mg·kg-1)处理下玉米地上部与地下部的铜含量与铜累积量、铜富集与转运系数、土壤全铜和有效铜含量的影响。结果表明:在间作和单作模式中玉米地上部铜含量最高的处理均为铜浓度200 mg·kg-1,而玉米地上部铜含量最低的处理在单作模式下是铜浓度600 mg·kg-1,间作模式下是100 mg·kg-1。相同铜浓度下,间作模式的玉米地上部铜含量均显著低于单作模式,其中降幅最大的为铜浓度100 mg·kg-1,降幅为49.4%;而间作模式的玉米地下部铜含量均显著高于单作模式,其中增幅最大的为铜浓度100 mg·kg-1,增幅为105.4%。间作模式的玉米地上部富集系数均显著低于单作,而地下部富集系数均显著高于单作。从种植系统整体来看,除铜浓度400 mg·kg-1处理外,其余各处理中间作玉米铜累积量均低于单作玉米,但差异不显著。除铜浓度0 mg·kg-1和400 mg·kg-1处理外,其余各铜浓度处理下,间作玉米富集系数均低于单作玉米,且所有间作模式的玉米转运系数均显著低于单作玉米。相同铜浓度下,不同玉米种植模式对土壤全铜和有效铜没有产生显著影响。总的来说,玉米间作豌豆能增加玉米地下部铜含量,降低玉米地上部铜含量,在提高间作系统总的铜累积量的同时,降低了铜元素从玉米地下部向地上部的转运。  相似文献   

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