首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2012-2013年度, 在温县和郑州大田条件下, 研究不同水氮处理对冬小麦品种豫麦49-198籽粒总酚、类黄酮、类胡萝卜素含量及抗氧化活性的影响。结果表明, 在施纯氮0~300 kg hm–2范围内, 所有观测指标均随施氮量的增加而增加, 以施氮300 kg hm–2处理最高。随灌水次数(0~2次)的增加, 总酚、类黄酮含量和抗氧化活性呈先增加后降低趋势, 以灌拔节水处理最高;类胡萝卜素含量在不同试点间表现不一致。水氮耦合, 以灌拔节水+施氮240~300 kg hm–2处理的抗氧化物含量及抗氧化活性较高, 而总酚、类黄酮及类胡萝卜素的积累量则以灌拔节和开花水+施氮240~300 kg hm–2处理较高。相关分析表明, 籽粒总酚、类黄酮含量与抗氧化活性均呈显著正相关, 表明总酚、类黄酮含量增加可以提高小麦籽粒抗氧化活性;不同深度土层土壤水分含量及硝态氮含量与籽粒抗氧化物质含量的相关性存在差异, 总体而言, 氮含量有助于总酚及类胡萝卜素含量的积累, 而水分含量可能有助于类黄酮含量的提高。  相似文献   

2.
    
Sustainable soil and crop management practices that reduce soil erosion and nitrogen (N) leaching, conserve soil organic matter, and optimize cotton and sorghum yields still remain a challenge. We examined the influence of three tillage practices (no-till, strip till and chisel till), four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secaele cereale L.)], vetch/rye biculture and winter weeds or no cover crop}, and three N fertilization rates (0, 60–65 and 120–130 kg N ha−1) on soil inorganic N content at the 0–30 cm depth and yields and N uptake of cotton (Gossypium hirsutum L.) and sorghum [Sorghum bicolor (L.) Moench]. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic, Plinthic Paleudults) from 1999 to 2002 in Georgia, USA. Nitrogen supplied by cover crops was greater with vetch and vetch/rye biculture than with rye and weeds. Soil inorganic N at the 0–10 and 10–30 cm depths increased with increasing N rate and were greater with vetch than with rye and weeds in April 2000 and 2002. Inorganic N at 0–10 cm was also greater with vetch than with rye in no-till, greater with vetch/rye than with rye and weeds in strip till, and greater with vetch than with rye and weeds in chisel till. In 2000, cotton lint yield and N uptake were greater in no-till with rye or 60 kg N ha−1 than in other treatments, but biomass (stems + leaves) yield and N uptake were greater with vetch and vetch/rye than with rye or weeds, and greater with 60 and 120 than with 0 kg N ha−1. In 2001, sorghum grain yield, biomass yield, and N uptake were greater in strip till and chisel till than in no-till, and greater in vetch and vetch/rye with or without N than in rye and weeds with 0 or 65 kg N ha−1. In 2002, cotton lint yield and N uptake were greater in chisel till, rye and weeds with 0 or 60 kg N ha−1 than in other treatments, but biomass N uptake was greater in vetch/rye with 60 kg N ha−1 than in rye and weeds with 0 or 60 kg N ha−1. Increased N supplied by hairy vetch or 120–130 kg N ha−1 increased soil N availability, sorghum grain yield, cotton and sorghum biomass yields, and N uptake but decreased cotton lint yield and lint N uptake compared with rye, weeds or 0 kg N ha−1. Cotton and sorghum yields and N uptake can be optimized and potentials for soil erosion and N leaching can be reduced by using conservation tillage, such as no-till or strip till, with vetch/rye biculture cover crop and 60–65 kg N ha−1. The results can be applied in regions where cover crops can be grown in the winter to reduce soil erosion and N leaching and where tillage intensity and N fertilization rates can be minimized to reduce the costs of energy requirement for tillage and N fertilization while optimizing crop production.  相似文献   

3.
长期施肥对夏玉米叶片氮代谢关键酶活性的影响   总被引:17,自引:0,他引:17       下载免费PDF全文
以“国家褐潮土土壤肥力与肥料效益长期监测基地”的大田肥料长期试验为平台,研究了长期施肥对夏玉米叶片中硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸合成酶(GOGAT)和谷氨酸脱氢酶(GDH)活性的影响。结果表明,长期N、P、K化肥配合(NPK处理)以及N、P、K化肥与有机肥或秸秆配合施用(NPKM与NPKS处理),叶片氮代谢酶(NR、GS、GOGAT和GDH)在籽粒灌浆时期均具有较高的活性,有利于玉米籽粒产量的形成;长期N、P、K化肥非平衡施肥的处理(NP、N、NK、PK处理)以及不施肥的CK,叶片氮代谢酶活性变化差异较大,且活性高峰期和籽粒灌浆关键期时间不一致,植株整体生产能力较弱,玉米籽粒产量较低。不同的酶对籽粒产量的贡献不同,因而系统研究长期定位配比施肥处理下玉米叶片的氮代谢酶活性具有重要的意义。  相似文献   

4.
为探讨低氮胁迫对玉米自交系幼苗生物量和根系形态的影响,以35份玉米自交系为材料,测定了两个氮素水平处理后14d玉米幼苗的单株干重、地上部干重、根干重、根冠比、总根长、根表面积、根体积、根平均直径、侧根数和初生根长。结果表明,低氮胁迫下玉米幼苗根干重、根冠比、根总表面积、根体积、侧根数、根平均直径和初生根长显著增加,地上部干重和单株干重显著减小,而总根长没有明显变化。通过主成分分析和聚类分析发现,同一氮素水平下,玉米幼苗各性状的综合表现存在基因型差异,且在正常氮素和低氮条件下均可以分为6组。低氮处理后,选取的9个自交系地上部氮素积累量均显著降低,PH4CV、B73和XY4的根系氮素积累量显著增加,其余6个自交系显著降低。此外,只有XY4的氮素吸收和利用效率均较高。综合分析表明,XY4是低氮高效型玉米自交系。  相似文献   

5.
黑河中游边缘绿洲沙地农田玉米水氮用量配合试验   总被引:6,自引:0,他引:6  
苏永中  张智慧  杨荣 《作物学报》2007,33(12):2007-2015
研究了黑河中游边缘绿洲沙地农田不同灌溉水平(常规灌溉,12 000 m3 hm-2;节水10%,10 800 m3 hm-2;节水20%,9 600 m3 hm-2)和施氮水平(0、150、225、300和375 kg N hm-2)下玉米产量、氮肥利用率、灌溉水生产力及硝态氮在土壤剖面中的分布。结果表明,常规高量灌溉(12 000 m3 hm-2)和节水10%和20%处理的玉米产量和地上生物量无显著差异;在施有机肥和磷、钾肥的基础上,施氮量150~375 kg N hm-2较不施氮处理增产74.8%~108.6%,施氮量超过225 kg N hm-2时,产量不再显著增加;平均氮肥利用率(NUE)为50.6%~83.7%,随施氮量的增加而下降,超过225 kg N hm-2时显著降低。在施用氮肥时,玉米灌溉水生产力(WP)为0.97~1.35 kg m-3,随灌溉量的增加而下降,施氮量超过225 kg N hm-2时,灌溉水生产力不再显著增加。水肥配合有显著的交互效应,高量的水氮配合可获得较高的产量,但水肥利用效率显著下降。对每次灌溉前土壤剖面水分含量的测定结果表明,3个灌溉水平下0~160 cm土层土壤水分含量无显著差异,表明常规高量灌溉并不能保持较长时间的有效水分供作物吸收利用;高量灌溉下,0~200 cm土壤剖面中NO3-N的积累量低于节水灌溉处理,表明高量灌溉使更多的NO3-N淋溶至更深的土层,对地下水污染风险加大。从水肥高效利用、降低氮污染风险和缓解水资源短缺综合考虑,进行合理的水肥调控、适度降低灌溉量和氮肥投入是沙地农田生态系统管理的合理选择。通过合理的水肥调控,沙地农田仍有很大的节水潜力。  相似文献   

6.
旨在探讨不同施肥条件对苜蓿干草产量、植株全氮含量、植株氮素累积动态以及肥料氮素利用率等指标的影响。采用田间小区试验方法,共设5个处理:不施肥对照处理( CK )、单施化肥处理( CF )、化肥与牛粪混施处理(DM1)、化肥与沼液混施处理(DT)和减量化肥与牛粪混施处理(DM2)。结果表明,施用氮肥不仅可以增加苜蓿干物质量和氮素累积量,而且由于大幅增加苜蓿刈割前期的干物质和氮素累积速率而可能缩短其刈割周期、增加年刈割次数;多次刈割的综合结果证实在施用化学氮肥的基础上再增施有机肥仍存在增产的空间,但有机肥由于其活性氮素含量低而不能完全替代化学氮肥。在有机、无机配施情况下,化学氮肥的表观利用率为46.7%~48.1%,腐熟牛粪的氮素利用率为~9.1%,而沼液的氮素利用率为~13.8%,因此,苜蓿生产中有机肥的氮素利用率明显低于化学氮肥。  相似文献   

7.
为了探索柳枝稷在边际土地规模化种植过程中肥料效应方面的基础数据,在日光温室内开展了沙土盆栽柳枝稷苗期氮磷钾肥料效应试验研究。结果表明,氮磷钾肥对沙土盆栽柳枝稷苗期的叶面积、株高、地上生物量、地下生物量、总生物量均具有明显的促进作用,而且,氮磷钾的单因素肥料效应均达到显著水平(P<0.05);柳枝稷苗期总生物量与氮磷钾之间存在着显著的三元二次回归关系,日光温室沙土盆栽条件下,获得柳枝稷苗期最高生物量所需要的适宜氮磷钾浓度分别为:氮(N)94.01mg/kg,磷(P2O5)40.18mg/kg,钾(K2O)117.96mg/kg。  相似文献   

8.
    
High rates of nitrogen (N) fertilizer may increase N leaching with drainage, especially when there is no further crop response. It is often discussed whether leaching is affected only at levels that no longer give an economic return, or whether reducing fertilization below the economic optimum could reduce leaching further. To study nitrate leaching with different fertilizer N rates (0–135 kg N ha−1) and grain yield responses, field experiments in spring oats were conducted in 2007, 2008 and 2009 on loamy sand in south-west Sweden. Nitrate leaching was determined from nitrate concentrations in soil water sampled with ceramic suction cups and measured discharge at a nearby measuring station. The results showed that nitrate leaching per kg grain produced had its minimum around the economic optimum, here defined as the fertilization level where each extra kg of fertilizer N resulted in a 10 kg increase in grain yield (85% DM). There were no statistically significant differences in leaching between treatments fertilized below this level. However, N leaching was significantly elevated in some of the treatments with higher fertilization rates and the increase in nitrate leaching from increased N fertilization could be described with an exponential function. According to this function, the increase was <0.04 kg kg−1 fertilizer N at and below the economic optimum. Above this fertilization level, the nitrate leaching response gradually increased as the yield response ceased and the increase amounted to 0.1 and 0.5 kg kg−1 when the economic optimum was exceeded by 35 and 100 kg N ha−1, respectively. The economic optimum fertilization level depends on the price relationship between grain and fertilizer, which in Sweden can vary between 5:1 and 15:1. In other words, precision fertilization that provides no more or no less than a 10 kg increase in grain yield per kg extra N fertilizer can be optimal for both crop profitability and the environment. To predict this level already at fertilization is a great challenge, and it could be argued that rates should be kept down further to ensure that they are not exceeded due to overestimation of the optimum rate. However, the development of precision agriculture with new tools for prediction may reduce this risk.  相似文献   

9.
氮肥和密度对高粱产量及氮肥利用率的影响   总被引:4,自引:1,他引:4       下载免费PDF全文
为了研究氮肥施用量和密度对高粱产量的影响,在大田试验条件下,采用裂区设计,以密度为主区,以氮肥施用量为副区,分别设置3个密度水平(7.5万、10.5万和13.5万株/hm 2)和5个氮肥水平(0、75、150、225和300kg/hm 2),对不同密度和氮肥处理的产量构成因素和农艺性状进行分析,结果表明:高粱的产量先随密度的增加和氮肥施用量的增加呈增加趋势,在密度为10.5万株/hm 2,施氮量为225kg/hm 2时,高粱的产量达到最高。在不同密度和氮肥处理,高粱的单位面积穗数和穗粒数变异较大,千粒重变异较小。密度主要是通过单位面积穗数,氮肥主要是通过穗粒数来影响产量的构成。施氮量与高粱产量是非线性关系,氮肥在高密度条件下对产量的调控更加明显。氮肥的农学利用率在高密度处理比低密度处理要高,并随着氮肥施用量的增加呈先增加后减少的变化趋势,在密度为13.5万株/hm 2,施氮量为150kg/hm 2时,氮肥的农学利用率达到最大。本研究表明,增加密度、控制氮肥用量是增加高粱产量和提高氮肥利用率的有效措施,建议晋杂23号在汾阳种植时宜采用密度为10.5万株/hm 2,施氮量为225kg/hm 2的种植模式。  相似文献   

10.
    
This work was aimed at providing a sustainable approach in the use of manure in irrigated maize crop under Mediterranean climatic conditions. To this end, the effect of continuous annual applications of dairy cattle manure, combined or not with mineral N fertilizer, on the following parameters was studied: grain yield, grain and plant N concentration, N uptake by plant, N use efficiency, and soil N and organic carbon. The experiment was conducted in a furrow-irrigated sandy soil under dry Mediterranean conditions during seven years. Three different rates of cattle manure (CM): 0, 30 and 60 Mg ha−1, were applied each year before sowing. These CM rates were combined with four mineral N rates (0, 100, 200 and 300 kg N ha−1) applied at sidedress.On average, the highest grain yields during the 7 years were obtained with the combination of CM at 30 Mg ha−1 and mineral fertilizer and with CM at 60 Mg ha−1 without mineral fertilizer. With CM at 30 Mg ha−1, mineral fertilizer increased yields during most of the growing seasons, meanwhile with CM at 60 Mg ha−1, there was not any significant effect of the joint application of mineral fertilizer on yields. Overall, best results were obtained exceeding maximum rates according to present legislation. The mean apparent nitrogen recovery (ANR) fraction during the 7 seasons was 29% for N exclusively applied as CM. Overall, increased N rates applied as CM resulted in decreased ANRs. However, ANR with CM at 30 and 60 Mg ha−1 increased during the first two seasons. This increased ANR ascribed to mineralization of residual organic N applied in previous seasons explained the increasing yields observed in the treatments along the study.The application of CM during 7 years increased the soil organic carbon in the first 30 cm by 5.7 and 9.9 Mg ha−1 with CM at 30 and 60 Mg ha−1, respectively, when compared to the initial stock. Thus, manure-based fertilization could be an alternative to mineral fertilizer in order to achieve high maize yields while improving soil quality under dry Mediterranean conditions.  相似文献   

11.
采用盆栽试验,研究了不同生物炭用量(0,1%,5%,10%(w/w)和不同氮肥水平(0,400,800 kg/hm2)及其交互效应对高粱( Sorghum bicolor( L.) Moench)苗期生长及有关生理特性的影响。结果表明,EC值低的土壤植株生长状况整体要优于EC值高的土壤;1%生物炭对作物生长略优于0处理,而5%和10%生物炭对高粱苗期生长具有抑制作用;不施氮肥与施400 kg/hm2氮肥间无显著差异,800 kg/hm2氮肥水平对植株生长产生抑制效应;生物炭用量、施氮量及其交互效应对2种土壤植株干质量均有显著影响;叶绿素的表现与其生长状况表现基本一致;还原糖含量受生物炭和氮肥影响表现不一;硝酸盐含量与氮肥水平呈显著正相关,与生物炭用量呈负相关。研究表明,低量生物炭(1%)有利于高粱种子发芽和幼苗生长,高量生物炭(5%和10%)和高氮水平(800 kg/hm2)在一定程度上抑制了高粱幼苗的生长;植株硝酸盐含量随生物炭施用量增加而相应减少,随氮肥水平提高而相应增加。  相似文献   

12.
  总被引:1,自引:0,他引:1  
Water availability is the key factor determining maize yields in NE Spain. Irrigation is needed to obtain economic yields but it is costly and water supply is sometimes insufficient. The aim of this research was to test a simple simulation model for evaluating different irrigation strategies, especially under water-limited conditions. The LINTUL model was adapted and parameterized using experimental data from the 1995 season. Most parameters were obtained from experiments, although some were taken from the literature. This model is based on the concept of light use efficiency, incorporates a soil water balance and simulates phenology, crop leaf area, biomass accumulation and yield. It was tested on independent data from the 1995 and 1996 seasons under different irrigation treatments. The model predicted the flowering date within ±5 days of the observed values. Leaf area index was predicted satisfactorily, except under extreme water-stress conditions, where it was overestimated. In general, soil moisture content and yield were accurately predicted. In the 1996 experiment measured yields ranged from 6.4 to 13.6 t ha−1 and simulated yields from 6.5 to 12.2 t ha−1. These results show that the LINTUL model can be used as a tool for exploring the consequences on maize yields of different irrigation strategies in NE Spain. Analysis of the model identified a process that strongly affects yield loss due to drought, but for which present understanding is still insufficient: the effects of drought on leaf senescence and canopy architecture.  相似文献   

13.
氮肥基因型差异对玉米吸氮量的反应   总被引:7,自引:0,他引:7       下载免费PDF全文
田间试验研究了11个玉米杂交种在不同施氮条件下的吸氮量。结果表明,玉米吸氮量具有明显的基因型差异。在低氮(N2)处理中,子粒、秸秆、地上部吸氮量高低品种相差分别为1.060、0.134、1.125g/kg,在高氮(N4)处理中,分别为0.836、0.154、0.954g/kg。不同基因型玉米的吸氮量差异低氮条件比高氮条件更大。施氮量对玉米吸氮量有显著的影响。玉米子粒、秸秆、地上部吸氮量和相应的产量呈极显著的正相关  相似文献   

14.
施氮对不同基因型玉米籽粒发育和氮效率的影响   总被引:2,自引:0,他引:2  
为解决生产中氮肥过度施用造成的资源浪费和环境污染问题,选择适宜的玉米氮高效品种至关重要。在不同施氮水平下,对不同基因型玉米籽粒发育及氮效率的差异进行了比较,采用田间试验,对屯玉99(TY)、潞玉19(LY)、先玉335(XY)3个玉米品种在4个施氮水平N0、N1、N2、N3(0,80,160,240 kg/hm2)条件下的籽粒发育和氮效率进行对比分析。结果表明,各品种玉米的籽粒干质量与氮含量差异在N3水平下最大,依次表现为N3N2N0N1;随着施氮量的增加,双高效型先玉335和高氮高效型屯玉99籽粒发育速率加快,籽粒干质量和籽粒氮含量在各生长时期都有明显增加,增施氮肥可以有效提高其氮肥利用率,促进氮在玉米植物体内的转移;低氮高效型潞玉19在低氮(N0、N1)水平下保持较高的产量,但随施氮量的增加,其籽粒干质量和氮含量无明显变化,产量甚至有所降低,导致氮利用效率降低。双高效型先玉335在低氮和高氮条件下都有较好的产量,是适合广泛种植的玉米品种;低氮高效型潞玉19适合在贫瘠土壤和施氮条件不良的条件下种植。  相似文献   

15.
周培禄  任红  齐华  赵明  李从锋 《作物学报》2017,43(2):263-276
旨在探明东北春玉米不同类型杂交种物质生产及氮素利用特征及其与产量的关系。本文以不同类型杂交种代表性品种郑单958(ZD958,Reid×唐四平头模式)和先玉335(XY335,Reid×Lancaster模式)为试验材料,2014年和2015年设置5个氮肥水平[0 kg hm–2(N0)、100 kg hm–2(N1)、200 kg hm–2(N2)、300 kg hm–2(N3)和400 kg hm–2(N4)]和2个种植密度(67 500株hm–2和90 000株hm–2)试验,比较研究了不同类型玉米杂交种干物质与氮素积累、运转及氮素利用的差异规律。结果表明,两年XY335品种的最高籽粒产量均高于ZD958,最优氮肥施用量明显降低4.8%~10.6%;相比ZD958,不施氮处理,两种种植密度下XY335品种干物质积累能力及物质运转效率都明显降低,而施氮条件下XY335品种的干物质积累量、花后干物质量及干物质运转效率均增加,同时增幅随着施氮量增加逐步提高,且在高密度条件下优势更为明显。开花期XY335叶片与茎鞘氮素含量显著高于ZD958(P0.05),而成熟期由于其较高物质的运转效率表现出明显较低的数值,籽粒氮素含量在高密度下差异较小,而低密度条件下相对ZD958显著提高(P0.05)。施氮条件下XY335品种花前、花后氮素积累量和氮素积累总量均高于ZD958,其中叶片中氮素的转运对籽粒的贡献率显著较高(P0.05)。两种种植密度处理最优施氮条件下XY335氮素利用效率和氮素吸收效率均显著高于ZD958(P0.05),而氮农学利用率和氮肥偏生产力差异不显著。可见,高密度条件下XY335类型品种表现出明显较高的物质积累能力以及花后物质运转对籽粒的贡献率,获得较高的氮素利用效率,表现出明显高氮高效的品种特征,因此生产上建议,东北春玉米区高密度种植条件下该类型品种在较高氮肥施用量时易获得高产高效。  相似文献   

16.
基于作物生长模型的夏玉米灌溉需求分析   总被引:13,自引:1,他引:13  
用校正后的作物模拟模型(PS123模型)和河北曲周县1966~1999年的逐日气象资料为依据,分析了当地夏玉米的需水量和优化灌溉方案.结果表明,该地区玉米生长季灌溉需水量的年际变异高达80%以上.用模拟的蒸散量计算的1999玉米水分利用效率一般在17~25kg*hm-2*mm-1之间,雨养条件下的水分利用效率较高,可达29kg*hm-2*mm-1.在引入灌  相似文献   

17.
研究西南地区玉米主要2种套作模式下氮素吸收利用差异及氮肥调控效应, 为氮素高效利用提供科学依据。在四川2个玉米主产区, 通过连续4年的大田试验, 对比研究了玉/豆和玉/薯模式下玉米氮素吸收利用差异和不同供氮水平对玉米氮素吸收的调控效应。结果表明, 玉/豆模式下玉米收获期植株中的氮素积累2个试验点平均较玉/薯模式增加7.11%, 氮收获指数增加2.00%左右, 氮素吸收效率增加7.83%, 成熟期籽粒中氮素的分配比例增加1.76%, 而叶、茎鞘中氮素的分配比例分别减少5.85%和2.75%。分带轮作后, 由于不同前茬对土壤养分影响不同, 再加上套作优势, 玉/豆模式下玉米在生长前期就表现出明显的优势, 到收获期植株氮素积累2个试验点平均较玉/薯增加11.85%, 氮素吸收效率增加11.84%。在玉米氮素积累关键时期, 玉/豆模式在低氮处理下玉米植株氮素的积累量显著高于玉/薯模式相同施氮处理, 而在高氮处理下2种模式间差异不大或者表现相反, 氮肥偏生产力、氮素农艺效率和氮肥利用率也有相似的结果; 玉/豆模式在180 kg hm-2施氮量下较其他处理显著提高了玉米氮素农学利用率、氮素吸收利用率和籽粒中氮素的分配量, 玉/薯模式下玉米氮素农学利用率和氮肥利用效率, 在180~270 kg hm-2施氮量处理下较高; 花后氮素同化量玉/豆模式显著高于玉/薯; 2种模式均以施纯氮180~270 kg hm-2处理有利于氮素转运和花后氮素同化量积累。  相似文献   

18.
    
The efficient use by crops of nitrogen from manures is an agronomic and environmental issue, mainly in double-annual forage cropping systems linked to livestock production. A six-year trial was conducted for a biennial rotation of four forage crops: oat-sorghum (first year) and ryegrass-maize (second year) in a humid Mediterranean area. Ten fertilization treatments were introduced: a control (without N); two minerals equivalent to 250 kg N ha−1 year−1 applied at sowing or as sidedressing; dairy cattle manure at a rate of 170, 250 and 500 kg N ha−1 year−1 and four treatments where the two lowest manure rates were supplemented with 80 or 160 kg mineral N ha−1 year−1. They were distributed according to a randomized block design with three blocks. The highest N mineral soil content was found in the summer of the third rotation, in plots where no manure was applied. The yearly incorporation of manure reduced, in successive cropping seasons, the amount of additional mineral N needed as sidedressing to achieve the highest yields. Besides, in the last two years, there was no need for mineral N application for the manure rate of 250 kg N ha−1 year−1. This amount always covered the oat-sorghum N uptake. In the ryegrass-maize sequence uptakes were as high as 336 kg N ha−1 year−1. In the medium term, the intermediate manure rate (250 kg N ha−1 year−1) optimizes nutrient recycling within the farming system, and it should be considered in the analysis of thresholds for N of organic origin to be applied to systems with high N demand.  相似文献   

19.
应用化学调控技术改善玉米的氮素代谢过程,从而实现“减氮增效”,是保障玉米绿色可持续生产的重要途径。试验以玉米单交种豫单9953为材料,设置乙矮合剂(ECK)和不同氮肥水平处理(0、96、132、168、204和240kg/hm2),喷施清水为对照处理(CK),于2019和2020年分别在河北燕郊和北京顺义进行大田试验,研究ECK对不同施氮量下夏玉米氮素代谢及产量的调控效应。结果表明,ECK处理提高了不同施氮量下夏玉米开花期叶片硝酸还原酶活性和可溶性蛋白含量,提高了施氮量204和240kg/hm2处理下叶片谷丙转氨酶和谷草转氨酶的活性以及灌浆中后期的谷氨酰胺合成酶活性。ECK处理显著提高了施氮量204kg/hm2下玉米植株氮素、籽粒氮素和总氮素积累量,较CK处理分别增加8.9%、8.3%和8.6%。ECK处理下施氮量为204kg/hm2时,夏玉米产量较CK处理显著增加7.5%。ECK处理可有效改善玉米的氮素代谢,促进氮素的吸收、同化和积累,提高产量,从而实现“减氮增效”。  相似文献   

20.
设置盆栽试验,以高粱品种辽糯10为试验材料,以常规施氮量(300 kg/hm2)为对照,N1~N3处理氮肥施用量呈10%梯度递减,分别为270、240和210 kg/hm2,N4~N6处理在N1~N3基础上增施3%的3,4-二甲基吡唑磷酸盐(DMPP),磷、钾肥施用量均为75 kg/hm2。结果表明,随着氮肥施用量减少,相对叶绿素含量(SPAD值)、干物质积累量、氮素积累总量、干物质生产效率、氮素干物质生产效率、氮素农艺效率和氮肥利用率等逐渐降低,增施DMPP后高粱生长发育恢复至常规施肥水平。与对照相比,N5处理(减氮20%配施3% DMPP)氮素积累总量增加4.67%;穗粒重和千粒重分别增加3.72%和5.58%;干物质生产效率增加8.77%;氮素干物质生产率增加1.14%,氮素农艺效率增加5.75%;氮肥利用率和氮肥农学利用率分别增加15.47%和45.12%。综上,氮肥施用量减少20%时,增施正常施氮量3%的DMPP可以提高高粱干物质生产效率及氮素利用率,具有一定的增产潜力。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号