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1.
针对西北绿洲灌区长期传统覆膜耕作造成土壤结构的稳定性下降、地膜残留过多和土壤质量下降等问题,研究覆膜免耕与禾豆间作种植模式对土壤物理性质和作物产量的影响,以期为试区优化耕作方式和作物种植模式提供理论支撑。田间试验于2013—2020年在河西绿洲灌区进行,设置传统耕作覆膜(CT)、覆膜免耕(NT) 2种耕作措施;单作豌豆(P)、单作玉米(M)、玉米间作豌豆(M//P) 3种种植模式,2019年和2020年玉米收获后测定土壤物理性状和作物产量等相关指标。结果表明：（1）0～30 cm土层≥0.25 mm水稳性团聚体含量、平均重量直径(MWD)、土壤容重和土壤总孔隙度在NT与CT处理间存显著差异,NT较CT≥0.25 mm水稳性团聚体含量提高2.02%～7.76%、MWD提高19.4%～26.0%、土壤容重降低1.31%～1.57%、总孔隙度增加1.97%～2.28%;(2)NT处理下,不同种植模式间存在显著差异,M//P分别较P和M处理水稳性大团聚体含量增加12.60%～20.11%和7.05%～11.55%,MWD分别较P和M处理增加9.61%～12.44%和4.01%～8.01%,土壤...  相似文献   

2.
以耐盐碱性不同的燕麦品种内燕5号和白燕2号为材料,研究施菌肥和不施菌肥(对照)两种措施对盐碱地土壤理化、生物学指标和燕麦根系分泌物的影响。结果表明,施菌肥可以提高燕麦根际与非根际土壤中可溶性糖和草酸含量,根际土壤中可溶性糖、草酸、苹果酸含量均高于非根际土壤;各处理有机酸含量与根区(水平0~5cm、垂直0~10cm)土壤微生物生物量氮含量、蔗糖酶活性均呈极显著正相关;施菌肥可降低两个燕麦品种根区土壤pH和电导率,也可有效提高土壤含水量、微生物生物量及土壤酶活性;各处理间燕麦根区土壤pH和电导率呈极显著正相关,土壤含水量与土壤微生物生物量氮含量及土壤酶活性间均表现出显著或极显著正相关关系。  相似文献   

3.
不同耕作方式对砂姜黑土理化性质和小麦产量的影响   总被引：3，自引：1，他引：2  
为探讨砂姜黑土农田适宜的耕作方式,提升砂姜黑土农田地力及作物产量,发挥地域资源优势,以‘百农207’为试验材料,通过田间试验,研究了免耕、旋耕(15 cm)和深耕(30 cm)3种耕作方式对砂姜黑土农田土壤容重、土壤含水量、硝态氮含量及小麦籽粒产量的影响。结果表明:在小麦越冬期和成熟期,3种耕作方式0~10 cm土层土壤容重差异不显著(P0.05),但深耕处理显著降低了10~40 cm土层土壤容重(P0.05)。在小麦苗期,3种耕作方式对0~40 cm土层土壤含水量影响规律不明显(P0.05),但在小麦越冬期、拔节期、成熟期,深耕处理显著增加了0~40 cm土层土壤含水量(P0.05)。在小麦成熟期,0~40 cm土层土壤硝态氮含量均为免耕旋耕深耕。与免耕处理相比,深耕处理通过增加小麦穗粒数和千粒重,使籽粒产量增加9.79%。综合研究区的土壤性质、作物生长、自然环境等因素,小麦季30 cm深耕可以降低土壤容重,增加土壤含水量,提高小麦籽粒产量,可作为砂姜黑土农田适宜的耕作方式。  相似文献   

4.
为建立以小麦和油菜轮作模式为基础的休耕制度提供理论依据,以休耕后的农田土壤及后茬作物油菜和小麦为研究对象,研究农田土壤生物学特性的变化规律以及作物产量对休耕的响应。2 a试验结果表明,各项指标受气候因素影响较小,均表现为休耕后的小麦和油菜田土壤生物学性状优于小麦-油菜常规轮作模式。休耕后茬小麦田和油菜田的土壤过氧化氢酶、蔗糖酶、脲酶和磷酸酶的活性都高于小麦-油菜常规轮作模式,其中过氧化氢酶和蔗糖酶活性的差异达到显著性差异(P0.05);休耕后茬土壤微生物量碳、氮和B/F值均高于小麦-油菜常规轮作模式,土壤细菌丰富度和多样性的差异在2 a间略有不同,但总体表现为大于小麦-油菜常规轮作模式,真菌表现相反;休耕后茬作物生物产量和经济产量显著高于小麦-油菜常规轮作模式(P0.05)。相关性分析表明,作物生物产量和经济产量与酶活性、微生物量和细菌丰富度呈正相关,而与真菌的丰富度呈负相关。休耕能提高后茬作物农田土壤的酶活性、微生物生物量、细菌的丰富度和多样性,降低真菌的丰富度和多样性,提升耕地质量,增加作物产量。  相似文献   

5.
秸秆生物炭对潮土区小麦产量及土壤理化性质的影响   总被引：3，自引：0，他引：3  
为了探讨生物炭施用对华北潮土农田土壤改良及小麦增产的效果,自2011年开始,在华北小麦-玉米轮作典型潮土农田通过设置0(BC0),2.25(BC2.25),6.75(BC6.75),11.25 t/hm2(BC11.25)4个秸秆生物炭处理的田间定位试验,系统研究了施用生物炭对小麦籽粒产量、土壤含水量及土壤理化性状的影响。结果表明,短期施用生物炭对小麦籽粒产量、生物量、土壤硝态氮、有机碳和全氮含量均无显著性影响,连续施用生物炭9季后,与BCO相比,BC2.25、BC6.75、BC11.25处理小麦籽粒产量分别显著增加24.5%,8.8%,9.1%(P0.05),小麦生物量分别显著增加18.8%,8.1%和6.1%。而且,随生物炭用量增加,土壤含水量和总孔隙度逐渐增加,容重逐渐降低,与对照相比,BC6.75和BC11.25处理土壤总孔隙度分别显著增加14.1%和26.0%(P0.05),含水量增加34.4%和42.2%,容重降低10.7%和19.6%。此外,生物炭长期施用BC6.75和BC11.25处理土壤硝态氮、有机碳和全氮含量均显著高于其他处理,与对照相比,第9季BC6.75处理土壤耕层硝态氮含量显著增加128.7%,BC6.75和BC11.25处理有机碳含量分别显著增加127.9%和179.6%(P0.05),全氮含量增加25.4%和30.5%,但BC6.75和BC11.25处理籽粒产量在第9季显著低于BC2.25处理。综上所述,生物炭长期连续施用能够起到降低土壤容重,增加土壤含水量和孔隙度,提高耕层硝态氮、有机碳和全氮含量,以及提高小麦籽粒产量和生物量的作用。从秸秆资源良性循环发展角度来看,研究地区适宜秸秆生物炭用量为2.25 t/hm2。  相似文献   

6.
海河低平原存在着严重的水资源危机,对该区大面积推广的杨树││(小麦-玉米)复合种植模式进行土壤水分消耗规律的研究十分必要.定位实验研究表明:杨树││(小麦-玉米)复合种植模式耗水量高于常规冬小麦-夏玉米的种植模式7.9%(2年林龄)～24.5%(5年林龄);0～4 m土壤贮水总量每年平均下降51.1 mm,相当于总贮水量的4.1%;耕层杨树根系与小麦的土壤水分竞争加剧;深层土壤水分消耗加快,2～4 m土壤层次因无水分回补出现干燥化趋势;土壤水亏缺及光照等其它原因造成复合系统农作物减产趋于严重,其中林龄3年的杨农复合系统的小麦玉米产量减产平均达到35%.对经济、生态效益的综合分析表明该模式在低平原贫水区的持续性发展不容乐观.  相似文献   

7.
为了揭示设施土壤中Cd与PAEs复合污染效应,通过盆栽试验验证了设施土壤中微生物生物量碳含量和脱氢酶活性对Cd-PAEs复合污染的响应。结果表明:移栽后20 d,施加低浓度Cd(≤2.0 mg/kg),可使土壤中微生物生物量碳含量增加,设施和大田土壤中分别增加了42.7%和96.5%。移栽后20 d时,施加PAEs(40,80 mg/kg)使设施土壤微生物生物量碳含量分别降低了56.2%和46.7%;移栽后30 d时,施加PAEs(40,80 mg/kg)使大田土壤微生物生物量碳含量分别降低了39.8%和提高了21.6%。Cd处理使大田土壤脱氢酶活性降低,但并未使设施土壤脱氢酶活性发生显著变化。施加高浓度PAEs(80 mg/kg)使大田土壤的脱氢酶活性提高了33.6%,但却使设施土壤脱氢酶活性降低了40.0%。Cd-PAEs复合效应对土壤微生物生物量碳表现为协同作用,但土壤脱氢酶活性则产生了拮抗作用。  相似文献   

8.
覆盖措施对春小麦田土壤含水量及耗水规律的影响   总被引：1，自引：1，他引：0  
马莉 《中国农学通报》2016,32(35):130-133
高效节水措施的使用有利于提高作物水分利用效率,缓解我国荒漠绿洲区灌溉农业生产中水资源不足的问题。基于此设定了大田定点观测试验研究不同覆盖措施对荒漠绿洲区春小麦耗水规律的影响,试验分别设置石子覆盖(S)、地膜覆盖(B)、秸秆覆盖(M)和对照(CK)4个处理。试验结果表明：覆盖措施使土面蒸发量降低了25.6%~37.9%,有效的提高了土壤含水量。春小麦耗水量分别为B处理减少了13%,M处理减少了14%,S减少了8%,但B处理下的春小麦水分利用效率(WUE)和灌溉水分利用效率(WUEi)最高。可见,地膜覆盖是是适合该地区最佳的节水种植方式。  相似文献   

9.
海河低平原存在着严重的水资源危机,对该区大面积推广的杨树||(小麦-玉米)复合种植模式进行土壤水分消耗规律的研究十分必要。定位实验研究表明:杨树||(小麦-玉米)复合种植模式耗水量高于常规冬小麦-夏玉米的种植模式7.9%(2年林龄)～24.5%(5年林龄);0～4m土壤贮水总量每年平均下降51.1mm,相当于总贮水量的4.1%;耕层杨树根系与小麦的土壤水分竞争加剧;深层土壤水分消耗加快,2～4m土壤层次因无水分回补出现干燥化趋势;土壤水亏缺及光照等其它原因造成复合系统农作物减产趋于严重,其中林龄3年的杨农复合系统的小麦玉米产量减产平均达到35%。对经济、生态效益的综合分析表明该模式在低平原贫水区的持续性发展不容乐观。  相似文献   

10.
在生产中农业机械替代人畜力从事农业生产劳动是必然的趋势。随着农业机械化水平的快速提高,土壤机械压实问题越来越突出。通过分析土壤机械压应力传递模型,以及土壤压实后土壤容重、坚实度增加,孔隙度、含水量降低,土壤的渗透性变差等土壤质量恶化现象,发现土壤压实可导致土壤质量下降,抑制作物的根系生长发育,对作物吸收土壤中的水分、养分产生不利影响。可造成玉米减产9.5%～14.4%,小麦减产4.0%～20.0%,大豆减产3.8%～13.4%,甜菜根产量降低5.81%～24.13%,含糖率降低0.49～0.81oZ。因此,在农业生产中必须要重视土壤压实问题,采取切实可行的技术措施,减轻农业机械化作业对土壤造成的负面影响,促进作物生长,提高农艺综合效益。  相似文献   

11.
Evening primrose (Oenothera spp.) is a high-value oilseed crop for temperate areas which may be either overwintered or spring–sown. Light absorption, light use efficiency, water loss and biomass water ratio were compared between overwintered and spring–sown crops of cv. Merlin in two years of field trials. An overwintered crop of cv. Peter was also studied in year two. The energy content of evening primrose plant material was shown to be similar to other crops. Both overwintered and spring–sown crops can achieve full canopy closure and maintain high fractional photosynthetically active radiation (PAR) interception for long periods but canopy closure occurred much later than in other temperate seed crops. In spring–sown evening primrose, maximum PAR interception did not occur until August, by which time incident light levels were declining and consequently the proportion of incident light energy captured during the main growing season was low. Most light was intercepted by green leaves and very little shading by senescent tissue and flowers occurred. Light conversion efficiencies for the main growing period were comparable with other temperate C3 crops, but in year two a steep decline in light conversion efficiency was observed as the crops matured and the soil water deficit exceeded 60 mm. In year one, water loss from both the overwintered and spring–sown crops were low and the soil water deficit increased relatively slowly. By contrast, in the year two crop water loss was high and the soil water deficit built up very rapidly between the end of June and crop maturity. No significant differences in biomass water ratio (water use efficiency) were recorded between overwintered and spring–sown crops but ratios were 50% higher in year one than in year two. Although no relationship was detected between biomass water ratio corrected for vapour pressure deficit (“normalised”) and soil water deficit, after canopy closure normalised daily water loss declined with increasing soil water deficit. Earlier canopy closure, particularly in the spring crop, and the avoidance of soil water deficits through irrigation, would lead to substantial improvements in the size and consistency of seed yields of evening primrose crops.  相似文献   

12.
The influence of alley cropping practices on trees, agricultural crops and arthropod diversity was studied in Duzce, Turkey. Six replications of three crops, maize (Zea mays L. var. rugosa), beans (Phaseolus vulgaris L.) and zucchini (Cucurbita pepo L.), were planted in the alleyways between rows of hybrid poplar [Populus euramericana (Dode) Guinier] in a plantation setting. Control plots included a poplar plot without crops and the three crops planted in plots without trees near the plantation. Sweep netting, sticky traps, pitfall traps, and cloth shaking were used four times throughout a growing season to sample arthropods in the research area. Alley cropping practices had both negative and positive effects on crop yield and a significant negative effect on poplar growth. A total of 10 284 arthropod specimens (15 orders and 122 families) were collected, 118 families in the agroforestry plots, 57 families in the treeless plots and 44 families in the poplar control plot. Diversity indices did not differ among plots, except for the Shannon index, for all dates and sampling methods combined. Evenness indices and family richness measures did not differ significantly among plots, but significant differences were found among collection dates and sampling methods. The tree canopy had a greater arthropod diversity than the ground vegetation. Beneficial arthropods were found in significantly greater numbers in the agroforestry plots compared to the monocrop plots. This suggests that trees provided a more favourable habitat for beneficial arthropods than herbaceous plants. We conclude that agroforestry may contribute to increasing arthropod diversity compared with monocrops.  相似文献   

13.
Trees are the dominant species in agroforestry systems, profoundly affecting the performance of understory crops. Proximity to trees is a key factor in crop performance, but rather little information is available on the spatial distribution of yield and yield components of crop species under the influence of trees in agroforestry systems. Also, little information is available on how crop density may be exploited to optimize the yield in such systems. Here we studied the performance of cotton in jujube/cotton agroforestry. Field experiments were conducted in 2012 and 2013 in Hetian, Xinjiang, China. Cotton was grown at a row distance of 60 cm in three densities, 13.5, 18.0 and 22.5 plants m−2 in six m wide paths between tree lines in a jujube plantation. Plant density affected both cotton aboveground dry matter and yield significantly. The highest yield was attained at the intermediate density of 18.0 plants m−2 (20.0 plants m−2 corresponding in sole cotton), lower than the optimal density in sole cotton (25.0 plants m−2). Yield at the lower density was constrained by the low number of bolls per m2 as a direct consequence of the low density, whereas at the high plant density yield was constrained by a lower allocation of assimilates to cotton seed and lint, as a consequence of intraspecific and interspecific competitions. There were strong gradients in yield and yield components in relation to the distance from the tree rows. Leaf area and total dry matter of cotton in rows close to the tree lines were reduced, especially in the rows next to the trees. Moreover, biomass allocation to cotton fruits was reduced in these rows. Competitive influences from the trees on cotton performance extended two rows deep in a six-year old jujube stand, and even three rows deep in a seven-year old stand. Shading effects on cotton yield were compensated by increasing plant density as a result of greater boll numbers per unit ground area. Data from this study help guide the design of optimal plant density of cotton in jujube plantations and give insight in the spatial distribution and dynamics of competitive effects in agroforestry systems in general.  相似文献   

14.
为探究缓/控释肥在不同水分条件下提高氮素利用率及增产机制。本研究以杂交中稻F优498为试验材料,在180 kg hm-2施氮量基础上,采用两因素裂区设计: 主区设控灌、干湿交替灌溉、传统灌水灌溉3种水分管理方式,副区设尿素一道清、尿素常规运筹、硫包膜缓释肥、树脂包膜控释肥4种氮肥种类,研究缓/控释肥和水分管理方式对水稻干物质量和氮素吸收、运转、分配和产量的影响及其互作效应。结果表明, 缓/控释肥和水分管理方式对水稻主要生育期干物质量和氮吸收、转运、分配及产量具显著影响及互作效应,产量构成因素与氮素在结实期转运总量及其分配呈显著正相关。干湿交替灌溉和缓/控释肥均能提高干物质量、氮素吸收及产量并表现出显著互作效应,施用缓/控释肥氮素表观利用率达42%~53%,相较于尿素一道清和传统的尿素常规运筹,氮肥偏生产力提高6%~23%,氮素农学利用率提高26%~71%,增产8%~19%。控灌条件下,缓/控释肥处理氮素有效性高,保证足穗、促进重穗;干湿交替灌溉条件下缓/控释肥处理能保持氮素的高效释放,有利于高产群体的形成,从而提高稻株氮素积累、协调氮素分配;淹水灌溉条件下,缓/控释肥处理无效分蘖减少,氮素入渗、淋溶降低,成穗率提高。综合产量与氮素吸收、运转的表现,干湿交替灌溉条件下施用缓控释肥为本试验最佳处理,能有效提高氮素利用率,促进高产形成。  相似文献   

15.
Effect of five planting patterns on the growth, yield and yield components of intercropped sunflower and sorghum was studied during 1989–90 planting seasons at University of Maiduguri, Nigeria. Generally, intercropping depressed the performance of sorghum more than sunflower. Sorghum plants grown in alternate hills with sunflower had the shortest stems, the least dry matter and total seed yields per hectare, while the highest dry matter and seed yields were obtained from sorghum planted in five alternating rows with sunflower. Similarly, in sunflower, plants grown in five alternating rows with sorghum had the highest yields compared with other planting patterns, but there were no significant differences in the dry matter and total seed yields of sorghum and sunflower intercropped in three and five alternating rows. Light transmission, leaf area index and yields of both crops followed similar trends under the various planting patterns. Interplanting in five alternating rows that allowed the highest leaf area also allowed the lowest light transmission and produced the highest yields. Land use efficiency was highly improved under three and five rows interplanting by 52 and 74 % respectively.  相似文献   

16.
The importance of reduced tillage in sustainable agriculture is well recognized. Reduced-tillage practices (which may or may not involve retention of crop residues) and their effects differ from those of conventional tillage in several ways: soil physical properties; shifts in host–weed competition; soil moisture availability (especially when sowing deeply or under stubble); and the emergence of pathogen populations that survive on crop residues. There may be a need for genotypes suited to special forms of mechanization (e.g. direct seeding into residues) and to agronomic conditions such as allelopathy, as well as specific issues relating to problem soils. This article examines issues and breeding targets for researchers who seek to improve crops for reduced-tillage systems. Most of the examples used pertain to wheat, but we also refer to other crops. Our primary claim is that new breeding initiatives are needed to introgress favourable traits into wheat and other crops in areas where reduced or zero-tillage is being adopted. Key traits include faster emergence, faster decomposition, and the ability to germinate when deep seeded (so that crops compete with weeds and use available moisture more efficiently). Enhancement of resistance to new pathogens and insect pests surviving on crop residues must also be given attention. In addition to focusing on new traits, breeders need to assess germplasm and breeding populations under reduced tillage. Farmer participatory approaches can also enhance the effectiveness of cultivar development and selection in environments where farmers’ links with technology providers are weak. Finally, modern breeding tools may also play a substantial role in future efforts to develop adapted crop genotypes for reduced tillage.  相似文献   

17.
In organic grain production, weeds are one of the major limiting factors along with crop nitrogen deficiency. Relay intercropping of forage legume cover crops in an established winter cereal crop might be a viable option but is still not well documented, especially under organic conditions.Four species of forage legumes (Medicago lupulina, Medicago sativa, Trifolium pratense and Trifolium repens) were undersown in six organic wheat fields. The density and aerial dry matter of wheat, relay-intercropped legumes and weeds were monitored during wheat-legume relay intercropping and after wheat harvest until late autumn, before the ploughing of cover crops.Our results showed a large diversity of aerial growth of weeds depending on soil, climate and wheat development. The dynamics of the legume cover crops were highly different between species and cropping periods (during relay intercropping and after wheat harvest). For instance, T. repens was two times less developed than the other species during relay intercropping while obtaining the highest aerial dry matter in late autumn. During the relay intercropping period, forage legume cover crops were only efficient in controlling weed density in comparison with wheat sole crop. The control of the aerial dry matter of weeds at the end of the relay intercropping period was better explained considering both legumes and wheat biomasses instead of legumes alone. In late autumn, 24 weeks after wheat harvest, weed biomass was largely reduced by the cover crops. Weed density and biomass reductions were correlated with cover crop biomass at wheat harvest and in late autumn. The presence of a cover crop also exhibited another positive effect by decreasing the density of spring-germinating annual weeds during the relay intercropping period.  相似文献   

18.
不同温湿度条件下杨树人工林土壤氮矿化特征研究   总被引：3，自引：0，他引：3  
为了掌握不同温度和湿度条件下杨树人工林土壤的氮矿化过程,探明土壤在干旱条件下的氮矿化特征,采用室内培养法,将含水量分别为田间持水量的20%(重度干旱处理)、40%(轻度干旱处理)和70%(对照处理)的杨树人工林表层土壤(0~10 cm),分别置于15、20、25、30℃恒温条件下进行了8周培养试验,研究不同温湿度条件下的土壤氮矿化特征。结果表明:(1)土壤净氮矿化量与温度呈极显著正相关关系(P0.01);(2)在较低温度条件下(15、20℃),不同湿度土壤净氮矿化量表现为轻度干旱重度干旱对照,而在较高温度条件下(25、30℃),培养前期的氮矿化量变化规律与低温处理一致,但至培养后期,则表现为对照轻度干旱重度干旱;(3)各种处理土壤矿质氮主要以硝态氮为主;(4)土壤电导率与土壤硝态氮含量、净氮矿化量呈极显著正相关关系(P0.01)。研究表明适度干旱能够促进土壤氮的早期矿化,但适宜的湿度更有利于土壤氮的长期矿化。  相似文献   

19.
Agroforesry is a common traditional practice in China, especially in the saline-alkaline regions, like the lower North China Plain (LNCP) characterized by lower yields of food crops. Adding trees to the agricultural land creates additional fruitsets or woody biomass besides food crops, enabling farmers to diversify the provision of farm commodities. However, the productivity of many agroforestry systems has been lower than expected in recent years, highlighting the need for a mechanistic understanding of below- or above-ground interactions. The study combined investigation and experimental data together to evaluate the effects of long-term intercropping agroforestry system [jujube tree (Zizyphus jujuba Mill. var. inermis (Bunge) Rehd.)/winter wheat–summer maize] on soil fertility balance, crop production and system economic efficiency over the past 22 years in LNCP, with a view to developing an effective fertilization management for the moderately alkaline soils. Except remain higher pH, the soils are basically free of sodic and soil salinity is not the major restriction factor for intercrops, even through there are some fluctuation with season and distance from jujube tree. The intercropping system significantly reduced soil nutrient contents, like soil organic C (SOC), total N (TN), available P (avail. P) and K (avail. K) in most parts of the ecotone of the system, but increased those nutrients in the belt of underneath the edge of tree canopy, The growth of intercrops at the belt of 3.5 m from tree was severely negative stressed by jujube tree in term of lower soil moisture, nitrate, avail. P and K although receiving more photosynthetically active radiation (PAR), whereas the winter wheat growing at the 2.5 m row had more water and nutrients supplied and thus produced more grain yield. Uneven fertilization to the ecotone (about 1–2.5 m of the intercrop field boundary) could partly offset the consumption and competition for nutrients between the tree and the intercrops, and improved the grain yields by 12.1% and 14.5% in the ecotone regions (distance from jujube trees) of 1.5 m for winter wheat and 2.5 m for summer maize by increasing respective yield components. Although the mean grain yield of intercropped winter wheat and summer maize was reduced by 35.6 and 35.2%, respectively, compared to sole cropping system, the intercropping system proved to be a profitable land use type based on net income and economic returns, in addition to the wood and ecological benefits of the jujube tree in the moderate desalinate- alkaline regions.  相似文献   

20.
土壤水分对冬小麦生长后期光能利用及水分利用效率的影响   总被引：15，自引：4，他引：15  
通过控制不同土壤水分条件形成不同的小麦（Triticum aestivum L.）群体结构,测定了抽穗到成熟期间小麦冠层光合有效辐射（PAR）截获及垂直分布、干物质积累和产量。研究表明,不同处理小麦冠层对PAR的截获量差异较小（小于15.7%）,但冠层上部（60~80 cm）的PAR截获量和生长后期PAR转化效率差异明显（100.7%和63.7%）,与产量和光能利用效率变化一致,可见土壤水分是通过改变小麦群体内PAR垂直分布及PAR转化效率对作物产量和光能利用效率产生影响。抽穗到成熟期间维持小麦冠层上部PAR截获率在50%左右是实现高产的重要保证。随着土壤水分改善,冬小麦光能利用率和产量持续增加,但水分利用效率却先于二者提前降低,说明改善水分利用效率是提高华北地区农业气候资源利用效率的关键。在底墒充足的条件下,分别在拔节和挑旗期灌水60 mm可获得较高的光能和水分利用效率及经济产量  相似文献   

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