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1.
为研究种植密度与施氮量对机采棉冠层叶面积指数、透光率和果枝长度等的影响,采用裂区试验设计,主区设2个种植密度D18(18万株/hm~2)和D24(24万株/hm~2),副区设4个施氮量N0(0kg/hm~2)、N170(170kg/hm~2)、N320(320kg/hm~2)和N470(470kg/hm~2)。结果表明,同一施氮量下,随种植密度增大,单株结铃数、单铃重与衣分减小,冠层上、中和下部叶面积指数增大,冠层上、中和下部果枝长度呈先降后增的趋势,冠层开度降低,冠层上、中和下部单铃重逐渐降低。同一种植密度下,当种植密度为D18时,随施氮量的增加,单株结铃数、单铃重、衣分、籽棉产量、皮棉产量、DIFN、冠层上、中和下部叶面积指数及果枝长度均呈上升趋势,表现为N470N320N170N0,种植密度D24条件下呈先升后降的趋势,表现为N320N470N170N0。D24N320处理虽然较最高籽棉产量略低,但差异不显著,其增产率及氮肥农学利用效率最高,在减少氮肥投入量的同时也减轻了由此产生的环境污染。因此,当种植密度为24万株/hm~2、施氮量为320kg/hm~2是本试验条件下最理想的种植密度与施氮量。 相似文献
2.
ZHANG Yuan-meng XUE Jun ZHAI Juan ZHANG Guo-qiang ZHANG Wan-xu WANG Ke-ru MING Bo HOU Peng XIE Rui-zhi LIU Chao-wei LI Shao-kun 《农业科学学报》2021,20(10):2627-2638
Nitrogen fertilizer application is an important measure to obtain high and stable corn yield, and the moisture content of corn grains is an important factor affecting the quality of mechanical grain harvesting. In this study, four different nitrogen fertilizer treatments from 0 to 450 kg ha~(–1) pure nitrogen were set for a planting density of 12.0×10~4 plants ha~(–1) in 2017 and 2018, and 18 different nitrogen fertilizer treatments from 0 to 765 kg ha~(–1) pure nitrogen were set for planting densities of 7.5×10~4 and 12.0×10~4 plants ha~(–1) in 2019, to investigate the effect of nitrogen application rate on the moisture content of corn grains. Under each treatment, the growth of corn, leaf area index(LAI) of green leaves, grain moisture content, and grain dehydration rate were measured. The results showed that, as nitrogen application increased from 0 to 765 kg ha~(–1), the silking stage was delayed by about 1 day, the maturity stage was delayed by about 1–2 days, and the number of physiologically mature green leaves and LAI increased. At and after physiological maturity, the extreme difference in grain moisture content between different nitrogen application rates was 1.9–4.0%. As the amount of nitrogen application increased, the corn grain dehydration rate after physiological maturity decreased, but it did not reach statistical significance between nitrogen application rate and grain dehydration rate. No significant correlation was observed between LAI at physiological maturity and grain dehydration rate after physiological maturity. In short, nitrogen application affected the grain moisture content of corn at and after physiological maturity, however, the difference in grain moisture content among different nitrogen application rates was small. These results suggest that the effect of nitrogen application on the moisture content of corn grains should not be considered in agricultural production. 相似文献
3.
Nitrogen Nutrition Index and Its Relationship with N Use Efficiency,Tuber Yield,Radiation Use Efficiency,and Leaf Parameters in Potatoes 
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下载免费PDF全文 Knowledge about crop growth processes in relation to N limitation is necessary to optimize N management in farming system. Plant-based diagnostic method, for instance nitrogen nutrition index (NNI) were used to determine the crop nitrogen status. This study determines the relationship of NNI with agronomic nitrogen use efficiency (AEN), tuber yield, radiation use efficiency (RUE) and leaf parameters including leaf area index (LAI), areal leaf N content (NAL) and leaf N concentration (NL). Potatoes were grown in field at three N levels: no N (N1), 150 kg N ha−1 (N2), 300 kg N ha−1 (N3). N deficiency was quantified by NNI and RUE was generally calculated by estimating of the light absorbance on leaf area. NNI was used to evaluate the N effect on tuber yield, RUE, LAI, NAL, and NL. The results showed that NNI was negatively correlated with AEN, N deficiencies (NNI<1) which occurred for N1 and N2 significantly reduced LAI, NL and tuber yield; whereas the N deficiencies had a relative small effect on NAL and RUE. To remove any effect other than N on these parameters, the actual ratio to maximum values were calculated for each developmental stage of potatoes. When the NNI ranged from 0.4 to 1, positive linear relationships were obtained between NNI and tuber yield, LAI, NL, while a nonlinear regression fitted the response of RUE to NNI. 相似文献
4.
棉花冠层光合有效辐射截获率(PARI)是影响干物质积累和产量形成的重要因素,然而对于不同覆膜方式下种植密度对棉花冠层光分布的影响尚未明确。在旱区一膜三行的机采种植模式下,设2种覆膜方式(有膜和无膜)与5种种植密度(D1:9×104株/hm2,D2:13.5×104株/hm2,D3:18×104株/hm2,D4:22.5×104株/hm2,D5:27×104株/hm2),研究不同覆膜方式下种植密度对棉花冠层PARI的影响。结果表明,在全生育期,有膜处理下棉花冠层光合有效辐射(PAR)的截获能力较强;冠层PARI与种植密度呈显著正相关关系,不同种植密度之间PARI存在差异;叶面积指数(LAI)随生育进程推进呈单峰曲线。有膜处理下,不同种植密度LAI在第94～98天达到峰值;无膜处理下,不同种植密度LAI在第109～113天达到峰值;随着种植密度的增加干物质积累量减少,其生殖... 相似文献
5.
种植密度对旱地不同株型春玉米品种光合特性与产量的影响 总被引：15，自引：4，他引：11
【目的】研究种植密度对渭北旱塬不同株型春玉米品种光合特性与产量差异的影响,旨在揭示旱地不同株型玉米品种对种植密度的响应规律,确定与降水资源相适应的适宜种植密度。【方法】于2015—2016年以豫玉22、郑单958和先玉335为供试品种,设置D1(5.25万株/hm~2)、D2(6.75万株/hm~2)、D3(8.25万株/hm~2)和D4(9.75万株/hm~2)4个种植密度处理,研究玉米各生育时期光合特性、叶面积指数(LAI)、干物质量和产量相关性状的变化规律。【结果】(1)随着种植密度增加,光合速率(Pn)、蒸腾速率(Tr)均降低,而LAI增加,密度每增加1万株/hm~2,Pn降低1.32μmol CO2·m-2·s-1,Tr降低0.297 mmol·m-2·s-1,LAI增加0.181。(2)有效穗数随种植密度增加而显著增加,但穗粒数和千粒重显著降低(P0.05),密度每增加1万株/hm~2,穗粒数平均减少45粒,千粒重平均减小12 g。3个品种籽粒产量均以D2密度最高,2015年豫玉22、郑单958、先玉335产量分别为10.52、9.59、9.14 t·hm-2,2016年分别为11.37、9.73、9.77 t·hm-2。密度从5.25万株/hm~2增加到6.75万株/hm~2,两年内平均籽粒产量分别提高了21.9%、19.5%和7.5%;密度从6.75万株/hm~2增加加到9.75万株/hm~2,籽粒产量分别降低了19.8%、15.4%和7.7%。(3)春玉米基部茎粗、穗长随种植密度增加而逐渐减小。密度每增加1万株/hm~2,穗长平均降低0.86 cm,基部茎粗平均减小0.09 cm,豫玉22和郑单958倒伏率随之增高,但先玉335各密度下均未出现倒伏。(4)收获指数在两年间差异较大,平均表现为2015年高于2016年,品种间表现为先玉335郑单958豫玉22。水分利用效率和光能利用率均随着种植密度增加而先增大后降低。【结论】渭北旱塬旱地豫玉22、郑单958和先玉335最适种植密度分别为7.25、7.40、7.32万株/hm~2,其中豫玉22稳产性和丰产性较高,不同类型玉米品种最适种植密度范围为7.26—7.40万株/hm~2,稀植型品种宜采用较低密度,密植型品种宜采用较高密度。 相似文献
6.
玉米密植栽培技术研究 总被引：14，自引：0，他引：14
4个直立叶型杂交种、3种种植方式(67cm等行条播、50cm等行条播、六角形穴播)、3个密度定额(6.0万株/hm2、7.5万株/hm2、9.0万株/hm2)的田间试验结果表明:在3种株行距配置下,玉米产量均随密度的增大而增大;但高密度下不同株行距下密植的增产幅度差异较大,以50cm等行条播增幅最大;玉米不同株行距配置的产量效应在中、低密度时不显现,在较高密度(7.50万～9.0万株/hm2、具体某一品种的高限密度及其以上)条件下才予以显现;50cm等行条播、六角形穴播较之67cm等行条播均表现出高密度下由于玉米个体营养的改善而导致群体产量增加的增产效应;六角形穴播较67cm等行条播、50cm等行条播玉米开花盛期LAI稍大,但较67cm等行条播高密度下增、减产差异不一致;同时玉米生长发育过程中追肥灌水不方便;株行距×密度×品种的最佳组合为选用V2(89-1w×5022)、V4(郑单958)这两类杂交种,实施50cm行距条播,密度9.0万株/hm2;在7.5万株/hm2、9.0万株/hm2下50cm等行距条播较67cm等行距条播分别增产21.4%、31.2%,增产显著,同时也有利于人类的耕作栽培。试验表明选用直立叶型强优势玉米杂交种、采用50cm等行距条播、增大密度至7.5万～9.0万株/hm2、进行水分和土壤营养足额供给下的规范化栽培构成高光效玉米群体冠层光合系统技术体系,在 相似文献
7.
不同株型玉米冠层光氮分布、衰老特征及光能利用对增密的响应 总被引：5，自引：1，他引：4
【目的】探究增密对不同株型玉米冠层光氮分布、衰老特征、及其对光能利用及产量的影响,为陕西春玉米高产高效栽培提供支撑。【方法】于2017—2018年以陕单609（紧凑型）和陕单8806（平展型）为试验材料,设置4个种植密度（45 000、60 000、75 000和90 000株/hm2）,测定了冠层光氮分布、叶片衰老、物质生产、光能利用及产量构成等指标。【结果】陕单609和陕单8806分别在90 000株/hm2（13 824 kg·hm-2）和60 000株/hm2（9 566 kg·hm-2）达到了最高产量,与45 000株/hm2相比,90 000株/hm2下陕单609和陕单8806的穗粒数（17.8%和30.1%）和百粒重（15.2%和19.6%）均降低。同一密度下,2个品种的冠层光能截获率和叶片氮素浓度表现为上层>中层>下层,随着密度的增加,2个品种冠层上部光能截获率和叶片氮素浓度不断增加,中层和下层的光能截获率和叶片氮素浓度不断下降,当密度增至90 000株/hm2时,陕单8806冠层中部和下部的光能截获率分别较陕单609低8.8%和70.6%,且陕单609中层和下层的叶片氮素浓度较陕单8806高16.0%和40.5%。当密度从45 000株/hm2增至90 000株/hm2,陕单609和陕单8806成熟期相对绿叶面积分别降低36.4%和63.3%,叶片平均衰老速率分别增加40.2%和34.6%,冠层不同层次叶片衰老启动的时间顺序为下层>上层>中层,与陕单8806相比,90 000株/hm2下陕单609生育后期冠层中上部的绿叶面积较高,且下层维持较高的绿叶面积。随种植密度的增加,吐丝前后的氮素吸收量和氮收获指数显著增加,当密度增至90 000株/hm2时,陕单609吐丝前后的氮素吸收量、氮收获指数分别较陕单8806高23.5%、43.9%、12.7%。增密后生物产量、收获指数、冠层光能截获量和光能利用率显著增加,密度增至90 000株/hm2时,陕单609的生物产量、冠层的光合有效辐射、光能利用率和收获指数分别较陕单8806高26.1%、10.2%、9.1%和14.8%。【结论】与陕单8806比,紧凑玉米陕单609密植下较好协同优化冠层光氮空间分布,增加了群体花后中下部光能截获量,延缓群体冠层花后中下层叶片衰老,促进群体花后干物质和氮素积累,获得更高的籽粒产量和光能利用率。 相似文献
8.
种植密度对夏玉米冠层光合特性的影响 总被引：6，自引：0，他引：6
以夏玉米品种郑单958和浚单20为材料,研究了不同密度条件下夏玉米群体冠层辐射特征和光合特性。结果表明,郑单958玉米叶面积指数随种植密度增加而升高,两品种吐丝期叶面积指数均在82 500株/hm2处理时最高。透光率随密度增加而减小,冠层顶部透光率显著高于冠层底部。吐丝期两品种叶绿素a和叶绿素总含量表现为75 000株/hm2、82 500株/hm2处理高于67 500株/hm2、90 000株/hm2处理。穗位上第3叶Fv/Fm、qP高于穗位叶和穗位下第3叶,NPQ低于穗位叶和穗位下第3叶。随生育进程茎粗在吐丝期达到最大值,浚单20茎粗随密度增加而减小。郑单958在密度为90 000株/hm2时产量最高,为12 166.070kg/hm2,而浚单20则在82 500株/hm2时产量最高,为9 705.709kg/hm2。 相似文献
9.
Increasing photosynthetic performance and post-silking N uptake by moderate decreasing leaf source of maize under high planting density 下载免费PDF全文
下载免费PDF全文 To date,little attention has been paid to the effects of leaf source reduction on photosynthetic matter production,root function and post-silking N uptake characteristics at different planting densities.In a 2-year field experiment,Xianyu 335,a widely released hybrid in China,was planted at 60 000 plants ha~(–1 )(conventional planting density,CD) and 90 000 plants ha~(–1) (high planting density,HD),respectively.Until all the filaments protruded from the ear,at which point the plants were subjected to the removal of 1/2 (T1),1/3 (T2) and 1/4 (T3) each leaf length per plant,no leaf removal served as the control(CK).We evaluated the leaf source reduction on canopy photosynthetic matter production and N accumulation of different planting densities.Under CD,decreasing leaf source markedly decreased photosynthetic rate (P_n),effective quantum yield of photosystem II (ΦPSII) and the maximal efficiency of photosystem II photochemistry (F_v/F_m) at grain filling stage,reduced post-silking dry matter accumulation,harvest index (HI),and the yield.Compared with the CK,the 2-year average yields of T1,T2 and T3 treatments decreased by 35.4,23.8 and 8.3%,respectively.Meanwhile,decreasing leaf source reduced the root bleeding sap intensity,the content of soluble sugar in the bleeding sap,post-silking N uptake,and N accumulation in grain.The grain N accumulation in T1,T2 and T3 decreased by 26.7,16.5 and 12.8% compared with CK,respectively.Under HD,compared to other treatments,excising T3 markedly improved the leaf P_n,ΦPSII and F_v/F_m at late-grain filling stage,increased the post-silking dry matter accumulation,HI and the grain yield.The yield of T3 was 9.2,35.7 and 20.1% higher than that of CK,T1 and T2 on average,respectively.The T3 treatment also increased the root bleeding sap intensity,the content of soluble sugar in the bleeding sap and post-silking N uptake and N accumulation in grain.Compared with CK,T1 and T2 treatments,the grain N accumulation in T3 increased by 13.1,40.9 and 25.2% on average,respectively.In addition,under the same source reduction treatment,the maize yield of HD was significantly higher than that of CD.Therefore,planting density should be increased in maize production for higher grain yield.Under HD,moderate decreasing leaf source improved photosynthetic performance and increased the post-silking dry matter accumulation and HI,and thus the grain yield.In addition,the improvement of photosynthetic performance improved the root function and promoted postsilking N uptake,which led to the increase of N accumulation in grain. 相似文献
10.
不同栽植密度杏树冠层受光特性分析 总被引：2，自引：0，他引：2
为了解杏树栽植密度与冠层受光关系,同时也为杏树栽培选择适宜栽植密度提供理论依据,运用HOBO ware Pro自动气象站及SUNSCAN冠层分析仪对6种不同栽植密度杏树冠层受光特性进行测定.结果表明,不同栽植密度下,在1d中树冠内的光合有效辐射(PAR)呈单峰曲线变化,且各个部位的PAR在1d中的最大值和出现的时间有差别;相同密度下,树冠不同部位和方位的PAR在ld中各时刻的变化情况是不一致的;叶面积指数(LAI)随株行距的增大而减小.PAR和LAI的变化与株行距、树冠大小、方位有关. 相似文献
11.
Effects of different agricultural treatments on narrowing winter wheat yield gap and nitrogen use efficiency in China 下载免费PDF全文
下载免费PDF全文 Under the limited cultivated land area and the pursuit of sustainable agricultural development,it is essential for the safety of grain production to study agricultural management approaches on narrowing the winter wheat yield gap and improving nitrogen use efficiency (NUE) in China.In this study,DSSAT-CERES-Wheat Model is used to simulate winter wheat yield under different agricultural treatments,and we analyze yield gaps and NUE with different management scenarios at regional scales and evaluate the suitable approaches for reducing yield gap and increasing NUE.The results show that,the potential of narrowing yield gap ranges 300–900 kg ha~(–1) with soil nutrients increase,400–1 200 kg ha~(–1) with sowing date adjustment and 0–400 kg ha~(–1) with planting density increase as well as 700–2 200 kg ha~(–1) with adding nitrogen fertilizer.Contribution rates of management measures of soil nutrients,sowing date adjusting,planting density,and nitrogen fertilizers are 5–15%,5–15%,0–4%,and 10–20%,respectively.Difference in nitrogen partial productivity ranges 3–10 kg kg~(–1) for soil nutrients,1–10 kg kg~(–1) for sowing date adjusting,1–5 kg kg~(–1) for planting density increase,and–12–0 kg kg~(–1) for adding nitrogen fertilizers,respectively.It indicates that four treatments can narrow yield gap and improve the NUE in varying degrees,but increasing nitrogen fertilizer leads to the decrease of NUE. 相似文献
12.
为探讨栽植密度对枣园冠层结构特征及果实性状的影响,以新疆阿克苏温宿县10 a生骏枣园为研究对象,利用LAI-2200植物冠层分析仪测定4种栽植密度(A.0.5 m×4.0 m、B.1.0 m×4.0 m、C.1.5 m×4.0 m、D.2.0 m×4.0 m)枣园叶面积指数(LAI)、平均叶倾角(MTA)、冠层开度(DIFN)与相对光合有效辐射(PAR)的物候变化,分析果实性状。结果表明,随着物候推进,枣园LAI和DIFN均呈现出先增大后减小的趋势,与不同物候期叶幕体积大小有关。随着株距不断增大,枣园LAI减小,树冠DIFN增大,相对PAR增强,光能利用率提高。C的单果重、可溶性糖含量、单株产量及每公顷产量均高于A和B,可滴定酸含量则明显低于A和B,糖酸比显著高于其他3种栽植密度。综合以上结果可知,1.5 m×4 m栽植密度能有效改善枣园冠层结构特征与光能利用效率,在稳定枣果产量的前提下提升了枣果品质。 相似文献
13.
Effects of Plant Density on Yield and Canopy Micro Environment in Hybrid Cotton 总被引：2，自引：0，他引：2 下载免费PDF全文
下载免费PDF全文 A rational plant population is an important attribute to high yield of cotton, because it can provide a beneficial micro environment within the canopy for plant growth and development as well as yield formation. A 2-yr field experiment was conducted to determine the optimal plant density based on cotton yield in relation to the canopy micro environment （canopy temperature, relative humidity and light transmittance）. Six plant densities （1.2-5.7 plants m^-2） were arranged with a completely randomized block design. The highest cotton yield （1 507 kg ha^-1） was obtained at 3.0 plants m^-2 due to more bolls per unit ground area （79 bolls m2）, while the lowest yield （1 091 kg ha1） was obtained at 1.2 plants m^-2. Under the moderate plant density （3.0 plants m^-2）, there was a lower mean daily temperature （MDT, 27. 1℃） attributing to medium daily minimum temperature （Train, 21.9℃） and the lowest daily maximum temperature （Tmax, 35.8℃）, a moderate mean canopy light transmittance of 0.51, and lower mean daily relative humidity （MRH） of 79.7% from June to October. The results suggest that 3.0 plants m^-2 would be the optimal plant density because it provides a better canopy micro environment. 相似文献
14.
In 2010, Chinese maize yields increased from 961.5 kg ha?1 in 1949 to 5 453.8 kg ha?1. This increase is the result of genetic improvements, an increase in nitrogen application, and refinement of planting densities. The objective of this study was to provide a theoretical basis for maize production research by analyzing the maize yield gain characteristics. Six varieties of maize were selected for the study; each selection is representative of a typical or commonly used maize variety from a specific decade, beginning from the 1950s and continuing through each decade into the 2000s. The selections and their corresponding decade were as follows: Baihe, 1950s; Jidan 101, 1960s; Zhongdan 2, 1970s; Yedan 13, 1980s; Zhengdan 958, 1990s; and Xianyu 335, 2000s. Each variety was planted under four different densities (37 500, 52 500, 67 500, and 82 500 plants ha?1) and four different nitrogen applications (0, 150, 225, and 300 kg ha?1) to study the effects on yield gain characteristics. The obtained results demonstrated that there was a maize yield increase of 123.19% between the 1950s variety and the 2000s variety. Modern Chinese maize varieties had a higher yield advantage. They also displayed the additional potential to acquire higher yield under increased planting densities and nitrogen applications. At the present cultivation levels (planting at 67 500 plants ha?1 with 225 kg ha?1 nitrogen application), the contribution types and corresponding yield increase percentages were as follows: genetic improvement, 45.37%; agronomic-management improvement, 30.94%; and genotype× agronomic-management interaction, 23.69%. At high-yielding cultivation levels (planting at 82 500 plants ha?1 with 300 kg ha?1 nitrogen application), the contribution types and corresponding yield increase percentages were as follows: genetic improvement, 31.30%; agronomic-management improvement, 36.23%; and genotype × agronomic-management interaction, 32.47%. The contribution of agronomic-management and genotype × agronomic-management interaction to yield increase would be larger with the corresponding management improvement. To further increase maize grain yield in China, researchers should further examine the effects of agronomic-management on maize yield and the adaptation of variety to agronomic-management. 相似文献
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Maize grain yield and water use efficiency in relation to climatic factors and plant population in northern China 下载免费PDF全文
下载免费PDF全文 LIU Yue-e HOU Peng HUANG Gui-rong ZHONG Xiu-li LI Hao-ru ZHAO Jiu-ran LI Shao-kun MEI Xu-rong 《农业科学学报》2021,20(12):3156-3169
Water scarcity has become a limiting factor for increasing crop production. Finding ways to improve water use efficiency (WUE) has become an urgent task for Chinese agriculture. To understand the response of different maize populations to changes in precipitation and the effects of changes in maize populations on WUE, this study conducted maize population experiments using maize hybrids with different plant types (compact and semi compact) and different planting densities at 25 locations across China. It was found that, as precipitation increased across different locations, maize grain yield first increased and then decreased, while WUE decreased significantly. Analyzing the relationship between WUE and the main climatic factors, this study found that WUE was significantly and negatively correlated with precipitation ($$ (daily mean precipitation) and R (accumulated precipitation)) and was positively correlated with temperature (TM (daily mean maximum temperature), TM–m (Tm, daily mean minimum temperature) and GDD (growing degree days)) and solar radiation ($$ (daily mean solar radiation) and Ra (accumulated solar radiation)) over different growth periods. Significant differences in maize grain yield, WUE and precipitation were found at different planting densities. The population densities were ranked as follows according to maize grain yield and WUE based on the multi-site experiment data: 60 000 plants ha–1 (P2)>90 000 plants ha–1 (P3)>30 000 plants ha–1 (P1). Further analysis showed that, as maize population increased, water consumption increased significantly while soil evaporation decreased significantly. Significant differences were found between the WUE of ZD958 (compact type) and that of LD981 (semi-compact type), as well as among the WUE values at different planting densities. In addition, choosing the optimum hybrid and planting density increased WUE by 21.70 and 14.92%, respectively, which showed that the hybrid played a more significant role than the planting density in improving WUE. Therefore, choosing drought-resistant hybrids could be more effective than increasing the planting density to increase maize grain yield and WUE in northern China. Comprehensive consideration of climatic impacts, drought-resistant hybrids (e.g., ZD958) and planting density (e.g., 60 000 plants ha–1) is an effective way to increase maize grain yield and WUE across different regions of China. 相似文献
16.
【目的】 研究核桃小麦(以下简称核麦)间作模式下,种植密度对冬小麦冠层结构及农田小气候的影响。【方法】 2016~2017年在核麦间作模式下,设置450×104株/hm2(M1)、525×104株/hm2(M2)、600×104株/hm2(M3)、675×104株/hm2(M4)、750×104株/hm2(M5)5种冬小麦种植密度,观测冬小麦冠层结构及冠层空气温度、湿度以及冠层透光率的变化过程。【结果】 核麦间作下,远冠区冬小麦单片单面积、株高、茎粗均高于冠下区;随着种植密度增加,冠下区、远冠区冬小麦各叶层叶面积、各节间长度和节间粗度均呈“先增后减”的趋势,株高变幅为76.49～81.66 cm(冠下区)和78.34～86.27 cm(远冠区)。冠下区、远冠区冠层空气温度呈“先升后降”的曲线,冠下区M1处理最高,远冠区M4、M5处理相对较高,冠下区上午升温、下午降温速度慢,高温持续期短,冠下区各密度冠层温度(18.19～35.99℃)的变幅低于远冠区(17.82～38.92℃);湿度呈“先降后升”的曲线,均在M1最低,远冠区冠层空气湿度上午降速、下午升速均慢,湿度低谷持续期短,冠下区冠层空气湿度(44.73%～100%)变幅高于远冠区(36.62%～100%)。小麦冠层顶部入射光合有效辐射量(PAR)冠下区明显低于远冠区;冠下区、远冠区的冠层光合有效辐射截获量(IPAR)随着密度的增加均呈“先升后降”的趋势,均在M2处理达到最大。【结论】 种植密度525×104株/hm2(M2)时,核麦间作下冬小麦冠层结构及其小气候较适宜。 相似文献
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种植密度对烟草冠层辐射和群体光合作用的影响 总被引：3，自引：0，他引：3
烟草群体光合能力是烟叶产量和品质形成的基础,种植密度是调节烟草个体生长和群体发展的重要因素。以烤烟品种‘云烟85’为材料,设置3个种植密度(D1:16 529株·hm~(-2);D2:18 182株·hm~(-2);D3:20 202株·hm~(-2))处理,研究密度对烟草群体叶面积动态、冠层辐射、群体光合作用及经济性状的影响。结果表明,烤烟群体发展动态表现为圆顶期叶面积指数(LAI)最大,行间叶尖距和冠层透光率最低,以后随着叶片的成熟采收,LAI逐渐减小,行间叶尖距和冠层透光率逐步增大。与此相应,群体光合速率(RCP)也以圆顶期较高。同一时期不同处理间相比,随密度增加LAI增大,行间叶尖距和冠层透光率减小。群体光合速率随密度的变化表现为,在圆顶期从D1到D2群体光合速率增加,从D2到D3有所下降,中部叶片采收后3个密度间差异不显著。相关分析表明,LAI与叶尖距、透光率呈显著负相关,与群体光合速率呈正相关,但不显著。表明群体光合速率并非随密度增大而持续提高,密度过大时,反而导致群体光合速率下降。产量和产值从D1到D2显著增加,从D2到D3则有所下降,上等烟比例以D2最高。从群体发展的协调性、田间管理的方便性及生产成本等综合考虑,烤烟品种云烟85的种植密度以18 182株·hm~(-2)左右较为适宜。 相似文献
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Response of dryland crops to climate change and drought-resistant and water-suitable planting technology: A case of spring maize 下载免费PDF全文
下载免费PDF全文 《农业科学学报》2023,22(7):2067-2079
Climate change has a significant impact on agriculture. However, the impact investigation is currently limited to the analysis of meteorological data, and there is a dearth of long-term monitoring of crop phenology and soil moisture associated with climate change. In this study, temperature and precipitation (1957–2020) were recorded, crop growth (1981–2019) data were collected, and field experiments were conducted at central and eastern Gansu and southern Ningxia, China. The mean temperature increased by 0.36°C, and precipitation decreased by 11.17 mm per decade. The average evapotranspiration (ET) of winter wheat in 39 years from 1981 to 2019 was 362.1 mm, demonstrating a 22.1-mm decrease every 10 years. However, the ET of spring maize was 405.5 mm over 35 years (1985–2019), which did not show a downward trend. Every 10 years, growth periods were shortened by 5.19 and 6.47 d, sowing dates were delayed by 3.56 and 1.68 d, and maturity dates advanced by 1.76 and 5.51 d, respectively, for wheat and maize. A film fully-mulched ridge–furrow (FMRF) system with a rain-harvesting efficiency of 65.7-92.7% promotes deep rainwater infiltration into the soil. This leads to double the soil moisture in-furrow, increasing the water satisfaction rate by 110-160%. A 15-year grain yield of maize increased by 19.87% with the FMRF compared with that of half-mulched flat planting. Grain yield and water use efficiency of maize increased by 20.6 and 17.4% when the density grew from 4.5×104 to 6.75×104 plants ha–1 and improved by 12.0 and 12.7% when the density increased from 6.75×104 to 9.0×104 plants ha–1, respectively. Moreover, responses of maize yield to density and the corresponding density of the maximum yield varied highly in different rainfall areas. The density parameter suitable for water planting was 174 maize plants ha–1 with 10 mm rainfall. Therefore, management strategies should focus on adjusting crop planting structure, FMRF water harvesting system, and water-suitable planting to mitigate the adverse effects of climate change and enhance sustainable production of maize in the drylands. 相似文献
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Effects of nitrogen application rates and irrigation regimes on grain yield and water use efficiency of maize under alternate partial root-zone irrigation 下载免费PDF全文
下载免费PDF全文 Faced with the scarcity of water resources and irrational fertilizer use, it is critical to supply plants with water and fertilizer in a coordinated pattern to improve yield with high water use efficiency (WUE). One such method, alternate partial root-zone irrigation (APRI), has been practiced worldwide, but there is limited information on the performance of different irrigation regimes and nitrogen (N) rates under APRI. The objectives of this study were to investigate the effects of varying irrigation regimes and N rates on shoot growth, grain yield and WUE of maize (Zea mays L.) grown under APRI in the Hexi Corridor area of Northwest China in 2014 and 2015. The three N rates were 100, 200 and 300 kg N ha−1, designated N1, N2 and N3, respectively. The three irrigation regimes of 45–50%, 60–65% and 75–80% field capacity (FC) throughout the maize growing season, designated W1, W2 and W3, respectively, were applied in combination with each N rate. The results showed that W2 and W3 significantly increased the plant height, stem diameter, crop growth rate, chlorophyll SPAD value, net photosynthetic rate (Pn), biomass, grain yield, ears per ha, kernels per cob, 1 000-kernel weight, harvest index, evapotranspiration and leaf area index (LAI) compared to W1 at each N rate. The N2 and N3 treatments increased those parameters compared to N1 in each irrigation treatment. Increasing the N rate from the N2 to N3 resulted in increased biomass and grain yield under W3 while it had no impact on those under the W1 and W2 treatments. The W3N3 and W2N2 and W2N3 treatments achieved the greatest and the second-greatest biomass and grain yield, respectively. Increasing the N rate significantly enhanced the maximum LAI (LAI at the silking stage) and Pn under W3, suggesting that the interaction of irrigation and fertilizer N management can effectively improve leaf growth and development, and consequently provide high biomass and grain yield of maize. The W2N2, W2N3 and W3N3 treatments attained the greatest WUE among all the treatments. Thus, either 60–65% FC coupled with 200–300 kg N ha−1 or 75–80% FC coupled with 300 kg N ha−1 is proposed as a better pattern of irrigation and nitrogen application with positive regulative effects on grain yield and WUE of maize under APRI in the Hexi Corridor area of Northwest China and other regions with similar environments. These results can provide a basis for in-depth understanding of the mechanisms of grain yield and WUE to supply levels of water and nitrogen. 相似文献
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先玉335适宜栽培密度与性状指标研究 总被引：3，自引：0，他引：3
[目的]寻求先玉335合理的种植密度,明确种植密度对玉米性状指标的影响。[方法]以优质高产豫凑型玉米品种先玉335为试材,采用大垄双行种植方式,设4种种植密度（6．75万、7．50万、8．25万、9．00万株／hm^2）,研究不同密度对产量及其相关性状指标的影响。[结果]在大垄双行种植备件下,先玉335的产量随种植密度的加大呈降低趋势,在6．75万株／hm^2密度时,产量较高,玉米群体具有合理的株高和冠层结构,棒三叶叶绿素相对含量也较高。对株高、穗位高度以及LAI垂直分布的研究表明,该试验条件下,种植密度的增加会使玉米群体的抗倒伏能力降低,单株叶面积减少,群体LAI有所增加,LAI最大值出现的层次有所上升,玉米群体适宜高产的LAI在5．7左右。[结论]在试验条件下,先玉335适宜的种植密度为6．75万株／hm^2;IAI最大值出现的层次随着密度的增加上移。 相似文献