• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Effect of Fertilizing Level and Planting Densities on Yield and Nitrogen Utilization in Maize

    2015-11-18 08:02:10HuaTANChenglinZOUDeboZHENGAihuaHUANGRunxiuMOXinxingWElYongshengWUWeipingJlANGhuiWElKaijianHUANGMaizeResearchInstituteGuangxiAcademicofAgricultureScienceNanning530227China
    Agricultural Science & Technology 2015年3期
    關(guān)鍵詞:農(nóng)學氮素學報

    HuaTAN,Chenglin ZOU,Debo ZHENG,Aihua HUANG,Runxiu MO,Xinxing WEl,Yongsheng WU,Weiping JlANG,hui WEl,Kaijian HUANGMaize Research Institute,Guangxi Academic of Agriculture Science,Nanning 530227,China

    Effect of Fertilizing Level and Planting Densities on Yield and Nitrogen Utilization in Maize

    HuaTAN,Chenglin ZOU,Debo ZHENG,Aihua HUANG,Runxiu MO,Xinxing WEl,Yongsheng WU,Weiping JlANG,hui WEl,Kaijian HUANG
    Maize Research Institute,Guangxi Academic of Agriculture Science,Nanning 530227,China

    Elite maize hybrid Guidan0810 was selected as material,and the effects of fertilizing level and planting densities on yield and nitrogen utilization were discussed in the study.In field experiments as per double-cropping system,4 main plots (fertilization levels)and 6 subplots (planting densities)were set in a split plot design.The results suggested that yield had close relationship with fertilization levels and planting densities.Different fertilization levels and planting densities significantly affected yield.With the increase of nitrogen fertilization,nitrogen use efficiency,nitrogen agronomic efficiency and nitrogen physiological efficiency declined.Under the same fertilization level,nitrogen use efficiency,nitrogen agronomic efficiency and nitrogen physiological efficiency grew a little with the increase of planting density,so nitrogen efficiency could be improved by regulating planting density.The results also showed that A2 (including N 225.0 kg/hm2,P2O575.0 kg/hm2,K2O 187.5 kg/hm2)matching to B3(52 500 plants/hm2)or B4(60 000 plants/hm2)was a better design,which could obtain a higher yield in the range of 7 913.2-8 207.8 kg/hm2,respectively.

    Maize hybrid;Fertilizing level;Planting density;Effects

    M aize is the largest grain plant in China,concerning crop safety[1].Since the 1960s,maize has always played a key role in resolving subsistence problem,guaranteeing crop and forage safety,developing national economy,and relieving energy crisis[2].As breeding technology advances of maize,the update of new maize species significantly promotes maize production and the cultivation technology of new species has drawn much more attention in terms of exploiting species potential and increasing maize yield in recent years.Therefore,it is of significance to explore the effects of fertilizer quantity and planting density on yield and nitrogen use for maize species.

    Density is an important factor affecting maize yield[3],as well as a factor deciding physiological trait.For example,environmental factors,such as fertilizer,water,sunshine and temperature,would be adjusted by changing density[4]and it can be concluded that density is key for accomplishing a high maize yield[5]with high quality.What’s more,a rational density would coordinate yield components well[6-7].Therefore,it is necessary to balance nutrient demands and supply by adjusting group structure and fully exploit yield potential to improve benefits by maximizing local eco-condition.

    It is notable that a rational density and scientific fertilization are crucial for increasing crop yield[10].In order to get a high maize yield,it is necessary to make use of a rational density and appropriate fertilizer quantity[11].Fertilization would considerably increase accumulated dry matter to enhance the number of kernels per spike and hundred-kernel weight for further growth of the maize yield[12].With fertilization at a specific quantity,maize yield is increasing upon planting density,but declines at a certain extent[13-14].Given a denser density,excessive photo-synthate would be consumed by nitrogen metabolism,so that leaf ages faster and maize yield would be limited[15-16].It can be concluded that scientific adjustment of water and fertilizer,rational group structure and full use of local eco-condition are crucial for achieving a high yield of maize[17-18].

    In southern ecotope,researches available are few on the effects of different densities on yield and the effect of nitrogen use.The research explored the effects of different densities on yield and nitrogen use with Guidan No. 0810,a new hybrid maize species,as test materials in order to seek a highyielding cultivation technology characterized by optimizing fertilization,saving costs,using suitable planting density,rational group structure and improving sunshine and temperatures,which provides references for highyielding optimized cultivation of maize.

    Materials and Methods

    Test materials

    The test was conducted in a subcentral test base of Nanning,National Maize Improvement Center,at 107° 19′E and 22°12′N,with an elevation of 105 m in spring and autumn in 2012. The test material is Guidan No.0810,a hybrid maize,and test soils are sandy loams,containing organic matter of 1.96%,total N of 0.196%,total P of 0.058%,total K of 0.396%,available nitrogen of 53.5 mg/kg,available P(P2O5)of 17.9 mg/kg and available K(K2O)of 125.0 mg/kg,with pH value of 7.5.The preceding crop was sown with a maize tractor.

    Test design

    The test was carried out as per split block design.Specifically,the primary treatment mainly involved fertilization,including treatment A1 with pure N of 321.0 kg/hm2,P2O5of 107.0 kg/hm2,and K2O of 268.0 kg/hm2,treatment A2 with pure N of 225.0 kg/hm2,P2O5of 75.0 kg/hm2,and K2O of 187.5 kg/hm2,treatment A3 with pure N of 160.5 kg/hm2,P2O5of 53.5 kg/hm2,and K2O of 134.0 kg/hm2,and treatment A4 which was a control group without fertilizers.Sub-treatment referred to density,including treatment B1 with 37 500 plants/hm2,treatment B2 with 45 000 plants/hm2,treatment B3 with 52 500 plants/hm2,treatment B4 with 60 000 plants/hm2,treatment B5 with 67 500 plants/hm2and treatment B6 with 75 000 plants/hm2.

    Test methods

    The test was conducted as per randomized block design,with three repetitions.Specifically,the test included four lines,with line length of 5 m and line distance of 0.7 m.Furthermore,plant distance was designed as per densities,and fertilizers were urea containing 46.0%N,calcium magnesium phosphate fertilizer containing 18.0%P5O2,and potassium chloride containing 60%K2O.In addition,the fertilizer prices were as follows:N at 5.87 yuan/kg,P2O5at 4.12 yuan/kg,K2O at 8.0 yuan/kg,and maize price was 2.3 yuan/kg.It is notable that all P fertilizer,20%N fertilizer,and 20%K fertilizer were taken as base fertilizer,20%N fertilizer and 60%K fertilizer were as additional fertilizer,and rest N and K fertilizers were applied when the 11thleaf spread.The farmlands were managed as local method and maize of the middle two lines was harvested and dried until water content reduced to 14%.

    Data collection and calculation

    During ripening period,10 plants were measured in terms of characters in sequence in different test regions and 5 plants were collected from different regions,followed by kill-out at 105℃and drying at 80℃to obtain a constant weight in order to compute biological yield.Finally,the materials were ground to measure total N of the plant.

    After harvest,10 ear samples were collected randomly from every test region to observe the characters and total N was measured.The dried samples were ground and digested with concentrated H2SO4-H2O2,followed by measurement as per kjeldah method.

    Nitrogen use rate=(T he absorbed N quantity by plants in N fertilized test areas-T he absorbed N quantity in test area without fertilization)/T he quantity of applied N fertilizer×100%;

    Agronomic efficiency=(The yield in N fertilized test areas-Yield in control group)/The quantity of applied N fertilizer×100%;

    Nitrogen physiological efficiency=(The yield in N fertilized test areas-Yield in control group)/(The absorbed N quantity by plants in N fertilized test areas-The absorbed N quantity in test area without fertilization).

    The averages of the two seasons were analyzed with Excel 2007 and SAS 9.0.

    Results and Analysis

    Effects of fertilizations and planting densities on maize yield

    As shown in Table 1,maize yield reached significant differences,with different fertilizations (A),and with the same fertilization,but varied planting densities (B);the yield showed insignificant differences in the treatments involving fertilization and planting density(A×B).These indicated that both of fertilization and planting density have dramatic effects on maize yield.

    Comparisons of primary treatments(fertilization)on maize yield

    According to analysis of variance,maize yields in treatments A1(6 894.6 kg/hm2),A2(7 484.2 kg/hm2),and A3(6 949.5 kg/hm2)were significantly higher compared with A4 (4 551.9 kg/hm2),which indicated fertilization plays a key role for maize yield.The statistics suggested that maize yield of treatment A2 was considerably higher compared with treatments A1 and A3,and the yields of A1 and A3 showed little differences,which incorporated that the fertilization of treatment A2 performed better compared with treatments A1 and A3(Table 2).

    Comparisons of sub-treatments(planting density)on maize yield

    As shown in Table 2,the effects of planting densities tended to be volatile on maize yield.For example,maize yields were as follows:B3(7 013.8 kg/hm2)>B4(6 780.0 kg/hm2)>B5(6563.3 kg/hm2)>B2(6 433.8 kg/hm2)>B6(6 290.0 kg/hm2)>B1(5 739.4 kg/hm2);the yield of B3 was of significant differences with the yields of B2,B6 and B1;yield differences among treatments B3,B4 and B5 were not so significant,which was also true among treatments B2,B4,B5 and B6;the yields of B2,B3,B4,B5 and B6 reached significant differences with treatment B1.When planting density grew from B1 (37 500 plants/hm2)toB3 (52 500 plants/hm2),maize yield increased from 5 739.4 to 7 013.8 kg/hm2,and when planting density grew from 52 500 to 75 000 plants/hm2,maize yield started declining from 7 013.8 to 6 290.0 kg/hm2.It can be concluded that a rational planting density is a beneficial factor for a high yield of maize and B2 of 52 500 plants/hm2proves the optimal density.

    Table 1 Variance analysis of yield

    Table 2 Average yields of treatments with different fertilizations and densities

    Comparisons of different planting densities on maize yield with fertilization fixed

    According to variance analysis of the treatment with the same fertilization but different densities,yields of B2,B3,B4 and B5 showed little differences with fertilization A1.Specifically,maize yield of treatment B3 performed significantly better compared with treatments B1 and B6;yield differences among B1,B2,B5 and B6 showed insignificant.With fertilization A2,maize yields of B3,B4 and B5 performed better compared with B1 and maize yields among B1,B2 and B6 showed insignificant differences. With fertilization A3,maize yields of B3 and B4 were significantly better compared with B1,maize yields of B2,B4,B5 and B6 reached insignificant differences,and maize yields of B1,B2,B5 and B6 were of insignificant differences.With A4,maize yields with different densities differed,with little differences(Table 3).It can be concluded that B3 density performed the best, followed by B4.

    Table 3 The effects of fertilization and planting density on maize yield and benefits

    Effects of fertilization and planting density on maize yield and benefit

    As shown in Table 3,with fertilization A3,maize yields tended to be volatile in the range of 6 135.2-7 609.1 kg/hm2as per different densities(B),as follows:B3>B4>B5>B2>B6>B1,and the yields increased in 1 813.4-3 035.7 kg/hm2compared with treatment A4.With fertilizer investment costs deducted,net profits kept in the range of 198.40 yuan/hm2(deficit)to 2 513.40 yuan/hm2(benefits)and input-output ratio referred to that net profits was in the range of 0.06 yuan/hm2(deficit)to 0.56 profits with one yuan fertilizer cost.In general,net profits and input-output ratios were as follows:B3﹥B4﹥B2﹥B5﹥B1﹥B6;with fertilizer A2,maize yields in treatment B maintained in 6 402.1-8 207.8 kg/hm2,and from high to low were B3>B4>B5>B6>B2>B1,which increased by 2 242.6-3 534.6 kg/hm2. With fertilizer cost deducted,net profit was in the range of 2 032.21-5 233.86 yuan/hm2,and input-output ratio in 0.65-1.67.What’s more,both of net profit and input-output ratio from high to low were B3>B4>B5>B2>B6>B1. With fertilization of A3,maize yields of treatment B kept in the range of 6 260.8-7 665.2 kg/hm2,and from high to low were B3>B4>B5>B2>B6>B1,increasing by 1 743.630 919 kg/hm2compared with treatment A4;with different densities,the increased yields were B3>B4>B2>B5>B1>B6. With fertilizer cost deducted,net profits tended to be volatile in 1 775.78-4 876.92 yuan/hm2,and input-output ratio was in 0.80-2.18;both of net profits and input-output ratio were B3>B4>B2>B5>B1>B6.

    It can be concluded with different fertilizer quantities,net profit and inputoutput ratio both kept decreasing upon fertilizer quantity and a high net profit and input-output ratio can be reached by adjusting planting density given a fixed fertilizer quantity.

    Effects of fertilization and planting density on maize biological yield and nitrogen use

    Fertilizer quantity and planting density have varying effects on maize biological yield and the use of nitrogen(Table 4).Specifically,in treatment A1,biological yields were in the range of 15 150.9-19 015.1 kg/hm2with different planting densities,the absorbed N quantity in the range of 183.0-218.9 kg/hm2and the use rate of nitrogen was in 21.0%-28.9%.It can be concluded that the fertilization of pure N per kg would obtain maize yield of 9.5-5.6 kg and physiological efficiency of crops was 23.0-32.7 kg in transforming absorbed nitrogen to economic yield.With fertilization A2,biological yields kept in the range of 14 922.0-19 415.5 kg/hm2,the absorbed pure N was in 172.9-209.7 kg/hm2,the use rate of nitrogen was in 25.5%-37.2%,agronomic efficiency was in 16.2-10.0 kg,and physiological efficiency of N maintained 43.5-33.7 kg under influence of different planting densities. With fertilization A3,biological yields kept in 14 727.4-17 839.7 kg/hm2,the absorbed N was in 158.3-192.8 kg/hm2,the use rate of nitrogen was in 26.9%-41.4%,agronomic efficiency was in 19.3-10.9 kg,and physiological efficiency of N maintained 25.3-50.2 kg under influence of different planting densities.It can be concluded from analysis and comparisons that as N quantity grew,the use rate,agronomic efficiency,and physiological efficiency of nitrogen all grew,and it is effective to make full use of nitrogen by adjusting planting density.However,it is notable that excessive high content of N actually increases the possibility of inorganic nitrogen into soils.

    Effects of fertilization and planting density on maize and yield components

    As shown in Table 5,plant height and ear height reached extremely significant differences with varying fertilizer quantities or the same fertilizer quantity but different densities;the effects from interplay of fertilizer quantity and planting density(A×B)differed little on plant and ear heights.Furthermore,for fertilizations A1 and A2,plant and ear heights differed insignificantly,which kept considerably higher compared with fertilizations A3 and A4;plant and ear heights of fertilization A3 performed higher compared with A4;among different fertilizer quantities(A)or with the same fertilizer quantity,but different densities(B),stem diameter showed little differences.These all incorporated that both of fertilization and density have dramatic effects on plant and ear heights,but little effects on stem diameter.

    Table 4 Effects of fertilization and planting density on biological yield and nitrogen use rate of maize

    With varied fertilizer quantities(A)or with the same fertilizer but different densities(B),ear length,ear diameter,hundred-kernel weight and the number of kernel reached extremely significant differences and the interplay of fertilization and density(A×B)has positive effects on ear length,ear diameter,hundred-kernel weight and the number of ear,with insignificant differences. For fertilizations A1,A2 and A3,ear length,ear diameter,and the number of ear differed insignificantly,but all performed better compared with A4;hundred-kernel weights in the fertilization treatments A1,A2 and A3 were significantly higher compared with treatment A4,and hundred-weight showed insignificant differences between A1 and A3 and A2 and A3.It can be concluded that maize bald-top rate showed insignificant differences among treatments with different fertilizer quantities (A)and different planting densities (B)with a fixed fertilizer quantity,which suggested that baldtop rate was less influenced.

    Conclusions and Discussions

    The research indicated that among treatments with different fertilizer quantities,maize yield in A2 reached 7 484.2 kg/hm2that was considerably higher compared with A1 of 6 894.6 kg/hm2and A3 of 6 949.5 kg/hm2.With the same fertilizer quantity,the effects of planting density(B)tended to be volatile on maize yield. For example,maize yield increased from 5 739.4 kg/hm2of B1 to 7 013.8 kg/hm2of B3 upon planting density. However,as the density grew,maize yield continued growth to75000 plants/hm2,followed by decreasing. These incorporated the effects of fertilizer quantity and planting density on maize yield,whose effects were much significant on ear length,the number of kernel,and hundred-kernel weight,which coincided with researches available[10-11,14].The research also showed that fertilization in A2 performed better compared with A1 and A3,and planting density of B3 was much suitable.

    The use rate of nitrogen reflects the recycling rate of N fertilizers in soils by crops;agronomic efficiency of nitrogen the increased number of kernel contributed by N fertilizer per unit;physiological efficiency of nitrogen is the increased yield of kernel of groundpart crops by absorbing nitrogen per unit fertilizer.These are indices indicating the use rate of N fertilizer from different perspectives,and the differences of yield are a result of nitrogen absorption and physiological utilization efficiency.

    According to the research,in treatment A1,the use rate of nitrogen was in the range of 21.0%-28.9%;maize yield was of 9.5-5.6 kg;nitrogen physiological efficiency of crops transforming absorbed nitrogen to economic yield was in the range of 23.0%-32.7%.In treatment A2,the use rate of nitrogen was in the range of25.5%-37.2%;maize yield was of 16.2-10.0 kg;nitrogen physiological efficiency of crops transforming absorbed nitrogen to economic yield was in the range of 43.5%-33.7%.In treatment A3,the use rate of nitrogen was in the range of 26.9%-41.4%;maize yield was of 19.3-10.9 kg;nitrogen physiological efficiency of crops transforming absorbed nitrogen to economic yield was in the range of 25.3%-50.2%.These demonstrated that with increasing of N fertilizer,nitrogen use rate,nitrogen agronomic efficiency and physiological efficiency all kept declining,and with the same fertilizer quantity,the three factors all improved as density grew,which are in consistent with researches available[7-8].The research indicated that with a fixed fertilizer quantity,the role played by nitrogen can be fully exploited by adjusting planting density.

    The research conducted a test on a double cropping system,and it is proved that maize yield can be as high as 7 913.2-8 207.8 kg/hm2with pure N of 225.0 kg/hm2,P2O5of 75.0 kg/hm2,K2O of 187.5 kg/hm2,and planting density of 52 500 (B3)-60 000(B4)plants/hm2.

    Still,the research just explored the effects of fertilization and planting density on yield and nitrogen use,and further attention should be paid to the effects of fertilization and planting density on nutrients of kernel,as well as nitrogen movements.

    References

    [1]QIU HG(仇煥廣),ZHANG SH(張世煌),YANGF J(楊軍),et al.Development of China’s maize industry challenges in the future and policy suggestions(中國玉米產(chǎn)業(yè)的發(fā)展趨勢、面臨的挑戰(zhàn)與政策建議)[J].Journal of Agricultural Science and Technology(中國農(nóng)業(yè)科技導(dǎo)報),2013,15(1):20-24

    [2]DAI JR(戴景瑞),E LZ(鄂立柱).Scientific and technological innovation of maize breeding in China(我國玉米育種科技創(chuàng)新問題的幾點思考)[J].Journal of Maize Sciences(玉米科學),2010,18(1):1-5

    [3]YAO JJ(要娟娟),XUE ZM(薛澤民),ZHAO PP(趙萍萍),et al.Effects of fertilization and planting density to SPAD value in spring corn(施肥與種植密度對春玉米SPAD值的影響)[J].Journal of Shanxi Agricultural Sciences(山西農(nóng)業(yè)科學),2011,39(10):1060-1063.

    [4]LIU WR(劉武仁),LIU FC(劉鳳成),F(xiàn)ENG YC(馮艷春),et al.Research of physical signs of maize under different densities(玉米不同密度的生理指標研究)[J]. Journal of Maize Sciences(玉米科學),2004,12(supplement):82-83,87.

    [5]BAI ZY(白志英),LI CD(李存東),ZHENG JF(鄭金風),et al.The effect of plant density on the physiological characters and yield of maize Xianyu 335 and Zhengdan 958(種植密度對玉米先玉335和鄭單958生理特性、產(chǎn)量的影響)[J].Act a Agricult urae Boreali-Sinica(華北農(nóng)學報),2010,25(Z1):166-169.

    [6]ZHANG JW(張吉旺),HU CH(胡昌浩),WANG KJ(王空軍),DONG ST(董樹亭),LIU P(劉鵬).Effects of plant density on forage nutritive value of whole plant corn(種植密度對全株玉米飼用營養(yǎng)價值的影響)[J].Scientia Agricultura Sinica(中國農(nóng)業(yè)科學),2005,38(6):1126-1131]

    [7]LIU X(劉霞),LI ZX(李宗新),WANG QC(王慶成),et al.Effects of planting density on filling process,yield and quality of different maize varieties(種植密度對不同粒型玉米品種子粒灌漿進程、產(chǎn)量及品質(zhì)的影響)[J].Journal of Maize Sciences(玉米科學),2007,15(6):75-78]

    [8]DUAN MX(段民孝).Some advice on corn breeding obtained from the elite varieties of Nongda 108 and Zhengdan 958(從農(nóng)大108和鄭單958中得到的玉米育種啟示)[J].Journal of Maize Sciences(玉米科學),2005,13(4):49-52.

    [9]XUE JQ(薛吉全),ZHANG RH(張仁和),MA GS(馬國勝),et al.Effects of plant density,nitrogen application and water stress on yield formation of maize(種植密度?氮肥和水分脅迫對玉米產(chǎn)量形成的影響)[J].Acta Agronomica Sinica(作物學報),2010,36(6):1022-1029.

    [10]WANG HT(王宏庭),WANG B(王斌),ZHAO PP(趙萍萍),et al.The effects of planting method,density,and fertilizer quantity on maize yield and fertilizer use rate(種植方式、密度、施肥量對玉米產(chǎn)量和肥料利用率的影響)[J].Journal of Maize Sciences(玉米科學),2009,17(5):104-107.

    [11]FAN HM(范厚明),F(xiàn)U YC(付業(yè)春).Research on the impact of planting density and amount of nitrogen fertilizer on high-yielding cultivation of hybrid corn(種植密度和氮肥用量在玉米高產(chǎn)栽培中的重要性研究)[J].Journal of Anhui Agricultural Sciences(安徽農(nóng)業(yè)科學),2009,37(16):7406-7407.

    [12]CAO SB(曹勝彪),ZHANG JW(張吉旺),DONG ST(董樹亭),et al.The effects of fertilizer quantity and planting density on yield and nitrogen use rate of high-yielding summer maize(施氮量和種植密度對高產(chǎn)夏玉米產(chǎn)量和氮素利用效率的影響)[J].Plant Nutrition and Fertilizer Science(植物營養(yǎng)與肥料學報),2012,18(6):1343-1353.

    [13]CHEN CY(陳傳永),HOU HP(侯海鵬),LI Q (李強),et al.Effects of planting density on photosynthetic characteristics and changes of carbon and nitrogen in leaf of different corn hybrids(種植密度對不同玉米品種葉片光合特性與碳、氮變化的影響)[J].Acta Agronomica Sinica(作物學報),2010,36(5): 871-878.

    [14]TIAN HL(田紅琳),YANG H(楊華),ZHOU RP(周汝平),et al.Effects of planting densityon maize characteristics and yields(種植密度對不同玉米性狀和產(chǎn)量的影響)[J].Chinese Agricultural Science Bulletin(中國農(nóng)學通報),2013,29(30):100-104.

    [15]LV LH(呂麗華),TAO HB(陶洪斌),WANG P(王璞),et al.Effects of planting density on carbon and nitrogen metabolism and nitrogen use rate by summer maize(種植密度對夏玉米碳氮代謝和氮利用率的影響)[J].Acta Agronomica Sinica(作物學報),2008,34(4): 718-723.

    [16]SHEN LX(申麗霞),WANG P(王璞),ZHANG RB(張軟斌).Effect of nitrogen supply on yield and grain filling in summer maize with different crop density(施氮對不同種植密度下夏玉米產(chǎn)量及子粒灌漿的影響)[J].Plant Nutrition and Fertilizer Science(植物營養(yǎng)與肥料學報),2005,11(3):314-319.

    [17]薛珠政,盧和頂,林建新,等.種植密度對玉米單株和群體效應(yīng)的影響[J].玉米科學,1999,7(2):52-54

    [18]XUE JQ(薛吉全),MA GS(馬國勝). Maize canopy characters and yield formation(玉米群體冠層特征與產(chǎn)量形成的研究).Essays of the 2ndNational Crop Cultivation Physiological Conferences by Young and Middle-aged People(第二屆全國中青年作物栽培作物生理學術(shù)會論文集),1996:321-327.

    [19]SONG B(宋碧),ZHANG J(張軍),LIU B(劉兵),et al.Effects of nitrogen application level on nitrogen absorption and efficiency of maize“Qianxing 201”(不同施氮量對玉米‘黔興201’氮素吸收特性及氮效率的影響)[J].Chinese A-gricultural Science Bulletin(中國農(nóng)學通報),2013,29(30):50-54.

    [20]ZHANG YL(張亞麗),F(xiàn)AN JB(樊劍波),DUAN YH(段英華),et al.Differences and assessment on nitrogen use rate of rice with varied genotypes(不同基因型水稻氮利用效率的差異及評價)[J]. Acta Pedologica Sinica(土壤學報),2008,45(2):267-273.

    [21]WU WG(吳文革),RUAN XM(阮新民),SHI FZ(施伏芝).Effects of fertilizations on nitrogen absorption rate and yield of Indica rice(不同施氮水平對中秈稻氮素吸收利用及其產(chǎn)量的影響)[J]. Journal of Anhui Agricultural Sciences(安徽農(nóng)業(yè)科學),2007,35(5):1403-1405.

    Responsible editor:Xiaoxue WANG

    Responsible proofreader:Xiaoyan WU

    施肥水平與種植密度對玉米產(chǎn)量和氮素利用的效應(yīng)

    譚 華,鄒成林,鄭德波,黃愛花,莫潤秀,韋新興,吳永升,蔣維萍,韋 慧,黃開健 (廣西農(nóng)業(yè)科學院玉米研究所,廣西南寧 530227)

    為探討不同施肥水平與種植密度對玉米產(chǎn)量及氮素利用的作用效應(yīng),以玉米雜交種‘桂單 0810’為材料,裂區(qū)設(shè)計,設(shè)置4個施肥水平和6個種植密度,進行一年兩季田間試驗。結(jié)果表明:不同施肥水平與不同種植密度對玉米產(chǎn)量都有顯著的作用效應(yīng);隨著施肥水平提高,氮素利用率、氮素農(nóng)學效率、氮素生理效率均有所降低,同一施肥水平隨密度增加,氮素利用率、氮素農(nóng)學效率、氮素生理效率均有所提高,通過調(diào)節(jié)種植密度可以較好發(fā)揮氮素的作用效率;以(A2)施純N 225.0 kg/hm2、P2O575.0 kg/hm2、K2O 187.5 kg/hm2與種植密度在 (B3)52 500株/hm2至 (B4)60 000株/hm2玉米產(chǎn)量可達7913.2~8207.8 kg/hm2是一種較優(yōu)的密、肥配合選擇。

    玉米雜交種;施肥水平;種植密度;效應(yīng)

    現(xiàn)代農(nóng)業(yè)產(chǎn)業(yè)技術(shù)體系廣西創(chuàng)新團隊建設(shè)專項(nycytxgxcxtd-07-B);國家支撐計劃子課題“廣西玉米抗旱關(guān)鍵技術(shù)集成與示范”(2012BAD40B04-2)。

    譚華(1959-),男,廣西貴港人,研究員,主要從事玉米遺傳育種及高產(chǎn)優(yōu)化栽培技術(shù)研究,E-mail:tanhua19881206@126.com。*通訊作者,研究員,主要從事玉米遺傳育種及科研管理,E-mail:hkjian@gxass.net。

    2015-01-03

    2015-02-13

    Supported by Gyangxi Innovation Team of Modern Agriculture Industry Technology System (nycytxgxcxtd-07-B);Sub-topic of National Science and Technology Support Program(2012BAD40B04-2)

    .E-mail:hkjian@gxass.net

    January 3,2015Accepted:February 13,2015

    猜你喜歡
    農(nóng)學氮素學報
    中國古代農(nóng)學風土論的形成、演變與價值
    蒲松齡《農(nóng)桑經(jīng)》的農(nóng)學思想及其當代啟示
    《廣西農(nóng)學報》投稿指南
    致敬學報40年
    農(nóng)學
    新校長(2016年5期)2016-02-26 09:29:00
    學報簡介
    學報簡介
    《深空探測學報》
    楸樹無性系苗期氮素分配和氮素效率差異
    基于光譜分析的玉米氮素營養(yǎng)診斷
    久久这里只有精品19| 欧美日韩中文字幕国产精品一区二区三区 | 一级a爱片免费观看的视频| 人妻一区二区av| а√天堂www在线а√下载 | 亚洲成av片中文字幕在线观看| а√天堂www在线а√下载 | 岛国毛片在线播放| 午夜老司机福利片| 午夜福利影视在线免费观看| 精品人妻1区二区| 1024香蕉在线观看| 亚洲第一av免费看| 国产在线精品亚洲第一网站| 日本vs欧美在线观看视频| 久久久国产成人免费| 色婷婷av一区二区三区视频| 人人妻人人澡人人看| 国产熟女午夜一区二区三区| 久久午夜亚洲精品久久| 一区在线观看完整版| 国产成人免费观看mmmm| 91麻豆av在线| 久久久久精品国产欧美久久久| 我的亚洲天堂| 天天躁日日躁夜夜躁夜夜| 成年人午夜在线观看视频| 亚洲熟女毛片儿| 悠悠久久av| 波多野结衣av一区二区av| 精品一品国产午夜福利视频| 99精品欧美一区二区三区四区| 1024视频免费在线观看| 丰满人妻熟妇乱又伦精品不卡| 757午夜福利合集在线观看| 新久久久久国产一级毛片| 女人久久www免费人成看片| 亚洲人成电影观看| 50天的宝宝边吃奶边哭怎么回事| 热re99久久精品国产66热6| 国产av一区二区精品久久| 久久人妻熟女aⅴ| 美女 人体艺术 gogo| 人妻丰满熟妇av一区二区三区 | 又大又爽又粗| 免费在线观看黄色视频的| 夜夜躁狠狠躁天天躁| 日韩中文字幕欧美一区二区| 国产欧美日韩精品亚洲av| 国产成人影院久久av| 色尼玛亚洲综合影院| 性少妇av在线| 亚洲国产欧美网| 国产欧美日韩一区二区三区在线| videosex国产| 精品国产一区二区久久| 天天躁日日躁夜夜躁夜夜| 人人妻,人人澡人人爽秒播| 国产亚洲欧美在线一区二区| 免费不卡黄色视频| 老司机深夜福利视频在线观看| 久久精品国产a三级三级三级| 啦啦啦 在线观看视频| tocl精华| 黄色毛片三级朝国网站| videos熟女内射| 国产男女超爽视频在线观看| 成年人午夜在线观看视频| 性色av乱码一区二区三区2| 桃红色精品国产亚洲av| 我的亚洲天堂| 久久国产精品影院| 叶爱在线成人免费视频播放| 中文字幕色久视频| 建设人人有责人人尽责人人享有的| 女人久久www免费人成看片| 午夜成年电影在线免费观看| 18禁国产床啪视频网站| 999久久久国产精品视频| av免费在线观看网站| 成年版毛片免费区| 亚洲三区欧美一区| 久久香蕉精品热| 妹子高潮喷水视频| 欧美亚洲日本最大视频资源| 亚洲精品国产区一区二| 亚洲欧美日韩另类电影网站| 欧美精品亚洲一区二区| 91成年电影在线观看| 国产99久久九九免费精品| 人人妻人人爽人人添夜夜欢视频| 黑人猛操日本美女一级片| 美女午夜性视频免费| av福利片在线| 久久人人97超碰香蕉20202| 久久久国产成人免费| 一级片免费观看大全| 午夜免费观看网址| 成人永久免费在线观看视频| www.精华液| 国产极品粉嫩免费观看在线| 在线看a的网站| 男女下面插进去视频免费观看| 欧美丝袜亚洲另类 | 一级毛片女人18水好多| 三上悠亚av全集在线观看| 深夜精品福利| 免费观看a级毛片全部| 精品少妇久久久久久888优播| 中文亚洲av片在线观看爽 | 亚洲在线自拍视频| 国产成人欧美| 国产精品.久久久| 欧美成狂野欧美在线观看| 成熟少妇高潮喷水视频| 国产精品1区2区在线观看. | 99久久综合精品五月天人人| 91在线观看av| 757午夜福利合集在线观看| 久久久久视频综合| 国产亚洲欧美在线一区二区| 久久人人97超碰香蕉20202| 亚洲国产中文字幕在线视频| 欧美日韩一级在线毛片| 1024视频免费在线观看| 午夜亚洲福利在线播放| 亚洲精品自拍成人| 9色porny在线观看| 自线自在国产av| 女人久久www免费人成看片| 视频区图区小说| 少妇猛男粗大的猛烈进出视频| www.自偷自拍.com| 天天操日日干夜夜撸| 国产男女内射视频| 亚洲精品中文字幕在线视频| 亚洲av电影在线进入| 精品无人区乱码1区二区| 亚洲午夜理论影院| 啦啦啦免费观看视频1| 亚洲七黄色美女视频| 精品欧美一区二区三区在线| 午夜两性在线视频| 国产精品九九99| 一进一出抽搐动态| 在线观看舔阴道视频| 十八禁高潮呻吟视频| 国产一区二区三区综合在线观看| 久久精品91无色码中文字幕| 两个人看的免费小视频| 亚洲国产精品合色在线| 精品视频人人做人人爽| 久久精品91无色码中文字幕| 日日摸夜夜添夜夜添小说| 侵犯人妻中文字幕一二三四区| 另类亚洲欧美激情| 久久这里只有精品19| 搡老熟女国产l中国老女人| 精品亚洲成a人片在线观看| 大陆偷拍与自拍| 亚洲精品乱久久久久久| 超碰97精品在线观看| 黄色视频不卡| 亚洲第一欧美日韩一区二区三区| 黄色成人免费大全| 国产av精品麻豆| 日韩一卡2卡3卡4卡2021年| 老司机亚洲免费影院| 热99久久久久精品小说推荐| 欧美日韩一级在线毛片| 精品一区二区三区av网在线观看| 精品高清国产在线一区| 亚洲成人国产一区在线观看| 久热这里只有精品99| 久久精品熟女亚洲av麻豆精品| 丰满的人妻完整版| 欧美日韩亚洲综合一区二区三区_| 黄片大片在线免费观看| 国产成人免费观看mmmm| 亚洲欧美日韩高清在线视频| 水蜜桃什么品种好| 啪啪无遮挡十八禁网站| 免费在线观看亚洲国产| 精品国产乱子伦一区二区三区| 国产精品乱码一区二三区的特点 | 亚洲人成伊人成综合网2020| xxx96com| 丝袜美足系列| 午夜福利影视在线免费观看| 久久久久久免费高清国产稀缺| 久久精品人人爽人人爽视色| 亚洲精品国产一区二区精华液| 在线观看66精品国产| 欧美黄色片欧美黄色片| 亚洲一区高清亚洲精品| 久热爱精品视频在线9| 19禁男女啪啪无遮挡网站| 在线观看免费午夜福利视频| 又黄又爽又免费观看的视频| 精品乱码久久久久久99久播| 女人被狂操c到高潮| 下体分泌物呈黄色| 免费高清在线观看日韩| 国产在线精品亚洲第一网站| 亚洲国产精品sss在线观看 | 免费不卡黄色视频| 亚洲成人手机| 欧美日韩瑟瑟在线播放| 在线观看免费午夜福利视频| 女警被强在线播放| 高清av免费在线| 午夜91福利影院| 午夜激情av网站| 亚洲专区中文字幕在线| 一级毛片高清免费大全| 国产成人av教育| 黑人巨大精品欧美一区二区mp4| 曰老女人黄片| 精品国内亚洲2022精品成人 | 欧美精品啪啪一区二区三区| 国产高清视频在线播放一区| 99热只有精品国产| 桃红色精品国产亚洲av| xxx96com| 久久久精品区二区三区| 天堂动漫精品| 国产色视频综合| 精品第一国产精品| 国产在视频线精品| 亚洲成人免费av在线播放| 亚洲熟妇中文字幕五十中出 | 久久这里只有精品19| 丝袜美足系列| 中文字幕人妻丝袜一区二区| 成熟少妇高潮喷水视频| 亚洲欧美日韩另类电影网站| av视频免费观看在线观看| 成人亚洲精品一区在线观看| 久久久久国产精品人妻aⅴ院 | 精品人妻熟女毛片av久久网站| 亚洲一码二码三码区别大吗| 中文字幕人妻熟女乱码| 两个人看的免费小视频| 久久久精品区二区三区| 午夜福利,免费看| 18在线观看网站| 欧美久久黑人一区二区| 欧美日韩黄片免| 热99久久久久精品小说推荐| 久久久久国内视频| 免费观看人在逋| 女人高潮潮喷娇喘18禁视频| 亚洲国产精品一区二区三区在线| 国产亚洲欧美98| 亚洲 欧美一区二区三区| 午夜视频精品福利| 中文字幕人妻丝袜一区二区| 黄色片一级片一级黄色片| 看免费av毛片| av免费在线观看网站| 国产又色又爽无遮挡免费看| 99re6热这里在线精品视频| 国产成人精品无人区| 久久久久视频综合| 热99国产精品久久久久久7| 亚洲欧美色中文字幕在线| 国产亚洲精品久久久久5区| 亚洲熟女精品中文字幕| 中文字幕精品免费在线观看视频| 精品人妻熟女毛片av久久网站| 自拍欧美九色日韩亚洲蝌蚪91| 久久久久久免费高清国产稀缺| 国产精品.久久久| 国产日韩一区二区三区精品不卡| 午夜免费成人在线视频| 国产av又大| 欧美日韩av久久| 国产精品一区二区在线观看99| 国产aⅴ精品一区二区三区波| 涩涩av久久男人的天堂| 亚洲一卡2卡3卡4卡5卡精品中文| 亚洲色图av天堂| 久久久国产精品麻豆| 国产人伦9x9x在线观看| 午夜福利欧美成人| 欧美人与性动交α欧美精品济南到| 亚洲自偷自拍图片 自拍| 天堂√8在线中文| 久久精品国产99精品国产亚洲性色 | 热99国产精品久久久久久7| 捣出白浆h1v1| 人人澡人人妻人| 国产xxxxx性猛交| 69精品国产乱码久久久| 国产精品1区2区在线观看. | 中文字幕高清在线视频| 欧美黑人欧美精品刺激| 在线播放国产精品三级| 精品一品国产午夜福利视频| 国产色视频综合| 成人18禁高潮啪啪吃奶动态图| 美女高潮到喷水免费观看| 色老头精品视频在线观看| av在线播放免费不卡| 国产欧美日韩一区二区三| 亚洲五月婷婷丁香| 香蕉久久夜色| 国产精品二区激情视频| 精品一区二区三区四区五区乱码| 欧美乱码精品一区二区三区| 久久亚洲精品不卡| 在线观看免费午夜福利视频| 午夜激情av网站| 视频区欧美日本亚洲| av一本久久久久| 99国产极品粉嫩在线观看| 国产精品 国内视频| 丁香六月欧美| 国产一区在线观看成人免费| 亚洲五月天丁香| 看片在线看免费视频| 久久狼人影院| 亚洲人成电影观看| 国产亚洲精品一区二区www | 亚洲五月天丁香| 一级毛片精品| 丁香欧美五月| 一区在线观看完整版| 香蕉久久夜色| 人妻一区二区av| 无人区码免费观看不卡| 女性被躁到高潮视频| 亚洲精品美女久久久久99蜜臀| 国产成人欧美在线观看 | 一级作爱视频免费观看| a级毛片黄视频| 免费高清在线观看日韩| 最近最新中文字幕大全电影3 | 成年动漫av网址| 亚洲一区二区三区欧美精品| 热re99久久国产66热| 丝袜在线中文字幕| 人人妻人人澡人人爽人人夜夜| 大片电影免费在线观看免费| 久久久精品区二区三区| 老熟女久久久| 日韩三级视频一区二区三区| 亚洲人成伊人成综合网2020| 精品福利观看| 国产一区二区三区综合在线观看| 亚洲一区高清亚洲精品| 午夜两性在线视频| 国产免费现黄频在线看| 一级片'在线观看视频| 黄色 视频免费看| 国产亚洲精品久久久久5区| 精品第一国产精品| 免费看a级黄色片| 这个男人来自地球电影免费观看| 99精品在免费线老司机午夜| 国产又爽黄色视频| 香蕉国产在线看| 香蕉久久夜色| 午夜福利,免费看| 精品久久久久久电影网| 欧美日韩亚洲高清精品| 最近最新免费中文字幕在线| 一级黄色大片毛片| 国产精品久久视频播放| 在线观看免费视频日本深夜| 男人的好看免费观看在线视频 | 黄网站色视频无遮挡免费观看| 午夜影院日韩av| 久久精品熟女亚洲av麻豆精品| 老鸭窝网址在线观看| 日日爽夜夜爽网站| 丁香欧美五月| 免费观看a级毛片全部| www日本在线高清视频| 成年人免费黄色播放视频| 女人精品久久久久毛片| 亚洲精品中文字幕在线视频| 69精品国产乱码久久久| 天天躁夜夜躁狠狠躁躁| 老司机午夜十八禁免费视频| 午夜福利视频在线观看免费| 两人在一起打扑克的视频| 亚洲av成人不卡在线观看播放网| 日本wwww免费看| 日韩欧美国产一区二区入口| 亚洲免费av在线视频| 涩涩av久久男人的天堂| 中出人妻视频一区二区| av在线播放免费不卡| 欧美日韩亚洲国产一区二区在线观看 | 大香蕉久久网| 真人做人爱边吃奶动态| 成在线人永久免费视频| 精品卡一卡二卡四卡免费| 五月开心婷婷网| 少妇猛男粗大的猛烈进出视频| 亚洲av电影在线进入| netflix在线观看网站| 国产av精品麻豆| 日韩免费高清中文字幕av| 亚洲性夜色夜夜综合| 好看av亚洲va欧美ⅴa在| 51午夜福利影视在线观看| 又黄又粗又硬又大视频| 国产成人精品无人区| 9热在线视频观看99| 69av精品久久久久久| 亚洲午夜精品一区,二区,三区| 免费人成视频x8x8入口观看| 真人做人爱边吃奶动态| 搡老岳熟女国产| 久久久久久人人人人人| 亚洲av电影在线进入| 搡老乐熟女国产| 热99久久久久精品小说推荐| 高清av免费在线| 国产一区有黄有色的免费视频| 国产国语露脸激情在线看| 曰老女人黄片| 男女免费视频国产| 在线观看免费高清a一片| 国产又爽黄色视频| 女人精品久久久久毛片| 999久久久国产精品视频| 十八禁人妻一区二区| 一本大道久久a久久精品| 国产一区二区激情短视频| 国产精品久久电影中文字幕 | 99精品欧美一区二区三区四区| 国产亚洲欧美精品永久| 久久久国产欧美日韩av| 桃红色精品国产亚洲av| 亚洲国产欧美网| 国产欧美亚洲国产| 最近最新中文字幕大全电影3 | 99在线人妻在线中文字幕 | 欧美老熟妇乱子伦牲交| 91麻豆av在线| 亚洲精品在线观看二区| 午夜精品在线福利| 亚洲一区中文字幕在线| 91av网站免费观看| 男男h啪啪无遮挡| 十八禁网站免费在线| 一级片'在线观看视频| 久久精品国产a三级三级三级| 看黄色毛片网站| 亚洲,欧美精品.| 99久久综合精品五月天人人| 午夜精品国产一区二区电影| 18在线观看网站| 超碰成人久久| 黄色视频,在线免费观看| 一级毛片女人18水好多| 国产精品国产av在线观看| 极品人妻少妇av视频| 国产精品1区2区在线观看. | 法律面前人人平等表现在哪些方面| 亚洲成人免费av在线播放| 欧美av亚洲av综合av国产av| 黄色视频不卡| 我的亚洲天堂| 91精品三级在线观看| 91老司机精品| 亚洲成av片中文字幕在线观看| 黑人欧美特级aaaaaa片| 亚洲熟妇中文字幕五十中出 | netflix在线观看网站| 欧美午夜高清在线| 国产人伦9x9x在线观看| 18禁国产床啪视频网站| 两个人看的免费小视频| 欧美黑人欧美精品刺激| 亚洲欧美日韩高清在线视频| 国产欧美日韩精品亚洲av| 国产片内射在线| 日韩欧美三级三区| 制服人妻中文乱码| 久久精品国产清高在天天线| 久久ye,这里只有精品| 日韩欧美三级三区| 精品一区二区三区av网在线观看| 99国产精品免费福利视频| 欧美久久黑人一区二区| 亚洲av成人av| av国产精品久久久久影院| 女人久久www免费人成看片| 午夜日韩欧美国产| 国产一区二区三区在线臀色熟女 | 亚洲色图av天堂| 久久久久久久久久久久大奶| 一边摸一边抽搐一进一出视频| 欧美日韩乱码在线| 亚洲一区二区三区不卡视频| 日本a在线网址| 亚洲国产精品合色在线| 国产精品 国内视频| 亚洲午夜精品一区,二区,三区| 久久精品国产亚洲av高清一级| 91九色精品人成在线观看| 国产男女超爽视频在线观看| 9191精品国产免费久久| 人人妻人人澡人人爽人人夜夜| 亚洲午夜理论影院| 国产精品一区二区在线观看99| 精品国产国语对白av| 黄色视频,在线免费观看| 成人黄色视频免费在线看| 黄色丝袜av网址大全| 久久国产精品男人的天堂亚洲| 99久久国产精品久久久| 纯流量卡能插随身wifi吗| 夜夜爽天天搞| 69精品国产乱码久久久| 国产精品1区2区在线观看. | 高清毛片免费观看视频网站 | 50天的宝宝边吃奶边哭怎么回事| 99精品欧美一区二区三区四区| 国产高清videossex| 国产男靠女视频免费网站| 99精品久久久久人妻精品| 亚洲欧美激情在线| 视频在线观看一区二区三区| 国产免费男女视频| 天堂中文最新版在线下载| 久久精品亚洲熟妇少妇任你| 精品福利永久在线观看| 国产亚洲av高清不卡| 欧美亚洲 丝袜 人妻 在线| 亚洲精品国产区一区二| 国产极品粉嫩免费观看在线| 日本五十路高清| 国产精品亚洲av一区麻豆| 精品亚洲成国产av| 免费久久久久久久精品成人欧美视频| 欧美午夜高清在线| 男女高潮啪啪啪动态图| 午夜福利,免费看| 91精品国产国语对白视频| 日韩欧美免费精品| 久久久久国产精品人妻aⅴ院 | 国产亚洲精品久久久久久毛片 | 亚洲第一av免费看| 女人高潮潮喷娇喘18禁视频| 欧美老熟妇乱子伦牲交| 免费观看精品视频网站| 亚洲第一av免费看| av国产精品久久久久影院| 国内毛片毛片毛片毛片毛片| 激情在线观看视频在线高清 | 久久亚洲真实| a级毛片黄视频| 一区二区三区精品91| 国产一区二区三区视频了| 操美女的视频在线观看| 天天躁夜夜躁狠狠躁躁| 大片电影免费在线观看免费| 亚洲精品久久成人aⅴ小说| 国产片内射在线| 亚洲精品美女久久久久99蜜臀| 日日爽夜夜爽网站| 91麻豆精品激情在线观看国产 | 在线十欧美十亚洲十日本专区| 视频在线观看一区二区三区| 国产亚洲av高清不卡| 精品国产一区二区久久| 91字幕亚洲| 色尼玛亚洲综合影院| 久热这里只有精品99| 久久热在线av| 欧美激情高清一区二区三区| 无限看片的www在线观看| 18禁裸乳无遮挡免费网站照片 | 国产精品久久久av美女十八| 精品第一国产精品| 日本精品一区二区三区蜜桃| 国产成人精品久久二区二区免费| 成人免费观看视频高清| 国产精品98久久久久久宅男小说| 一区在线观看完整版| 亚洲伊人色综图| 国产aⅴ精品一区二区三区波| 亚洲成人国产一区在线观看| 中文字幕精品免费在线观看视频| 午夜福利在线免费观看网站| 美女国产高潮福利片在线看| 夜夜爽天天搞| 老熟女久久久| 99久久精品国产亚洲精品| 欧美激情 高清一区二区三区| 欧美乱色亚洲激情| 国产精品久久久久久人妻精品电影| 亚洲专区中文字幕在线| 最新在线观看一区二区三区| 高清视频免费观看一区二区| 久久国产精品人妻蜜桃| 亚洲精品一二三| 少妇猛男粗大的猛烈进出视频| 亚洲熟妇熟女久久| 亚洲av成人一区二区三| 国产伦人伦偷精品视频| 亚洲国产欧美日韩在线播放| 欧美日韩福利视频一区二区| 在线观看免费视频网站a站| 成人18禁在线播放| 极品教师在线免费播放| 悠悠久久av| 夜夜夜夜夜久久久久| 99国产精品免费福利视频| 亚洲av成人一区二区三|