【作者】 闫春娟；

【导师】 韩晓增；

【作者基本信息】 东北农业大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 作物的生物产量是子粒产量的基础,植物干物质的积累有90～95%来自光合作用,而蒸腾作用可以保证光合作用的正常进行,气孔既是水蒸气溢出的通道,又是同化作用中CO2的入口。土壤中的水分及钾肥均会影响作物的光合作用,水分不足会抑制气孔开放和光合作用;而钾肥能调节气孔开放,从而调控光合、蒸腾作用的强弱。据此本文通过设置不同的钾素和水分水平,来探讨农田黑土下水钾耦合对大豆生理特性及产量品质的影响,以期为黑龙江省大豆生产提出更好的栽培管理措施,指导农业生产实践。盆栽条件下,以大豆品种黑农35为供试材料,于2006年在中国科学院海伦农业生态实验站进行,试验设三个钾肥水平及五个水分水平,共15个处理组合,随机区组设计,分别在大豆的营养生长期(V2-R1),开花期(R1-R3),结荚期(R3-R5)三个关键生育时期进行水分调控,研究不同供钾水平下水分状况对大豆不同生育时期生理特性及产量品质的影响。其中采用CI–301Ps光合作用测定仪进行净光合速率、蒸腾速率、气孔导度及胞间CO2浓度的测定;采用乙醇提取法测定叶绿素含量;采用CI-203手持式激光叶面积仪测定叶面积;各个生育时期控水后取样,以测定植株各部位的鲜重及干物重(105℃杀青30min,80℃烘至恒重);收获后测定子实产量及其构成要素;采用半微量凯氏定氮法测定蛋白质含量;采用干样索氏脂肪抽提法测定脂肪含量。其结果表明:同一生育时期控水条件下,水分及钾肥均会影响大豆的光合生理特性,但水分的效应要优于钾肥,并且光合速率、蒸腾速率与气孔导度的变化趋势相一致,水分对它们有明显的正效应,其中以W4水平效果最好。水分对大豆的植物生理水分利用效率表现为正效应,而钾肥为负效应,随着生育进程的推进植株的水分利用效率表现为先急剧增大后下降的趋势,即花期>结荚期>营养生长期。水分胁迫对叶绿素浓度的影响具有二重性,“特旱(W1)”条件下降低了叶片的叶绿素浓度,而“略旱(W2)”条件则提高了叶片的叶绿素浓度。同一生育时期控水条件下,水分及钾肥对叶面积指数的影响同对光合速率的影响相近,随着生育进程的推进,叶面积指数逐渐增大。大豆株高的积累主要在出苗至结荚前这段时间,结荚期开始后,株高增量较少。营养生长期、开花期控水条件下植株各部位生物量的分配表现为叶重>茎重>根重;结荚期控水条件下植株各部位生物量的分配表现为子粒重>叶重>茎重>根重。水分及钾肥影响植株各部位生物量的形成,水分对生物量形成的影响为正效应,以W4水平效果最优;相同水分条件下施用钾肥的处理生物量要优于未施钾肥的处理。水钾耦合对地上部、地下部干物重及根冠比的影响表现为:对地上部干物重的影响要大于对根干重的影响,大于对根冠比的影响;土壤水分状况对干物质的积累及根冠比的影响优于钾肥所产生的效应,水多有利于干物质的积累,但根冠比随着水分的增加而减小。无论何生育时期控水,钾肥均有提高大豆脂肪、降低蛋白质含量的趋势。土壤水分对大豆蛋白质含量的影响因控水时期不同而各异,营养生长期控水,相同钾肥水平下,随着土壤含水量的增加蛋白质含量增加,而开花、结荚期控水条件下则以W3水分条件下蛋白质含量最高;土壤水分对脂肪含量的影响表现为:同一生育时期控水条件下,相同钾肥水平下均以W3处理脂肪含量最高。生物产量最优的处理并未表现出最高的子粒产量,无论何生育时期控水条件下均以处理W3K3产量最高,比对照增加了10.90%,为本次试验中最佳处理组合。营养生长期(V2-R1)控水下大豆的产量效应表现为:钾肥>水分>水钾互作,而花期(R1-R3)、结荚期(R3-R5)控水条件下,大豆产量的变异主要是由水分引起的,钾肥与水钾互作只引起极小的一部分。比较不同生育时期各处理组合产量的差别时发现:当土壤水分含量较低时,结荚期控水减产最大,其次是花期控水,营养生长期控水减产幅度较小;而同一生育时期控水下水分对大豆产量的影响要高于钾肥;旱涝都将影响大豆子粒产量的形成,但干旱引起大豆的减产程度大于涝害。本研究发现大豆对水分较为敏感的时期是开花期和结荚期,而营养生长期土壤水分状况对产量的影响相对较小,因此生产上要注意花期、荚期的水分管理,建立良好的灌溉排水设施。一定量的钾肥能促进产量的形成,但只有在水分供应适宜条件下其效果才显著,因此生产上要依据土壤中的水分状况进行合理施用钾肥,注重二者的耦合效果。本试验还发现当作物生长前期土壤含水量较高,而后期较低时,可能会使土壤中的一些可交换性钾转化为非交换性钾,从而降低了钾离子的有效性,因此在实际生产上当大豆生长前期水分较充足,而后期干旱时应施钾肥,以提高土壤中速效钾的含量。本试验结果表明在高肥水条件下,虽然干物质积累很高,但子粒产量却没有相应地提高,这主要是由于高肥水往往使大豆的营养体过于茂密,器官平衡不合理,致使子粒产量不高,因此生产上应合理施肥与灌水。更多还原

【Abstract】 Vegetal biomass constitutes the foundation of seed yield, and plant dry matter accumulation which come from photosynthesis account for 90%-95% in all. Transpiration ensures photosynthesis on the rails. Stoma is both the channels of vapour overflow and the portal of CO2 assimilation. However, potassium fertilizer and soil moisture impact plant photosynthesis, and soil water stress lowers stoma ringent extent and weakens plant photosynthesis; potassium fertilizer regulates the open and close of stoma first, and then regulates plant photosynthesis and transpiration. So diffierent potassium fertilizer and water levels applied in this experiment were to elucidate the effect of water-potassium coupling on physiological characteristics, yield and quality of soybean in order to provide practical agricultural measures for soybean production in Heilongjiang province.Pot experiments were carried out in Hailun Agro-ecological Experimental Station in 2006. In this experiment, five water supply levels and three potassium fertilizer application levels were included in terms of soil water content controlled at vegetative stage(V2-R1), flowering stage(R1-R3) and podding stage(R3-R5), respectively. The purpose is to investigate effects of water supply levels in different growth stages on physiological characteristics, yield and quality of soybean under different potassium fertilizer levels. The methods of each tested index are as follows: (1)Photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO2 concentration were measured by using a portable CI-301PS photosynthesis system(CID,Inc.,USA); (2) chlorophyll was distilled with ethanol and was determined by the specific absorption coefficients at 663 nm and 645 nm by using spectrophotometry; (3) leaf area was measured by using a portable CI-203PS leaf area system(CID,Inc.,USA); (4) protein content was determined by the Kjaldahl method; (5)The soybean oil was extracted with aether.When soil moisture was controlled at the same growth stage, both soil moisture and potassium ferlizer influenced photosynthetic characteristics of soybean, but soil water content played a more important role than potassium fertilzer. Photosynthesis rate, transpiration rate and stomatal conductance had the similar changes at the same stage, and soil water content had positive effects on them, W4 was the optimum water treatment. Soil water content had positive effect on WUE but potassium fertilizer played the opposite. The WUE of soybean increased and then decreased with the growthing of soybean, the positive effect of soybean WUE showed in the order: flowering stage>poding stage>vegetitive stage. Soil water stress had double edged influences on chlorophyll content which decreased under exceeding drought condition(W1) but increased under mild drought condition(W2). When soil moisture was controlled at the same stage, the coupling of water-potassium fertilizer exerted similar effects on leaf area index to photosynthetic rate. The leaf area index increased with the growthing of soybean in an order of poding stage>flowering stage> vegetitive stage. The plant height developed mainly come from seedling stage to flowering stage, thereafter the increment of soybean plant height were little. When soil water content was controlled at vegetitive stage and flowering stage, biomass distribution of each apparatus showed the order of leaf weight>stem weight>root weight. When soil water content was controlled at podding stage, the order was: seed weight> leaf weight>stem weight>root weight. Soil moisture and potassium fertilizer had impacts on the formation of biomass in different part of soybean, and soil water content had a negative effect on the formation of biomass, W4 level was the optimal soil water treatment. The biomass accumulation of applying potassium fertilizer treatments was superior to other treatments under the same soil water content condition. Coupling of water-potassium influenced shoot dry matter weight more than on root dry matter weight, and the influence on the ratio of root to shoot was the least. Soil water supply had more significant effect on dry matter weight and the ratio of root to shoot than potassium fertilizer application did. The sufficient soil moisture enhanced the accumulation of dry matter, while the ratio of root to shoot decreased with the increase of soil water content.Potassium fertilizer played a vital role in protein accumulation but not in oil accumulation for all the stages. When soil moisture was controlled at different growth stage, soil water content had different influences on protein content. When soil moisture was controlled at vegetative stage, protein content increased with the increase of soil water content under the same potassium fertilizer level. When soil moisture was controlled at flowering stage and podding stage, protein content at W3 level was optimical under the same potassium fertilizer level.The treament with the highest biomass accumulation was not the one of the optimum seed yield. The hightest seed yield of all treaments was combination of W3K3 which increased seed yield by 10.90% than control, and it was the classic treament of all in this experiment. When soil water content was controlled during the vegetative stage, the effect of different treatments on yield decreased in the order of potassium fertilizer >water>water-potassium fertilizer; when the soil water content was controlled during flowering stage and podding stage, the yield difference was mainly attributed to the water supply, while potassium fertilizer and the interaction of water-potassium fertilizer played a little role in yield. The reduction of yield under deficient soil water condition at different stages showed in an order: podding stage> flowering stage>vegetative stage. The contribution of water supply to the yield formation was more central than potassium application in the light of soil water controlled at the same growth stage. Both drought and water logging conditions were found to influence the yield of soybean, in which drought condition reduced the yield more significantly.This reseach found that the sensitive stages of the soybean yield to soil water were flowering and podding stages, while soil water condition had relative small impact on the seed yield of soybean at vegetative stage, so attention should be paid to regulating soil moisture at flowering stage and podding stage, and good irrigation and drainage equipment should be set up. Applying potassium fertilizer at a certain extent may increase the yield of soybean together with suitable water supply, so optimical potassium fertilizer should be applied for agriculture production in terms of soil water condition, and the coupling effect of water-potassium fertilizer should be paid to on soybean growth and development. The availability of potassium became lower at later growth stages of soybean due probably to the transformation of exchangible potassium to non-exchangible potassium when soil water content was higher at early growth stage and lower at later growth stage. Potassium fertilizer should be applied at later growth stages in order to increase the content of available potassium when soil water was sufficient at early growth stage and drought took place at later growth stage. The seed yield did not increase corresponding to the increase of dry matter accumulation under the condition of higher water content and fertilizer application, which might be attributed to the inbalance of development of vegetable organs resulting in suppression of seed yield, it is of great significance to harmonize fertilization with water supply in agriculture production.更多还原