【作者】 杜桂娟；

【导师】 曹敏建；

【作者基本信息】 沈阳农业大学 ， 作物栽培学与耕作学， 2009， 博士

【摘要】 在分析了两熟不足区优质粗饲料短缺和鲜食玉米、马铃薯、小麦等短季作物缺少合适下茬的基础上,提出了利用短季作物下茬复种青贮玉米的多熟种植模式。以筛选适宜的复种青贮玉米品种为切入点,采用田间试验与室验室研究相结合的方法,研究提出了复种青贮玉米高产栽培技术、复种青贮玉米加工利用方法,并对以青贮玉米为后作的三种复种模式的资源利用、综合效益等进行了分析与评价。经过连续两年试验,得到如下研究结果:1.与一季春玉米相比,马铃薯复种青贮玉米、覆膜鲜食玉米复种青贮玉米、小麦复种青贮玉米三种复种模式的光能生产效率、积温生产效率、降水生产率、净增能、产量、产值和纯效益等指标均明显提高。三种复种模式的纯效益分别为25462元/hm²、22993元/hm²和14216元/hm²,较一季春玉米分别提高136.5%、113.5%和32.0%。2.根据不同玉米品种对夏播气候条件的适应性和优质青贮玉米饲料要求,筛选出三个适宜复种的青贮玉米品种:郑单958、高油4515和先玉335。3.明确了不同播期青贮玉米的生长发育特点、干物质积累规律、产量效应以及气候条件对青贮玉米的影响等,确定了复种青贮玉米的播期极限。选用郑单958和高油4515两个品种,播期最好不要超过7月19日。建立了青贮玉米产量与活动积温之间的回归方程,郑单958青体产量与活动积温的回归方程为y=-8×10^-5x²+0.3349x-278.1（r=0.998）;郑单958干物质产量与活动积温的回归方程为y=0.0233x-25.921（r=0.9968）,高油4515青体产量与活动积温的回归方程为y=-8×10^-5x²+0.3153x-251.24（r=0.9968）;高油4515干物质产量与活动积温的回归方程为y=0.0185x-17.188（r=0.9968）。4.弄清了一穴双株的增产机理、潜力以及最适群体密度。在相同密度条件下,一穴双株较正常播群体结构得到改善,主要农艺性状、光合指标有所提高,但增产未达到显著水平。增加一穴双株群体密度,加剧了植株个体之间竞争,株高、茎粗、单株叶面积等农艺指标以及叶片光合速率、气孔导度、蒸腾速率等光合指标降低,同时由于群体优势作用,单位面积产量先增后减,呈二次曲线变化趋势。一穴双株群体密度为10.0万株/hm²最为适宜,青体产量和干物质产量最高,分别为69.61 t/hm²和20.26 t/hm²。一穴双株群体密度超过12.0万株/hm²,群体优势不能抵消个体发育所受的影响,产量开始下降。5.弄清了氮、磷肥对复种青贮玉米的影响,提出了合理的化肥施用量。在有机质中等偏上、氮含量中等、磷缺乏的土壤条件下,中氮高磷对主要农艺性状和产量均有利。高氮高磷导致玉米植株生长发育过于旺盛,群体郁蔽,造成后期早衰,穗长、穗行数、行粒数减少,单位面积产量降低。当施氮量（N）为250 kg/hm²,施磷量（P₂O₅）为100 kg/hm²时,青体产量最高,为61.08 t/hm²;施氮量（N）为200 kg/hm²,施磷量（P₂O₅）为100kg/hm²时,青体产量次之,为60.99 t/hm²。如果兼顾产量和经济效益的话,选择第2种施肥方案更合理。6.明确了不同成熟度复种青贮玉米单贮、去穗青贮、复种青贮玉米与紫花苜蓿混贮、复种青贮玉米与干秸秆混贮等不同青贮利用方法的青贮效果和营养价值。7月5日至7月12日播种的青贮玉米全株青贮后,青贮等级为1级,青贮效果较佳。粗蛋白、粗脂肪、粗纤维、粗灰分、无氮浸出物等指标基本上达到或接近优质青贮饲料的标准。7月19日播种的青贮玉米全株青贮后,青贮等级和营养价值降低;去穗后青贮粗蛋白、粗脂肪、无氮浸出物等营养成份均有所降低,粗纤维含量增加,青贮等级为1-2级,青贮也较成功。复种青贮玉米与紫花苜蓿混贮,青贮等级可以达到1-2级,较紫花苜蓿单贮有明显改善。从营养价值上看,当紫花苜蓿占青贮料比例达到二分之一时,混贮的粗蛋白含量达到14.92%,是复种青贮玉米单贮的2.3倍。二者混贮将禾本科饲草与豆科饲草的优点集成,有效地解决了紫花苜蓿单贮不易成功和复种青贮玉米单贮蛋白含量低的问题。复种青贮玉米与干秸秆混贮,青贮等级可以达到1-2级,较干秸秆单贮有明显改善。从营养价值上看,当复种青贮玉米占青贮料比例达到二分之一时,粗蛋白含量为7.49%,粗脂肪含量为1.40%,与干秸秆单贮差异达到极显著水平。采取复种青贮玉米与干秸秆混贮,改善干秸秆的营养品质,是不发达地区解决青绿饲料短缺,提高粗饲料水平的一条有效途径。更多还原

【Abstract】 At the view of current shortage of high-quality roughage and the lack of a suitable stubble crop for the short-season crops such as fresh corn, potato, wheat and et al in insufficient double cropping region, a cultivation pattern of multiple cropping was proposed to use silage corn as the stubble crop of short-season crops. Taking screening of appropriate silage corn varieties as the breakthrough point, combining the methods of field trail and laboratory experiment, high yielding cultivation technology and processing and utilization methods of multiple cropping silage corn were studied, and an analysis and evaluation were done on use of resources and comprehensive benefits of three multiple cropping patterns in which silage corn was used as the stubble crop. The result of two-years-research was shown as:1. Compared with one-quarter spring corn, the energy production efficiency, accumulated temperature production efficiency, precipitation productivity, net increased energy, production, output value and pure benefits of the three multiple cropping patterns of potato to green silage corn, filmed fresh corn to green silage corn and wheat to green silage corn were markedly improved. The pure economic benefits of the three multiple cropping patterns were 25462 yuans, 22993 yuans and 14216 yuans per ha. respectively, which were 136.5 %、113.5% and 32.0% higher than that of the one-quarter spring corn respectively.2. According to the adaptability of corn variety to climatic conditions of summer planting and the criterion of high-quality corn silage, three silage corn varieties fit for multiple cropping, Zhengdan958, Gaoyou4515 and Xianyu335, were screened out.3. The growth and development characteristics, dry matter accumulation, yield and dry matter content of silage corn as well as effects of climatic conditions on silage corn were cleared, and the sowing time limit of silage were determined. The sowing time limit of Zhengdan958 and Gaoyou4515 were both no more later than July 19. The regression equations of silage corn yield to active accumulated temperature were established. For Zhendan958, the regression equation of fresh yield to active accumulated temperature was as y = -8x 10^-5x² + 0.3349x - 278.1（r=0.998）, that of dry matter yield to active accumulated temperature was as y = 0.0233x - 25.921（r=0.9968）. For Gaoyou451, that of fresh yield to active accumulated temperature was as y =-8 x 10^-5x² + 0.3153x - 251.24（r=0.9968）, that of dry matter yield to active accumulated temperature was as y = 0.0185x - 17.188（r=0.9968）.4. The yield increasing mechanism and potential as well as suitable planting density of two plants per hole were revealed. At the same planting density, compared with single planting, the colony structure of bunch planting was improved, its main agronomic traits and photosynthesis characteristics were enhanced, but yield increase was not significant. Increase of bunch planting density can lead to aggravation of competition between individuals, decline of some agronomic traits like plant height, stem width, leaf area per plant, and photosynthesis characteristics like leaf photosynthesis rate, stomatal conductance, transpiration rate. At the same time, because of the colony advantage, with increase of planting density, the change of yield per area showed a trend of conics, decrease after increase. The most appropriate bunch planting density was 100000 plants per hektare, at which, fresh yield and dry matter yield were the most, 69.61t/hm² and 20.26t/hm² respectively. When the density was over 120000 plants per hektare, yield decreased because colony advantage could not offset the impact on individual development.5. The effects of nitrogen and phosphorus fertilizer on multiple cropping silage corn were understood further, the reasonable fertilization amount was put forward. Under the soil condition with middle or more organic matter, middle nitrogen content, and lack phosphorus, fertilizer application of middle nitrogen and high phosphate was benefit to agronomic traits and yield, but that of high nitrogen and high phosphorus may caused corn plants grew too strong, colony canopied and closed, which resulted in premature senescence, decrease of ear length, rows per ear and grains per row, and even yield. When fertilization amount of nitrogen （N） was 250 kg/hm², and that of phosphorous （P₂O₅） was 100 kg/hm², the fresh yield was the mostly 61.08 t/hm², when fertilization amount of nitrogen （N） was 200 kg/hm², and that of phosphorous（P₂O₅） was 100 kg/hm², the fresh yield was secondly 60.99 t/hm². If taking both yield and economic benefits into account at the same time, the second fertilization methods was more reasonable.6. The silage effects and nutritional value of different silage methods such as single silage and silage without ear of silage corn at different maturity degree, mixed silage of silage corn with alfalfa, and mixed silage of silage corn with dry straw, were determined. When the silage corn sowed on from July 5 to July 12 was ensilaged by whole plant, the silage grade was one, and silage effect was the best. The content of crude protein, crude fat, crude fiber, crude ash, extract without nitrogen, and et al basically reach or approach the standard of high-quality silage. When the silage corn sowed on July 12 was ensilaged by whole plant, silage grade and nutritional value were lower, if ensilaged by removing ear, the content of crude protein, crude fat, extract without nitrogen decreased, and that of crude fiber increased, and silage grade was 1-2, which was also more successful. The silage grade of mixed silage of silage corn with alfalfa can reach 1-2, which was better than that of single silage of alfalfa. On the view of nutritional value, when the proportion of alfalfa reached 1/2 of the whole silage materials, the crude protein content can reached 14.49%, which was 2.3 times that of single silage of silage corn. Mixed silage of corn and alfalfa integrated the advantages of both gramineae and leguminosae forage, effectively solved the problems that it is not easily to succeed for single silage of alfalfa and protein content was very low in single silage of silage corn. The silage grade of mixed silage of silage corn with straw may reach 1-2, which was better obviously than that of single silage of straw. On the view of nutritional value, when silage corn accounted for 1/2 of the whole silage materials, the crude protein content was 7.49%, and that of crude of fat was 1.40%, which were different significantly from that of single silage of dry straw. Mixed silage of silage corn with dry straw can improved nutritional quality of dry straw, which is an effective method to solve the problem of shortage of silage and raise the level of roughage.更多还原