【作者】 王建光；

【导师】 孙启忠；

【作者基本信息】 中国农业科学院 ， 草业科学， 2012， 博士

【摘要】 为推动农牧交错区发展苜蓿型奶业，历时3年（2009～2011）在内蒙古土默川地区研究了苜蓿（Medicago sativa L.）与无芒雀麦（Bromus innermis Leyss）、老芒麦(Elymus sibiricus L.)和直穗鹅观草(Roegneria turczaninovii (Drob.) Nevski)的混播模式及技术。研究结果表明：（1）建立短期高产刈割利用型混播草地适宜模式为苜蓿和老芒麦按行比3:1或2:2间条播的播量比3:1或1:1混播组合，建立长期放牧刈割兼用型混播草地适宜模式为苜蓿和无芒雀麦按行比2：2间条播的播量比1:1混播组合，建立旱作长期刈割利用型混播草地适宜模式为苜蓿和直穗鹅观草按行比1:1或2:2间条播的播量比1:1混播组合。（2）混播对土壤杂草种子库容量没有造成显著影响，证实人工草地土壤杂草种子库数量和结构特征不会因混播草地组分及其比例变化而发生根本性改变。但杂草季节性入库量，由草种引起的变化幅度明显高于混播组合或比例引起的变幅，禾草普遍高于苜蓿，无芒雀麦最易使杂草入侵。因此，苜蓿与无芒雀麦混播应特别注意每年6月和8月杂草入库高峰期之前的杂草防控。（3）混播总产量主要由灌溉、施肥及其水肥耦合效应三者起作用，其中灌溉和施肥的增产效应达极显著，而水肥耦合效应不显著。苜蓿对灌溉敏感，老芒麦对施肥敏感，合理施肥可适当缓减水分不足引起的减产幅度。苜蓿—禾草混播草地土壤含水量至少要维持在田间持水量65%以上，此时每次施肥量（㎏/hm2）氮磷钾施用比为3.5:1.2:0.7或3.5:3.5:2.0时可取得明显增产效果，同时对混播牧草的营养价值和饲用价值也有显著作用。（4）苜蓿和禾草混播群落种间竞争走向受控于苜蓿种群，生长第一年因各种群未成型而种间竞争不大，第二年各种群因强夺群落优势生态位致使种间竞争激烈，第三年各种群因各自生态位就位使得种间竞争趋于平稳。苜蓿与各禾草混播，群落种间竞争最终趋于平稳的豆禾密度比分别是，苜蓿和老芒麦混播群落为33.4:66.6，苜蓿和无芒雀麦混播群落为63.3～50.0:36.7～50.0，苜蓿和直穗鹅观草混播群落为43.7～46.4:56.3～53.6。（5）以近红外光（760nm）和绿光（600nm）光谱变量组合提出了绿色优化土壤调节植被指数（GOSAVI），以此为自变量构建了苜蓿和无芒雀麦混播草地群落鲜草总产量最优二次方程式高光谱遥感估算模型。（6）苜蓿—禾草混播明显提高了混播草地干草叶量且比单播禾草增产提质，但与单播苜蓿相比是否增产提质尚不能定论，苜蓿和无芒雀麦混播可基本稳产且可维持营养价值和饲用价值，苜蓿和老芒麦混播有增产可能且基本维持营养价值但饲用价值明显下降，苜蓿和直穗鹅观草混播仅可维持饲用价值但产量和营养价值下降很大。更多还原

【Abstract】 In order to promote the development of alfalfa-dairy industry in farming-pasture region widely, thiswork has made a lot of research on mixed-sowing modes and techniques of alfalfa （Medicago sativaL.）, smooth brome （Bromus innermis Leyss）, siberian wildryegrass （Elymus sibiricus L）andupright-spikelet roegneria （Roegneria turczaninovii (Drob.) Nevski） for3years in the Tumochuanregion of Inner Mongolia,China. The results show that:1) Mixed-sowing mode of alfalfa and siberian wildryegras is optimal for the short-termhigh-production cutting used grasslands with3:1or2:2row ratio and3:1or1:1broadcast ratio ininterlacing drill mode respectively. Mixed-sowing mode of alfalfa and smooth brome is optimal forthe long-term grazing-cutting used grasslands with2:2row ratio and1:1broadcast ratio ininterlacing drill mode. Mixed-sowing mode of alfalfa and upright-spikelet roegneria is optimal forthe dry-land long-term cutting used grasslands with1:1or2:2row ratio and1:1broadcast ratio ininterlacing drill mode.2) The total capacity of the soil weed seedbank is not affected by mixed-sowing. It proves that thestructural characteristics of the soil weed seedbank could not factually changed by the biomass ratioof mixed grasses. However, weeds seasonal storage changes more significantly by the plant speciesthan by that of the mixed sowing combination or row ratio and broadcast ratio. Among that, grassesis higher than alfalfa. Smooth brome is the most vulnerable. So, it is indicated to prevent andcontrol of weeds for the mixed-sowing of alfalfa and smooth brome before the peak of weedsstorage in June and August of each year.3) The total output of mixed pastures is effected by irrigation，fertilization and the coupling effect ofthem. Among it, the significant effect of increase production is cased by irrigation and fertilization,but the coupling effect of irrigation and fertilization is not significant. Alfalfa is sensitive toirrigation, while siberian wildryegrass is sensitive to fertilization. The range of reduction of outputwhich caused by lacking of water can be appropriate eased by reasonable fertilization. The soilmoisture content of the mixed-sowing should be maintained above65%of the field capacity at least.At the same time, the fertilization（㎏/hm2） proportion of N:P:K at3.5:1.2:0.7or3.5:3.5:2.0canincrease significicant the production. And this will affect the mixture forage nutritional value andfeeding value significantly.4) Alfalfa population controls the direction of the community competition in the alfalfa and grassesmixed-sowing region. Populations’ competition relationship is not built in the first year because ofunformed; then the populations compete intensely in the second year in order to usurp the dominantniche, finally they tend to be steady in the third year with a stable niche. The stable density ratio is33.4:66.6of alfalfa and siberian wildryegras,63.3～50.0:36.7～50.0of alfalfa and smooth brome,43.7～46.4:56.3～53.6of alfalfa and upright-spikelet roegneria respectively.5) This dissertation proposes green optimized soil adjusted vegetation index (GOSAVI) caculated bynear-infrared light (760nm) and green light (600nm). Based on GOSAVI, the optimal quadratic equation estimation model of fresh total production of alfalfa and smooth brome mixed grassland isalso established.6) The leaves amount of hay yield, hay nutritional value and cows feeding value of mixed-sowingmode is higher than the single-grass mode. Smooth brome mixture is the best choice. Comparedwith it, siberian wildryegras could decrease cows feeding value and upright-spikelet roegneria coulddecrease the nutritional value and yield.更多还原