高寒地区多年生禾草混作草地适应性评价

发布时间：2018-05-16 09:05

本文选题：混作草地 + 高寒地区　；参考：《甘肃农业大学》2015年硕士论文

【摘要】：以甘肃农业大学天祝高山草原试验站2012年建植的8个多年生混作禾草地为对象,分别从越冬性、生长发育特性、生产性能、光合生理生态特性、杂草动态、刈割影响、土壤理化特性等方面进行了综合分析和评价,研究结果如下:1.建植混作草地的禾草皆于4月中下旬返青。冷地早熟禾(Poa crymophila)返青最早,青牧1号老芒麦(Elymus sibiricus cv Qinghai No.1)返青最迟。青牧1号老芒麦和中华羊茅(Festuca sinensis)生育期较长,达到150d以上,其余禾草生育期在140d-150d之间。2.混作草地混合牧草的营养价值随生育期呈动态变化态势。混作草地地上混合牧草粗蛋白含量呈下降趋势,地下根部粗蛋白含量和有机碳含量先下降后上升,地上混合牧草有机碳含量和酸性洗涤纤维含量上升,地上混合牧草和地下根部生物量、地下根部中性洗涤纤维含量先上升后下降。混作草地组合M06于枯黄期地下可溶性糖和淀粉含量高于其它组合,返青期不同组合间差异不显著。。3.多年生混作禾草地建植第1年,杂草以密花香薷(Elsholtzia densa)、迷果芹(Sphallerocarpus gracilis)、藜(Chenopodium glaucum)等1、2年生植物为优势;建植第3年,杂草则以迷果芹、甘露子(Stachys sieboldi)、密花香薷、西伯利亚蓼(Polygonim sibircum)为优势,多年生杂草明显增加;与1龄草地相比,3龄混播草地杂草的密度、盖度和生物量降低,Shannon-weiner多样性指数和Pielou均匀度指数增大。建植第1年,不同混作组分间丰富度指数、Pielou指数、Shannon-weiner多样性指数差异不显著。建植第3年,随混作组分的增加,杂草的丰富度、均匀度和多样性增加,地上生物量、盖度和密度下降。杂草群落与单播草地间的相似系数K值随着混作组分的增加呈减小趋势。4.刈割处理时的6cm和8cm留茬高度显著提高了牧草的产量、相对生长速率和有机碳含量(P0.05),降低了牧草的粗纤维含量。5.混作草地牧草的不同生育期土壤理化性状变化明显。随生育期的推进,土壤温度和土壤呼吸速率先增加后降低,0-10cm土壤全氮含量先降低再上升再下降,10-20cm先下降后上升,20-30cm先上升后下降;土壤相对湿度呈现先上升再下降再上升。6.通过混作草地灰色关联度分析发现,中华羊茅+青海扁茎早熟禾+无芒雀麦+青牧1号老芒麦4组合为最佳的混作栽培草地组合,中华羊茅+青海扁茎早熟禾+青牧1号老芒麦次之。
[Abstract]:Eight perennial grasses were planted in Tianzhu Alpine grassland Experimental Station of Gansu Agricultural University in 2012. They were overwintering, growth and development characteristics, production performance, photosynthetic physiological and ecological characteristics, weed dynamics and mowing effects. The physical and chemical properties of soil were comprehensively analyzed and evaluated. The results are as follows: 1. 1. The grass of mixed grassland was turned green in the middle and late April. POA crymophila) was the first to turn green, and Euphrates us sibiricus cv Qinghai No. 1 was the last. The growth period of Qingmu No. 1 and Festuca sinensis was longer than 150 days, and the growth period of the other grasses was between 140d-150d. 2. The nutritional value of mixed pasture showed a dynamic change with the growth period. The crude protein content of mixed forage grass decreased, the content of crude protein and organic carbon in underground root decreased first and then increased, and the content of organic carbon and acid detergent fiber in aboveground mixed forage grass increased. The biomass of aboveground mixed forage and underground root increased firstly and then decreased. The content of underground soluble sugar and starch of mixed grassland combination M06 was higher than that of other combinations in the dry yellow period, but there was no significant difference between different combinations in the green stage. In the first year of establishment of perennial mixed grasses, the dominant weeds were Elsholtzia densa, Sphallerocarpus gracilisus, Chenopodium glaucumum and so on, while in the third year of planting, they were dominated by parsley, Stachys sieboldii, Elsholtzia sholtzia, Polygonim sibircumum and Polygonim sibircumum. The density, coverage and biomass of weeds in the mixed grass of the third and the first instar grassland decreased significantly, and the Shannon-weiner diversity index and the Pielou evenness index increased in comparison with the first instar grassland. In the first year of planting, there was no significant difference in diversity index of Shannon-weiner and Pielou index. In the third year of planting, the richness, evenness and diversity of weeds increased, while the aboveground biomass, coverage and density decreased. The similarity coefficient K value between weed community and monoculture grassland decreased with the increase of mixed elements. The stubble height of 6cm and 8cm significantly increased the yield of forage, the relative growth rate and organic carbon content (P0.05), and decreased the crude fiber content of forage. The physical and chemical properties of soil in different growth stages of mixed grassland were obviously changed. With the development of growth period, the soil temperature and soil respiration rate increased first, then decreased, then increased, then decreased, and the soil relative humidity increased first, then decreased, and then increased. 6. Through grey correlation analysis of mixed grassland, it was found that four combinations of Laomangmai No. 1, Qingmao Qingmu, Qingmu No. 1, were the best combination of mixed cultivation grassland. Chinese fescue Qinghai flat stem Kentucky bluegrass Qingmu No. 1 Laomang wheat followed.
【学位授予单位】：甘肃农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S812

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