【摘要】 研究天然草场牧草产量及养分的季节动态,选择青海湖南岸的高寒草甸作为研究对象,于2015年的返青期(5月)、盛草期(8月)、枯黄期(10月)和枯草期(1月)分别采集地上生物样品,对可食牧草的产量以及养分质量分数进行分析测定.结果显示,天然草场返青期总产草量(风干重)平均52.21 g/m~2,盛草期154.66 g/m~2,枯黄期92.90 g/m~2,枯草期25.83 g/m~2,可食牧草分别占66%、76%、83%、100%;返青期牧草中w(粗蛋白)最高,显著高于其他时期; w(粗灰分)、w(水不溶灰分)、w(酸不溶灰分)均从返青期到枯草期逐渐递增,且不同时期差异显著; w(水溶性灰分)从返青期到枯草期递减(2.42%～0.59%);盛草期和枯黄期w(粗脂肪)远高于其他时期(P<0.05); w(中性洗涤纤维)、w(酸性洗涤纤维)和w(纤维素)随生育期延长逐渐增加.天然草场盛草期的营养输出高于其他时期,枯草期最低.研究区高寒草场可食牧草数量多,可食性好.枯草期与青草期相比,无论从量还是质上都处于一年中最低点.估算青海湖南岸高寒草甸适宜载畜量,即数量载畜量,为2.57羊单位/hm~2.更多还原

【Abstract】 In order to explore the seasonal dynamics of yield and nutrient content of edible pasture in natural grazing grassland, selected alpine meadows on the south bank of the Qinghai Lake served as the object of study, and aboveground biomass was collected in January 2015(hay stage), May(regreening stage), August(growing stage) and October(wilt stage), and then the yield and nutrient contents of edible herbage were determined and analyzed. The results showed that the total yield(dry weight) of a natural grassland had an average of 52.21 g/m~2 in regreening stage, 154.66 g/m~2 in growing stage, 92.90 g/m~2 in wilt stage, and 25.83 g/m~2 in hay stage, and the edible forage percent was 66%, 76%, 83% and 100%,respectively. w(crude protein) in the regreening stage was the highest(P < 0.05), and w(crude ash),w(water-insoluble ash) and w(acid-insoluble ash) were increasing with the period of duration, and the difference between the periods was remarkable(P < 0.05), w(water-soluble ash) was decreasing from regreening to hay stage, w(fat) in the growing and wilt stage were higher than that in other periods(P < 0.05), w(neutral detergent fiber), w(acid detergent fiber) and w(cellulose) were increasing with the period of duration. The nutrient output of the natural grassland in the growing stage was higher than that of other periods, and it was the lowest in the hay stage. For its high per unit yield, the nutrient output of an artificial grassland was higher than that in a natural grassland. The amount of edible herbage was more in the researched alpine rangeland. Compared with the growing stage, the hay period was at the lowest level in a year in terms of quantity or quality. The estimation of the alpine meadow carrying capacity, i.e. the number of carrying capacity, was 2.57 sheep/hm~2.更多还原