西藏野生垂穗披碱草是青藏高原上较常见的一种多年生禾本科牧草,具有营养价值丰富,适口性好,种子繁殖力高,抗逆性强的优质野生草种。本研究通过在西藏曲水县拉萨河谷地进行为期3年(2006-2008年)的田间试验,探究西藏野生垂穗披碱草种子在人工繁育条件下N肥的施用量对其产量组分、产量和质量的影响,不同收获时间对其种子产量和质量的影响,分析其种子成熟过程中含水量、产量和活力的变化规律,明确其适宜收获时期。结果表明,施氮量为250 kg/hm2时,西藏野生垂穗披碱草种子分蘖数/m2为1 816.3枝/m2,种子产量可达到2 016.5kg/hm2;其次分别为施氮量210和290 kg/hm2的,它们的分蘖数/m2分别为1 565.0和1 508.2枝/m2。种子的最佳收获时间为盛花期后第28-31天,种子含水量下降到42.00%-36.59%,此时活力处于很高水平,种子干重和种子产量接近最高值。
Tibetan wild Eylmus nutans is a common perennial forage grass adapted to local climatic conditions,and it has high nutritional value,palatability,and excellent resistance.A 3-year(2006-2008) study was conducted on Tibetan wild E.nutans seed production the region's unique natural and climatic features of Qushui county,Lhasa valley,Tibet,The field experiments explored the,yield and quality of seeds at different harvest times,to find the most appropriate harvest period.A comprehensive analysis was made on seed maturity,water content,production and vitality changes in artificial conditions,to investigate the effects of nitrogen fertilization and appropriate harvest time on seed yield and seed quality to provide a scientific basis for grass-seed production and management.A nitrogen application rate of 250 kg/ha was best for Tibetan wild E.nutans' seeds: seed tiller numbers of 1 816.3/m2 could be achieved.This was followed by nitrogen applications of 210 or 290 kg/ha,which achieved tiller numbers of 1 565.0/m2 and 1 508.2/m2 respectively.Seed production of 2 016.5 kg/ha may be achievable.The best time for seed harvest is 28-31 d in the period of full flowering stage,when seed water content has dropped to 42%-36.59%,and the seed dry weight and seed yield are close to the maximum value.