【作者】 周学辉； 常根柱； 杨红善； 路远； 侯彦会；

【Author】 Zhou Xuehui;Chang Genzhu;Yang Hongshan;Luyuan;Hou Yanhui;Lanzhou Institute of Animal & Veterinary Pharmaceutics Sciences,Chinese Academy of Agricultural Science;

【机构】 中国农业科学院兰州畜牧与兽药研究所；

【摘要】 用氮素(¹⁵N)示踪技术对温性荒漠化草原不同放牧强度草地经济施肥量进行了研究,并以"标记肥料氮素损失量/植物氮素回收量"的大小来确定草地的经济施肥量。结果表明,随着施氮量的增加,中度放牧草地氮素的"损失量/回收量"值依次为1.52、3.22、4.97和11.92,逐渐增大。重度放牧草地该比值依次为0.34、3.33、5.60和2.82,先升高后降低。除重牧区施氮量为12.25gN·m^-2处理时小于1外,其它各处理时氮素的损失量均大于回收量（大于1）,对该温性荒漠化草原施加氮素风险较大,应谨慎计划。中度和重度放牧草地,施氮量为12.25gN·m^-2时其"损失量/回收量"比值最小,施氮量为12.25gN·m^-2为该温性化荒漠草原的最经济施氮量,在此类退化草原生态系统的恢复更新中可资参考。更多还原

【Abstract】 We use the labeled¹⁵ N technique to study the economical fertilizing amount of the different grazing intensities in temperate desertification grassland.And we use the different amount of the ratio of "loss amount of labeled N / recovery of plant N" to get the certain amount of the economical fertilizing amount.The results show that as the increase of the N,the ratios of the loss / recovery of the moderate pasturage grassland were 1.52,3.22,4.97 and 11.92.In the severe pasturage grassland the ratios were 0.34,3.33,5.60 and 2.82 which increased at first and then went down.Except the amount of nitrogen re-pastoral 12.25 gN ? m^-2 processing was less than one,the other ratios were more than one.So we should be more cautious when we use N in the desertification grassland of the temperate zone.To the moderate and the severe pasturage grassland,when the amount is 12.25gN·m^-2,the ratio of the loss / recovery is the smallest,so this is the most economical one,and we can refer to this ratio when we want to recover this kind of ecosystem of the grassland.更多还原