Abstract: Effect of irrigation amount on water use efficiency(WUE) and water consumption coefficient(WCC) of alfalfa(Medicago sativa L) was studied in Bashang area,Hebei Province,using large scale no-weighting-lysimeter.The results show that the water consumption of alfalfa in Bashang area inceased from 335.5 to 712.8 mm,the forage yield multiplied from 3304.7 to 7423.3 kg/hm²(P<0.05) when the irrigation amount changed from 0 to 400 mm.WUE based on biological and economic yield of first harvest declined from 10.5 and 12.2 to 6.8 and 7.9 kg·mm.hm^-2,respectively.On the contrast,those of the second harvest boosted from 9.5 and 11.1 to 19.0 and 22.1 kg·mm·hm^-2,respectively.But the differences of those in the whole growing season were not significant.WCC based on biological and economic yield of first harvest boosted from 956 and 822 kg·mm·hm^-2 to 1480 and 1273 kg·mm.hm^-2,respectively.On the contrast,those of the second harvest declined from 1053 and 906 to 527 and 453 kg·mm.hm^-2,respectively.But the differences of those in the whole growing season were not significant.The differences of WUE and WCC between different harvest times were significant(P<0.05).

Key words: Alfalfa, Water use efficiency, Water consumption coefficient, Irrigation amount, Water consumption, Bashang area

摘要： 采用大型非称重式蒸渗仪法,在河北省坝上地区研究灌溉量对紫花苜蓿(Medicago sativa L.)水分利用效率和耗水系数的影响。结果表明:随着灌溉量由0增至400 mm,紫花苜蓿耗水量由335.5增至712.8 mm,干物质产量由3304.7增至7423.3 kg/hm²,二者差异显著(P<0.05);第1茬生物产量和经济产量水分利用效率分别由10.5和12.2降至6.8和7.9 kg/(mm·hm²),第2茬则相反,分别由9.5和11.1增至19.0和22.1 kg/(mm·hm²),但第1~2茬差异不显著;第1茬耗水系数分别由956和822升至1480和1273,第2茬则相反,分别由1053和906降至527和453,但1~2茬差异不显著;不同茬次间水分利用效率及耗水系数差异显著(P<0.05)。

关键词: 紫花苜蓿, 水分利用效率, 耗水系数, 灌溉量, 耗水量, 坝上地区