灌溉量对紫花苜蓿水分利用效率和耗水系数的影响

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)。

Effect of Irrigation Amount on Water Use Efficiency and Water Consumption Coefficient of Alfalfa

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).