灌溉量对紫花苜蓿水分利用效率和耗水系数的影响

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

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（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）.