中文摘要：

在甘肃省定西半干旱黄土丘陵区采用完全随机设计，研究不同覆盖材料（普通地膜CMR、生物可降解地膜BMR和土垄SR）和不同沟垄比（60cm：30cm、60cm：45cm和60cm：60cm）对径流效率、土壤贮水量、土壤含水量、紫花苜蓿干草产量和水分利用效率的影响．结果表明：SR、BMR和CMR的平均径流效率分别为32．0％、90．7％和96．4％．在紫花苜蓿生育前期（4-_6月），各处理之间土壤贮水量差异不显著；在紫花苜蓿生育后期（7—10月），BMR和CMR的土壤贮水量显著高于SR，SR的土壤贮水量显著高于平作，如在紫花苜蓿孕蕾期，平作、SR、BMR和CMR0～140cm土层土壤贮水量分别为223．27、248．56、277．81和284．16mm．平作、SR、BMR和CMR全生育期实际干草产量分别为4112．1、3397．5、4317．8和4523．8kg·hm～，水分利用效率分别为11．08、10．48、14．56、14．95kg·mm～·hm～．在同一覆盖材料下，不同沟垄比对土壤贮水量和水分利用效率的影响不显著．当沟垄比为60cm：44cm时，CMR和BMR处理的实际产量均达到最大．

英文摘要：

A field experiment with complete random design was conducted to investigate the effects of different mulching materials [ common plastic film （CMR）, biodegradable mulch film （BMR） , and soil crust （SR） ] and different ratios of furrow to ridge （60 cm：30 cm, 60 cm：45 cm, and 60 cm：60cm） on the runoff efficiency, soil water storage, soil water content, and hay yield and water use efficiency of alfalfa in semiarid areas of the Loess Plateau. The runoff efficiency in treat- ments SR, BMR, and CMR was 32.0% , 90.7% , and 96.4% , respectively. In the early growth period of alfalfa （from April to June）, the soil water storage between the treatments had no signifi- cant difference, but in the late growth period （from July to September） , the soil water storage in CMR and BMR was significantly higher than that in SR. The soil water storage in SR was signifi- cantly higher than that in traditional planting （TP）. At budding stage, the soil water storage in TP, SR, BMR, and CMR was 223.27, 248.56, and 277.81, and 284.16 ram, respectively. In the whole growth period, the hay yield of alfalfa in TP, SR, BMR, and CMR was 4112.1, 3397.5, 4317.8, and 4523.8 kg- hm-2, and the water use efficiency was 11.08, 10.48, 14.56, and 14.95 kg ~ mm-1 ~ hm-2, respectively. The ratio of furrow to ridge had no significant effects on the water use efficiency in the same treatments. When the ratio of furrow to ridge was 60 cm：44 era, the hay yield in CMR and BMR reached the maximum.