陇中黄土高原混播草地生产性能

为了指导黄土高原丘陵沟壑区栽培草地建植及草食畜牧业的持续健康发展，本研究选择当地推广种植面积较大的紫花苜蓿(Medicago sativa)和红豆草(Onobrychis viciaefolia)两个草种为研究对象，于2016?2018年在甘肃省定西市安定区李家堡镇黄金村开展了紫花苜蓿与红豆草在1 ? 0 (H1)、7 ? 3 (H2)、5 ? 5 (H3)、3 ? 7 (H4)和0 ? 1 (H5)的混播比例下草地生产性能的相关研究。结果表明：1)建植生长第2年，H2、H3、H4处理的地上生物量分别比H1处理提高46.0%、34.0%和12.0%，但均低于H5处理；第3年，H2、H3、H4处理的地上生物量分别比H1处理提高36.5%、40.0%和23.5%，比H5处理提高34.9%、38.4%和22.1%，混播效应明显。2)随着混播组合中紫花苜蓿比例的降低，紫花苜蓿相对于红豆草的种间竞争力减小。3)紫花苜蓿与红豆草在3 ? 7混播比例下，2种牧草的粗蛋白含量均最高，且紫花苜蓿高于红豆草；与单播相比，混播后相对饲喂价值提高，提高了4.4%～49.73%，7 ? 3混播比例下，紫花苜蓿的相对饲喂价值较高，3 ? 7混播比例下，红豆草的相对饲喂价值较高。综合来看，紫花苜蓿与红豆草在7 ? 3和5 ? 5混播比例下，于生长第2年和第3年可获得相对较高的地上生物量和营养物质产量，可在生产实践中大面积推广应用。

Production performance of mixed grassland in the Loess Plateau of Longzhong

In this study, we aimed to guide the sustainable and healthy development of artificial grasslands and herbivorous animal husbandry in hilly and gully regions of the Loess Plateau. In this study, alfalfa and sainfoin were selected as experimental materials to treat the forage productivity for alfalfa mixed with sainfoin at ratios of 1 ? 0 (H1), 7 ? 3 (H2), 5 ? 5 (H3), 3 ? 7 (H4), and 0 ? 1 (H5) at the Golden Village of Lijiabao Town in Dingxi City, Gansu Province, between 2016 and 2018. The following results were obtained: (1) In the second year, the aboveground biomasses after H2, H3, and H4 treatment were 46.0%, 34.0%, and 12.0% higher than that after H1 treatment, respectively, but all were lower than that after H5 treatment. In the third year, the aboveground biomasses after H2, H3, and H4 treatment were higher by 36.5%, 40.0%, and 23.5% than those after H1 treatment, respectively, and higher by 34.9%, 38.4%, and 22.1% than that after H5 treatment, respectively. (2) When the proportion of alfalfa was reduced in the mixed sowing combination, the interspecific competitiveness of alfalfa relative to sainfoin decreased. (3) The crude protein content of alfalfa and sainfoin was the highest, and the relative feeding value of alfalfa was higher than that of sainfoin. In conclusion, under the mixed sowing ratio of alfalfa and sainfoin of 7 ? 3 and 5 ? 5, a relatively high aboveground biomass and nutrient yield can be obtained in the second and third years of growth, and these proportions can be employed during production.