Effects of mixed combination and proportion between leguminous and graminaceous forages grown in Ningxia desert steppe

Effects of mixed combination and proportion on economic input-output ratio, yield of grass and main nutrientional ingrendient, relative total yield (RYT) and competitive relationship between two leguminous forages (Medicago sativa and Astragalus adsurgens) and two graminaceous forages (Leymus chinensis and Elymus sibiricus) mixed-sowing growing were studied under three mixture proportion, i.e. ratio of leguminous forages to graminaceous forages being 3∶7, 5∶5, 7∶3, respectively in Ningxia Central Semiarid Belt with suplemental irrigation. The two-year experiment showed that the yield of mixed sowing between two forages was significantly higher (P0.05) than the yield of the graminaceous forages single sowing. The yields of the mixed-sowing combinations between M. sativa and graminaceous forages were significantly higher (P0.05) than those between A. adsurgen and graminaceous forages in 2013 and 2014. The combination of M. sativa and L. chinensis with ratio of 7∶3 displayed the highest yield of dry grass (P0.05), crude protein and lipid and the lowest economic input-output ratio among all the mixedsowing combinations. The competitive rate (CR) of leguminous forage in the mixed-sowing combinations between M. sativa and graminaceous forages was higher than that in the mixedsowing combinations between A. adsurgen and graminaceous forages. There were more combination with RYT1 in the mixed-sowing combinations between A. adsurgen and graminaceous forages than the mixed-sowing combinations between M. sativa and graminaceous forages. The RYT of combination between A. adsurgen and L. chinensis with ratio of 7∶3 was highest. All of these results suggested that the combination between M. sativa and L. chinensis with ratio of 7∶3 had positive yield performance and lowest economic input-output ratio whereas the combination between A. adsurgen and L. chinensis with ratio of 7∶3 had relative balanced growth between different species when establishing artificial grassland in Ningxia Central Semi-arid Belt.