禾草种类与混播比例对苜蓿-禾草混播系统生产力及种间关系的影响

Effects of Sowing Patterns on Productivity and Interspecific Relationship of Alfalfa-Grass Mixture System

以紫花苜蓿(Medicago sativa)-无芒雀麦(Bromus inermis)、紫花苜蓿-垂穗披碱草(Elymus nutans)和紫花苜蓿-虉草(Phalaris arundinacea)(分别用A1,A2,A3表示)按豆禾行数比1∶1,2∶2,1∶2和2∶1(分别用B1,B2,B3,B4表示)混播系统为研究对象,通过测定建植第1年至第3年混播牧草产量,研究禾草种类和混播比例对混播系统生产力(SP)、种群相对产量(RY)、相对产量总和(RYT)和种间竞争率(CR)的影响。结果表明,禾草种类和混播比例对混播系统生产力和种间关系有明显影响。第1年至第3年SP分别以A2,A1和A3组合最高。第1年A2组合禾草RY,CR和RYT显著高于A1和A3组合,且RYT>1。第2年A1,A2和A3组合的RYT及禾草与苜蓿的RY,CR均无显著差异,且RYT>1。第3年A1组合禾草RY和CR显著高于A2组合,其余组合间无显著差异;A3组合RYT(1.0)显著高于A1(0.92)和A2(0.91)组合。在不同混播比例处理中,B4处理三年内SP最高,其次为B1处理, B3处理最低。第1年不同混播比例间禾草RY和CR(B1的CR除外)差异不显著;第2年和第3年B2处理禾草RY(第2年B1的RY除外)和CR显著高于B1,B3和B4处理。综合考虑混播系统生产力及禾草种群稳定性,在科尔沁沙地紫花苜蓿与无芒雀麦或虉草2:2间行混播较适宜。

In order to investigate the effects of species and sowing ratios on productivity and interspecific relationship of legume-grass mixture system, three mixed sowing patterns(Medicago sativa-Bromus inermis, A1;M. sativa-Elymus nutans, A2;M.sativa-Phalaris arundinacea, A3) and four sowing ratios(legume and grass row ratio of 1:1, 2:2, 1:2 and 2:1, represented by B1, B2, B3 and B4) were established as the experimental area with complete randomized block, we compared the response of productivity(SP), relative yield of population(RY), relative yield total(RYT) and interspecific competition rate(CR). The results showed that the combination of A2, A1 and A3 has highest SP from 2016 to 2018. In the first year(2016), RY, CR and RYT of A2 combination were significantly higher than those of A1 and A3 combinations(P<0.05), and RYT>1. In the second year(2017), RYT, RY and CR of A1, A2 and A3 combinations had no significant difference(P>0.05), and RYT>1. In the third year(2018), RY and CR of the A1 combination were significantly higher than those of the A2 combination(P<0.05), and there was no significant difference among the other combinations(P>0.05). The RYT(1.0) of the A3 combination was significantly higher than that of the A1(0.92) and A2(0.91) combinations. Among the different treatments, B4 treatment had the highest SP, followed by the B1 treatment, and that of B3 treatment had the lowest SP in three years. In the first year, there was no significant difference in RY and CR(except for CR of B1) among the different treatments, in the second and third year, the RY(except RY of B1 treatment in the second year) and CR of B2 were significant higher than those of B1, B3 and B4 treatments. The optimal treatment was intercropping mixture with 2 rows of alfalfa and 2 rows of smooth bromegrass or reed canarygrass at the productivity of the mixed system and the stability of the grass population by comprehensive consideration in the Horqin Sandy Land.