黄土丘陵区白羊草与达乌里胡枝子混播草地生产力与土壤水分利用研究

Study on Biomass Production and Soil Water Use of Bothriochloa isaemum and Lespedeza davurica Mixture Grassland in Loess Hilly-gully Region

为合理利用黄土丘陵区优良乡土草种,并寻求利用其进行人工草地建设的最佳混播比例组合,选取白羊草(Bothriochloa isaemum)和达乌里胡枝子(Lespedeza davurica)为研究材料,采用生态替代法,按照二者行比设置7种混播比例组合(即0∶10,2∶8,4∶6,5∶5,6∶4,8∶2和10∶0),比较研究混播比例对草地植株株高、地上生物量和水分利用效率等的影响。结果表明:混播草地中白羊草与达乌里胡枝子的株高均明显高于各自单播草地;混播草地的地上生物量和水分利用效率均显著高于二者各自单播草地;草地地上生物量和水分利用效率以白羊草和达乌里胡枝子混播比例为6∶4的显著最高,单播达乌里胡枝子草地(即0∶10比例组合)显著最低。表明,白羊草与达乌里胡枝子存在混播互补效应,其中比例组合为6∶4的草地在生物量和水分利用效率方面具有比较优势。

The purpose of the study is to rationally use and seek ideal mixture ratio of native species in loess hilly-gully region so as to establish artificial grassland.One field experiment was conducted by using a replacement series design in which Bothriochloa ischaemum and Lespedeza davurica were sowed as row ratios of 0∶10,2∶8,4∶6,5∶5,6∶4,8∶2and 10∶0in the same plot.The plant height,aboveground biomass production,water use efficiency of grassland under each mixture ratio were investigated and compared.The results indicated that plant heights of the two species in mixtures were significantly higher than those in their respective monoculture.The aboveground biomass production and water use efficiency of the two-species mixture grassland were higher than their respective monoculture.The aboveground biomass production and water use efficiency were significantly higher at B.ischaemum∶ L.davuricaratio 6∶4,and the minimum was in L.davuricain monoculture（i.e.0∶10ratio）.All these suggest that the existed complementary effect between B.ischaemum and L.davuricain mixture grassland,and the B.ischaemum∶ L.davuricaratio of 6∶4had comparative advantage in aboveground biomass production and water use efficiency.