单播与混播对两个冬小麦品种产量和水分利用效率的影响

选取黄土旱塬两个冬小麦品种长武135和平凉40,采用生态替代法连续两年在田间条件下研究了单播和混播方式对冬小麦产量和水分利用效率的影响.结果表明:单播条件下平凉40单位面积根量为367.60 g·m-2,显著大于长武135的297.31 g·m-2,且其根系在各土层中分布较均匀,表明与长武135相比,平凉40吸收土壤水分的能力较强,但其在单播条件下的产量和水分利用效率较低.混播增加了平凉40和长武135根系在较深土层中的根量分布,两品种根量分别比单播条件下多13.36和8.50 g·m-2,混播增强了小麦根系对深层土壤水分的吸收利用,提高了单位面积总产量,增加了群体水分利用效率.与平凉40相比,长武135分配了更多的干物质到繁殖器官,使其根量和地上营养器官的生物量减小,从而提高了籽粒产量和收获指数,表现出较高的水分利用效率.

Effects of mono- and mixed culture on the grain yield and water use efficiency of two winter wheat cultivars

Taking two winter wheat (Triticum aestivum L.) cultivars Changwu 135 and Pingliang 40 commonly cultivated in the semi-arid area on Loess Plateau as test materials, and by the method of ecological replacement, a 2-year field experiment was conducted to study the effects of mono- and mixed culture on the grain yield and water use efficiency of the cultivars. The results showed that under mono-culture, Pingliang 40 had a much higher unit area root biomass (367.60 g x m(-2)) than Changwu 135 (297.31 g x m(-2)), and a more uniform root distribution (i.e., a better root type for water absorption), but its grain yield and water use efficiency were lower than Changwu 135. Under mixed culture, the population root biomass of Pingliang 40 and Changwu 135 was 13.36 g * m(-2) and 8.50 g x m(-2) higher than that under mono-culture, respectively, suggesting that mixed population could absorb the water in deeper soil layers, and had higher total unit area biomass, which in turn increased the water use efficiency. Comparing with Pingliang 40, Changwu 135 allocated more dry matter to its productive organ, leading to its higher grain yield, harvest index, and water use efficiency.