不同饲草作物间作模式对地上生物量及竞争力的影响

Effects of different forage crop intercropping patterns on above-ground biomass and competitiveness

为探讨饲草作物搭配和带型配置对间作系统地上生物量及竞争力的影响,筛选出适合西北半干旱地区种植推广的间作组合和间作模式,研究了玉米(Zea mays)||高丹草(Sorghum bicolor×S.Sudanense)、玉米||燕麦(Avena sativa)和高丹草||燕麦在宽行(460 cm)、中行(300 cm)和窄行(140 cm)模式下的地上生物量、增产率、增产贡献率、土地当量比(land equivalent ratio,LER)、相对拥挤系数(relative crowding coefficient,RCC)、竞争比率(competition ratio,CR)、实际产量损失指数(actual yield loss index,AYL)和系统生产力指数(system productivity index,SPI)。结果表明,间作系统的LER>1、AYL>0、系统增产率达到19.63%~40.49%,具有一定的间作优势。间作高丹草相对于玉米为竞争优势物种,间作燕麦的竞争力大于玉米、高丹草。玉米|高丹草组合在中行模式下的系统增产率、LER、AYL和SPI值均表现最高,其土地利用效率比单作下高20.2%,生产力和资源利用效率最佳。

To explore the effects of forage crop collocation and stripe configuration on the above-ground biomass and competitiveness in an intercropping system,as well as screen out the intercropping combinations and patterns suitable for cultivation in the semi-arid areas of Northwest China,three forage crop collocations,corn||sorghum hybrid sudangrass,corn||oat,and sorghum hybrid sudangrass||oat,and three stripe configurations,wide row(460 cm),middle row(300 cm),and narrow row(140 cm),were set up in this experiment.The above-ground biomass,yield increase rate,contribution rate of increasing yield,land equivalent ratio(LER),relative crowding coefficient(RCC),competition ratio(CR),actual yield loss index(AYL),and system productivity index(SPI)were tested in each intercropping system.The results showed that the intercropping system had certain advantages,with LER>1 and AYL>0,and the system increased the yield rate to19.63%~40.49%.In intercropping systems,the sorghum hybrid sudangrass was a competitive dominant species relative to corn and the competitiveness of oat was greater than that of corn and sorghum hybrid high grass.The system yield,LER,AYL,and SPI of the corn||sorghum hybrid sudangrass collocation peaked in the middle row pattern,with land utilization exceeding that of the monoculture by 20.2%,thereby achieving the best productivity and resource utilization efficiency.