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

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 to 19.63%～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.