Effects of fertilization and mixed sowing on restoration of degraded grassland in Songnen Plain
[Objective]To explore the best restoration mode suitable for moderately degraded grassland and pro-vide technical support for the protection and restoration of degraded grassland in Songnen Plain.[Method]The study examined two types of mixed sowing,involving Medicago sativa and Leymus chinensis(legume∶grass inter-row pat-terns of 2∶2(B1)nand 1∶2(B2)),along with seven levels of nitrogen fertilization of 0,50,100,150,200,250,300 kg/hm2.The aim was to identify the optimal restoration model for moderately degraded grassland in Songnen Plain by analyzing soil nutrient content,forage quality and yield.[Result]Fertilizer levels significantly affected community species richness(P<0.01).Additionally,fertilizer levels,mixed sowing proportions,and their interaction signifi-cantly affected soil organic matter,Shannon-Wiener diversity index,crude protein content and forage yield(P<0.05).Significant positive correlations were observed between soil total nitrogen,forage crude protein content and ni-trogen application(P<0.01).The variation in soil total nitrogen corresponded to the nitrogen application rate under both mixed sowing proportions.Forage crude protein content with 300 kg/hm2 N reached 20.22%,significantly higher than other treatments(P<0.05).[Conclusion]Nitrogen application rate of 200～250 kg/hm2 yielded the best results in the autumn of 2021 and the spring of 2022.The Margalef richness index and Shannon-Wiener diversity in-dex of legume-grass in the 1∶2 configuration were higher than those in the 2∶2 configuration,with 150 kg/hm2 N iden-tified as optimal.
legume-grass mixed sowingsoil nutrientforage yieldcrude protein contentcommunity composi-tion
NETL
NSTL
万方数据
