行距和播种量对高寒区老芒麦生长和产草量的影响及综合分析OA北大核心CSTPCD

[Objective]This study aimed to investigate the effects of row spacing and seeding rate on forage yield of Elymus sibiricus(E.sibiricus)in alpine region,further to screen out the optimum planting row spacing and seeding rate for forage production of E.sibiricus in the Qinghai-Tibet Plateau,and to reveal the influence process and path coefficient of planting row spacing and seeding rate on forage yield of E.sibiricus,and hence,so as to provide the data support for efficient forage production in the Qinghai-Tibet Plateau.[Method]In this study,E.sibiricus cv.Qingmu No.1 and E.sibiricus cv.Qingmu No.2 were selected as experimental material,and the two-factor split zone experimental design was adopted.Three row spacings were set as the main factors,including R1:15 cm,R2:30 cm,and R3:45 cm,respectively,and three seeding rates(S1:15.0 kg·hm-2,S2:22.5 kg·hm-2,and S3:30.0 kg·hm-2)were used as secondary factors.And thus,there were 9 treatments,3 repetitions,27 plots of each variety,and a total of 54 plots with each area 15 m2(3 m×5 m),which was carried out in Gonghe County,Qinghai Province in 2022-2023.Random block arrangement was used to analyze the effects of different row spacings and seeding rates on growth character,forage yield and economic benefit of E.sibiricus,and the structural equation model was performed to study the influence process of row spacing and seeding rate on forage yield of E.sibiricus and its path coefficient.[Result]Both row spacing and seeding rate had significant effects on stem diameter,tillers,fertile tillers per,stem-leaf ratio and forage yield of Qingmu No.1 and Qingmu No.2.Under the same row spacing,the plant height and stem diameter of Qingmu No.1 and Qingmu No.2 decreased with the increasing of seeding rates,tillers and fertile tillers increased first and then decreased with the increasing of seeding rates.Under the same seeding rates,the plant height,stem diameter and dry-fresh ratio of Qingmu No.1 and Qingmu No.2 increased with the increasing of row spacing,and the tillers and fertile tillers decreased with the increasing of row spacing.Hence,the row spacing was 15 cm and the seeding rate was 22.5 kg·hm-2,the forage yield and economic benefit of Qingmu No.1 and Qingmu No.2 were the highest,the forage yield of Qingmu No.1 was 12 668.16 kg·hm-2,and the economic benefit was 13 731.97 yuan·hm-2.The forage yield of Qingmu No.2 was 12 180.94 kg·hm-2,and the economic benefit was 13 064.03 yuan·hm-2.Pearson correlation analysis showed that forage yield was positively correlated with tillers and fertile tillers.The structural equation model showed that tillering was the primary driving factor for improving the forage yield of E.sibiricus under row spacing and seeding rate.[Conclusion]The comprehensive evaluation of TOPSIS model showed that the row spacing was 15 cm and the seeding rate was 22.5 kg·hm-2,which could not only maintain higher forage yield,but also significantly improve economic benefits,so it was the best row spacing and seeding rate amount,which was suitable for the forage production of E.sibiricus in chernozem of alpine region.