Analysis Of The Production Performance And Soil Ecological Effects Of Grasses Mixed With Legumes In Hulunbuir Region

In this study,the purpose of improving the quality of artificial grassland in Hulunbuir area,high-yield oat varieties were selected through introduction experiment,and the superior-quality and high-yield oat varieties for suitable local cultivation were determined by using production performance and quality evaluation index of forage.The mixed sowing experiments selected oat varieties with Vicia sativa（Lanjian No.2）and Glycine max（Longxiaoli No.2）as test material,set three mixture sowing ratios（grasses-legumes,1:1 and 2:1）and mixture different sowing methods（peer mixed sowing,interrow mixed sowing）compared to CK,amount to 15 treatment.The high yield model of mixed sown grassland in Hulunbuir area was determined by measuring the indexes of production performance,nutritional quality,feeding value,field lodging character,soil ecological effect.The results will provide a reference for the high-yield and high-efficiency planting mode for local forage production,and supply the basis for the high-efficiency mechanism of mixed sowing grassland in further exploration.The main results are as follows:In this study,the comprehensive performance of 10 introduced oat varieties was evaluated by grey correlation degree method.Qingyin No.1,Jiayan No.2 and Qinghai.No.444 ranked first in comprehensive evaluation,and had higher production performance,nutritional quality and feeding value at flowering stage,as high-yield and superior quality oat variety with production potential in the Hulunbuir area.The yield advantage of Qinghai No.444 is better than other varieties（P<0.05）,had the highest yield of fresh herbage(36620 kg·ha^-1,P<0.05),and had the highest hay yield(9990kg·ha^-1,P<0.05).Plant height and stem diameter are the main indexes that positively affect forage yield.Qingyin No.1 and Jiayan No.2 had significant advantages in seed yield（P<0.05）,the stem diameter and kernel weight were the main indexes that positively affected the grain yield of oat.The mixed sowing mode of grassland could improve the lodging resistance of oats.The length of basal internodes reducing and the thickness of basal culm wall increasing improved the lodging resistance of Oats.The stem strength,center of gravity height,the first stem diameter,the second internode length,the first stem breaking force and the second stem breaking force of oat play a decisive role in the stem lodging index.The results of comprehensive evaluation indicate that the lodging characters were ranked first and the lodging resistance was strong under the modes of G1:1J,V1:1T,G1:2J,V1:1J（Note:G indicated mixed sowing of oats and Glycine max,V indicated mixed sowing of oats and Vicia sativa,1:1,1:2,2:1 indicated mixed sowing ratio,T indicated peer mixed sowing,J indicated interrow mixed sowing,same below）.The forage yield under the mixed sowing mode of grass-legumes has a significant advantage.Among them,the fresh grass yield increased significantly（P<0.05）in V2:1T and G1:2J models,and the hay yield increased significantly in V1:1T,G1:2J,G1:1J and G2:1J models.At the same time,mixed sowing of grass-legumes increased the content and RFV of crude protein,crude fat and crude ash of forage grass.The results revealed that the forage quality of the mixed sowing mode of V1:2T and V1:2J reached the first grade forage standard,and the mixed pasture of oat and soybean（G1:2T,G1:1T,G2:1T,G1:2J,G1:1J and G2:1J）all reached the first grade forage standard.Mixed sowing of grass-legumes increased the contents of soil total nitrogen and organic matter,and increased the activities of urease and sucrase.The content of total nitrogen decreased with the increase of soil depth,and the content of total nitrogen in surface soil was the highest under the mixed sowing mode of V1:2T and G1:2J,and the activity of sucrase increased with the increase of soil depth.Based on the comprehensive analysis of the above results,Qingyin No.1,Jiayan No.2 and Qinghai No.444 oat varieties have the potential to be popularized and planted in Hulunbuir area as high-quality oat varieties;The yield and quality of forage grass were better and the lodging resistance was stronger under the two mixed sowing modes of oat and common vetch 1:1（V1:1T）and oat and soybean 1:2（G1:2J）,indicating that V1:1T and G1:2J were the best mixed sowing modes of grass-legumes in Hulunbuir area.The content of soil total nitrogen and organic matter and the activities of urease and sucrase were increased,improving the local soil fertility.