Effects Of Reseeding Grass On The Productivity,Nutritional Quality And Soil Characteristics Of Degraded Alfalfa Land

In order to improve 260,000 hm2(including Haiyuan county)degraded alfalfa(Medicago saliva L.)grassland in the southern mountainous area of Ningxia,the experiment was arranged by random block group.Reseed reed shape fescue(Festuca arundinacea Schreb.),chinensis(Leymus chinensis(Trin.)Tzvel.),and inflorescences(Dactylis glomerata L.),cover with alkali grass(Elymus nurtans),no mans nutans(Bromus inermis Leyss)and perennial ryegrass(Lolium perenne L.),6 kinds of grasses to reseed for control(CK),The results show that:(1)The effect of supplementary planting grass on the performance of degraded alfalfa was significant(P<0.05).Reseed reed of festuca,alfalfa than the plant height,number of primary branches,leaf,grass yield and leaf area were significantly higher than that of other reseed processing,the vegetation productivity index weighted sorting,shape of the reed fescue reseed processing maximum weighted value,the degradation of alfalfa to comprehensive production performance has a prominent effect,can effectively improve the degradation of alfalfa productivity.(2)The nutrient content of alfalfa was significantly affected by supplementary planting(P<0.05).In the first crop(June),compared with other treatments,the coarse ash content and acid washing fiber content of alfalfa were the smallest,while the crude protein content,relative feeding value and crude fat content of alfalfa were the highest.In the second crop(August),the content of alfalfa crude protein,crude fat and relative feeding value were the highest under the treatment of duck grass,and the content of neutral and acid washing fiber was the lowest.Therefore,the nutrient quality of alfalfa grass in degraded alfalfa grassland could be improved significantly by supplementary planting.(3)The effects of supplementary planting grass on soil physical and chemical properties and fertility of degraded alfalfa were significant(P<0.05).In the soil layer of 0-20cm,the field water holding capacity,total nitrogen content and the number of fungi in the soil of the reseeding neophyte had the maximum value;in the soil layer of 20-40cm,the capillary porosity,capillary water holding capacity,available phosphorus content,organic matter and actinomycetes in the soil of the reseeding neophyte had the maximum value.The results showed that it could effectively improve soil physical and chemical properties,increase soil nutrient accumulation and promote soil microbial activities.Based on the comprehensive analysis,it is concluded that reed-planting of festuca reed-like can effectively improve the productivity of degraded alfalfa grassland,the quality of alfalfa grass can be effectively improved by reed-planting of festuca reed-like can effectively improve the soil characteristics of degraded alfalfa grassland.Therefore,in the practice of grass land renewal and rejuvenation of degraded alfalfa in the mountain area of southern ningxia,different grasses can be selected for supplementary sowing according to different needs.