Effects Of Mixed Sowing Of Oats And Legumes On Grassland Interspecific Relationship And Production Performance In Arid Area Of Ningxia

Mixed sowing not only has the characteristics of high yield,high quality and stability,but also has more advantages in maintaining the nitrogen nutrition balance of grassland ecosystem,improving soil fertility and realizing sustainable production.Ningxia arid area is one of the important animal husbandry production bases in China.However,due to the influence of human activities and natural factors,the growth of forage grass is hindered,the plant is low,and the vegetation is sparse,which limits the productivity of forage grass and reduces the nutritional quality of forage grass.In view of this,a 6:4 mixed sowing ratio of oat(Avena sativa)and two legumes was set up for peer mixed sowing and inter-row mixed sowing,namely oat+Vicia villosa peer mixed sowing(TM),oat+Vicia sativa peer mixed sowing(JM),oat+Vicia villosa inter-row mixed sowing(JM),oat+Vicia villosa inter-row mixed sowing(JJ),and oat monoculture(YD),Vicia villosa monoculture(MD)and Vicia villosa monoculture(JD),a total of 7 treatments.The effects of mixed sowing of oat and legume on main agronomic traits,production performance,nutritional quality,interspecific competition and land equivalent ratio were studied.The main results are as follows:(1)Oats and legumes and intercropping can significantly improve grassland productivity.The highest plant height of oat was JJ,up to 101.0 cm.The tiller number,stem diameter,leaf number,leaf length and leaf area of oats treated with YD were the largest,which were 411.2/m2,3.46 mm,5.0/plant,187.69 mm and 1574.75 mm2,respectively.The treatments with the highest fresh-dry ratio and leaf-stem ratio were TJ and JM,respectively.The fresh yield and hay yield of oats and legumes were higher than those of inter-row mixed sowing.The total fresh yield and total hay yield reached the highest under JM treatment,which were 39564.22 kg/hm2 and 8524.56 kg/hm2,respectively.The highest crude protein yield of mixed grassland was treatment JM,reaching 1122.34 kg/hm2,which was 30.8%higher than that of oat monoculture.(2)Oats and legumes and intercropping can significantly improve the nutritional quality of forage.The crude ash content of mixed sowing treatment and oat monoculture was the highest under TM treatment,reaching 12.72%.The crude protein content and relative feeding value of JM treatment were the highest,which were 13.17%and 109.73,respectively,which were 19.5%and 12.2%higher than those of oat monoculture.The content of neutral detergent fiber in TM treatment was the lowest,and the dry matter intake was the highest,which was 51.57%and 2.33%,respectively.YD treatment had the highest acid detergent fiber content and dry matter digestibility,which were 35.04%and 61.42%,respectively.(3)The mixed sowing of oats and legumes can significantly improve the land use efficiency,showing the advantage of increasing production,and oats have obvious competitive advantages in the community when oats are mixed with legumes.Oats are the dominant species of mixed sowing of oats and legumes,showing that interspecific competition is greater than intraspecific competition,and there is resource competition.Among them,different mixed sowing methods of oat,hairy vetch and common vetch were all mixed sowing advantages,and LER was greater than 1.Among them,JM had the largest land equivalent ratio of 1.42,which could improve the utilization rate of land by 42%.Different mixed sowing methods of oat,hairy vetch and common vetch all showed yield increase advantages,and AYL was greater than 0,showing yield increase.Among them,JM had the largest real yield loss,with a yield increase of 69.71%.The competition ratio and competition intensity of oat were higher than that of leguminous grass,and oat had obvious competitive advantage in the mixed community with leguminous grass.The total relative yield of JM was the highest,reaching 2.65.The JM system had the highest productivity of 4911.62 kg/hm2.The inter-row mixed sowing(JM)of oat and hairy vetch at a mixed ratio of 6:4 is beneficial to improve grassland production performance,improve forage nutritional quality,improve land use efficiency and increase yield.It can be used as a cultivation measure for oat mixed sowing under drip irrigation in arid areas of Ningxia.