| Ningxia Yellow River Irrigation Area is the main forage production and supply area in Ningxia,and it is also an important area for animal husbandry production.However,the shortage and low quality of forage seriously restrict the development of local animal husbandry.In order to make full use of light and heat resources,improve land utilization,and improve the economic benefits of forage production,it is a good choice to carry out a one-year two-crop planting model.However,under the planting mode of two crops in one year,the yield,quality and economic benefits of two forages under different mixed sowing ratios are not clear.In view of this,in this study,’Xiyue ’ oat and common hairy vetch were used as experimental materials,and six treatments were set up,including oat monoculture(Y),hairy vetch monoculture(M)and oat:hairy vetch mixed sowing ratio(5:5,6:4,7:3 and 8:2,treatment names were H1,H2,H3 and H4,respectively).The effects of different mixed sowing ratios of oat and hairy vetch on forage yield,nutritional quality and economic benefits,and the influence mechanism of interspecific competitiveness on yield formation under different mixed sowing ratios were studied.The main results are as follows:(1)Oat and hairy vetch mixed sowing can significantly improve the land use efficiency.Under each mixed sowing treatment,the land equivalent ratio(LER)was greater than 1,showing the advantage of mixed sowing.Among them,under H2 treatment,LER reached 1.29,saving 29%of land demand compared with monoculture oats.The trend of land equivalent ratio,real yield loss(AYL)and relative yield total(RYT)in the mixed community of oat and hairy vetch was consistent.Under the mixed ratio of 6:4,the LER value,AYL value and RYT were the largest,and the average values of the two crops were 1.29,0.39 and 2.39,respectively.The competition ratio(CR)and invasion intensity(A)of oat were greater than those of hairy vetch,which showed that oat was the dominant species in oat-hair vetch mixed cropping system.The system productivity index was the highest under H2 treatment,with an average of 7.53 in two stubbles.(2)Mixed sowing can improve grassland productivity.In terms of oat plant height,the single sowing oat plant height was the highest,with an average of 108.20 cm.The tiller number of oats in Y treatment was the largest,with an average of 350.35/m2,and the stem diameter was 3.62 mm.The flag leaf length and leaf area reached the maximum under H3 treatment,which were 276.03 mm and 1617.80 mm2,respectively.In terms of total hay yield,the average total hay yield of H2 treatment was 6.65 t·hm-2,which was 13.68%higher than that of oat monoculture.There were significant differences in crude protein yield among different treatments(P<0.05).With the increase of oat mixed sowing ratio,crude protein yield increased first and then decreased.It reached the highest under H2 treatment,with an average of 933.87 kg·hm-2,which was 51.82%higher than that of Y treatment.Compared with H1,H3,H4 and M treatments,it increased by 4.98%,16.72%,18.12%and 59.45%,respectively.(3)Mixed sowing can improve the forage quality,increase the crude protein content of mixed forage,and reduce the neutral and acid detergent fiber content.Under the mixed sowing treatment,the crude protein content and relative feeding value of H1 treatment were the highest,with an average of 15.16%and 110.62,respectively,which were 44.31%and 14.19%higher than those of oat monoculture.Combined with the results of the two experiments,except for the hairy vetch monoculture treatment,when the ratio of oats to hairy vetch was 5:5,the crude protein content was the highest,the neutral detergent fiber and acid detergent fiber were the lowest,and the relative feeding value was the highest.At the same time,with the increase of the proportion of oats,the crude protein content decreased significantly(P<0.05),the neutral and acid detergent fibers increased significantly,and the relative feeding value decreased.(4)Bean-grass mixed cropping has higher economic benefits.The net income of monoculture oat was 17240 yuan/hm2,while the net income of monoculture hairy vetch was 8460 yuan/hm2.The net income of mixed sowing was 1.90～2.31 times that of monoculture hairy vetch,and 0.93～1.14 times that of monoculture oat.Under the 6:4 treatment of oats and hairy vetch,the net income of one year was 19568 yuan/hm2,and the net income of farmers increased by 13.50%.Except for H1 treatment,the overall economic benefit of oat-hairy vetch mixed cropping was higher than that of oat and hairy vetch monoculture.Based on the forage yield,main nutrients and economic benefits of the two crops,a reasonable mixed sowing ratio has a great relationship with the high quality and high yield of oats and hairy vetch.The mixed sowing ratio of oats and hairy vetch at 6:4 is beneficial to improve the grassland production performance,and shows better nutritional quality and the highest economic benefits.After comprehensive consideration,oats and hairy vetch 6:4 mixed sowing is worthy of popularization and application in Ningxia Yellow River irrigation area. |
PDF Full Text Request