| Leymus wildrye,as one of the main grass species for improving natural grasslands and ecological construction,is also an important forage for the development of animal husbandry in China.The development of high-quality artificially cultivated sheep grassland is of great significance for promoting the sustainable development of animal husbandry and environmental protection in the ecologically fragile zone of Yulin region.With the rapid development of animal husbandry in this region,the quality and yield of forage have gradually become limiting factors in the development process of forage industry.Reasonable fertilization is the main measure to improve the production performance and quality of forage.However,there is currently little research on the reasonable fertilization ratio for Leymus wildrye planting in the Yulin agricultural pastoral ecotone.Based on this,this study used different nitrogen and phosphorus fertilization ratios as the treatment,with Leymus wildrye as the research object.Using a randomized block design,three levels of nitrogen and phosphorus fertilizers were set up in the field,with the fertilization levels being N1(120 kg/hm2),N2(180 kg/hm2),N3(240 kg/hm2),P1(60 kg/hm2),P2(90 kg/hm2),and P3(120 kg/hm2);The experimental treatments were CK,N1,N2,N3,N1P1,N1P2,N1P3,N2P1,N2P2,N2P3,N3P1,N3P2,and N3P3,with CK being the non fertilization treatment.The correlation analysis method was used to analyze the relationship between the growth indicators of Leymus wildrye and hay yield.The effects of nitrogen and phosphorus application on the production performance and quality of Leymus wildrye were analyzed through membership function and grey correlation analysis.The optimal fertilizer combination suitable for planting Leymus wildrye in Yulin sandy land was selected The main results are as follows:(1)Fertilization has effectively improved the production performance of Leymus wildrye.Two years of fertilization treatment both improved the hay yield of Leymus wildrye,and the yield increase effect of nitrogen and phosphorus combined application was better.Among them,the hay yield of N2 P3 treatment was the highest for two consecutive years,with 11567 kg/hm2 and 11700 kg/hm2,respectively.Moreover,the hay yield of the same fertilization treatment in 2022 increased to varying degrees compared to 2021.Two years of fertilization treatment improved plant height,and the effect of nitrogen and phosphorus combination application was greater than that of nitrogen fertilizer application alone.Among them,the plant height of N2P3 treatment was the highest for two consecutive years,with 99.8 cm and 103.4 cm,respectively.The leaf length of N2P3 treatment was the highest for two consecutive years,with 31.20 cm and 31.83 cm,respectively.The combination of medium nitrogen and high phosphorus and high nitrogen and medium phosphorus is more conducive to the growth of leaf width.The highest number of leaves in 2021 and 2022 is 6 and 7,respectively.The stem diameter of N2P3 treatment was the highest for two consecutive years,with 1.51 mm and 1.62 mm,respectively.The production performance indicators of most of the same fertilization treatments in 2022 increased compared to 2021.(2)Fertilization has improved the nutritional quality of Leymus wildrye.Two years of fertilization treatment both increased the crude protein and ether extract content of Leymus wildrye.The combined application of nitrogen and phosphorus had a greater effect on the increase of crude protein and ether extract content than the single application of nitrogen fertilizer.The treatments with the highest crude protein content in 2021 and 2022 were N3P2 and N3P1,with 12.36%and 14.03%,respectively;The treatment with the highest ether extract content for two years was also N3P2 and N3P1,with 2.71%and 3.28%,respectively;The crude protein content of the same fertilization treatment in 2022 increased compared to 2 02 1,and the ether extract content of most of the same fertilization treatments in 2022 increased compared to 2021.All fertilization treatments reduced the crude ash and crude fiber content of Leymus wildrye.The treatment with the lowest crude ash content for two consecutive years was N1P3,with 6.45%and 6.3 8%,respectively;The treatment with the lowest crude fiber content for two consecutive years was N2P3,with 30.3 5%and 29.5 8%respectively;The combined application of nitrogen and phosphorus has a greater effect on reducing crude ash and crude fiber than single application of nitrogen fertilizer.All fertilization treatments resulted in a decrease in the content of acid detergent fiber,and the best reduction effect was observed with N2P3 treatment for two consecutive years,with 33.71%and 33.27%respectively;The majority of acid detergent fiber treated with the same fertilization in 2022 decreased compared to 202 1.The neutral detergent fiber content of all fertilization treatments decreased after fertilization,but there was no significant difference between the treatments.Compared with 2021,the neutral detergent fiber content of the same fertilization treatment in 2022 decreased to varying degrees.The relative feed value of all fertilization treatments was higher than that of CK treatment,and compared to 2021,the relative feed value of the same fertilization treatment in 2022 was improved to varying degrees.(3)Through the analysis of membership function and grey correlation degree,it was found that the top three treatments in terms of comprehensive trait performance of Leymus wildrye were N2P3,N3P2,and N3P1.Among them,N2P3 treatment had the highest membership function and weighted correlation degree values,with 0.894 and 0.921 respectively.In summary,both single application of nitrogen fertilizer and combined application of nitrogen and phosphorus can improve the production performance and nutritional quality of Leymus wildrye.Among them,the N2P3 combination is the optimal fertilizer ratio for planting Leymus wildrye in Yulin sandy land. |
