Effects Of Nitrogen And Phosphorus And Microelement Fertilizer On Productivity Of Alfalfa Under Drip Irrigation

Objective:In this study,alfalfa was taken as the research object.The effects of different nitrogen and phosphorus interaction modes,spraying boron and molybdenum fertilizers on the hay yield and nutritional quality of alfalfa were studied to improve the hay yield and nutritional quality of alfalfa under drip irrigation and provide data reference for scientific fertilization in Xinjiang oasis region.Methods:1)This experiment adopted two randomized block design factors of nitrogen fertilizer:105 and210 kg·ha^-1?referred to as N₁ and N₂,respectively?and 0,50,100 and 150 kg·ha^-1 of phosphorus fertilizer?referred to as P₀,P₁,P₂,and P₃,respectively?.2)In this experiment,four treatments of application molybdenum?Mo?,application boron?B?,application of boron and molybdenum?B+Mo?and non-fertilization?CK?were established.The application rates of ammonium molybdate and boron fertilizer were 0.45 kg/hm² and 0.69 kg/hm²,respectively.Fertilization was carried out by leaf spraying.3)Phosphorus fertilizer was applied in one go in the regreening stage.The nitrogen fertilizer was applied at the regreening stage and after each cutting.The amount of nitrogen fertilizer was 75 kg/hm² at every time and phosphorus fertilizer was 150 kg/hm².Results:1)The total hay yield under N₁P₂ treatment was the highest,which was 22039.09 kg/ha².Under the condition of nitrogen application,except for the first cut,the crude protein content of alfalfa leaves and stems reached the highest value under P₂ treatment.The crude protein content of alfalfa leaves showed that N₁ treatment was greater than N₂ treatment under the same phosphorus application conditions in the last three cuts.Under N₁ treatment,except for the fourth cut,the ADF and NDF contents of alfalfa leaves and stems under drip irrigation reached the minimum under P₂ treatment,while under N₂ treatment,the ADF content of alfalfa leaves reached the minimum under P₁ treatment in the first three cuts.Except for the second cuts,the ADF and NDF contents in leaves and stems of alfalfa showed that N₁ treatment was lower than N₂ treatments under the same phosphorus application.Under the same phosphorus application,nitrogen uptake efficiency,nitrogen partial factor productivity,phosphorus use efficiency and phosphorus uptake efficiency of N₁ treatment were significantly higher than N₂ treatment.Under the same nitrogen application,P₂ treatment was significantly higher than P₀ treatment in nitrogen uptake efficiency and nitrogen partial factor productivity.Through fuzzy similarity priority ratio,the optimal fertilization mode under drip irrigation of alfalfa at each cuts was the N₁P₂ treatment at different nitrogen and phosphorus treatments.2)The growth traits indexes and nutritional value of alfalfa under drip irrigation,the effect of application of B and Mo was the greatest,followed by B application.The hay yield of alfalfa under drip irrigation sprayed with B and Mo was the highest.The relative feeding value and phosphorus uptake of alfalfa in the application B and Mo were significantly larger than Mo application and CK treatments?P<0.05?.If only one element is considered,the effect of application of B on alfalfa under drip irrigation is greater than application of Mo.3)From the total hay yield of alfalfa,124 and 130 regiments with 4 cuts was higher than 142,147regiments with 3 cuts.The RFV of 124 regiment 12 company was significantly higher than 4,8 company of142 regiment and 147 regiment 5 company.The economic benefits of 9,12 company of 124 regiment was greater than 4,8 company of 142 regiments.Generally,the production performance of 124 regiment and7,9 company of 147 regiment was better than 130 and 142 regiments of alfalfa under drip irrigation.Conclusion:1)Among different nitrogen and phosphorus treatments,the annual total hay yield under N₁P₂?N:105 kg/hm²,P₂O₅:100 kg/hm²?treatment was highest of alfalfa under drip irrigation.Under this treatment,the crude protein content of leaves and stems was the highest,the NDF content of leaves was the lowest,and the nitrogen absorption efficiency,nitrogen factor partial productivity and phosphorus use efficiency were the highest.2)The hay yield,crude protein content and relative feeding value were significantly increased by spraying boron and molybdenum fertilizer of alfalfa under drip irrigation.If a single element was considered,the effect of boron fertilizer on the production performance and nutritional quality was greater than molybdenum fertilizer of alfalfa under drip irrigation.3)The production performance of 124 regiment and 7,9 company of 147 regiment was better than 130 and142 regiments of alfalfa under drip irrigation.