Effects Of "3414" Fertilization Of Bromus Inermis Leyss And Agropyron Mongolicum Keng On Production Performance And Soil Nutrients

The arid area of Ningxia has superior geographical location,flat terrain,deep soil and good configuration.It is a golden area for the production of forage and seeds of Bromus inermis Leyss and Agropyron mongolicum Keng.However,the optimal fertilization ratio of N（Nitrogen）,P（Phosphorus）and K（Kalium）suitable for the cultivation of Bromus inermis Leyss and Agropyron mongolicum Keng in this area is not clear,which limits the further development of forage and seed quality and yield potential.In view of this,this experiment used the ’3414 ’ experimental design to study the effects of fertilization on the production performance and soil nutrients of perennial grasses Bromus inermis and Agropyron mongolicum Keng,and comprehensively evaluated by fitting regression equations and establishing models,principal component analysis,and redundancy analysis.The aim was to clarify the optimal N,P,and K fertilization ratio suitable for the efficient production of forage and seeds of Bromus inermis and Agropyron mongolicum Keng in arid areas of Ningxia,and to provide theoretical and technical support for planting Bromus inermis and Agropyron mongolicum Keng in this area.The main results are as follows:（1）Fertilization had significant effects on plant height,stem diameter,leaf-stem ratio,hay yield and fresh grass yield of Bromus inermis and Agropyron mongolicum Keng（P<0.05）,and had significant effects on total tiller number of Bromus inermis,but had no significant effects on total tiller number of Agropyron mongolicum Keng.Among them,The yield-increasing effects of each single factor were K>N≈P.Through the comprehensive analysis of principal components,it is concluded that N3P2K2 have the highest comprehensive scores;By fitting the model of ternary quadratic equation,it is concluded that the optimal fertilization ratio of N,P and K for Bromus inermis forage production is 75.20,78.91 and 55.26 kg hm^-2,and the corresponding yield is 5423.12 kg hm^-2.The single-factor yield-increasing effect of Agropyron mongolicum Keng is P>K>N.According to the principal component score,the nutritional quality of the hay was evaluated,and it was found that N2P2K2 had the highest score.The recommended fertilization rates of nitrogen fertilizer（N）,phosphorus fertilizer（P）and Kalium fertilizer（K）were 73.04,84.26 and 64.08 kg hm^-2,respectively,and the corresponding maximum yield was 7559.41 kg hm^-2.（2）Fertilization had significant effects on the number of reproductive branches,spikelets/inflorescence,florets/spikelets,seeds/spikelets,seed setting rate,actual seed yield and potential seed yield of Bromus inermis and Agropyron mongolicum Keng（P<0.05）.Through the single factor regression analysis of Bromus inermis seed yield and the application amount of nitrogen,phosphorus and potassium fertilizer,the results showed that the single factor yield-increasing effect was P>K>N;By establishing the ternary quadratic regression equation,it is concluded that the optimal fertilization ratio of N,P and K for seed production is 71.42,97.49 and 48.96 kg hm^-2,and the highest seed yield is 1395.43 kg hm^-2.The single factor effect of Agropyron mongolicum Keng on increasing seed yield ranked as N>P>K;Furthermore,through the analysis of two-factor interaction effect,it is concluded that the interaction of N,P and K fertilizers is beneficial to the fertilizer efficiency.（3）There were significant differences in soil nutrients between Bromus inermis and Mongolian wheatgrass（P<0.05）,but no significant effect on pH.In the soil environment under the treatment of N2P2K2,the nutrient utilization rate of crops is higher and the nutrient loss content is less.The ratio of nitrogen,phosphorus and potassium is suitable for improving soil fertility,promoting crop absorption and reducing environmental pollution.