Effects Of Sowing Density And Fertilization On The Growth And Seed Propagation Characteristics Of Agropyron Mongolicum

Native pasture seeds are an important material for ensuring the restoration of local natural grasslands and the establishment of artificial grasslands,especially in arid and semi-arid regions.In order to study the effects of seeding density and fertilization on the growth and seed reproduction characteristics of a new line of Agropyron mongolicum in the arid area of eastern Ningxia,In this experiment,（1）line spacing（20 cm,30 cm,40 cm,50 cm）and sowing rate（10 kg/hm²,15 kg/hm²,20 kg/hm²,25 kg/hm²）and（2）nitrogen Combined application of phosphorus and potassium（3 factors of N,P,K,each with 4 levels:0 level does not fertilize,2 level is N=90 kg/hm²,P2O5=105 kg/hm²,K2O=60 kg/hm²,1 level 0.5 times of 2 levels,3 levels of 1.5 times of 2 levels）2 independent experiments on the effects of Agropyron mongolicum on the growth and seed reproduction characteristics of the new line,Agropyron mongolicum,to determine the high yield of the new line of Agropyron mongolicum under the drought conditions in eastern Ningxia The optimal seeding density and scientific ratio of nitrogen,phosphorus and potassium are planned,in order to provide seed reserves of fine pastures for the replanting of natural grasslands and the establishment of artificial grasslands in this area and other arid areas.The main results of this study are as follows:（1）Both line spacing and sowing rate significantly affected the photosynthetic characteristics,growth traits of Agropyron mongolicum.Overall assess indicated that,the line spacing was 20-40 cm and the sowing rate was 20 kg/hm² was the best sowing density.（2）Both line spacing and sowing rate significantly affected the components of Agropyron mongolicum seed yield.Under the same sowing rate,the changes of the components of Agropyron mongolicum seed yield showed different variation laws with the increase of line spacing,but in general,the Agropyron mongolicum seed yield was the highest when the line spacing was 20 cm;at the same line spacing,the Agropyron mongolicum seed yield composition The changes of factors also showed different changing laws with the increase of sowing rate,but generally the seed yield of Agropyron mongolicum was the highest when the sowing rate was 20 kg/hm².Therefore,comprehensive analysis showed that the seed yield of Agropyron mongolicum was the highest when the line spacing was 20 cm and the seeding rate was 20 kg/hm²,which was 1031.54 kg/hm².（3）The combined application of nitrogen,phosphorus and potassium significantly affected the photosynthesis and growth characteristics of Agropyron mongolicum.At the P₂K₂ level,the best fertilization effect was N₂;at the N₂K2 level,the P2 fertilization effect was the best;and at the N₂P2 level,the K2 fertilization effect was the best.The 13 combinations were better than the control,but the effects of all the combinations on photosynthesis and growth characteristics did not change regularly.（4）The combined application of nitrogen,phosphorus and potassium significantly affected the components of Agropyron mongolicum seed yield.Among them,the variation law of seed yield among the components of seed yield is as follows:at the levels of P₂K₂,N₂K2,and N₂P2,the seed yield of Agropyron mongolicum increased first and then decreased with the increase of nitrogen,phosphorus and potassium fertilizers,respectively;In terms of application effect,the overall seed yield value of Agropyron mongolicum was the highest under N₂P₂K₂ treatment,which was 886.5 kg/hm².（5）The combined application of nitrogen,phosphorus and potassium significantly affected the nutrient absorption of Agropyron mongolicum.The contents of nitrogen,phosphorus and potassium in plants were the highest in the treatments of N₂P₂K₃,N₂P3K2 and N₂P₂K₂.The results of correlation analysis showed that the N₂P₂K₂ level was beneficial to the nutrient uptake and utilization of Agropyron mongolicum.（6）The plant height,number of tillers,reproductive branches,ear length and number of spikelets were significantly correlated with seed yield,indicating that the research and improvement of the above indicators should be paid attention to in the process of seed breeding of Agropyron mongolicum in the future..（7）There is a significant correlation between soil nitrogen,phosphorus and potassium content and the growth and seed reproduction characteristics of Agropyron mongolicum,indicating that soil nitrogen,phosphorus and potassium content has an important impact on seed reproduction.Pay attention to reducing soil pH and improving soil moisture conditions to ensure high seed yield and high quality goals.In conclusion,when the line spacing was 20 cm and the sowing rate was 20 kg/hm²,the yield of Agropyron mongolicum seeds was the highest;When the ratios of N,P and K were at N₂P₂K₂（90 kg/hm²,105 kg/hm²,60 kg/hm²）,the yield of Agropyron mongolicum seeds was the highest;the optimal theoretical fertilization rates were N=78.42 kg/hm²,P=100.91 kg/hm² and K=57.5 kg/hm²,the theoretical maximum seed yield was 875.079 kg/hm².