Effects Of Combined Application Of Nitrogen And Phosphorus On Growth,Yield And Seed Vigor Of Spring Wheat

In order to provide the theoretical basis for the high quality and high yield of spring wheat,the effects of nitrogen and phosphorus fertilizers on the growth and development,yield and seed vigor of spring wheat were studied by using the experiment.In the experiment,the amount of phosphorus was the main factor,the amount of nitrogen applied was the secondary factor,the phosphorus level was 3,and the nitrogen level was 5 levels.The dosage of P₂O₅ was 0 kg·hm^-2,75 kg·hm^-2 and 150 kg·hm^-2,respectively?P₀,P₁ and P₂?.The amounts of nitrogen were 0 kg hm^-2?Control CK?150 kg·hm^-2,300 kg·hm^-2,450 kg·hm^-2 and 600kg·hm^-2,are recorded as?N₀,N₁,N₂,N₃ and N₄?,a total of 15 treatments,no nitrogen and phosphorus?N₀P₀?as control.The main results are as follows:?1?Phosphorus and nitrogen content had significant effects on plant height,stem diameter,panicle length,internode length and SPAD value of spring wheat.The above agronomic traits had significant positive correlation with nitrogen application rate,and the correlation coefficients were 0.92,0.89,0.73 and0.90.The spike length and grains per spike increased with the increase of nitrogen and phosphorus,while the panicle number and grain weight increased first and then decreased.The yield increased first and then decreased with the increase of nitrogen application rate,with the increase in phosphorus and increase,but more than a reasonable range showed a downward trend.?2?The dry matter accumulation of the plant increased first and then decreased after 25 days of flowering,and began to decline after 30 days of flowering.The dry matter accumulation in each organ was different.The distribution of dry matter in each organ was as follows:grain>stem>glume>leaf>leaf sheath.Under different treatments,the dry matter transfer rate and the contribution rate of dry matter to different grains were different with the increase of nitrogen application rate.The contribution rate of dry matter to grain after anthesis was first increased Reduce the trend.?3?With the advance of the postnatal period,the nitrogen content of wheat stem decreased first and then decreased gradually.The nitrogen content of grain and leaf showed a trend of increasing gradually.The content of phosphorus in stem and leaf decreased,the phosphorus content reached the highest value at5 d after flowering.The accumulation of nitrogen increased with the increase of the number of days after anthesis,and the accumulation of phosphorus was gradually decreased.The nitrogen accumulation and distribution ratio of different organs were expressed as kernel>Leaves>stems.Stem and leaf distribution were increasing,while the grain distribution ratio decreased.The phosphorus accumulation and distribution ratio of different organs were expressed as grain>stem>leaf,and the effect of phosphorus and nitrogen on plant stem,leaf and grain was significant.The interaction between nitrogen and phosphate had no significant effect on stem and kernel except for the effect of leaf.?4?Appropriate increase of nitrogen and phosphate fertilizer can improve the vigor index of spring wheat seed,and it is beneficial to the improvement of germination rate,germination potential and germination index and so on.It is beneficial to seedling growth and development,promote seedling growth and increase seedling dry matter accumulation,increase the length of wheat seedling root length,and nitrogen and phosphorus fertilizer application rate beyond the reasonable range will affect the vitality of spring wheat seeds,is not conducive to the further increase in vitality indicators.At the level of P₂ and N₂,the seed vigor index decreased at 8 days after aging,which was significantly higher than that of other levels.The seed quality of spring wheat harvested at 35 days after flowering was the best,and the seed vigor was good.The harvest period was the best harvest time of spring wheat seed.Considering the indexes,when the amount of phosphorus applied to Xinchun 31 was 150 kg·hm^-2 and the nitrogen application rate was 300 kg·hm^-2,the yield of spring wheat was the best.