| In view of the problems of excessive nitrogen application,excessive nitrogen application,low surface fertilization yield and low nitrogen utilization rate in the current rice production process in the cold region,method of spot deep fertilization for rice was proposed,fertilizer pellets were applied to one side of seedling belt to increase fertilizer distribution in soil and reduce ammonia volatilization and runoff loss.The experiment was carried out in potted plants.The nitrogen application mode and nitrogen application amount were completely random in the experiment design,nitrogen application method 2 level(A1(full layer fertilization,A2 point deep fertilization);nitrogen application level 5(B1 conventional nitrogen application,B2 reduced nitrogen 10%,B3 reduced nitrogen 20%,B4 reduced nitrogen30%,B5 reduced nitrogen40%);nitrogen free zones were set up for full layer fertilization and point deep fertilization.The aim was to provide theoretical basis and technical support for determining the reasonable nitrogen application rate of rice in cold region.The main research results are as follows:1.The yield of spot deep fertilization method was better than that of whole layer fertilization,which increased by 5.71%,the number of ears increased by 8.35%.Under the fact or of nitrogen application rate,the yield of conventional nitrogen application was higher than that of reduced nitrogen fertilization,and the interaction of the two factors was the best with deep fertilization and conventional nitrogen application.2.The dry matter accumulation in tillering stage,panicle stage,grout stage and maturity stage of point deep fertilization method was better than that of full layer fertilization,compared with the whole layer fertilization,it increased by 60.00%,2.75%,12.43% and 9.82%,respectively;nitrogen application had no significant effect on the dry matter accumulation of some plants on the ground.The leaf area during tillering and filling stage of spot deep fertilization was better than full-layer fertilization,which increased by 43.99% and 22.57%,respectively,compared with full-layer fertilization;the amount of nitrogen applied had no significant effect on the leaf area during tillering,panicle and filling stages.The interaction of nitrogen application mode and nitrogen application rate on aboveground dry matter accumulation at tillering stage was the highest in the treatment of reducing nitrogen by 40%,and the interaction of nitrogen application mode and nitrogen application rate on leaf area at tillering stage was the highest.3.The total root length,average diameter,total root surface area,total root volume and root dry weight of point-deep fertilization were better than that of full-layer fertilization,which increased by 10.60%,8.51%,57.49% and 13.66%,respectively.Nitrogen application hadsignificant or extremely significant effects on average diameter,total root surface area and total root volume.The interaction between nitrogen application mode and nitrogen application rate of average diameter was the highest in the treatment of reducing nitrogen by 40% in the whole layer,and the interaction between nitrogen application and nitrogen application in the total root surface area was the highest in the conventional nitrogen application of point deep fertilization.the interaction between nitrogen application mode and nitrogen application rate of root dry weight was the highest in the treatment of nitrogen reduction of 30% in root dry weight,and the interaction of nitrogen application mode and nitrogen application rate of root-shoot ratio was the highest in the treatment of nitrogen reduction of 10% in full-layer fertilization.4.The nitrogen accumulation of each organ at full heading stage and filling stage of point deep fertilization was better than that of full-layer fertilization,which increased by 9.48%,2.84%,31.45% and 24.50% respectively;the factor of nitrogen application rate had a significant or extremely significant effect on the nitrogen accumulation of each organ during the filling stage.The interaction between nitrogen application mode and nitrogen application rate of leaf nitrogen accumulation at filling stage was the highest in conventional nitrogen application with point deep fertilization,the interaction between nitrogen application mode and nitrogen application rate of stem and sheath panicle nitrogen accumulation at filling stage was the highest with deep fertilization and conventional nitrogen application.Compared with full-layer fertilization,the aboveground nitrogen uptake,nitrogen contribution rate and partial productivity of fertilizer increased by 30.56%,11.32% and 5.72%,respectively.respectively;the factors of nitrogen application rate had significant effects on nitrogen absorption and utilization rate,nitrogen fertilizer contribution rate,soil nitrogen dependence rate,aboveground nitrogen uptake and nitrogen partial productivity.5.There was no significant difference in processing quality and appearance quality of nitrogen application,the amylose content of deep fertilization was lower than that of full-layer fertilization,the protein content of full-layer fertilization was lower than that of deep fertilization,and the taste value of full-layer fertilization was the highest.Nitrogen application rate had no significant effect on aroma,luster,taste,taste and taste value.The interaction of nitrogen application mode and nitrogen application rate on head rice rate was the highest in the treatment of full-layer fertilization and nitrogen reduction of 10%,the interaction of nitrogen application mode and nitrogen application rate on chalky grain rate was the best in the treatment of point deep fertilization and nitrogen reduction by 40%,for the interaction of chalkiness degree with nitrogen application mode and nitrogen application rate,the treatment of reducing nitrogen by40% by point deep fertilization is the best,the interaction of nitrogen application mode andnitrogen application rate on protein content was the lowest in the treatment of full-layer fertilization and nitrogen reduction of 10%. |
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