The Study On Increasing Efficiency And Yield Of Spring Wheat Under Reducing Chemical Fertilizer Conditions In Hetao Irrigation District

In view of the current situation of serious fertilizer waste and low fertilizer utilization efficiency in crop production in Hetao Irrigation District,this study takes spring wheat in Hetao Irrigation District as the research object and aims to increase efficiency and increase production.According to the nutritional absorption of wheat,the characteristics of soil nutrient supply and fertilizer effects,On the basis of farmer fertilization,through the experimental research of reducing the application of chemical fertilizers and organic fertilizer instead of chemical fertilizer to clarify the relationship between wheat growth and development,photosynthetic characteristics,material accumulation,yield and quality formation and fertilizer utilization,it is clear that wheat is suitable for achieving high yield,high efficiency,and high quality.The scope of fertilizer application and corresponding fertilization measures provide a basis for establishing a technical system for reducing fertilizer application,increasing efficiency,and increasing yield of wheat in the Hetao Irrigation District.The main findings are as follows:(1)Based on the conventional fertilization rate of farmers,with the decrease of nitrogen and phosphorus fertilizer application,wheat grain yield and its constituent factors both increased first and then decreased,and were affected by the nitrogen application rate to reach a significant level.There was no significant difference in 1000-grain weight between phosphorus treatments,and the interaction between nitrogen and phosphorus had significant effects on yield and its constituent factors.On the basis of organic fertilizer applied at the bottom,the effects of nitrogen and phosphorus fertilizer application rates and their interactions on grain yield reached extremely significant levels.There were significant differences in the number of spikes between different nitrogen and phosphorus fertilizer application rates.The effects of nitrogen application rate and nitrogen-phosphorus interaction on the number of spikes also reached a significant level.(2)Based on the conventional fertilization amount of farmers,with the decrease of nitrogen fertilizer amount,the plant height of wheat decreased,and the stem thickness and upper three leaf area increased first and then decreased;with the decrease of phosphorus fertilizer amount,plant height,stem thickness and upper three leaf area did not change significantly.Compared with conventional fertilization by farmers,the senescence of wheat leaves during the grain filling stage was relatively slow under moderate fertilization treatment,and the leaf SPAD value,Fv/Fm value,and net photosynthetic rate were higher.Maintaining larger population green leaf area and leaf photosynthetic activity promoted Grain filling and population dry matter accumulation are the physiological basis for reducing fertilizer application and increasing wheat yield in Hetao irrigation area.(3)Based on the conventional fertilization amount of farmers,the amount of nitrogen and phosphorus fertilizers was reduced one by one,and the nitrogen and phosphorus content and nitrogen and phosphorus absorption of the plants showed a single-peak curve change.With the decrease of nitrogen application rate,the agricultural efficiency of nitrogen and partial productivity of nitrogen fertilizers showed an increasing trend;with the decrease of phosphorus application,the agricultural efficiency of nitrogen and partial productivity of nitrogen fertilizers also increased and then decreased.Appropriate reduction of nitrogen and phosphorus fertilizers is beneficial to the absorption of nitrogen and phosphorus by wheat plants,and increases the utilization efficiency of nitrogen and phosphorus fertilizers.Correlation analysis showed that the application rates of nitrogen and phosphorus fertilizers were significantly positively correlated with the nitrogen and phosphorus content and nitrogen and phosphorus absorption of the plants,and were significantly negatively correlated with most nitrogen and phosphorus fertilizer utilization indicators.(4)Except for test weight,flour extraction and water absorption rate,the effects of nitrogen fertilizer,phosphate fertilizer,and their interactions on wheat grain quality indexes all reached significant levels.At the same nitrogen application level,most of the quality indicators showed a trend of increasing first and then decreasing with the decrease of phosphorus application rate;under the same phosphorus application level,there were no significant differences in grain quality indicators among different nitrogen application rates.Based on the amount of fertilizer applied by farmers,the main quality indicators of wheat grains with a moderate reduction in chemical fertilizer application did not decrease.According to comprehensive analysis,the suitable nitrogen application rate(pure N)for achieving high yield,high efficiency,and high quality of wheat in Hetao irrigation area is 99.7?193.3 kg·hm-2,and the phosphorus application rate(P2O5)is 66.2?94.2 kg·hm-2.Compared with the current conventional fertilization rate of farmers(pure N:240.0 kg·hm-2,P2O5:130.3 kg·hm-2),nitrogen fertilizer can be reduced by more than 19.5%,and phosphorus fertilizer can be reduced by more than 27.8%.