节水减氮对灌区玉米干物质积累、氮肥利用效率及产量的影响OA

[Objective]The objective of the study was to analyze the effects of water-saving and nitrogen-reducing on dry matter accumulation,nitrogen fertilizer utilization efficiency,and yield of maize in the irrigation area,providing a basis for efficient cultivation of maize with water-saving and nitrogen-reducing in the Ningxia Yellow River irrigation area.[Method]Using the Xianyu 1225 com variety,which was mainly planted in the Yellow River irrigation area of Ningxia,as the test material,a split zone experimental design was adopted.The main plot consis-ted of three irrigation treatments:traditional irrigation amount(W1:4200 m3/hm2,control),20％reduction in irrigation amount under drip irrigation conditions(W2:3360 m3/hm2),and 40％reduction in irrigation amount(W3:2520 m3/hm2).The subplot consisted of four ni-trogen application treatments:traditional nitrogen application rate(N300:300 kg/hm2,control),25％reduction in nitrogen application(N225:225 kg/hm2),50％reduction in nitrogen application(N150:150 kg/hm2),and no nitrogen fertilizer application(N0:0 kg/hm2),totaling 12 treatments.[Result]The dry matter accumulation of corn in the Yellow River irrigation area of Ningxia showed a trend of first in-creasing and then decreasing with the increase of nitrogen application rate.The maximum dry matter mass of corn was achieved when the ni-trogen application rate was 225 kg/hm2,and it decreased significantly with the decrease of irrigation rate.It decreased significantly when the irrigation rate was 2520 m3/hm2.Among them,the W2N225 treatment had the highest dry matter accumulation of corn,which increased by 20.30％compared with traditional irrigation and fertilization(W1N300).The total nitrogen accumulation in maize showed a trend of first in-creasing and then decreasing with the decrease of irrigation rate.Among them,W2N225 and W2N300 treatments had higher nitrogen accumu-lation in maize,and W2N300 treatment had the highest nitrogen transport amount,nitrogen transport rate,and nitrogen transport contribution to the grain.At the same time,W2N225 treatment maintained a high level,which was significantly different from the control W1N300.The ni-trogen fertilizer utilization efficiency of corn was highest in the W2N225 treatment,reaching 47.52％.At the same time,the nitrogen fertilizer agronomic efficiency,nitrogen fertilizer partial productivity,and nitrogen harvest index remained high.Among them,the nitrogen fertilizer uti-lization efficiency,nitrogen fertilizer agronomic efficiency,and nitrogen fertilizer partial productivity of corn were significantly higher than those of the control W1N300 treatment.Irrigation and nitrogen application significantly affect the grain yield and number of grains per ear of maize.The grain yield of maize shows a trend of first increasing and then decreasing with the increase of nitrogen application.The N225 treat-ment improves the grain yield of maize compared to the control N300,and the W2N225 treatment has the highest yield of 16 906.78 kg/hm2,which is 4.32％higher than the W1N300 treatment.[Conclusion]In the Ningxia Yellow River irrigation area,the model of 20％water-sav-ing(3360 m3/hm2)and 25％nitrogen reduction(225 kg/hm2)is more suitable.