In order to explore the nitrogen reducing effect of synergists on dryland wheat in Sichuan

the following 9 treatments were set up in this study: blank control (CK0); Conventional nitrogen application without topdressing (CK1

nitrogen application amount 187.5 kg/hm2); The ratio of basal dressing to topdressing under conventional nitrogen application rate is 6∶4 (CK2

nitrogen application rate is 187.5 kg/hm2); Synergistic auxiliary mixed with conventional compound fertilizer

reducing nitrogen by 20% (jf—20%) and 30% (jf—30%); Synergistic auxiliary chelating urea formaldehyde reduces nitrogen by 20% (jn—20%)

30% (jn—30%) and 40% (jn—40%); Synergistic auxiliary chelated urea formaldehyde fertilizer + lecithin organic fertilizer 3 000 kg/hm2 reduced nitrogen by 27% (jny—27%); The dynamics of soil nitrogen

wheat chlorophyll content

leaf area index

growth rate

nitrogen accumulation and transport

yield and its composition

and nitrogen utilization efficiency were analyzed and measured under different treatments. The results showed that each treatment of jf

jn and jny model significantly reduced the content of ammonia nitrogen and nitrate nitrogen in soil at flowering and mature stages

which were 6.8%~9.8% and 8.7%~14.5% lower than that of CK1 at flowering stage

and 14.9%~20.8% and 15.9%~20.0% lower at mature stage

respectively. At 30 days after anthesis

the leaf area index of jn—20% and jny—27% was the highest

5.3% and 5.8% higher than that of CK1 and CK2

respectively. The leaf area index of jn—20% and jny—27% was 5.83% and 5.24% higher than that of CK1; Each treatment of jf

jn and jny mode significantly increased the post anthesis nitrogen accumulation compared with CK1 and CK2

with the amplitude of 33.7%~73.1% and 29.8%~68.0% respectively

and the post anthesis nitrogen transport increased by 116.1%~217.8% and 107.1%~204.0% respectively. The growth rate of each treatment of jf

jn and jny in flowering maturity stage was higher than that of CK1

and the range was 13.2%~33.8%. Moreover

wheat yield will not decrease after nitrogen fertilizer reduction and synergist application. The yield increase of jf—20%

jn—20% and jny—27% was 0.2%~2.9%

and the yield of jn—20% and jny—27% treatment was the highest

2.6% and 2.9% higher than that of CK1

however

there is no significant difference with CK1 and CK2. jn

jf and jny modes significantly improved nitrogen utilization efficiency and partial productivity of nitrogen fertilizer

which were 6.7%~24.0% and 10.3%~25.8% higher than CK1 respectively. According to the research

the synergists can improve the fertilizer utilization rate by promoting nutrient absorption and reducing nitrogen residues in the soil

so as to reduce nitrogen without reducing production. The application of synergists to mix fertilizer and synergists to chelate urea formaldehyde can reduce nitrogen by 20%

and synergists to chelate urea formaldehyde with lecithin organic fertilizer 3 000 kg/hm2 can reduce nitrogen by 27%.