To ascertain the optimal urea-formaldehyde slow-release nitrogen (UFN) fertilization ratio

a wheat field experiment was conducted to study the effect of UFN on soil nutrients

grain production

nitrogen-use efficiency

and economic income in Huanghuaihai Plain. UFN treatments were set as five ratios with 30%

40%

50%

60%

and 70% of total nitrogen fertilizer

abbreviated as UFN30

UFN40

UFN50

UFN60

and UFN70. The results were as follows

the trends for nitrogen release during the crop growth season showed as “raise-decline-raise-decline” under all UFN treatments. Relative to traditional urea fertilization treatment

both UFN40 and UFN50 treatments had the most favorable capacity that nitrogen was supplied to plants

which helped to maintain high nitrate

ammonium nitrogen

and alkaline nitrogen content in soils. This was beneficial to provide higher nitrogen nutrition for wheat growth. The grain yield in UFN40 and UFN50 was 11.36%~13.67% higher than that of conventional nitrogen fertilization treatment

respectively

while UFN30

UFN60

and UFN70 did not significantly change plant yield-related components. Nitrogen utilization efficiency increased by 13.65%~103.87% and-14.73%~75.47% with UFN application

as compared with urea basal fertilization and urea basal fertilization+ urea topdressing fertilization

respectively. UFN40 and UFN50 increased nitrogen-use efficiency and economic income by 31.83%~103.87% and 1 350 yuan~1 591 yuan per hectare

respectively. In a conclusion

urea-formaldehyde slow-release fertilizer taking as 40%~50% of total nitrogen should be recommended in wheat field.