To investigate the effects of controlled-release urea on vertical distribution and migration of nutrients in the profile of double-rice cropping field

a long-term field experiment was conducted to compare common urea (U) and reduction of controlled-release urea (CRU) in nutrient accumulation and distribution of paddy field profile. Results showed that with the increase of soil depth

total N

NO3--N

organic matter

total P

available P and total K content in soil decreased; NH4+-N content first decreased and then increased; available K content increased; soil pH increased to be stable. Fertilization could reduce pH and available K content in 0-20 cm soil. Compared with U treatment

total N content in 0-20 cm soil under CRU treatments increased by 7.72%~19.45%

and increased with the increase of N fertilizer rate; soil NH4+-N content in 40-60 cm under CRU treatments reduced by 6.99%~19.23%. Application of CRU could effectively reduce soil NH4+-N leaching

and increase total N and NO3--N content in 0-40 cm soil

to prevent soil N loss. Application of CRU had no significant effect on organic matter

available P

total P

available K

total K and pH in different depths of soil

but more reduction of CRU resulted in the decrease of organic matter. Reduced of CRU by 10%~20% treatments significantly increased N

P

K uptakes of double-cropping rice at maturity. Correlation analysis showed that N

P

K uptakes at maturity by different rates of CRU treatments was significantly positively related with grain yield in early- and late-rice. In conclusion

CRU treatments can effectively reduce N leaching and the potential non-point source pollution by N fertilizer application

and can improve soil nutrient levels and fertility

and finally promote nutrients accumulation

to realize win-win situation of ecological and economic benefits.