The distribution and movement features of nitrogen in 1 m soil layer under different nitrogen fertilizer application were studied through artificial soil column simulation experiment in laboratory to reveal the dynamic changes of nitrogen in farmland soil. Results indicated that FN (the amount of inorganic nitrogen used by farmers) and RN (inorganic nitrogen dosage recommended by soil nutrient supply and crop demand) significantly increased the leaching of NH4+-N and NO3--N from upper soil layer to lower soil layer. The treatments of RN+HA (zinc humic acid urea equivalent to the recommended inorganic nitrogen with RN) and RN40%+OMB (60% inorganic nitrogen fertilizer of RN with homemade organic substances) could prolong the peak time of NH4+-N in the upper soil layer and reduce the NH4+-N in the lower soil layer. At the end of leaching experiment

comparing with RN

the application of humic acid (HA) decreased the NH4+-N residue by 29.7%~54.2% in the soil layer below 60 cm under the same amount of nitrogen

and reduced the accumulation of NO3--N by 17.4% in 60-80 cm soil layer. In RN 40%+OMB treatment

the dosage of inorganic nitrogen fertilizer was the minimum

and NH4+-N was the highest in 0-20 cm soil layer and it was stable at 2.0 mg/kg in 40-100 cm soil layer. Comparing with RN+HA

NO3--N in 0-20 cm and 20-40 cm soil layer in this treatment increased by 12.3% and 2.0%

respectively

and the NO3--N residue in the soil layer lower than 40 cm was significantly reduced. Contrasted with RN

the total inorganic nitrogen residue of RN+HA and RN40%+OMB decreased by 7.4% and 20.2%

respectively

and the apparent leaching rate was decreased. Therefore

RN40%+OMB could inhibite the downward movement of nitrogen and reduce the risk of nitrogen leaching

and these results provide a scientific basis for reducing the nitrogen leaching.