The experiment was conducted under pool culture with a 65cm width un-cropped strip and 6 rows wheat of 23.5 cm row spacing were planted in both side of the strip. Label ()~(15)
N fertilizer was applied on the strip as base and urea was supplied in the area where wheat was planted. Two treatments were set up, one was sowing 2 rows
spinach on the strip with a row spacing of 25cm, the other one was no crop in the strip (CK). The results showed that there was a significant
border effect in CK pattern, but the border effect was sharply decreased in wheat
intercropped with spinach, compared with CK. There was a close relationship between border effect and N absorption of border row. There was serious competition for N nutrient under the system of wheat intercropped with spinach, the N uptake of the border row of wheat was decreased because spinach absorbed more N during the growing stage of both crops. After the spinach was harvested, the border row of wheat absorbed more N nutrient and showed higher content than inner row. The
intercropping system had higher utilization efficiency, lower content left in the soil and lower loss in anyway of base ()~(15)N fertilizer than those of CK.