Effect of Reducing Nitrogen Fertilizer Rate in Rotation of Rice and Rape

Based on the traditional nitrogen fertilizer rate,20% nitrogen fertilizer rate was reduced to conduct rice and rape rotation experiment.Through applying measures,which were increasing organic fertilizer rate,split applying nitrogen fertilizer and applying slow release nitrogen fertilizer,to increase available nitrogen content in soil,total nitrogen content in plant and yield of rice and rape.The experimental results showed that when applying 80% traditional nitrogen rate combined with 20% organic nitrogen fertilizer,the effect was the best that rice yield increased by 6.94% and rape increased by 6.88%.With the extend of growing period,the available nutrients in soi1 and total nutrients in plant all decreased gradually;when rice and rape were ripeness,the nutrients that nitrogen and phosphorus in both crops were mostly stored in the grain,and the kalium nutrition in both crops was concentrated in the stem.