The effect of different nitrogen applied level on nitrogen transformation form and runoff loss content were studied in the north plain region of Zhejiang province by oilseed rape field experiments.The results showed that,the fertilized period and rain fertilization interval had a significant influence on nitrogen export form and concentration in the runoff loss water.Nitrate was the main form nitrogen,and the ratio of nitrate nitrogen to inorganic nitrogen was from 0.56 to 0.95 in the runoff loss water.Howe...