Estimation on the loss amount of N in the paddy fields of the middle and lower reaches of Yangtse RiVer—A case study from Baimu Town，Jingjiang City，Jiangsu Province

The pollution status of applying N fertilizer in the typical paddy fields of the middle and lower reaches of Yangtse River tO the surface water is monitored．Combining the model，the depth of flowing path of precipitation in this area is obtained，and the dissolved N contamination amount is estimated for the paddy fields and the tota1 value is 36．04kg／hm²，it is 17．3％ of the N fertilizer amount used in the fields．