中文摘要：

沟渠是农田氮、磷营养物质排入地表水体的通道.对嘉兴大田、集约化菜地、集约化果园、集约化养殖场4种土地利用方式下的农村沟渠0～5 cm表层底泥氮、磷的形态分布特征进行了研究.结果表明：67个沟渠底泥样品的w（全氮）为1 560～7 480mg/kg,其中w（交换态氮）为31.15～704.38 mg/kg,占w（全氮）的1.29%～10.01%;交换态氮中以铵态氮为主,占w（交换态氮）的62.15%～100%.沟渠底泥样品的w（全磷）为580～6 420 mg/kg,w（碳酸氢钠溶解磷）为19.53～359.72 mg/kg,占w（全磷）的2.05%～18.96%;w（水溶性磷）为0.29～18.88 mg/kg,占w（碳酸氢钠溶解磷）的1.11%～14.63%.土地利用方式对沟渠底泥氮、磷的形态分布有显著影响（P〈0.01）,集约化养殖场沟渠底泥中的w（全氮）,w（交换态氮）,w（铵态氮）,w（硝态氮）,w（交换态氮）/w（全氮）,w（全磷）,w（水溶性磷）,w（碳酸氢钠溶解磷）均显著高于其他土地利用方式.底泥w（全氮）,w（交换态氮）,w（铵态氮）和w（硝态氮）两两间以及w（全磷）,w（水溶性磷）,w（碳酸氢钠溶解磷）两两间均在α=0.01时显著相关,w（全磷）与w（碳酸氢钠溶解磷）的相关性（r=0.81,P〈0.01）好于与w（水溶性磷）的相关性（r=0.51,P〈0.01）.

英文摘要：

Agricultural drainage ditches serve as N, P transport pathways from fields to surface water. Fractional characteristics of nitrogen and phosphorus in 0-5 cm surface ditch sediments were investigated, including main land, intensive vegetable land, intensive orchard land and intensive livestock land in Jiaxing. Total nitrogen （TN） of the 67 sediments was 1,560-7,480 mg/kg, and exchangeable nitrogen （EN） was 31.15-704.38 mg/kg, accounting for 1.29%-10.01% of TN. The main form of EN was NH4^＋-N, which accounted for 62.15%-100% of EN. Total phosphorus （TP）, Olsen P and water-soluble phosphorus （WSP） of ditch sediments was 580-6,420 mg/kg, 19.53-359.72 mg/kg and 0.29-18.88 mg/kg, respectively. Olsen P accounted for 2.05%-18.96% of TP, while WSP accounted for 1.11%-14.63% of Olsen P. The TN, EN, NH4^＋ -N, NO3^- -N, EN/TN, TP, WEP and Olsen P of ditch sediments within intensive livestock land were significantly higher than the others （P 〈 0.01）. There were significant correlations among TN, EN, NH4^＋ -N, NO3^--N and among TP, WSP, Olsen P. TP was better correlated with Olsen P （r =0.81, P 〈0.01） than WEP （r =0.51, P 〈0.01）.