中文摘要：

生物炭、石灰以其良好的有毒金属固化与生态环境效应成为近年来土壤污染修复及作物安全生产研究的热点。选取典型重金属复合污染水稻田开展原位实验，分析不同原料生物炭、石灰添加处理对稻田淹水溶解态 Cd、Pb、Zn、As析出特征及其自然降雨事件面源输出负荷的影响。生物炭添加为20 t/hm2，石灰添加为750 kg/hm^2。通过连续2年的观测与实验得出，稻田淹水期溶解平衡后，与对照相比，稻秆生物炭添加稻田水中溶解态 Cd、Pb、Zn浓度分别降低56%-80%、60%-75%和63%-90%，豆秆生物炭添加溶解态 Cd、Pb、Zn浓度分别降低61%-83%、51%-76%和55%-80%，石灰添加可略微降低 Cd、Pb、Zn浓度，但差异不显著。2种原料生物炭添加比石灰和对照处理均显著提高了稻田水中溶解态 As浓度。因此，自然降雨过程，稻秆和豆秆生物炭添加均可显著降低溶解态 Cd、Pb、Zn面源输出负荷，但明显增加溶解态 As面源负荷，加大受纳水体 As超标风险。因降雨和径流量的变异较大，Cd、Pb、Zn、As的面源输出负荷季节性规律尚不明显。

英文摘要：

Owing to the strong ability to immobilize some toxic heavy metals immobilization in contaminated soils,biochar and lime received increasing interests from the community of soil remediation and crops safety in recent years. This study conducted a two-year in situ field experiment in a paddy soil which had been contaminated by complex heavy metals,in Hunan province,China. The objective is to investigate the effects of different treatments of biochars and lime additives on the solution and non-pointe load of Cd, Pb,Zn. The additive rate was 20 t/hm^2 for biochars and 750 kg/hm2 for lime. The results show that rice biochar additive evidently reduced soluble Cd, Pb, Zn concentrations in waterlogged paddy by 56 %-80 %, 60 %-75 %, 63 %-90 % respectively, and bean biochar additive reduced soluble Cd, Pb, Zn concentrations by 61%-83%,51%-76% and 55%-80% respectively,comparing to the control treatment. No obvious changes of soluble Cd, Pb, Zn, As concentrations was observed in the treatment of lime application compared to the control treatment. However,both rice and bean biochar additives significantly increased soluble metalloid As concentrations in waterlogged paddy,compared to the lime additive and the control treatments. In conclusion, both rice and bean biochar applications could significantly decrease the non-point load of Cd, Pb and Zn during rainfall events, while increase the non-point load of metalloid As, leading to higher risk of As contamination of the receiving water. No obvious seasonality of non-point load of Cd, Pb,Zn and As was observed in this study,which may be due to the large variation of precipitation.