聚丙烯酰胺与几种强化剂联合作用对土壤氮素吸附-解吸和迁移释放的影响

Effect of Polyacrylamide in Combination with Several Enhancers on Adsorption-Desorption and Release of Nitrogen from Typical Purple soil

通过等温吸附-解吸试验和模拟淹水试验,研究了聚丙烯酰胺（PAM）与几种强化剂协同作用对紫色土氮素的吸附-解吸和向水体迁移释放的影响。结果表明,PAM（CK1）可以有效提高土壤对铵氮的吸附容量,而PAM与强化剂联合施用可以进一步提高其吸附能力,除配施石灰处理外,配施强化剂处理其最大吸附量较单施PAM处理（CK1）增加37.5%～83.3%,差异均达显著水平（P〈0.05）。同时联合施用还提高吸持强度,降低解吸率,弥补单施PAM后土壤铵氮吸持强度下降的缺陷;经PAM和强化剂处理可以抑制土壤氨氮向硝态氮转化的速率,其中以PAM＋柠檬酸的抑制效果最为明显,可使水体中的硝态氮浓度始终保持在较低的水平（0.11～2.10μg/ml）,同时与柠檬酸配合处理对水体TN的释放也有很好地抑制作用。

Isothermal adsorption-desorption and simulated flooding experiment were processed for investigating the effect of water soluble polyaerylamide （PAM） and several chemical enhancers on the adsorption-desorption mechanism of nitrogen from typical purple soil, and release of nitrogen from sediment under flooding condition. The results suggested that, PAM alone and plus enhancers application both promoted ammonianitrogen adsorption capacity of soil in comparison with control group （CK）, which combination with several enhancers was better. The maximum ammonia-nitrogen adsorption （Xm） of all treatments increased significantly in a range of 37. 5%〈83.3% except PAM plus Lime treatment （P〈0.05）. Though PAM alone application decreased the storage capacity of purple soil for nitrogen, all treatments with enhancers decreased desorption for offsetting the drawback of storage capacity decreasing. Moreover, combination application inhibited the transforming rate of ammonia-nitrogen into nitrate-nitrogen, which in all treatments, PAM plus citric acid inhibited nitrate nitrogen release and keep nitrate nitrogen concentration in a lower level （0.11--2. 10 μg/ml）, while this treatment had significantly inhibitive action for TN release to adjacent water.