云南主要植烟土壤不同土层氮矿化研究

Nitrogen mineralization in Yunnan tobacco major growing soil

为了解云南不同植烟土壤类型土壤的供氮能力,在主要植烟区选择紫色土、水稻土和红壤3种土壤分层采集土样,室内20℃和30℃条件下培养,应用间歇淋洗好气培养法测定氮矿化量。结果表明,不同土壤类型的氮矿化累积量在表层0～20 cm和亚表层20～40 cm表现为紫色土氮矿化强度较大,氮矿化累积量较高,红壤相对较低,而在60～80 cm和80～100 cm土层以水稻土氮矿化累积量最高,紫色土最低。不同土层土壤以0～20 cm土层氮矿化速率和矿化量最高,其次是20～40 cm土层,再次是40～60 cm土层,最低的是60～80 cm土层和80～100 cm土层。随着培养时间延长,土壤中的氮矿化量随之降低。30℃条件下的土壤氮矿化速率和矿化量高于20℃条件。

To determine the nitrogen mineralization in Yunnan tobacco major growing soil types, the different soil depths of purple soil, paddy soil and red soil were collected, the samples were incubated under aerobic condition at 20℃ and 30℃. The results showed that at the 0 -20 cm and 20 - 40 cm depths, purple soil had a greater nitrogen mineralization value than the other two soil types, the red soil had the less value; On the contrary, at the 60 -80 em and 80 - 100 cm soil depths, the paddy soil had a greater nitrogen mineralization value while the purple soil had the less value. For the different soil depths, the soil nitrogen mineralization rate and value were as follows ： 0 - 20 cm 〉 20 - 40 cm 〉 40- 60 cm 〉 60 - 80 cm, 80 - 100 cm. Whatever the situation, the mineralization nitrogen value decreased with the increasing incubation days. The soil nitrogen mineralization rate and value incubated at 30℃ was higher than at 20℃.