金沙江干热河谷银合欢人工林对土壤养分的影响

Effects of Soil Nutrients on Planted Leucaena leucocephala Forest in the Dry-hot Jinshajiang River Valley

通过干热河谷银合欢人工林对土壤改良效应5年的研究,结果表明:银合欢林具有很好的土壤改良效应,土壤有机质明显高于CK,在0～20 cm,20～40 cm和40～60 cm的土层中,比CK分别高52.61%,51.09%和43.52%,土壤有机质随着土壤深度的增加而减少。pH在0～20 cm,20～40 cm和40～60 cm的土层中,比CK分别低8.28%,2.41%和2.19%。全N含量上层土壤明显高于下层,水解N比CK高43.75%,随着土壤深度的增加,水解N呈现下降趋势,并具有显著性相关关系。全P含量比CK高0.05 mg/kg,相差不是很明显。有效P含量与CK相差不是很明显,在不同土层深度有效P含量的变化非常一致。全K含量比CK高0.98 mg/kg,银合欢的生长对土壤全K含量的影响并不明显。速效K含量平均为136.79 mg/kg,变化幅度较大,比CK高69.45 mg/kg,银合欢的生长对土壤速效K含量的影响明显。

The soil improvement effect on the planted Leucaena leucocephala forest in the dry-hot Jinshajiang River Valley was researched for five years.The results show that the soil improvement effect on the forest was obvious.Soil organic matter content was obviously higher than CK,its values at soil depths of 0-20 cm,20-40 cm and 40-60 cm under the forest were 52.61%,51.09% and 43.52% higher than CK respectively,and it decreased with the increase of soil depth.At soil depths of 0-20 cm,20-40 cm and 40-60 cm,the pH values of forest soil were 8.28%,2.41% and 2.19% lower than CK respectively.Total soil N content was 43.75% higher than CK,it decreased with the increase of soil depth,and there was a significant correlation between total soil N content and soil depth.Total soil P content was 0.05 mg/kg higher than CK only.The difference of available P content between the forest soil and CK was not obvious.Total soil K content was 0.98 mg/kg higher than CK,and the effect of total K content on the forest was not obvious.The available K content in the forest soil was 136.79 mg/kg,and it was 69.45 mg/kg higher than CK.