种植方式和裸岩率对喀斯特洼地土壤养分空间分异特征的影响

选取桂西北典型喀斯特洼地，研究了种植方式和裸岩率对土壤养分空间分布的影响.结果表明:种植方式对土壤有机碳(SOC)、全氮(TN)、全磷(TP)、全钾(TK)、碱解氮(AN)、速效磷(AP)、速效钾(AK)和C/N有显著影响；裸岩率对SOC、TN、TP、TK、AN、AK和C/N有显著影响，对SOC、TN、TP和AN的影响程度大于种植制度的影响，这主要与农户在裸岩率较低的地段耕作强度较大有关；木豆 板栗地的SOC、TN、TP、TK、AN、AK等含量显著高于其它种植方式，说明退耕在一定程度上有利于土壤养分的积累；受地形地貌特征和土地利用结构的影响，SOC的空间分布表现为坡脚大于洼地;AP的空间分布与SOC不同，主要受施肥影响，表现为洼地高于坡脚.

Effects of planting pattern and bare rock ratio on spatial distribution of soil nutrients in Karst depression area.

This paper studied the effects of planting pattern and bare rock ratio on the spatial distribution of soil nutrients in Karst depression area of northwest Guangxi. The results showed that planting pattern had significant effects on soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP), available potassium (AK), and C/N. Bare rock ratio also had significant effects on SOC, TN, TP, TK, AN, AK and C/N, and was the crucial factor in determining the spatial variability of SOC, TN, TP and AN, which was mainly due to the higher intensity of cultivation in the places covered with less bare rock. Fields planted with Cajanus cajan-Castanca mollissima had significantly higher contents of SOC, TN, TN, TK, AN, and AK than those with other planting patterns, suggesting that converting farmland into forestland had positive effects on the accumulation of soil nutrients. Due to the effects of local topography and land use structure, foot slope had a higher content of SOC than depression, while fertilization made the depression have a higher content of AP than foot slope.