甘肃省陇西县中药材产区耕作土壤养分空间变异研究

  目的  基于中药材种植区土壤养分及其空间分布的高精度数据分析，探究县域尺度土壤养分空间变异特征并类比和优化评价方法。  方法  采用类比经典统计学、地统计学以及GIS评价方法，对中药材种植区土壤养分及综合肥力空间分布格局进行研究。  结果  ① 研究区土壤呈碱性（pH = 8.50）,有机质、全氮、全磷、全钾平均含量分别为7.54 g kg?1、0.73 g kg?1、0.73 g kg?1、17.96 g kg?1，电导率为108.63 ms cm?1；从变异系数来看，除pH为弱变异外，有机质、全氮、全磷、全钾、电导率均属中等变异。② 土壤养分的空间分布特征表现为，土壤有机质含量总体呈现西南部高于东北部分布；全氮含量呈斑块状分布，主要表现为南部高东部低的特征；全磷含量空间变异中等，在研究区西南侧有岛状高含量点分布；全钾含量呈中部略高四周低的分布趋势；电导率空间异质性大，呈斑块状分布。③ 土壤综合肥力空间分布呈现西高东低，中部向南、北部降低的趋势。此外，根据内梅罗综合指数法、主成分分析法和模糊综合评价法综合评价得分可将该区土壤肥力分成5级，三种评价方式中，肥力等级为III等级及以下的区域分别占研究区总面积的74.97%、43.28%和67.57%。  结论  中药材长期不合理的种植会降低土壤整体肥力；增施有机肥、氮磷钾平衡施肥、轮作、休耕和培肥土壤等措施有助于当地中药材的可持续种植。

Spatial Distribution Patterns of Soil Fertility in Producing Area of Traditional Chinese Medicine of Longxi County,Gansu Province

  Objective  Soil fertility has an extremely important influence on the yield and quality of medicinal plants in semi-arid areas, and soil fertility will gradually decline with the increase of planting years of Traditional Chinese medicine. This paper took the traditional Chinese medicine planting area in Longxi County as the research area to explore the influence of long-term planting of traditional Chinese medicine on spatial variation of soil nutrients.   Method  Based on the statistics, geo-statistics and GIS, the spatial distribution pattern of tillage soil nutrients and comprehensive fertility was studied.   Result  ① Here soil electrical conductivity and pH were 108.63 ms cm?1 and 8.50. Average contents of organic matter, total nitrogen (TN), total phosphorus (TP) and total potassium (TK) in the study region were 7.54 g kg?1, 0.73 g kg?1, 0.73 g kg?1 and 17.96 g kg?1, respectively. Meanwhile, the variable coefficient illustrated soil pH was the weak variation but organic matter, TN, TP, TK and electrical conductivity were moderate variation. ② Soil organic matter was high at the southwest and low at the northeast. TN content of soil presented the patch distribution, which was characterized by high at the south and lower at the east. Interestingly, soil TP content of this region ranged from 0.60 - 0.80 g kg?1, and TP showed a climax at the southwest in the study region. Soil TK was higher at the center of the county than that in other directions. Soil electrical conductivity also presented the patch distribution. ③ The spatial distribution of soil fertility in the Longxi County illustrated a trend of high at the west and low at the northeast, and soil fertility of the center was higher than that in the north and the south. Furthermore, according to the comprehensive scores of Nemerow Comprehensive Index ( IFI₁), Principal Component Analysis (IFI₂ ) and Fuzzy Comprehensive Assessment (IFI₃ ), soil fertility of the Longxi County was distinguished as five levels. Across three methods, we found that land area in the soil fertility lowing to the III level accounted for 74.97%, 43.28%, and 67.57% of the total area in the study region.   Conclusion  Long-term and unscientific planting of Chinese medicine decreased the total soil fertility. Lower soil fertility of the Longxi County can be improved by adding organic fertilizer and the mixed fertilizer of N:P:K in a scientific ratio, crop rotation and unplanted and so on.