石漠化治理区主栽经果林地土壤肥力诊断与评价

Diagnosis and Evaluation of Soil Fertility in Economic Fruit Forests of Rocky Desertification Control Area

【目的】探明贵州石漠化治理区刺梨与核桃经果林地土壤肥力的丰缺现状,可以为当地石漠化治理区合理林地经营和科学施肥提供参考依据。【方法】利用改进后的内梅罗综合指数法,对石漠化治理区主栽品种刺梨和核桃两类林地的土壤肥力进行研究。选取土壤的pH值、有机质、全氮、全磷、全钾、碱解氮、速效磷、速效钾8个指标,对土壤养分进行分析,并参照全国第二次土壤普查分级标准对土壤肥力进行综合评价与因子分析。【结果】石漠化治理区两类林地土壤综合肥力系数变幅为1.36～1.49之间,总体上土壤肥力属一般水平,以土壤全氮、有机质和速效磷为两类林地土壤肥力组成的重要影响因子,而土壤全钾和速效钾为两类林地土壤的限制性因子。【结论】两类林地的土壤肥力保持较为一般,仍有进一步优化上升的空间。钾素的缺乏可能成为贵州石漠化治理区刺梨和核桃两类林地土壤质量提高的限制性因子,应有针对性地补充含钾素的有机肥料。

[Objective] The objective of this study was to explore the status of soil fertility of economic fruit forests dominated by Rosaroxbunghii and Juglans regia in the Guizhou desertification control area and to provide a reference for scientific fertilization of rational forest management in the local desertifi- cation control area. [Method] Soil fertility of economic fruit forests mainly planted with Rosaroxbunghii and Juglans regia in the rocky desertification control area was evaluated using improved Nemerow in- dex method. Eight factors were analyzed in this study,such as soil pH, organic matter, total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus and available potassium and soil nutrients. Comprehensive evaluation and factorial analysis of soil fertility was conducted according to national second soil census nutrient classification standards. [Result] The integrated fertility index of the two forests in the rocky desertification control area varied from 1.36 to 1.49 and soil fertility was gener ally at middle level. Soil total nitrogen, organic maner and available phosphorus were important factors of soil fertility in Rosaroxbunghii and Juglans regia forests but soil potassium and available potassium were limited factors for Rosaroxbunghii and Juglans regia forests. [Conclusion] Soil fertility of two forest types remained relatively moderate. More efforts should be needed to improve soil fertility of this area. The lack of potassium may be a factor limiting soil quality in both forests of rocky desertification control area of Guizhou Province. Organic fertilizer with contain potassium should be added purposely.